TY - JOUR A1 - Botteri, Edoardo A1 - Peveri, Giulia A1 - Berstad, Paula A1 - Bagnardi, Vincenzo A1 - Chen, Sairah L. F. A1 - Sandanger, Torkjel M. A1 - Hoff, Geir A1 - Dahm, Christina C. A1 - Antoniussen, Christian S. A1 - Tjonneland, Anne A1 - Eriksen, Anne Kirstine A1 - Skeie, Guri A1 - Perez-Cornago, Aurora A1 - Huerta, Jose Maria A1 - Jakszyn, Paula A1 - Harlid, Sophia A1 - Sundstroem, Bjoern A1 - Barricarte, Aurelio A1 - Monninkhof, Evelyn M. A1 - Derksen, Jeroen W. G. A1 - Schulze, Matthias Bernd A1 - Bueno-de-Mesquita, Bas A1 - Sanchez, Maria-Jose A1 - Cross, Amanda J. A1 - Tsilidis, Konstantinos K. A1 - De Magistris, Maria Santucci A1 - Kaaks, Rudolf A1 - Katzke, Verena A1 - Rothwell, Joseph A. A1 - Laouali, Nasser A1 - Severi, Gianluca A1 - Amiano, Pilar A1 - Contiero, Paolo A1 - Sacerdote, Carlotta A1 - Goldberg, Marcel A1 - Touvier, Mathilde A1 - Freisling, Heinz A1 - Viallon, Vivian A1 - Weiderpass, Elisabete A1 - Riboli, Elio A1 - Gunter, Marc J. A1 - Jenab, Mazda A1 - Ferrari, Pietro T1 - Changes in lifestyle and risk of colorectal cancer in the European prospective investigation into cancer and nutrition JF - The American journal of gastroenterology : AJG N2 - INTRODUCTION: We investigated the impact of changes in lifestyle habits on colorectal cancer (CRC) risk in a multicountry European cohort. METHODS: We used baseline and follow-up questionnaire data from the European Prospective Investigation into Cancer cohort to assess changes in lifestyle habits and their associations with CRC development. We calculated a healthy lifestyle index (HLI) score based on smoking status, alcohol consumption, body mass index, and physical activity collected at the 2 time points. HLI ranged from 0 (most unfavorable) to 16 (most favorable). We estimated the association between HLI changes and CRC risk using Cox regression models and reported hazard ratios (HR) with 95% confidence intervals (CI). RESULTS: Among 295,865 participants, 2,799 CRC cases were observed over a median of 7.8 years. The median time between questionnaires was 5.7 years. Each unit increase in HLI from the baseline to the follow-up assessment was associated with a statistically significant 3% lower CRC risk. Among participants in the top tertile at baseline (HLI > 11), those in the bottom tertile at follow-up (HLI <= 9) had a higher CRC risk (HR 1.34; 95% CI 1.02-1.75) than those remaining in the top tertile. Among individuals in the bottom tertile at baseline, those in the top tertile at follow-up had a lower risk (HR 0.77; 95% CI 0.59-1.00) than those remaining in the bottom tertile. DISCUSSION: Improving adherence to a healthy lifestyle was inversely associated with CRC risk, while worsening adherence was positively associated with CRC risk. These results justify and support recommendations for healthy lifestyle changes and healthy lifestyle maintenance for CRC prevention. Y1 - 2022 U6 - https://doi.org/10.14309/ajg.0000000000002065 SN - 0002-9270 SN - 1572-0241 VL - 118 IS - 4 SP - 702 EP - 711 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Gimenez-Garcia, Ana A1 - Shenar, Tomer A1 - Torrejon, J. M. A1 - Oskinova, Lidia M. A1 - Martinez-Nunez, S. A1 - Hamann, Wolf-Rainer A1 - Rodes-Roca, J. J. A1 - González-Galan, A. A1 - Alonso-Santiago, J. A1 - González-Fernández, C. A1 - Bernabeu, Guillermo A1 - Sander, Andreas Alexander Christoph T1 - Measuring the stellar wind parameters in IGR J17544-2619 and Vela X-1 constrains the accretion physics in supergiant fast X-ray transient and classical supergiant X-ray binaries JF - Siberian Mathematical Journal N2 - Aims. To close this gap, we perform a comparative analysis of the optical companion in two important systems: IGR J175442619 (SFXT) and Vela X-1 (SGXB). We analyze the spectra of each star in detail and derive their stellar and wind properties. As a next step, we compare the wind parameters, giving us an excellent chance of recognizing key differences between donor winds in SFXTs and SGXBs. Methods. We use archival infrared, optical and ultraviolet observations, and analyze them with the non-local thermodynamic equilibrium (NLTE) Potsdam Wolf-Rayet model atmosphere code. We derive the physical properties of the stars and their stellar winds, accounting for the influence of X-rays on the stellar winds. Results. We find that the stellar parameters derived from the analysis generally agree well with the spectral types of the two donors: O9I (IGR J17544-2619) and B0.5Iae (Vela X-1). The distance to the sources have been revised and also agree well with the estimations already available in the literature. In IGR J17544-2619 we are able to narrow the uncertainty to d = 3.0 +/- 0.2 kpc. From the stellar radius of the donor and its X-ray behavior, the eccentricity of IGR J17544-2619 is constrained to e < 0.25. The derived chemical abundances point to certain mixing during the lifetime of the donors. An important difference between the stellar winds of the two stars is their terminal velocities (v(infinity) = 1500 km s(-1) in IGR J17544-2619 and v(infinity) = 700 km s(-1) in Vela X-1), which have important consequences on the X-ray luminosity of these sources. Conclusions. The donors of IGR J17544-2619 and Vela X-1 have similar spectral types as well as similar parameters that physically characterize them and their spectra. In addition, the orbital parameters of the systems are similar too, with a nearly circular orbit and short orbital period. However, they show moderate differences in their stellar wind velocity and the spin period of their neutron star which has a strong impact on the X-ray luminosity of the sources. This specific combination of wind speed and pulsar spin favors an accretion regime with a persistently high luminosity in Vela X-1, while it favors an inhibiting accretion mechanism in IGR J17544-2619. Our study demonstrates that the relative wind velocity is critical in class determination for the HMXBs hosting a supergiant donor, given that it may shift the accretion mechanism from direct accretion to propeller regimes when combined with other parameters. KW - accretion, accretion disks KW - methods: observational KW - techniques: spectroscopic KW - stars: atmospheres KW - X-rays: binaries KW - stars: winds, outflows Y1 - 2016 U6 - https://doi.org/10.1051/0004-6361/201527551 SN - 1432-0746 VL - 591 PB - EDP Sciences CY - Les Ulis ER - TY - JOUR A1 - Robrade, Jan A1 - Oskinova, Lidia M. A1 - Schmitt, J. H. M. M. A1 - Leto, Paolo A1 - Trigilio, C. T1 - Outstanding X-ray emission from the stellar radio pulsar CU Virginis JF - Astronomy and astrophysics : an international weekly journal N2 - Context. Among the intermediate-mass magnetic chemically peculiar (MCP) stars, CU Vir is one of the most intriguing objects. Its 100% circularly polarized beams of radio emission sweep the Earth as the star rotates, thereby making this strongly magnetic star the prototype of a class of nondegenerate stellar radio pulsars. While CU Vir is well studied in radio, its high-energy properties are not known. Yet, X-ray emission is expected from stellar magnetospheres and confined stellar winds. Aims. Using X-ray data we aim to test CU Vir for intrinsic X-ray emission and investigate mechanisms responsible for its generation. Methods. We present X-ray observations performed with XMM-Newton and Chandra and study obtained X-ray images, light curves, and spectra. Basic X-ray properties are derived from spectral modelling and are compared with model predictions. In this context we investigate potential thermal and nonthermal X-ray emission scenarios. Results. We detect an X-ray source at the position of CU Vir. With LX approximate to 3 x 10(28) erg s(-1) it is moderately X-ray bright, but the spectrum is extremely hard compared to other Ap stars. Spectral modelling requires multi-component models with predominant hot plasma at temperatures of about T-X = 25MK or, alternatively, a nonthermal spectral component. Both types of model provide a virtually equivalent description of the X-ray spectra. The Chandra observation was performed six years later than those by XMM-Newton, yet the source has similar X-ray flux and spectrum, suggesting a steady and persistent X-ray emission. This is further confirmed by the X-ray light curves that show only mild X-ray variability. Conclusions. CU Vir is also an exceptional star at X-ray energies. To explain its full X-ray properties, a generating mechanism beyond standard explanations, like the presence of a low-mass companion or magnetically confined wind-shocks, is required. Magnetospheric activity might be present or, as proposed for fast-rotating strongly magnetic Bp stars, the X-ray emission of CU Vir is predominantly auroral in nature. KW - individual: CU Vir KW - stars: activity KW - stars: chemically peculiar KW - stars: magnetic field KW - X-rays: stars Y1 - 2018 U6 - https://doi.org/10.1051/0004-6361/201833492 SN - 1432-0746 VL - 619 PB - EDP Sciences CY - Les Ulis ER - TY - JOUR A1 - Hamaguchi, K. A1 - Oskinova, Lidia M. A1 - Russell, C. M. P. A1 - Petre, R. A1 - Enoto, T. A1 - Morihana, K. A1 - Ishida, M. T1 - DISCOVERY OF RAPIDLY MOVING PARTIAL X-RAY ABSORBERS WITHIN GAMMA CASSIOPEIAE JF - The astrophysical journal : an international review of spectroscopy and astronomical physics N2 - detected six rapid X-ray spectral hardening events called "softness dips" in a similar to 100 ks observation in 2011. All the softness dip events show symmetric softness-ratio variations, and some of them have flat bottoms apparently due to saturation. The softness dip spectra are best described by either similar to 40% or similar to 70% partial covering absorption to kT similar to 12 keV plasma emission by matter with a neutral hydrogen column density of similar to(2-8) x 10(21) cm(-2), while the spectrum outside these dips is almost free of absorption. This result suggests the presence of two distinct X-ray-emitting spots in the.. Cas system, perhaps on a white dwarf (WD) companion with dipole mass accretion. The partial covering absorbers may be blobs in the Be stellar wind, the Be disk, or rotating around the WD companion. Weak correlations of the softness ratios to the hard X-ray flux suggest the presence of stable plasmas at kT similar to 0.9 and 5 keV, which may originate from the Be or WD winds. The formation of a Be star and WD binary system requires mass transfer between two stars; gamma Cas may have experienced such activity in the past. KW - blue stragglers KW - stars: emission-line, Be KW - stars: individual (gamma Cassiopeiae) KW - stars: winds, outflows KW - white dwarfs KW - X-rays: stars Y1 - 2016 U6 - https://doi.org/10.3847/0004-637X/832/2/140 SN - 0004-637X SN - 1538-4357 VL - 832 SP - 33 EP - 49 PB - IOP Publ. Ltd. CY - Bristol ER - TY - JOUR A1 - Shrader, C. R. A1 - Hamaguchi, K. A1 - Sturner, Steven J. A1 - Oskinova, Lidia M. A1 - Almeyda, T. A1 - Petre, R. T1 - Hifg-energy properties of the enigmatic be STAR gamma Cassiopeiae JF - The astrophysical journal : an international review of spectroscopy and astronomical physics N2 - We present the results of a broadband X-ray study of the enigmatic Be star Gamma Cassiopeiae (herein gamma Cas) based on observations made with both the Suzaku and INTEGRAL observatories.. Cas has long been recognized as the prototypical example of a small subclass of Be stars with moderately strong X-ray emission dominated by a hot thermal component in the 0.5-12 keV energy range (L-x approximate to 10(32)-10(33) erg s(-1)). This places them at the high end of the known luminosity distribution for stellar emission, but several orders of magnitude below typical accretion-powered Be X-ray binaries. The INTEGRAL observations spanned an eight-year baseline and represent the deepest measurement to date at energies above similar to 50 keV. We find that the INTEGRAL data are consistent within statistics to a constant intensity source above 20 keV, with emission extending up to similar to 100 keV, and that searches for all of the previously reported periodicities of the system at lower energies led to null results. We further find that our combined Suzaku and INTEGRAL spectrum, which we suggest is the most accurate broadband X-ray measurement of gamma Cas to date, is fitted extremely well with a thermal plasma emission model with a single absorption component. We found no compelling need for an additional non-thermal high-energy component. We discuss these results in the context of a currently favored models for gamma Cas and its analogs. KW - gamma rays: stars KW - stars: emission-line, Be KW - stars: individual (gamma Cassiopeiae) KW - white dwarfs KW - X-rays: binaries KW - X-rays: stars Y1 - 2015 U6 - https://doi.org/10.1088/0004-637X/799/1/84 SN - 0004-637X SN - 1538-4357 VL - 799 IS - 1 PB - IOP Publ. Ltd. CY - Bristol ER - TY - CHAP A1 - Mucha, Anne A1 - Engels, James J. A1 - Whibley, Fred A1 - Uegaki, Wataru A1 - Wamsley, James C. A1 - Dawson, Virginia A1 - Gruzdeva, Anastasija A1 - Alhazova, Anna A1 - Golovnina, Anna A1 - Nasyrova, Regina A1 - Sadkovsky, Feudor A1 - Weingartz, Siena A1 - Hohaus, Vera A1 - Cisse, Ousmane A1 - Coppock, Elizabeth A1 - Agodio, Badiba Olivier A1 - Jenks, Peter A1 - Sande, Hannah A1 - Zimmermann, Malte A1 - Berezovskaya, Polina A1 - Chen, Sihwei A1 - Renans, Agata ED - Lecavelier des Etangs-Levallois, Jeanne ED - Geick, Niklas ED - Grubic, Mira ED - Bharadwaj, Prarthanaa ED - Zimmermann, Malte T1 - Proceedings of TripleA 10 BT - fieldwork perspectives on the semantics of African, Asian and Austronesian languages T2 - Proceedings of TripleA N2 - The TripleA workshop series was founded in 2014 by linguists from Potsdam and Tübingen with the aim of providing a platform for researchers that conduct theoretically-informed linguistic fieldwork on meaning. Its focus is particularly on languages that are under-represented in the current research landscape, including but not limited to languages of Africa, Asia, and Australia, hence TripleA. For its 10th anniversary, TripleA returned to the University of Potsdam on the 7-9th of June 2023. The programme included 21 talks dealing with no less than 22 different languages, including three invited talks given by Sihwei Chen (Academia Sinica), Jérémy Pasquereau (Laboratoire de Linguistique de Nantes, CNRS) and Agata Renans (Ruhr-Universität Bochum). Nine of these (invited or peer-reviewed) talks are featured in this volume. N2 - Die TripleA-Workshop-Reihe wurde 2014 von Linguisten aus Potsdam und Tübingen mit dem Ziel gegründet, eine Plattform für Forscherinnen und Forscher zu bieten, die theoretisch informierte Feldforschung zu sprachlicher Bedeutung betreiben. Der Fokus liegt insbesondere auf Sprachen, die in der aktuellen Forschungslandschaft unterrepräsentiert sind, einschließlich (aber nicht ausschließlich) auf Sprachen aus Afrika, Asien und Australien: daher der Name TripleA. Zu seinem 10-jährigen Bestehen kehrte TripleA vom 7. Bis 9. Juni 2023 an die Universität Potsdam zurück. Das Programm umfasste 21 Vorträge zu nicht weniger als 22 verschiedenen Sprachen, darunter drei eingeladene Vorträge von Sihwei Chen (Academia Sinica), Jérémy Pasquereau (Laboratoire de Linguistique de Nantes, CNRS) und Agata Renans (Ruhr-Universität Bochum). Neun dieser (eingeladenen oder begutachteten) Vorträge sind in diesem Band abgedruckt. KW - African languages KW - Asian languages KW - Austronesian languages KW - fieldwork KW - semantics KW - afrikanische Sprachen KW - asiatische Sprachen KW - austronesische Sprachen KW - Feldforschung KW - Semantik Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-647980 ER - TY - JOUR A1 - Pedoja, K. A1 - Jara Muñoz, Julius A1 - De Gelder, G. A1 - Robertson, J. A1 - Meschis, M. A1 - Fernandez-Blanco, D. A1 - Nexer, M. A1 - Poprawski, Y. A1 - Dugue, O. A1 - Delcaillau, B. A1 - Bessin, P. A1 - Benabdelouahed, M. A1 - Authemayou, C. A1 - Husson, L. A1 - Regard, V. A1 - Menier, D. A1 - Pinel, B. T1 - Neogene-Quaternary slow coastal uplift of Western Europe through the perspective of sequences of strandlines from the Cotentin Peninsula (Normandy, France) JF - Geomorphology : an international journal on pure and applied geomorphology N2 - The Cotentin Peninsula (Normandy, France) displays sequences of marine terraces and rasas, the latter being wide Late Cenozoic coastal erosion surfaces, that are typical of Western European coasts in Portugal, Spain, France and southern England. Remote sensing imagery and field mapping enabled reappraisal of the Cotentin coastal sequences. From bottom to top, the N Cotentin sequence includes four previously recognized Pleistocene marine terraces (T1 to T4) at elevations <40 m as well as four higher and older rasas (R1 to R4) reaching 200 +/- 5 m in elevation. Low-standing marine terraces are not observed in the central part of the Peninsula and a limited number of terraces are described to the south. The high-standing rasas are widespread all over the peninsula. Such strandline distributions reveal major changes during the Late Cenozoic. Progressive uplift of an irregular sea-floor led to subaerial exposure of bathymetric highs that were carved into rocky platforms, rasas and marine terraces. Eventually, five main islands coalesced and connected to the mainland to the south to form the Cotentin Peninsula. On the basis of previous dating of the last interglacial maximum terrace (i.e. Marine Isotopic Stage, MIS 5e), sequential morphostratigraphy and modelling, we have reappraised uplift rates and derived: (i) mean Upper Pleistocene (i.e. since MIS 5e similar to 122 +/- 6 ka, i.e. kilo annum) apparent uplift rates of 0.04 +/- 0.01 mm/yr, (ii) mean Middle Pleistocene eustasy-corrected uplift rates of 0.09 +/- 0.03 mm/yr, and (iii) low mean Pleistocene uplift rates of 0.01 mm/yr. Extrapolations of these slow rates combined with geological evidence implies that the formation of the sequences from the Cotentin Peninsula occurred between 3 Ma (Pliocene) and 15 Ma (Miocene), which cannot be narrowed down further without additional research. Along the coasts of Western Europe, sequences of marine terraces and rasas are widespread (169 preserve the MIS Se benchmark). In Spain, Portugal, S England and other parts of western France, the sequences morphostratigraphy is very similar to that of Cotentin. The onset of such Western European sequences occurred during the Miocene (e.g. Spain) or Pliocene (e.g. Portugal). We interpret this Neogene-Quaternary coastal uplift as a symptom of the increasing lithospheric compression that accompanies Cenozoic orogenies. (C) 2017 Elsevier B.V. All rights reserved. KW - Marine terrace KW - Rasa KW - Cotentin and Western Europe KW - Neogene and Quaternary coastal uplift Y1 - 2017 U6 - https://doi.org/10.1016/j.geomorph.2017.11.021 SN - 0169-555X SN - 1872-695X VL - 303 SP - 338 EP - 356 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Pessanha, Tatiana A1 - Paschoalino, Waldemir J. A1 - Deroco, Patricia B. A1 - Kogikoski Junior, Sergio A1 - Moraes, Ana C. M. de A1 - Carvalho Castro de Silva, Cecilia de A1 - Kubota, Lauro T. T1 - Interfacial capacitance of graphene oxide films electrodes BT - Fundamental studies on electrolytes interface aiming (bio)sensing applications JF - Electroanalysis : an internatinal journal devoted to electroanalysis, sensors and bioelectronic devices N2 - The understanding of bidimensional materials dynamics and its electrolyte interface equilibrium, such as graphene oxide (GO), is critical for the development of a capacitive biosensing platform. The interfacial capacitance (C-i) of graphene-based materials may be tuned by experimental conditions such as pH optimization and cation size playing key roles at the enhancement of their capacitive properties allowing their application as novel capacitive biosensors. Here we reported a systematic study of C-i of multilayer GO films in different aqueous electrolytes employing electrochemical impedance spectroscopy for the application in a capacitive detection system. We demonstrated that the presence of ionizable oxygen-containing functional groups within multilayer GO film favors the interactions and the accumulation of cations in the structure of the electrodes enhancing the GO C-i in aqueous solutions, where at pH 7.0 (the best condition) the C-i was 340 mu F mg(-1) at -0.01 V vs Ag/AgCl. We also established that the hydrated cation radius affects the mobility and interaction with GO functional groups and it plays a critical role in the Ci, as demonstrated in the presence of different cations Na+=640 mu F mg(-1), Li+=575 mu F mg(-1) and TMA(+)=477 mu F mg(-1). As a proof-of-concept, the capacitive behaviour of GO was explored as biosensing platform for standard streptavidin-biotin systems. For this system, the C-i varied linearly with the log of the concentration of the targeting analyte in the range from 10 pg mL(-1) to 100 ng mL(-1), showing the promising applicability of capacitive GO based sensors for label-free biosensing. KW - Interfacial capacitance KW - Graphene oxide KW - Functional groups KW - Electrochemical impedance KW - Graphene derivates Y1 - 2021 U6 - https://doi.org/10.1002/elan.202100220 SN - 1521-4109 SN - 1040-0397 VL - 34 IS - 4 SP - 692 EP - 700 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Yang, Xiaohui A1 - Müller, David C. A1 - Neher, Dieter A1 - Meerholz, Klaus T1 - Highly efficient polymeric electrophosphorescent diodes N2 - Polymeric electrophosphorescent LEDs with internal quantum efficiencies approaching unity have been fabricated. Such performance levels are previously unknown for OLEDs. The key to this success is redox chemically doped oxetane- crosslinkable hole-transporting layers with multilayer capability (see figure). They improve hole injection and act as electron-blocking layers, without the need to include exciton-or hole-blocking layers Y1 - 2006 UR - 1960 = DOI: 10.1002/adma.200501867 ER - TY - JOUR A1 - Egbe, D. A. M. A1 - Ulbricht, C. A1 - Orgis, Thomas A1 - Carbonnier, B. A1 - Kietzke, Thomas A1 - Peip, M. A1 - Metzner, M. A1 - Gericke, M. A1 - Birckner, Eckhard A1 - Pakula, T. A1 - Neher, Dieter A1 - Grumm, U. W. T1 - Odd-even effects and the influence of length and specific positioning of alkoxy side chains on the optical properties of PPE-PPV polymers N2 - This contribution reports the combined influences of odd-even effects and the specific positioning of alkoxy side chains OR1 = (OCn+H-10(2(n+10)+1)) and OR2 = (OCnH2n+1) (with n = 6, 7, 8, 9) on the phenylene-ethynylene and phenylene- vinylene segments, respectively, on the optical properties of hybrid polymers P(n+10)/n of general repeating unit: -Ph-C equivalent to C-Ph-C equivalent to C-Ph-CH=CH-Ph-CH=CH-. For the polymeric materials, visual color impression varies alternatively between orange red (P16/6 and P18/8) and yellow (P17/7 and P19/9) according to the odd and even features of the alkoxy side chains, where odd or even relates to the total number of sp(3)-hybridized atoms within the side chains. This side chain related effect is ascribed to both absorptive and emissive behaviors of the polymers on the basis of photophysical investigations in the bulk. Almost identical thin film absorption spectra were obtained for all four materials; however, the photoluminescence of the odd polymers, P16/6 (lambda(f) = 556 nm) and P18/ 8 (lambda(f) = 614 nm), was red-shifted relative to that of their even counterparts (lambda(f) = 535 nm). Further, the P18/8 maximum at 614 nm can be readily assigned to excimer emission, as evidenced by the largest Stokes shift (5600 cm(- 1)), largest fwhmf-value (3700 cm(-1))(,) and the lowest Phi(f)-value of 24%. The strong pi-pi interchain interaction in P18/8, due to loose alkoxy side chains packing, does not only favor fluorescence quenching but also enable an effective inter- as well as intra-molecular recombination of the generated positive and negative polarons in electrolurninescence, which explains the good EL properties of this polymer irrespective of the solvent used. A voltage-dependent blue shift of the EL spectra of up to 100 nm was observed for P18/8 devices prepared from aromatic solvents. This red to green EL shift as observed with increasing voltage is assigned to conformational changes of the polymer chains with increasing temperature Y1 - 2005 SN - 0897-4756 ER - TY - JOUR A1 - Zen, Achmad A1 - Neher, Dieter A1 - Bauer, C. A1 - Asawapirom, Udom A1 - Scherf, Ullrich A1 - Hagen, R. A1 - Kostromine, S. A1 - Mahrt, R. F. T1 - Polarization-sensitive photoconductivity in aligned polyfluorene layers Y1 - 2002 ER - TY - JOUR A1 - Oda, Masao A1 - Nothofer, Heinz-Georg A1 - Lieser, G. A1 - Scherf, Ullrich A1 - Meskers, S. C. J. A1 - Neher, Dieter T1 - Circularly-polarized electroluminescence from liquid-crystalline chiral polyfluorenes Y1 - 2000 ER - TY - JOUR A1 - Bauer, C. A1 - Böhmer, Roland A1 - Moreno-Flores, S. A1 - Richert, R. A1 - Sillescu, H. A1 - Neher, Dieter T1 - Capacitive scanning dilatometry and frequency dependent thermal expansion of polymer films Y1 - 2000 ER - TY - JOUR A1 - Oda, Masao A1 - Meskers, S. C. J. A1 - Nothofer, Heinz-Georg A1 - Scherf, Ullrich A1 - Neher, Dieter T1 - Chiroptical properties of chiral-substituted polyfluorenes Y1 - 2000 ER - TY - JOUR A1 - Luft, Laura A1 - Neumann, C. A1 - Itzerott, S. A1 - Lausch, A. A1 - Doktor, D. A1 - Freude, M. A1 - Blaum, Niels A1 - Jeltsch, Florian T1 - Digital and real-habitat modeling of Hipparchia statilinus based on hyper spectral remote sensing data JF - International journal of environmental science and technology N2 - The abandonment of military areas leads to succession processes affecting valuable open-land habitats and is considered to be a major threat for European butterflies. We assessed the ability of hyper spectral remote sensing data to spatially predict the occurrence of one of the most endangered butterfly species (Hipparchia statilinus) in Brandenburg (Germany) on the basis of habitat characteristics at a former military training area. Presence-absence data were sampled on a total area of 36 km(2), and N = 65 adult individuals of Hipparchia statilinus could be detected. The floristic composition within the study area was modeled in a three-dimensional ordination space. Occurrence probabilities for the target species were predicted as niches between ordinated floristic gradients by using Regression Kriging of Indicators. Habitat variance could be explained by up to 81 % with spectral variables at a spatial resolution of 2 x 2 m by transferring PLSR models to imagery. Ordinated ecological niche of Hipparchia statilinus was tested against environmental predictor variables. N = 6 variables could be detected to be significantly correlated with habitat preferences of Hipparchia statilinus. They show that Hipparchia statilinus can serve as a valuable indicator for the evaluation of the conservation status of Natura 2000 habitat type 2330 (inland dunes with open Corynephorus and Agrostis grasslands) protected by the Habitat Directive (Council Directive 92/43/EEC). The authors of this approach, conducted in August 2013 at Doberitzer Heide Germany, aim to increase the value of remote sensing as an important tool for questions of biodiversity research and conservation. KW - Habitat gradients KW - Military areas KW - Natura 2000 KW - hyper spectral KW - Vegetation continuum KW - Kriging Y1 - 2016 U6 - https://doi.org/10.1007/s13762-015-0859-1 SN - 1735-1472 SN - 1735-2630 VL - 13 SP - 187 EP - 200 PB - Springer CY - New York ER - TY - JOUR A1 - Kihampa, Charles A1 - Nkunya, Mayunga H. H. A1 - Joseph, Cosam C. A1 - Magesa, Stephen M. A1 - Hassanali, Ahmed A1 - Heydenreich, Matthias A1 - Kleinpeter, Erich T1 - Antimosquito and antimicrobial clerodanoids and a chlorobenzoid from Tessmannia species N2 - The clerodane diterpenoids trans-kolavenolic acid, 18-oxocleroda-3,13(E)-dien-15-oic acid, ent-(18- hydroxycarbonyl)-cleroda- 3,13(E)-dien-15-oate, 2-oxo-ent-cleroda-3,13(Z)-dien-15-oic acid and trans-2-oxo-ent-cleroda- 13(Z)-en-15-oic acid, and the chlorobenzenoid O-(3-hydroxy-4-hydroxycarbonyl-5-pentylphenyl)-3-chloro-4-methoxy-6-pentyl- 2-oxybenzoic acid were isolated from Tessmannia martiniana var pauloi and T. martiniana var matiniana. Structures were established based on interpretation of spectroscopic data. Some of the compounds exhibited significant antimosquito, antifungal and antibacterial activities. Y1 - 2010 UR - http://www.naturalproduct.us/ SN - 1934-578X ER - TY - JOUR A1 - Jeltsch, Florian A1 - Blaum, Niels A1 - Brose, Ulrich A1 - Chipperfield, Joseph D. A1 - Clough, Yann A1 - Farwig, Nina A1 - Geissler, Katja A1 - Graham, Catherine H. A1 - Grimm, Volker A1 - Hickler, Thomas A1 - Huth, Andreas A1 - May, Felix A1 - Meyer, Katrin M. A1 - Pagel, Jörn A1 - Reineking, Björn A1 - Rillig, Matthias C. A1 - Shea, Katriona A1 - Schurr, Frank Martin A1 - Schroeder, Boris A1 - Tielbörger, Katja A1 - Weiss, Lina A1 - Wiegand, Kerstin A1 - Wiegand, Thorsten A1 - Wirth, Christian A1 - Zurell, Damaris T1 - How can we bring together empiricists and modellers in functional biodiversity research? JF - Basic and applied ecology : Journal of the Gesellschaft für Ökologie N2 - Improving our understanding of biodiversity and ecosystem functioning and our capacity to inform ecosystem management requires an integrated framework for functional biodiversity research (FBR). However, adequate integration among empirical approaches (monitoring and experimental) and modelling has rarely been achieved in FBR. We offer an appraisal of the issues involved and chart a course towards enhanced integration. A major element of this path is the joint orientation towards the continuous refinement of a theoretical framework for FBR that links theory testing and generalization with applied research oriented towards the conservation of biodiversity and ecosystem functioning. We further emphasize existing decision-making frameworks as suitable instruments to practically merge these different aims of FBR and bring them into application. This integrated framework requires joint research planning, and should improve communication and stimulate collaboration between modellers and empiricists, thereby overcoming existing reservations and prejudices. The implementation of this integrative research agenda for FBR requires an adaptation in most national and international funding schemes in order to accommodate such joint teams and their more complex structures and data needs. KW - Biodiversity theory KW - Biodiversity experiments KW - Conservation management KW - Decision-making KW - Ecosystem functions and services KW - Forecasting KW - Functional traits KW - Global change KW - Monitoring programmes KW - Interdisciplinarity Y1 - 2013 U6 - https://doi.org/10.1016/j.baae.2013.01.001 SN - 1439-1791 VL - 14 IS - 2 SP - 93 EP - 101 PB - Elsevier CY - Jena ER - TY - JOUR A1 - Griscom, Bronson W. A1 - Busch, Jonah A1 - Cook-Patton, Susan C. A1 - Ellis, Peter W. A1 - Funk, Jason A1 - Leavitt, Sara M. A1 - Lomax, Guy A1 - Turner, Will R. A1 - Chapman, Melissa A1 - Streck, Charlotte T1 - National mitigation potential from natural climate solutions in the tropics JF - Biological sciences N2 - Better land stewardship is needed to achieve the Paris Agreement's temperature goal, particularly in the tropics, where greenhouse gas emissions from the destruction of ecosystems are largest, and where the potential for additional land carbon storage is greatest. As countries enhance their nationally determined contributions (NDCs) to the Paris Agreement, confusion persists about the potential contribution of better land stewardship to meeting the Agreement's goal to hold global warming below 2 degrees C. We assess cost-effective tropical country-level potential of natural climate solutions (NCS)-protection, improved management and restoration of ecosystems-to deliver climate mitigation linked with sustainable development goals (SDGs). We identify groups of countries with distinctive NCS portfolios, and we explore factors (governance, financial capacity) influencing the feasibility of unlocking national NCS potential. Cost-effective tropical NCS offers globally significant climate mitigation in the coming decades (6.56 Pg CO(2)e yr(-1) at less than 100 US$ per Mg CO(2)e). In half of the tropical countries, cost-effective NCS could mitigate over half of national emissions. In more than a quarter of tropical countries, cost-effective NCS potential is greater than national emissions. We identify countries where, with international financing and political will, NCS can cost-effectively deliver the majority of enhanced NDCs while transforming national economies and contributing to SDGs. This article is part of the theme issue 'Climate change and ecosystems: threats, opportunities and solutions'. KW - natural climate solutions KW - climate mitigation KW - protection KW - land management KW - restoration KW - Paris Agreement Y1 - 2020 U6 - https://doi.org/10.1098/rstb.2019.0126 SN - 0962-8436 SN - 1471-2970 VL - 375 IS - 1794 SP - 1 EP - 11 PB - The Royal Society Publishing CY - London ER - TY - JOUR A1 - Noonan, Michael J. A1 - Tucker, Marlee A. A1 - Fleming, Christen H. A1 - Akre, Thomas S. A1 - Alberts, Susan C. A1 - Ali, Abdullahi H. A1 - Altmann, Jeanne A1 - Antunes, Pamela Castro A1 - Belant, Jerrold L. A1 - Beyer, Dean A1 - Blaum, Niels A1 - Boehning-Gaese, Katrin A1 - Cullen Jr, Laury A1 - de Paula, Rogerio Cunha A1 - Dekker, Jasja A1 - Drescher-Lehman, Jonathan A1 - Farwig, Nina A1 - Fichtel, Claudia A1 - Fischer, Christina A1 - Ford, Adam T. A1 - Goheen, Jacob R. A1 - Janssen, Rene A1 - Jeltsch, Florian A1 - Kauffman, Matthew A1 - Kappeler, Peter M. A1 - Koch, Flavia A1 - LaPoint, Scott A1 - Markham, A. Catherine A1 - Medici, Emilia Patricia A1 - Morato, Ronaldo G. A1 - Nathan, Ran A1 - Oliveira-Santos, Luiz Gustavo R. A1 - Olson, Kirk A. A1 - Patterson, Bruce D. A1 - Paviolo, Agustin A1 - Ramalho, Emiliano Estero A1 - Rosner, Sascha A1 - Schabo, Dana G. A1 - Selva, Nuria A1 - Sergiel, Agnieszka A1 - da Silva, Marina Xavier A1 - Spiegel, Orr A1 - Thompson, Peter A1 - Ullmann, Wiebke A1 - Zieba, Filip A1 - Zwijacz-Kozica, Tomasz A1 - Fagan, William F. A1 - Mueller, Thomas A1 - Calabrese, Justin M. T1 - A comprehensive analysis of autocorrelation and bias in home range estimation JF - Ecological monographs : a publication of the Ecological Society of America. N2 - Home range estimation is routine practice in ecological research. While advances in animal tracking technology have increased our capacity to collect data to support home range analysis, these same advances have also resulted in increasingly autocorrelated data. Consequently, the question of which home range estimator to use on modern, highly autocorrelated tracking data remains open. This question is particularly relevant given that most estimators assume independently sampled data. Here, we provide a comprehensive evaluation of the effects of autocorrelation on home range estimation. We base our study on an extensive data set of GPS locations from 369 individuals representing 27 species distributed across five continents. We first assemble a broad array of home range estimators, including Kernel Density Estimation (KDE) with four bandwidth optimizers (Gaussian reference function, autocorrelated‐Gaussian reference function [AKDE], Silverman's rule of thumb, and least squares cross‐validation), Minimum Convex Polygon, and Local Convex Hull methods. Notably, all of these estimators except AKDE assume independent and identically distributed (IID) data. We then employ half‐sample cross‐validation to objectively quantify estimator performance, and the recently introduced effective sample size for home range area estimation ( N̂ area ) to quantify the information content of each data set. We found that AKDE 95% area estimates were larger than conventional IID‐based estimates by a mean factor of 2. The median number of cross‐validated locations included in the hold‐out sets by AKDE 95% (or 50%) estimates was 95.3% (or 50.1%), confirming the larger AKDE ranges were appropriately selective at the specified quantile. Conversely, conventional estimates exhibited negative bias that increased with decreasing N̂ area. To contextualize our empirical results, we performed a detailed simulation study to tease apart how sampling frequency, sampling duration, and the focal animal's movement conspire to affect range estimates. Paralleling our empirical results, the simulation study demonstrated that AKDE was generally more accurate than conventional methods, particularly for small N̂ area. While 72% of the 369 empirical data sets had >1,000 total observations, only 4% had an N̂ area >1,000, where 30% had an N̂ area <30. In this frequently encountered scenario of small N̂ area, AKDE was the only estimator capable of producing an accurate home range estimate on autocorrelated data. KW - animal movement KW - kernel density estimation KW - local convex hull KW - minimum convex polygon KW - range distribution KW - space use KW - telemetry KW - tracking data Y1 - 2018 U6 - https://doi.org/10.1002/ecm.1344 SN - 0012-9615 SN - 1557-7015 VL - 89 IS - 2 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Benassi, Rois A1 - Bertarini, C. A1 - Kleinpeter, Erich A1 - Taddei, F. A1 - Thomas, Steffen T1 - Exocyclic push-pull conjugated compounds : Part 1 ; theoretical study of the effect of ring size on the structure, electronic properties and rotational barriers of cyclic analogoues of 1,1-diamino-2.2-dicyanoethylene Y1 - 2000 ER - TY - JOUR A1 - Benassi, Rois A1 - Bertarini, C. A1 - Kleinpeter, Erich A1 - Taddei, F. T1 - Exocyclic push-pull conjugated compounds, Part 2 : the effect of donor and acceptor substituents on the rotational barrier of push-pull ethylenes Y1 - 2000 ER - TY - JOUR A1 - Benassi, Rois A1 - Bertarini, C. A1 - Hilfert, Liane A1 - Kempter, Gerhard A1 - Kleinpeter, Erich A1 - Spindler, Jürgen A1 - Taddei, F. A1 - Thomas, Steffen T1 - Exocyclic push-pull conjugated compounds : Part 3 Y1 - 2000 ER - TY - JOUR A1 - Griel, C. A1 - Ströhl, D. A1 - Jeschkeit, H. A1 - Kleinpeter, Erich T1 - Synthetische und NMR-spektroskopische Untersuchungen der Benzzyl-aminaddition an N-Maleyl- aminosäurederivaten Y1 - 1992 ER - TY - JOUR A1 - Kihampa, Charles A1 - Nkunya, Mayunga H. H. A1 - Joseph, Cosam C. A1 - Magesa, Stephen M. A1 - Hassanali, Ahmed A1 - Heydenreich, Matthias A1 - Kleinpeter, Erich T1 - Anti-mosquito and antimicrobial nor-halimanoids, isocoumarins and an anilinoid from Tessmannia densiflora N2 - The nor-halimane diterpenoid tessmannic acid and its methyl, 2-methylisopropyl and 1-methylbutyl esters, the unusual isocoumarins 8-hydroxy-6-methoxy-3-pentylisocoumarin and 7-chloro-8-hydroxy-6-methoxy-3-pentylisocoumarin, and 5- pentyl-3-methoxy-N-butylaniline were isolated from the stem and root bark extracts of Tessmannia densiflora Harms (Caesalpiniaceae) that showed mosquito larvicidal activity. The structures were determined on interpretation of spectroscopic data. Tessmannic acid and its methyl ester exhibited antibacterial and antifungal activity. The compounds also caused high larvae and adult Anopheles gambiae mosquitoe mortality effects, and stronger mosquito repellency than that shown by the standard repellent DEET, hence indicating Tessmannia species to be potential sources of bioactive natural products. Y1 - 2009 UR - http://www.sciencedirect.com/science/journal/00319422 U6 - https://doi.org/10.1016/j.phytochem.2009.07.024 SN - 0031-9422 ER - TY - JOUR A1 - Kihampa, Charles A1 - Joseph, Cosam C. A1 - Nkunya, Mayunga H. H. A1 - Magesa, Stephen M. T1 - Larvicidal and IGR activity of extract of Tanzanian plants against malaria vector mosquitoes N2 - Background & objectives: This paper reports the larvicidal activity of seventeen Tanzanian plant species against the malaria vector, Anopheles gambiae s.s. Giles larvae. Some of the plants are used traditionally as sources of insecticidal materials. Methods: The crude extracts from the leaves, stem and root barks of the investigated plants were obtained by solvent extraction and then bio-assayed following WHO protocols showed LC50 values 10 to 400 ppm after 24 h exposure. The structures were determined on interpretation of spectroscopic data. Results: The most active extracts were those from the stem and root barks of Annona squamosa, Uvaria faulknerae, U. kirkii and Uvariodendron pycnophyllum, all of which had LC50 values between 10 and 100 ppm. Long-term exposure beyond 24 h also showed more susceptibility of the larvae to the extracts. Larvae deformities by forming tail-like structures were observed for the methanol extracts of Tessmannia martiniana var pauloi. Interpretation & conclusion: The results suggest that the investigated plant extracts are promising as larvicides against An. gambiae s.s. Giles mosquitoes and could be useful leads in the search for new and biodegradable plant derived larvicide products. Y1 - 2009 UR - http://www.mrcindia.org/journal/ SN - 0972-9062 ER - TY - GEN A1 - Dietze, Elisabeth A1 - Mangelsdorf, Kai A1 - Andreev, Andrei A1 - Karger, Cornelia A1 - Schreuder, Laura T. A1 - Hopmans, Ellen C. A1 - Rach, Oliver A1 - Sachse, Dirk A1 - Wennrich, Volker A1 - Herzschuh, Ulrike T1 - Relationships between low-temperature fires, climate and vegetation during three late glacials and interglacials of the last 430 kyr in northeastern Siberia reconstructed from monosaccharide anhydrides in Lake El’gygytgyn sediments T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Landscapes in high northern latitudes are assumed to be highly sensitive to future global change, but the rates and long-term trajectories of changes are rather uncertain. In the boreal zone, fires are an important factor in climate-vegetation interactions and biogeochemical cycles. Fire regimes are characterized by small, frequent, low-intensity fires within summergreen boreal forests dominated by larch, whereas evergreen boreal forests dominated by spruce and pine burn large areas less frequently but at higher intensities. Here, we explore the potential of the monosaccharide anhydrides (MA) levoglucosan, mannosan and galactosan to serve as proxies of low-intensity biomass burning in glacial-to-interglacial lake sediments from the high northern latitudes. We use sediments from Lake El'gygytgyn (cores PG 1351 and ICDP 5011-1), located in the far north-east of Russia, and study glacial and interglacial samples of the last 430 kyr (marine isotope stages 5e, 6, 7e, 8, 11c and 12) that had different climate and biome configurations. Combined with pollen and non-pollen palynomorph records from the same samples, we assess how far the modern relationships between fire, climate and vegetation persisted during the past, on orbital to centennial timescales. We find that MAs attached to particulates were well-preserved in up to 430 kyr old sediments with higher influxes from low-intensity biomass burning in interglacials compared to glacials. MA influxes significantly increase when summergreen boreal forest spreads closer to the lake, whereas they decrease when tundra-steppe environments and, especially, Sphagnum peatlands spread. This suggests that low-temperature fires are a typical characteristic of Siberian larch forests also on long timescales. The results also suggest that low-intensity fires would be reduced by vegetation shifts towards very dry environments due to reduced biomass availability, as well as by shifts towards peatlands, which limits fuel dryness. In addition, we observed very low MA ratios, which we interpret as high contributions of galactosan and mannosan from biomass sources other than those currently monitored, such as the moss-lichen mats in the understorey of the summergreen boreal forest. Overall, sedimentary MAs can provide a powerful proxy for fire regime reconstructions and extend our knowledge of long-term natural fire-climate-vegetation feedbacks in the high northern latitudes. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1439 KW - molecular tracers KW - organic aerosols KW - emission factors KW - carbonaceous aerosols KW - pollen records KW - core PG1351 KW - biomass KW - holocene KW - levoglucosan KW - charcoal Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-516843 SN - 1866-8372 IS - 2 ER - TY - JOUR A1 - van Loon, Jacco Th. A1 - Bailey, M. A1 - Tatton, B. L. A1 - Apellaniz, Jesus Maiz A1 - Crowther, P. A. A1 - de Koter, A. A1 - Evans, C. J. A1 - Henault-Brunet, V. A1 - Howarth, I. D. A1 - Richter, Philipp A1 - Sana, Hugues A1 - Simon Díaz, Sergio A1 - Taylor, W. A1 - Walborn, N. R. T1 - The VLT-FLAMES tarantula survey IX. - the interstellar medium seen through diffuse interstellar bands and neutral sodium JF - Astronomy and astrophysics : an international weekly journal N2 - Context. The Tarantula Nebula (a.k.a. 30 Dor) is a spectacular star-forming region in the Large Magellanic Cloud (LMC), seen through gas in the Galactic disc and halo. Diffuse interstellar bands (DIBs) offer a unique probe of the diffuse, cool-warm gas in these regions. Aims. The aim is to use DIBs as diagnostics of the local interstellar conditions, whilst at the same time deriving properties of the yet-unknown carriers of these enigmatic spectral features. Methods. Spectra of over 800 early-type stars from the Very Large Telescope Flames Tarantula Survey (VFTS) were analysed. Maps were created, separately, for the Galactic and LMC absorption in the DIBs at 4428 and 6614 angstrom and - in a smaller region near the central cluster R 136 - neutral sodium (the Na ID doublet); we also measured the DIBs at 5780 and 5797 angstrom. Results. The maps show strong 4428 and 6614 angstrom DIBs in the quiescent cloud complex to the south of 30 Dor but weak absorption in the harsher environments to the north (bubbles) and near the OB associations. The Na maps show at least five kinematic components in the LMC and a shell-like structure surrounding R 136, and small-scale structure in the Milky Way. The strengths of the 4428, 5780, 5797 and 6614 angstrom DIBs are correlated, also with Na absorption and visual extinction. The strong 4428 angstrom DIB is present already at low Na column density but the 6614, 5780 and 5797 angstrom DIBs start to be detectable at subsequently larger Na column densities. Conclusions. The carriers of the 4428, 6614, 5780 and 5797 angstrom DIBs are increasingly prone to removal from irradiated gas. The relative strength of the 5780 and 5797 angstrom DIBs clearly confirm the Tarantula Nebula as well as Galactic high-latitude gas to represent a harsh radiation environment. The resilience of the 4428 angstrom DIB suggests its carrier is large, compact and neutral. Structure is detected in the distribution of cool-warm gas on scales between one and > 100 pc in the LMC and as little as 0.01 pc in the Sun's vicinity. Stellar winds from the central cluster R 136 have created an expanding shell; some infalling gas is also detected, reminiscent of a galactic "fountain". KW - ISM: individual objects: Tarantula Nebula (30 Doradus Nebula) KW - ISM: molecules KW - ISM: kinematics and dynamics KW - ISM: lines and bands KW - ISM: structure KW - local insterstellar matter Y1 - 2013 U6 - https://doi.org/10.1051/0004-6361/201220210 SN - 0004-6361 VL - 550 IS - 9 PB - EDP Sciences CY - Les Ulis ER - TY - JOUR A1 - Li, Tian-yi A1 - Benduhn, Johannes A1 - Qiao, Zhi A1 - Liu, Yuan A1 - Li, Yue A1 - Shivhare, Rishi A1 - Jaiser, Frank A1 - Wang, Pei A1 - Ma, Jie A1 - Zeika, Olaf A1 - Neher, Dieter A1 - Mannsfeld, Stefan C. B. A1 - Ma, Zaifei A1 - Vandewal, Koen A1 - Leo, Karl T1 - Effect of H- and J-Aggregation on the Photophysical and Voltage Loss of Boron Dipyrromethene Small Molecules in Vacuum-Deposited Organic Solar Cells JF - The journal of physical chemistry letters N2 - An understanding of the factors limiting the open-circuit voltage (V-oc) and related photon energy loss mechanisms is critical to increase the power conversion efficiency (PCE) of small-molecule organic solar cells (OSCs), especially those with near-infrared (NIR) absorbers. In this work, two NIR boron dipyrromethene (BODIPY) molecules are characterized for application in planar (PHJ) and bulk (BHJ) heterojunction OSCs. When two H atoms are substituted by F atoms on the peripheral phenyl rings of the molecules, the molecular aggregation type in the thin film changes from the H-type to J-type. For PHJ devices, the nonradiative voltage loss of 0.35 V in the J-aggregated BODIPY is lower than that of 0.49 V in the H-aggregated device. In BHJ devices with a nonradiative voltage loss of 0.35 V, a PCE of 5.5% is achieved with an external quantum efficiency (EQE) maximum of 68% at 700 nm. Y1 - 2019 U6 - https://doi.org/10.1021/acs.jpclett.9b01222 SN - 1948-7185 VL - 10 IS - 11 SP - 2684 EP - 2691 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Piro, Vitor C. A1 - Dadi, Temesgen H. A1 - Seiler, Enrico A1 - Reinert, Knut A1 - Renard, Bernhard Y. T1 - ganon BT - precise metagenomics classification against large and up-to-date sets of reference sequences JF - Bioinformatics N2 - Motivation: The exponential growth of assembled genome sequences greatly benefits metagenomics studies. However, currently available methods struggle to manage the increasing amount of sequences and their frequent updates. Indexing the current RefSeq can take days and hundreds of GB of memory on large servers. Few methods address these issues thus far, and even though many can theoretically handle large amounts of references, time/memory requirements are prohibitive in practice. As a result, many studies that require sequence classification use often outdated and almost never truly up-to-date indices. Results: Motivated by those limitations, we created ganon, a k-mer-based read classification tool that uses Interleaved Bloom Filters in conjunction with a taxonomic clustering and a k-mer counting/filtering scheme. Ganon provides an efficient method for indexing references, keeping them updated. It requires <55 min to index the complete RefSeq of bacteria, archaea, fungi and viruses. The tool can further keep these indices up-to-date in a fraction of the time necessary to create them. Ganon makes it possible to query against very large reference sets and therefore it classifies significantly more reads and identifies more species than similar methods. When classifying a high-complexity CAMI challenge dataset against complete genomes from RefSeq, ganon shows strongly increased precision with equal or better sensitivity compared with state-of-the-art tools. With the same dataset against the complete RefSeq, ganon improved the F1-score by 65% at the genus level. It supports taxonomy- and assembly-level classification, multiple indices and hierarchical classification. Y1 - 2020 U6 - https://doi.org/https://doi.org/10.1093/bioinformatics/btaa458 SN - 1367-4811 SN - 1367-4803 VL - 36 SP - 12 EP - 20 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Allan, Eric A1 - Weisser, Wolfgang W. A1 - Fischer, Markus A1 - Schulze, Ernst-Detlef A1 - Weigelt, Alexandra A1 - Roscher, Christiane A1 - Baade, Jussi A1 - Barnard, Romain L. A1 - Bessler, Holger A1 - Buchmann, Nina A1 - Ebeling, Anne A1 - Eisenhauer, Nico A1 - Engels, Christof A1 - Fergus, Alexander J. F. A1 - Gleixner, Gerd A1 - Gubsch, Marlen A1 - Halle, Stefan A1 - Klein, Alexandra-Maria A1 - Kertscher, Ilona A1 - Kuu, Annely A1 - Lange, Markus A1 - Le Roux, Xavier A1 - Meyer, Sebastian T. A1 - Migunova, Varvara D. A1 - Milcu, Alexandru A1 - Niklaus, Pascal A. A1 - Oelmann, Yvonne A1 - Pasalic, Esther A1 - Petermann, Jana S. A1 - Poly, Franck A1 - Rottstock, Tanja A1 - Sabais, Alexander C. W. A1 - Scherber, Christoph A1 - Scherer-Lorenzen, Michael A1 - Scheu, Stefan A1 - Steinbeiss, Sibylle A1 - Schwichtenberg, Guido A1 - Temperton, Vicky A1 - Tscharntke, Teja A1 - Voigt, Winfried A1 - Wilcke, Wolfgang A1 - Wirth, Christian A1 - Schmid, Bernhard T1 - A comparison of the strength of biodiversity effects across multiple functions JF - Oecologia N2 - In order to predict which ecosystem functions are most at risk from biodiversity loss, meta-analyses have generalised results from biodiversity experiments over different sites and ecosystem types. In contrast, comparing the strength of biodiversity effects across a large number of ecosystem processes measured in a single experiment permits more direct comparisons. Here, we present an analysis of 418 separate measures of 38 ecosystem processes. Overall, 45 % of processes were significantly affected by plant species richness, suggesting that, while diversity affects a large number of processes not all respond to biodiversity. We therefore compared the strength of plant diversity effects between different categories of ecosystem processes, grouping processes according to the year of measurement, their biogeochemical cycle, trophic level and compartment (above- or belowground) and according to whether they were measures of biodiversity or other ecosystem processes, biotic or abiotic and static or dynamic. Overall, and for several individual processes, we found that biodiversity effects became stronger over time. Measures of the carbon cycle were also affected more strongly by plant species richness than were the measures associated with the nitrogen cycle. Further, we found greater plant species richness effects on measures of biodiversity than on other processes. The differential effects of plant diversity on the various types of ecosystem processes indicate that future research and political effort should shift from a general debate about whether biodiversity loss impairs ecosystem functions to focussing on the specific functions of interest and ways to preserve them individually or in combination. KW - Bottom-up effects KW - Carbon cycling KW - Ecological synthesis KW - Ecosystem processes KW - Grasslands KW - Jena experiment KW - Nitrogen cycling Y1 - 2013 U6 - https://doi.org/10.1007/s00442-012-2589-0 SN - 0029-8549 VL - 173 IS - 1 SP - 223 EP - 237 PB - Springer CY - New York ER - TY - JOUR A1 - Manning, Pete A1 - Gossner, Martin M. A1 - Bossdorf, Oliver A1 - Allan, Eric A1 - Zhang, Yuan-Ye A1 - Prati, Daniel A1 - Blüthgen, Nico A1 - Boch, Steffen A1 - Böhm, Stefan A1 - Börschig, Carmen A1 - Hölzel, Norbert A1 - Jung, Kirsten A1 - Klaus, Valentin H. A1 - Klein, Alexandra-Maria A1 - Kleinebecker, Till A1 - Krauss, Jochen A1 - Lange, Markus A1 - Müller, Jörg A1 - Pasalic, Esther A1 - Socher, Stephanie A. A1 - Tschapka, Marco A1 - Türke, Manfred A1 - Weiner, Christiane A1 - Werner, Michael A1 - Gockel, Sonja A1 - Hemp, Andreas A1 - Renner, Swen C. A1 - Wells, Konstans A1 - Buscot, Francois A1 - Kalko, Elisabeth K. V. A1 - Linsenmair, Karl Eduard A1 - Weisser, Wolfgang W. A1 - Fischer, Markus T1 - Grassland management intensification weakens the associations among the diversities of multiple plant and animal taxa JF - Ecology : a publication of the Ecological Society of America N2 - Land-use intensification is a key driver of biodiversity change. However, little is known about how it alters relationships between the diversities of different taxonomic groups, which are often correlated due to shared environmental drivers and trophic interactions. Using data from 150 grassland sites, we examined how land-use intensification (increased fertilization, higher livestock densities, and increased mowing frequency) altered correlations between the species richness of 15 plant, invertebrate, and vertebrate taxa. We found that 54% of pairwise correlations between taxonomic groups were significant and positive among all grasslands, while only one was negative. Higher land-use intensity substantially weakened these correlations(35% decrease in rand 43% fewer significant pairwise correlations at high intensity), a pattern which may emerge as a result of biodiversity declines and the breakdown of specialized relationships in these conditions. Nevertheless, some groups (Coleoptera, Heteroptera, Hymenoptera and Orthoptera) were consistently correlated with multidiversity, an aggregate measure of total biodiversity comprised of the standardized diversities of multiple taxa, at both high and lowland-use intensity. The form of intensification was also important; increased fertilization and mowing frequency typically weakened plant-plant and plant-primary consumer correlations, whereas grazing intensification did not. This may reflect decreased habitat heterogeneity under mowing and fertilization and increased habitat heterogeneity under grazing. While these results urge caution in using certain taxonomic groups to monitor impacts of agricultural management on biodiversity, they also suggest that the diversities of some groups are reasonably robust indicators of total biodiversity across a range of conditions. KW - Biodiversity indicators KW - correlation KW - fertilization KW - grassland management KW - grazing KW - land-use change KW - land-use intensity KW - mowing KW - multidiversity KW - multitrophic interactions Y1 - 2015 U6 - https://doi.org/10.1890/14-1307.1 SN - 0012-9658 SN - 1939-9170 VL - 96 IS - 6 SP - 1492 EP - 1501 PB - Wiley CY - Washington ER - TY - JOUR A1 - Qu, J. Q. A1 - Zhang, J. Y. A1 - Grimsdale, A. C. A1 - Mullen, K. A1 - Jaiser, Frank A1 - Yang, X. H. A1 - Neher, Dieter T1 - Dendronized perylene diimide emitters : Synthesis, luminescence, and electron and energy transfer studies N2 - Aggregation of chromophores in the solid state commonly causes undesirable red shifts in the emission spectra and/or emission quenching. To overcome this problem, we have prepared soluble perylenetetracarboxidiimide dyes in which the chromophores are effectively shielded by polyphenylene dendrimers attached in the bay positions. Models show that attachment of the shielding units in the bay position should provide more efficient shielding than attaching them via the imide moieties. The dendrimers possess excellent film-forming properties due to alkyl substituents on their peripheries. The lack of a red shift in emission upon going from solution to the solid state indicates the dendrons suppress interaction of the emissive cores, leading to pure red-orange emission. Single-layer LEDs produce red-orange emission with relatively low efficiency especially for the higher generation dendrons, which is attributed to poor charge conduction. LEDs using blends of the dendrimers and the undendronized dye as a model compound in PVK have been investigated, and a model to extract relative charge injection rates through the dendritic scaffold from the spectral contributions in the EL spectra is developed Y1 - 2004 SN - 0024-9297 ER - TY - JOUR A1 - Steyrleuthner, Robert A1 - Schubert, Marcel A1 - Jaiser, Frank A1 - Blakesley, James C. A1 - Chen, Zhihua A1 - Facchetti, Antonio A1 - Neher, Dieter T1 - Bulk electron transport and charge injection in a high mobility n-type semiconducting polymer N2 - Bulk electron transport in a high mobility n-type polymer is studied by time-of-flight photocurrent measurements and electron-only devices. Bulk electron mobilities of similar to 5 x 10(-3) cm(2)/Vs are obtained. The analysis of the electron currents suggests the presence of an injection barrier for all conventionally used low workfunction cathodes. Y1 - 2010 UR - http://www3.interscience.wiley.com/cgi-bin/jhome/10008336 U6 - https://doi.org/10.1002/adma.201000232 SN - 0935-9648 ER - TY - JOUR A1 - Hagoort, Iris A1 - Vuillerme, Nicolas A1 - Hortobágyi, Tibor A1 - Lamoth, Claudine J. C. T1 - Outcome-dependent effects of walking speed and age on quantitative and qualitative gait measures JF - Gait & posture N2 - Background: Walking speed predicts many clinical outcomes in old age. However, a comprehensive assessment of how walking speed affects accelerometer based quantitative and qualitative gait measures in younger and older adults is lacking. Research question: What is the relationship between walking speed and quantitative and qualitative gait outcomes in younger and older adults? Methods: Younger (n = 27, age: 21.6) and older participants (n = 27, age: 69.5) completed 340 steps on a treadmill at speeds of 0.70 to a maximum of 1.75 m.s(-1). We used generalized additive mixed models to determine the relationship between walking speed and quantitative (stride length, stride time, stride frequency and their variability) and qualitative (stride regularity, stability, smoothness, symmetry, synchronization, predictability) gait measures extracted from trunk accelerations. Results: The type of relationship between walking speed and the majority of gait measures (quantitative and qualitative) was characterized as logarithmic, with more prominent speed-effects at speeds below 1.20 m.s(-1). Changes in quantitative measures included shorter strides, longer stride times, and a lower stride frequency, with more variability at lower speeds independent of age. For qualitative measures, we found a decrease in gait symmetry, stability and regularity in all directions with decreasing speeds, a decrease in gait predictability (Vertical, V, anterior-posterior, AP) and stronger gait synchronization (AP-mediolateral, ML, AP-V), and direction dependent effects of gait smoothness, which decreased in V direction, but increased in AP and ML directions with decreasing speeds. We found outcome-dependent effects of age on the quantitative and qualitative gait measures, with either no differences between age-groups, age-related differences that existed regardless of speed, and age-related differences in the type of relationship with walking speed. Significance: The relationship between walking speed and quantitative and qualitative gait measures, and the effects of age on this relationship, depends on the type of gait measure studied. KW - Gait quality and quantity KW - Aging KW - Walking speed KW - Treadmill KW - Generalized KW - additive mixed models Y1 - 2022 U6 - https://doi.org/10.1016/j.gaitpost.2022.01.001 SN - 0966-6362 SN - 1879-2219 VL - 93 SP - 39 EP - 46 PB - Elsevier CY - Clare ER - TY - JOUR A1 - Ullbrich, Sascha A1 - Benduhn, Johannes A1 - Jia, Xiangkun A1 - Nikolis, Vasileios C. A1 - Tvingstedt, Kristofer A1 - Piersimoni, Fortunato A1 - Roland, Steffen A1 - Liu, Yuan A1 - Wu, Jinhan A1 - Fischer, Axel A1 - Neher, Dieter A1 - Reineke, Sebastian A1 - Spoltore, Donato A1 - Vandewal, Koen T1 - Emissive and charge-generating donor-acceptor interfaces for organic optoelectronics with low voltage losses JF - Nature materials N2 - Intermolecular charge-transfer states at the interface between electron donating (D) and accepting (A) materials are crucial for the operation of organic solar cells but can also be exploited for organic light-emitting diodes(1,2). Non-radiative charge-transfer state decay is dominant in state-of-the-art D-A-based organic solar cells and is responsible for large voltage losses and relatively low power-conversion efficiencies as well as electroluminescence external quantum yields in the 0.01-0.0001% range(3,4). In contrast, the electroluminescence external quantum yield reaches up to 16% in D-A-based organic light-emitting diodes(5-7). Here, we show that proper control of charge-transfer state properties allows simultaneous occurrence of a high photovoltaic and emission quantum yield within a single, visible-light-emitting D-A system. This leads to ultralow-emission turn-on voltages as well as significantly reduced voltage losses upon solar illumination. These results unify the description of the electro-optical properties of charge-transfer states in organic optoelectronic devices and foster the use of organic D-A blends in energy conversion applications involving visible and ultraviolet photons(8-11). KW - Electronics, photonics and device physics KW - Optoelectronic devices and components KW - Photonic devices KW - Solar energy and photovoltaic technology Y1 - 2019 U6 - https://doi.org/10.1038/s41563-019-0324-5 SN - 1476-1122 SN - 1476-4660 VL - 18 IS - 5 SP - 459 EP - 464 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Kraffert, Felix A1 - Steyrleuthner, Robert A1 - Albrecht, Steve A1 - Neher, Dieter A1 - Scharber, Markus C. A1 - Bittl, Robert A1 - Behrends, Jan T1 - Charge Separation in PCPDTBT : PCBM Blends from an EPR Perspective JF - The journal of physical chemistry Y1 - 2014 U6 - https://doi.org/10.1021/jp509650v SN - 1932-7447 VL - 118 IS - 49 SP - 28482 EP - 28493 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Donges, Jonathan A1 - Schleussner, C. -F. A1 - Siegmund, Jonatan F. A1 - Donner, Reik Volker T1 - Event coincidence analysis for quantifying statistical interrelationships between event time series JF - European physical journal special topics N2 - Studying event time series is a powerful approach for analyzing the dynamics of complex dynamical systems in many fields of science. In this paper, we describe the method of event coincidence analysis to provide a framework for quantifying the strength, directionality and time lag of statistical interrelationships between event series. Event coincidence analysis allows to formulate and test null hypotheses on the origin of the observed interrelationships including tests based on Poisson processes or, more generally, stochastic point processes with a prescribed inter-event time distribution and other higher-order properties. Applying the framework to country-level observational data yields evidence that flood events have acted as triggers of epidemic outbreaks globally since the 1950s. Facing projected future changes in the statistics of climatic extreme events, statistical techniques such as event coincidence analysis will be relevant for investigating the impacts of anthropogenic climate change on human societies and ecosystems worldwide. Y1 - 2016 U6 - https://doi.org/10.1140/epjst/e2015-50233-y SN - 1951-6355 SN - 1951-6401 VL - 225 SP - 471 EP - 487 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Collado-Fregoso, Elisa A1 - Hood, Samantha N. A1 - Shoaee, Safa A1 - Schröder, Bob C. A1 - McCulloch, Iain A1 - Kassal, Ivan A1 - Neher, Dieter A1 - Durrant, James R. T1 - Intercalated vs Nonintercalated Morphologies in Donor-Acceptor Bulk Heterojunction Solar Cells: PBTTT:Fullerene Charge Generation and Recombination Revisited JF - The journal of physical chemistry letters N2 - In this Letter, we study the role of the donor:acceptor interface nanostructure upon charge separation and recombination in organic photovoltaic devices and blend films, using mixtures of PBTTT and two different fullerene derivatives (PC70BM and ICTA) as models for intercalated and nonintercalated morphologies, respectively. Thermodynamic simulations show that while the completely intercalated system exhibits a large free-energy barrier for charge separation, this barrier is significantly lower in the nonintercalated system and almost vanishes when energetic disorder is included in the model. Despite these differences, both femtosecond-resolved transient absorption spectroscopy (TAS) and time-delayed collection field (TDCF) exhibit extensive first-order losses in both systems, suggesting that geminate pairs are the primary product of photoexcitation. In contrast, the system that comprises a combination of fully intercalated polymer:fullerene areas and fullerene-aggregated domains (1:4 PBTTT:PC70BM) is the only one that shows slow, second-order recombination of free charges, resulting in devices with an overall higher short-circuit current and fill factor. This study therefore provides a novel consideration of the role of the interfacial nanostructure and the nature of bound charges and their impact upon charge generation and recombination. Y1 - 2017 U6 - https://doi.org/10.1021/acs.jpclett.7b01571 SN - 1948-7185 VL - 8 SP - 4061 EP - 4068 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Nikolis, Vasileios C. A1 - Benduhn, Johannes A1 - Holzmueller, Felix A1 - Piersimoni, Fortunato A1 - Lau, Matthias A1 - Zeika, Olaf A1 - Neher, Dieter A1 - Koerner, Christian A1 - Spoltore, Donato A1 - Vandewal, Koen T1 - Reducing Voltage Losses in Cascade Organic Solar Cells while Maintaining High External Quantum Efficiencies JF - dvanced energy materials N2 - High photon energy losses limit the open-circuit voltage (V-OC) and power conversion efficiency of organic solar cells (OSCs). In this work, an optimization route is presented which increases the V-OC by reducing the interfacial area between donor (D) and acceptor (A). This optimization route concerns a cascade device architecture in which the introduction of discontinuous interlayers between alpha-sexithiophene (alpha-6T) (D) and chloroboron subnaphthalocyanine (SubNc) (A) increases the V-OC of an alpha-6T/SubNc/SubPc fullerene-free cascade OSC from 0.98 V to 1.16 V. This increase of 0.18 V is attributed solely to the suppression of nonradiative recombination at the D-A interface. By accurately measuring the optical gap (E-opt) and the energy of the charge-transfer state (E-CT) of the studied OSC, a detailed analysis of the overall voltage losses is performed. E-opt - qV(OC) losses of 0.58 eV, which are among the lowest observed for OSCs, are obtained. Most importantly, for the V-OC-optimized devices, the low-energy (700 nm) external quantum efficiency (EQE) peak remains high at 79%, despite a minimal driving force for charge separation of less than 10 meV. This work shows that low-voltage losses can be combined with a high EQE in organic photovoltaic devices. KW - energy losses KW - nonradiative recombination KW - open-circuit voltage KW - organic solar cells KW - voltage losses Y1 - 2017 U6 - https://doi.org/10.1002/aenm.201700855 SN - 1614-6832 SN - 1614-6840 VL - 7 SP - 122 EP - 136 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Ryppa, C. A1 - Senge, Mathias O. A1 - Hatscher, S. S. A1 - Kleinpeter, Erich A1 - Wacker, Philipp A1 - Schilde, Uwe A1 - Wiehe, A. T1 - Synthesis of mono- and disubstituted porphyrins : A- and 5,10-A(2)-type systems N2 - General syntheses have been developed for meso-substituted porphyrins with one or two substituents in the 5,10- positions and no beta substituents. 5-Substituted porphyrins with only one meso substituent are easily prepared by an acid-catalyzed condensation of dipyrromethane, pyrrole-2-carbaldehyde. and an appropriate aldehyde using a "[2+1+1]" approach. Similarly, 5,10-disubstituted porphyrins are accessible by simple condensation of unsubstituted tripyrrane with pyrrole and various aldehydes using a "[3+1]" approach. The yields for these reactions are low to moderate and additional formation of either di- or mono-substituted porphyrins due to scrambling of the intermediates is observed. However, the reactions can be performed quite easily and the desired target compounds are easily removed due to large differences in solubility. A complementary and more selective synthesis involves the use of organolithium reagents for SNAr reactions. Reaction of in situ generated porphyrin (porphine) with 1.1-8 equivalents of RLi gave the monosubstituted porphyrins, while reaction with 3-6 equivalents of RLi gave the 5,10-disubstituted porphyrins in yields ranging from 43 to 90%. These hitherto almost inaccessible compounds complete the series of different homologues of A-, 5,15-A(2)-, 5,10-A(2)-, A(3)-, and A(4)-type porphyrin's and allow an investigation of the gradual influence of type, number, and regiochemical arrangement of substituents on the properties of meso-substituted porphyrins. They also present important starting materials for the synthesis of ABCD porphyrins and are potential synthons for supramolecular materials requiring specific substituent orientations Y1 - 2005 SN - 0947-6539 ER - TY - JOUR A1 - Blaum, Niels A1 - Schwager, Monika A1 - Wichmann, Matthias C. A1 - Rossmanith, Eva T1 - Climate induced changes in matrix suitability explain gene flow in a fragmented landscape - the effect of interannual rainfall variability JF - Ecography : pattern and diversity in ecology ; research papers forum N2 - In fragmented landscapes, the survival of species and the maintenance of populations with healthy genetic structures will largely depend on movement/dispersal of organisms across matrix areas. In this article, we highlight that effects of fragmentation and climate change occur simultaneously and may enhance or mitigate each other. We systematically analyzed the effect of increasing interannual variation in rainfall on the genetic structure of two neighbouring small mammal subpopulations in a fragmented savanna landscape. The effect of interannual rainfall variation is analyzed for two contrasting scenarios that differ in mean annual rainfall and are both close to a dispersal threshold. Scenario 1 (low mean annual rainfall) lies slightly below this threshold and scenario 2 (high mean annual rainfall) slightly above, i.e. the amount of rainfall in an average rainfall year prevents dispersal in scenario 1, but promotes gene flow in scenario 2. We show that the temporal dynamics of the matrix was crucial for gene flow and the genetic structure of the neighbouring small mammal subpopulations. The most important result is that the increase in rainfall variability could both increase and decrease the genetic difference between the subpopulations in a complex pattern, depending on the scenario and on the amount of variation in rainfall. Finally, we discuss that the relevance of the matrix as temporarily suitable habitat may become a key aspect for biodiversity conservation. We conclude to incorporate temporal changes in matrix suitability in metapopulation theory since local extinctions, gene flow and re-colonization are likely to be affected in fragmented landscapes with such dynamic matrix areas. Y1 - 2012 U6 - https://doi.org/10.1111/j.1600-0587.2011.07154.x SN - 0906-7590 VL - 35 IS - 7 SP - 650 EP - 660 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Dietze, Elisabeth A1 - Mangelsdorf, Kai A1 - Andreev, Andrei A1 - Karger, Cornelia A1 - Schreuder, Laura T. A1 - Hopmans, Ellen C. A1 - Rach, Oliver A1 - Sachse, Dirk A1 - Wennrich, Volker A1 - Herzschuh, Ulrike T1 - Relationships between low-temperature fires, climate and vegetation during three late glacials and interglacials of the last 430 kyr in northeastern Siberia reconstructed from monosaccharide anhydrides in Lake El’gygytgyn sediments JF - Climate of the Past N2 - Landscapes in high northern latitudes are assumed to be highly sensitive to future global change, but the rates and long-term trajectories of changes are rather uncertain. In the boreal zone, fires are an important factor in climate-vegetation interactions and biogeochemical cycles. Fire regimes are characterized by small, frequent, low-intensity fires within summergreen boreal forests dominated by larch, whereas evergreen boreal forests dominated by spruce and pine burn large areas less frequently but at higher intensities. Here, we explore the potential of the monosaccharide anhydrides (MA) levoglucosan, mannosan and galactosan to serve as proxies of low-intensity biomass burning in glacial-to-interglacial lake sediments from the high northern latitudes. We use sediments from Lake El'gygytgyn (cores PG 1351 and ICDP 5011-1), located in the far north-east of Russia, and study glacial and interglacial samples of the last 430 kyr (marine isotope stages 5e, 6, 7e, 8, 11c and 12) that had different climate and biome configurations. Combined with pollen and non-pollen palynomorph records from the same samples, we assess how far the modern relationships between fire, climate and vegetation persisted during the past, on orbital to centennial timescales. We find that MAs attached to particulates were well-preserved in up to 430 kyr old sediments with higher influxes from low-intensity biomass burning in interglacials compared to glacials. MA influxes significantly increase when summergreen boreal forest spreads closer to the lake, whereas they decrease when tundra-steppe environments and, especially, Sphagnum peatlands spread. This suggests that low-temperature fires are a typical characteristic of Siberian larch forests also on long timescales. The results also suggest that low-intensity fires would be reduced by vegetation shifts towards very dry environments due to reduced biomass availability, as well as by shifts towards peatlands, which limits fuel dryness. In addition, we observed very low MA ratios, which we interpret as high contributions of galactosan and mannosan from biomass sources other than those currently monitored, such as the moss-lichen mats in the understorey of the summergreen boreal forest. Overall, sedimentary MAs can provide a powerful proxy for fire regime reconstructions and extend our knowledge of long-term natural fire-climate-vegetation feedbacks in the high northern latitudes. KW - molecular tracers KW - organic aerosols KW - emission factors KW - carbonaceous aerosols KW - pollen records KW - core PG1351 KW - biomass KW - holocene KW - levoglucosan KW - charcoal Y1 - 2020 U6 - https://doi.org/10.5194/cp-16-799-2020 SN - 1814-9332 SN - 1814-9324 VL - 16 IS - 2 SP - 788 EP - 818 PB - Copernicus Publications CY - Göttingen ER - TY - JOUR A1 - Wang, Y. A1 - Herzschuh, Ulrike A1 - Shumilovskikh, L. S. A1 - Mischke, Steffen A1 - Birks, H. John B. A1 - Wischnewski, J. A1 - Böhner, Jürgen A1 - Schluetz, F. A1 - Lehmkuhl, F. A1 - Diekmann, Bernhard A1 - Wuennemann, B. A1 - Zhang, C. T1 - Open Access Quantitative reconstruction of precipitation changes on the NE Tibetan Plateau since the Last Glacial Maximum - extending the concept of pollen source area to pollen-based climate reconstructions from large lakes JF - Climate of the past : an interactive open access journal of the European Geosciences Union N2 - Pollen records from large lakes have been used for quantitative palaeoclimate reconstruction, but the influences that lake size (as a result of species-specific variations in pollen dispersal patterns that smaller pollen grains are more easily transported to lake centre) and taphonomy have on these climatic signals have not previously been systematically investigated. We introduce the concept of pollen source area to pollen-based climate calibration using the north-eastern Tibetan Plateau as our study area. We present a pollen data set collected from large lakes in the arid to semi-arid region of central Asia. The influences that lake size and the inferred pollen source areas have on pollen compositions have been investigated through comparisons with pollen assemblages in neighbouring lakes of various sizes. Modern pollen samples collected from different parts of Lake Donggi Cona (in the north-eastern part of the Tibetan Plateau) reveal variations in pollen assemblages within this large lake, which are interpreted in terms of the species-specific dispersal and depositional patterns for different types of pollen, and in terms of fluvial input components. We have estimated the pollen source area for each lake individually and used this information to infer modern climate data with which to then develop a modern calibration data set, using both the multivariate regression tree (MRT) and weighted-averaging partial least squares (WA-PLS) approaches. Fossil pollen data from Lake Donggi Cona have been used to reconstruct the climate history of the north-eastern part of the Tibetan Plateau since the Last Glacial Maximum (LGM). The meanannual precipitation was quantitatively reconstructed using WA-PLS: extremely dry conditions are found to have dominated the LGM, with annual precipitation of around 100 mm, which is only 32% of present-day precipitation. A gradually increasing trend in moisture conditions during the Late Glacial is terminated by an abrupt reversion to a dry phase that lasts for about 1000 yr and coincides with "Heinrich event 1" in the North Atlantic region. Subsequent periods corresponding to the Bolling/Allerod interstadial, with annual precipitation (P-ann) of about 350 mm, and the Younger Dryas event (about 270 mm P-ann) are followed by moist conditions in the early Holocene, with annual precipitation of up to 400 mm. A drier trend after 9 cal. ka BP is followed by a second wet phase in the middle Holocene, lasting until 4.5 cal. ka BP. Relatively steady conditions with only slight fluctuations then dominate the late Holocene, resulting in the present climatic conditions. The climate changes since the LGM have been primarily driven by deglaciation and fluctuations in the intensity of the Asian summer monsoon that resulted from changes in the Northern Hemisphere summer solar insolation, as well as from changes in the North Atlantic climate through variations in the circulation patterns and intensity of the westerlies. Y1 - 2014 U6 - https://doi.org/10.5194/cp-10-21-2014 SN - 1814-9324 SN - 1814-9332 VL - 10 IS - 1 SP - 21 EP - 39 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Al-Sa'di, Mahmoud A1 - Jaiser, Frank A1 - Bagnich, Sergey A. A1 - Unger, Thomas A1 - Blakesley, James C. A1 - Wilke, Andreas A1 - Neher, Dieter T1 - Electrical and optical simulations of a polymer-based phosphorescent organic light-emitting diode with high efficiency JF - Journal of polymer science : B, Polymer physics N2 - A comprehensive numerical device simulation of the electrical and optical characteristics accompanied with experimental measurements of a new highly efficient system for polymer-based light-emitting diodes doped with phosphorescent dyes is presented. The system under investigation comprises an electron transporter attached to a polymer backbone blended with an electronically inert small molecule and an iridium-based green phosphorescent dye which serves as both emitter and hole transporter. The device simulation combines an electrical and an optical model. Based on the known highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels of all components as well as the measured electrical and optical characteristics of the devices, we model the emissive layer as an effective medium using the dye's HOMO as hole transport level and the polymer LUMO as electron transport level. By fine-tuning the injection barriers at the electron and hole-injecting contact, respectively, in simulated devices, unipolar device characteristics were fitted to the experimental data. Simulations using the so-obtained set of parameters yielded very good agreement to the measured currentvoltage, luminancevoltage characteristics, and the emission profile of entire bipolar light-emitting diodes, without additional fitting parameters. The simulation was used to gain insight into the physical processes and the mechanisms governing the efficiency of the organic light-emitting diode, including the position and extent of the recombination zone, carrier concentration profiles, and field distribution inside the device. The simulations show that the device is severely limited by hole injection, and that a reduction of the hole-injection barrier would improve the device efficiency by almost 50%. KW - conjugated polymers KW - high performance polymers KW - organic electronics KW - organic light-emitting diode KW - simulations KW - TCAD Y1 - 2012 U6 - https://doi.org/10.1002/polb.23158 SN - 0887-6266 VL - 50 IS - 22 SP - 1567 EP - 1576 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Kwamen, C. A1 - Rössle, Matthias A1 - Reinhardt, M. A1 - Leitenberger, Wolfram A1 - Zamponi, Flavio A1 - Alexe, Marin A1 - Bargheer, Matias T1 - Simultaneous dynamic characterization of charge and structural motion during ferroelectric switching JF - Physical review : B, Condensed matter and materials physics N2 - Monitoring structural changes in ferroelectric thin films during electric field induced polarization switching is important for a full microscopic understanding of the coupled motion of charges, atoms, and domainwalls in ferroelectric nanostructures. We combine standard ferroelectric test sequences of switching and nonswitching electrical pulses with time-resolved x-ray diffraction to investigate the structural response of a nanoscale Pb(Zr0.2Ti0.8)O-3 ferroelectric oxide capacitor upon charging, discharging, and polarization reversal. We observe that a nonlinear piezoelectric response of the ferroelectric layer develops on a much longer time scale than the RC time constant of the device. The complex atomic motion during the ferroelectric polarization reversal starts with a contraction of the lattice, whereas the expansive piezoelectric response sets in after considerable charge flow due to the applied voltage pulses on the electrodes of the capacitor. Our simultaneous measurements on a working device elucidate and visualize the complex interplay of charge flow and structural motion and challenges theoretical modeling. Y1 - 2017 U6 - https://doi.org/10.1103/PhysRevB.96.134105 SN - 2469-9950 SN - 2469-9969 VL - 96 PB - American Physical Society CY - College Park ER - TY - JOUR A1 - Post, Julia C. A1 - Class, Fabian A1 - Kohler, Ulrich T1 - Unit nonresponse biases in estimates of SARS-CoV-2 prevalence JF - Survey research methods N2 - Since COVID-19 became a pandemic, many studies are being conducted to get a better understanding of the disease itself and its spread. One crucial indicator is the prevalence of SARS-CoV-2 infections. Since this measure is an important foundation for political decisions, its estimate must be reliable and unbiased. This paper presents reasons for biases in prevalence estimates due to unit nonresponse in typical studies. Since it is difficult to avoid bias in situations with mostly unknown nonresponse mechanisms, we propose the maximum amount of bias as one measure to assess the uncertainty due to nonresponse. An interactive web application is presented that calculates the limits of such a conservative unit nonresponse confidence interval (CUNCI). KW - COVID-19 KW - prevalence KW - probability samples KW - unit nonresponse KW - conservative confidence limits KW - nonresponse bias Y1 - 2020 U6 - https://doi.org/10.18148/srm/2020.v14i2.7755 SN - 1864-3361 VL - 14 IS - 2 SP - 115 EP - 121 PB - European Survey Research Association CY - Duisburg ER - TY - CHAP A1 - Wang, Victor C. A1 - Mayer, Frank A1 - Dorenkamp, Marc A1 - Bonaventura, Klaus T1 - Three-dimensional global area tracking is a valuable quantitative parameter for left ventricular function in athletes T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2012 SN - 0195-9131 VL - 44 SP - 850 EP - 850 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Martinez-Valdes, Eduardo Andrés A1 - Negro, F. A1 - Laine, C. M. A1 - Falla, D. A1 - Mayer, Frank A1 - Farina, Dario T1 - Tracking motor units longitudinally across experimental sessions with high-density surface electromyography JF - The Journal of Physiology N2 - A new method is proposed for tracking individual motor units (MUs) across multiple experimental sessions on different days. The technique is based on a novel decomposition approach for high-density surface electromyography and was tested with two experimental studies for reliability and sensitivity. Experiment I (reliability): ten participants performed isometric knee extensions at 10, 30, 50 and 70% of their maximum voluntary contraction (MVC) force in three sessions, each separated by 1 week. Experiment II (sensitivity): seven participants performed 2 weeks of endurance training (cycling) and were tested pre-post intervention during isometric knee extensions at 10 and 30% MVC. The reliability (Experiment I) and sensitivity (Experiment II) of the measured MU properties were compared for the MUs tracked across sessions, with respect to all MUs identified in each session. In Experiment I, on average 38.3% and 40.1% of the identified MUs could be tracked across two sessions (1 and 2 weeks apart), for the vastus medialis and vastus lateralis, respectively. Moreover, the properties of the tracked MUs were more reliable across sessions than those of the full set of identified MUs (intra-class correlation coefficients ranged between 0.63-0.99 and 0.39-0.95, respectively). In Experiment II, similar to 40% of the MUs could be tracked before and after the training intervention and training-induced changes in MU conduction velocity had an effect size of 2.1 (tracked MUs) and 1.5 (group of all identified motor units). These results show the possibility of monitoring MU properties longitudinally to document the effect of interventions or the progression of neuromuscular disorders. Y1 - 2016 U6 - https://doi.org/10.1113/JP273662 SN - 0022-3751 SN - 1469-7793 VL - 595 SP - 1479 EP - 1496 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Menz, Stephan A1 - Latorre, Juan C. A1 - Schütte, Christof A1 - Huisinga, Wilhelm T1 - Hybrid stochastic-deterministic solution of the chemical master equation JF - Multiscale modeling & simulation : a SIAM interdisciplinary journal N2 - The chemical master equation (CME) is the fundamental evolution equation of the stochastic description of biochemical reaction kinetics. In most applications it is impossible to solve the CME directly due to its high dimensionality. Instead, indirect approaches based on realizations of the underlying Markov jump process are used, such as the stochastic simulation algorithm (SSA). In the SSA, however, every reaction event has to be resolved explicitly such that it becomes numerically inefficient when the system's dynamics include fast reaction processes or species with high population levels. In many hybrid approaches, such fast reactions are approximated as continuous processes or replaced by quasi-stationary distributions in either a stochastic or a deterministic context. Current hybrid approaches, however, almost exclusively rely on the computation of ensembles of stochastic realizations. We present a novel hybrid stochastic-deterministic approach to solve the CME directly. Our starting point is a partitioning of the molecular species into discrete and continuous species that induces a partitioning of the reactions into discrete-stochastic and continuous-deterministic processes. The approach is based on a WKB (Wentzel-Kramers-Brillouin) ansatz for the conditional probability distribution function (PDF) of the continuous species (given a discrete state) in combination with Laplace's method of integral approximation. The resulting hybrid stochastic-deterministic evolution equations comprise a CME with averaged propensities for the PDF of the discrete species that is coupled to an evolution equation of the related expected levels of the continuous species for each discrete state. In contrast to indirect hybrid methods, the impact of the evolution of discrete species on the dynamics of the continuous species has to be taken into account explicitly. The proposed approach is efficient whenever the number of discrete molecular species is small. We illustrate the performance of the new hybrid stochastic-deterministic approach in an application to model systems of biological interest. KW - chemical master equation KW - hybrid model KW - multiscale analysis KW - partial averaging KW - asymptotic approximation KW - WKB ansatz Y1 - 2012 U6 - https://doi.org/10.1137/110825716 SN - 1540-3459 VL - 10 IS - 4 SP - 1232 EP - 1262 PB - Society for Industrial and Applied Mathematics CY - Philadelphia ER - TY - JOUR A1 - Balci, K. A1 - Akkaya, Y. A1 - Akyuz, S. A1 - Collier, W. B. A1 - Stricker, M. C. A1 - Stover, D. D. A1 - Ritzhaupt, G. A1 - Koch, Andreas A1 - Kleinpeter, Erich T1 - The effects of conformation and zwitterionic tautomerism on the structural and vibrational spectral data of anserine JF - Vibrational spectroscopy : an international journal devoted to applications of infrared and raman spectroscopy N2 - In this study, the stable conformers of neutral anserine were searched by molecular dynamics simulations and energy minimization calculations using the MM2 force field. Thermochemical calculations at B3LYP/6-31G(d) level of theory followed these preliminary calculations. The results confirmed that neutral anserine has quite a flexible structure and many stable gauche and trans conformers at room temperature. Nevertheless, two are considerably more favourable in energy than the others and expected to dominate the gas-phase and matrix IR spectra of the molecule. The corresponding structural and vibrational spectral data for these two conformers of neutral anserine, whose relative stabilities were also examined by high-accuracy energy calculations carried out using G3MP2B3 method, and for the most stable conformer of anserine in zwitterion form were calculated at B3LYP/6-311++G(d,p) level of theory. The calculated harmonic force constants were refined using the Scaled Quantum Mechanical Force Field (SQM-FF) method and then used to produce the refined wavenumbers, potential energy distributions (PEDs) and IR and Raman intensities. These refined data together with the scaled harmonic wavenumbers obtained using another method, Dual Scale factors (DS), enabled us to correctly analyse the observed IR and Raman spectra of anserine and revealed the effects of conformation and zwitterionic tautomerism on its structural and vibrational spectral data. (C) 2016 Elsevier B.V. All rights reserved. KW - Anserine KW - Matrix IR spectrum KW - Tautomerism KW - SQM-FF KW - Dual scale factors Y1 - 2016 U6 - https://doi.org/10.1016/j.vibspec.2016.08.003 SN - 0924-2031 SN - 1873-3697 VL - 86 SP - 277 EP - 289 PB - Elsevier CY - Amsterdam ER -