TY  - JOUR
A1  - Wurzbacher, Christian
A1  - Warthmann, Norman
A1  - Bourne, Elizabeth Charlotte
A1  - Attermeyer, Katrin
A1  - Allgaier, Martin
A1  - Powell, Jeff R.
A1  - Detering, Harald
A1  - Mbedi, Susan
A1  - Grossart, Hans-Peter
A1  - Monaghan, Michael T.
T1  - High habitat-specificity in fungal communities in oligo-mesotrophic, temperate Lake Stechlin (North-East Germany)
JF  - MycoKeys
N2  - Freshwater fungi are a poorly studied ecological group that includes a high taxonomic diversity. Most studies on aquatic fungal diversity have focused on single habitats, thus the linkage between habitat heterogeneity and fungal diversity remains largely unexplored. We took 216 samples from 54 locations representing eight different habitats in the meso-oligotrophic, temperate Lake Stechlin in North-East Germany. These included the pelagic and littoral water column, sediments, and biotic substrates. We performed high throughput sequencing using the Roche 454 platform, employing a universal eukaryotic marker region within the large ribosomal subunit (LSU) to compare fungal diversity, community structure, and species turnover among habitats. Our analysis recovered 1027 fungal OTUs (97% sequence similarity). Richness estimates were highest in the sediment, biofilms, and benthic samples (189-231 OTUs), intermediate in water samples (42-85 OTUs), and lowest in plankton samples (8 OTUs). NMDS grouped the eight studied habitats into six clusters, indicating that community composition was strongly influenced by turnover among habitats. Fungal communities exhibited changes at the phylum and order levels along three different substrate categories from littoral to pelagic habitats. The large majority of OTUs (> 75%) could not be classified below the order level due to the lack of aquatic fungal entries in public sequence databases. Our study provides a first estimate of lake-wide fungal diversity and highlights the important contribution of habitat heterogeneity to overall diversity and community composition. Habitat diversity should be considered in any sampling strategy aiming to assess the fungal diversity of a water body.
KW  - Freshwater fungi
KW  - aquatic fungi
KW  - metabarcoding
KW  - LSU
KW  - GMYC
KW  - habitat specificity
KW  - Chytridiomycota
KW  - Cryptomycota
KW  - Rozellomycota
KW  - community ecology
KW  - lake ecosystem
KW  - biofilm
KW  - sediment
KW  - plankton
KW  - water sample
KW  - benthos
KW  - reed
KW  - fungal diversity
Y1  - 2016
U6  - https://doi.org/10.3897/mycokeys.16.9646
SN  - 1314-4057
SN  - 1314-4049
VL  - 41
SP  - 17
EP  - 44
PB  - Pensoft Publ.
CY  - Sofia
ER  - 
TY  - JOUR
A1  - Rosa, Angelika D.
A1  - Pohlenz, Julia
A1  - de Grouchy, C.
A1  - Cochain, B.
A1  - Kono, Y.
A1  - Pasternak, S.
A1  - Mathon, O.
A1  - Irifune, Tetsuo
A1  - Wilke, Max
T1  - In situ characterization of liquid network structures at high pressure and temperature using X-ray absorption spectroscopy coupled with the Paris-Edinburgh press
JF  - High pressure research
N2  - We review recent progress in studying structural properties of liquids using X-ray absorption spectroscopy coupled with the Paris-Edinburgh press at third-generation synchrotron facilities. This experimental method allows for detecting subtle changes in atomic arrangements of melts over a wide pressure-temperature range. It has been also employed to monitor variations of the local coordination environment of diluted species contained in glasses, liquids and crystalline phases as a function of the pressure and temperature. Such information is of great importance for gaining deeper insights into the physico-chemical properties of liquids at extreme condition, including the understanding of such phenomena as liquid-liquid phase transitions, viscosity drops and various transport properties of geological melts. Here, we describe the experimental approach and discuss its potential in structural characterization on selected scientific highlights. Finally, the current ongoing instrumental developments and future scientific opportunities are discussed.
KW  - X-ray absorption
KW  - Paris-Edinburgh press
KW  - liquid structure
KW  - high pressure and temperature
KW  - EXAFS
Y1  - 2016
U6  - https://doi.org/10.1080/08957959.2016.1199693
SN  - 0895-7959
SN  - 1477-2299
VL  - 36
SP  - 332
EP  - 347
PB  - American Geophysical Union
CY  - Abingdon
ER  - 
TY  - JOUR
A1  - Kayser, Daniela Niesta
A1  - Graupmann, Verena
A1  - Fryer, James W.
A1  - Frey, Dieter
T1  - Threat to Freedom and the Detrimental Effect of Avoidance Goal Frames
BT  - Reactance as a Mediating Variable
JF  - Frontiers in psychology
N2  - Two experiments examined how individuals respond to a restriction presented within an approach versus an avoidance frame. In Study 1, working on a problem-solving task, participants were initially free to choose their strategy, but for a second task were told to change their strategy. The message to change was embedded in either an approach or avoidance frame. When confronted with an avoidance compared to an approach frame, the participants’ reactance toward the request was greater and, in turn, led to impaired performance. The role of reactance as a response to threat to freedom was explicitly examined in Study 2, in which participants evaluated a potential change in policy affecting their program of study herein explicitly varying whether a restriction was present or absent and whether the message was embedded in an approach versus avoidance frame. When communicated with an avoidance frame and as a restriction, participants showed the highest resistance in terms of reactance, message agreement and evaluation of the communicator. The difference in agreement with the change was mediated by reactance only when a restriction was present. Overall, avoidance goal frames were associated with more resistance to change on different levels of experience (reactance, performance, and person perception). Reactance mediated the effect of goal frame on other outcomes only when a restriction was present.
KW  - freedom restriction
KW  - goal frames
KW  - avoidance
KW  - approach
KW  - reactance
KW  - self threat
KW  - change
Y1  - 2016
U6  - https://doi.org/10.3389/fpsyg.2016.00632
SN  - 1664-1078
VL  - 7
PB  - Frontiers Research Foundation
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Kayser, Daniela Niesta
A1  - Graupmann, Verena
A1  - Fryer, James W.
A1  - Frey, Dieter
T1  - Threat to Freedom and the Detrimental Effect of Avoidance Goal Frames: Reactance as a Mediating Variable
JF  - Frontiers in psychology
N2  - Two experiments examined how individuals respond to a restriction presented within an approach versus an avoidance frame. In Study 1, working on a problem-solving task, participants were initially free to choose their strategy, but for a second task were told to change their strategy. The message to change was embedded in either an approach or avoidance frame. When confronted with an avoidance compared to an approach frame, the participants’ reactance toward the request was greater and, in turn, led to impaired performance. The role of reactance as a response to threat to freedom was explicitly examined in Study 2, in which participants evaluated a potential change in policy affecting their program of study herein explicitly varying whether a restriction was present or absent and whether the message was embedded in an approach versus avoidance frame. When communicated with an avoidance frame and as a restriction, participants showed the highest resistance in terms of reactance, message agreement and evaluation of the communicator. The difference in agreement with the change was mediated by reactance only when a restriction was present. Overall, avoidance goal frames were associated with more resistance to change on different levels of experience (reactance, performance, and person perception). Reactance mediated the effect of goal frame on other outcomes only when a restriction was present.
KW  - freedom restriction
KW  - goal frames
KW  - avoidance
KW  - approach
KW  - reactance
KW  - self threat
KW  - change
Y1  - 2016
U6  - https://doi.org/10.3389/fpsyg.2016.00632
SN  - 1664-1078
VL  - 7
PB  - Frontiers Research Foundation
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Beurskens, Rainer
A1  - Haeger, Matthias
A1  - Kliegl, Reinhold
A1  - Roecker, Kai
A1  - Granacher, Urs
T1  - Postural Control in Dual-Task Situations
BT  - Does Whole-Body Fatigue Matter?
JF  - PLoS one
N2  - Postural control is important to cope with demands of everyday life. It has been shown that both attentional demand (i.e., cognitive processing) and fatigue affect postural control in young adults. However, their combined effect is still unresolved. Therefore, we investigated the effects of fatigue on single- (ST) and dual-task (DT) postural control. Twenty young subjects (age: 23.7 ± 2.7) performed an all-out incremental treadmill protocol. After each completed stage, one-legged-stance performance on a force platform under ST (i.e., one-legged-stance only) and DT conditions (i.e., one-legged-stance while subtracting serial 3s) was registered. On a second test day, subjects conducted the same balance tasks for the control condition (i.e., non-fatigued). Results showed that heart rate, lactate, and ventilation increased following fatigue (all p < 0.001; d = 4.2–21). Postural sway and sway velocity increased during DT compared to ST (all p < 0.001; d = 1.9–2.0) and fatigued compared to non-fatigued condition (all p < 0.001; d = 3.3–4.2). In addition, postural control deteriorated with each completed stage during the treadmill protocol (all p < 0.01; d = 1.9–3.3). The addition of an attention-demanding interference task did not further impede one-legged-stance performance. Although both additional attentional demand and physical fatigue affected postural control in healthy young adults, there was no evidence for an overadditive effect (i.e., fatigue-related performance decrements in postural control were similar under ST and DT conditions). Thus, attentional resources were sufficient to cope with the DT situations in the fatigue condition of this experiment.
Y1  - 2016
U6  - https://doi.org/10.1371/journal.pone.0147392
SN  - 1932-6203
VL  - 11
IS  - 1
SP  - 1
EP  - 15
PB  - PLoS
CY  - Lawrence, Kan.
ER  - 
TY  - JOUR
A1  - Vences, Miguel
A1  - Lyra, Mariana L.
A1  - Kueneman, Jordan G.
A1  - Bletz, Molly C.
A1  - Archer, Holly M.
A1  - Canitz, Julia
A1  - Handreck, Svenja
A1  - Randrianiaina, Roger-Daniel
A1  - Struck, Ulrich
A1  - Bhuju, Sabin
A1  - Jarek, Michael
A1  - Geffers, Robert
A1  - McKenzie, Valerie J.
A1  - Tebbe, Christoph C.
A1  - Haddad, CLio F. B.
A1  - Glos, Julian
T1  - Gut bacterial communities across tadpole ecomorphs in two diverse tropical anuran faunas
JF  - The science of nature
N2  - Animal-associated microbial communities can play major roles in the physiology, development, ecology, and evolution of their hosts, but the study of their diversity has yet focused on a limited number of host species. In this study, we used high-throughput sequencing of partial sequences of the bacterial 16S rRNA gene to assess the diversity of the gut-inhabiting bacterial communities of 212 specimens of tropical anuran amphibians from Brazil and Madagascar. The core gut-associated bacterial communities among tadpoles from two different continents strongly overlapped, with eight highly represented operational taxonomic units (OTUs) in common. In contrast, the core communities of adults and tadpoles from Brazil were less similar with only one shared OTU. This suggests a community turnover at metamorphosis. Bacterial diversity was higher in tadpoles compared to adults. Distinct differences in composition and diversity occurred among gut bacterial communities of conspecific tadpoles from different water bodies and after experimental fasting for 8 days, demonstrating the influence of both environmental factors and food on the community structure. Communities from syntopic tadpoles clustered by host species both in Madagascar and Brazil, and the Malagasy tadpoles also had species-specific isotope signatures. We recommend future studies to analyze the turnover of anuran gut bacterial communities at metamorphosis, compare the tadpole core communities with those of other aquatic organisms, and assess the possible function of the gut microbiota as a reservoir for protective bacteria on the amphibian skin.
KW  - Amphibia
KW  - Anura
KW  - Tadpoles
KW  - Gutmicrobiota
KW  - 16S rRNA
KW  - Stable isotopes
Y1  - 2016
U6  - https://doi.org/10.1007/s00114-016-1348-1
SN  - 0028-1042
SN  - 1432-1904
VL  - 103
SP  - 68
EP  - 73
PB  - Springer
CY  - Heidelberg
ER  - 
TY  - JOUR
A1  - Schennen, Stephan
A1  - Tronicke, Jens
A1  - Wetterich, Sebastian
A1  - Allroggen, Niklas
A1  - Schwamborn, Georg
A1  - Schirrmeister, Lutz
T1  - 3D ground-penetrating radar imaging of ice complex deposits in northern East Siberia
JF  - Geophysics
N2  - Ice complex deposits are characteristic, ice-rich formations in northern East Siberia and represent an important part in the arctic carbon pool. Recently, these late Quaternary deposits are the objective of numerous investigations typically relying on outcrop and borehole data. Many of these studies can benefit from a 3D structural model of the subsurface for upscaling their observations or for constraining estimations of inventories, such as the local carbon stock. We have addressed this problem of structural imaging by 3D ground-penetrating radar (GPR), which, in permafrost studies, has been primarily used for 2D profiling. We have used a 3D kinematic GPR surveying strategy at a field site located in the New Siberian Archipelago on top of an ice complex. After applying a 3D GPR processing sequence, we were able to trace two horizons at depths below 20 m. Taking available borehole and outcrop data into account, we have interpreted these two features as interfaces of major lithologic units and derived a 3D cryostratigraphic model of the subsurface. Our data example demonstrated that a 3D surveying and processing strategy was crucial at our field site and showed the potential of 3D GPR to image geologic structures in complex ice-rich permafrost landscapes.
Y1  - 2016
U6  - https://doi.org/10.1190/GEO2015-0129.1
SN  - 0016-8033
SN  - 1942-2156
VL  - 81
SP  - WA195
EP  - WA202
PB  - Society of Exploration Geophysicists
CY  - Tulsa
ER  - 
TY  - JOUR
A1  - Allroggen, Niklas
A1  - Tronicke, Jens
T1  - Attribute-based analysis of time-lapse ground-penetrating radar data
JF  - Geophysics
N2  - Analysis of time-lapse ground-penetrating radar (GPR) data can provide information regarding subsurface hydrological processes, such as preferential flow. However, the analysis of time-lapse data is often limited by data quality; for example, for noisy input data, the interpretation of difference images is often difficult. Motivated by modern image-processing tools, we have developed two robust GPR attributes, which allow us to distinguish amplitude (contrast similarity) and time-shift (structural similarity) variations related to differences between individual time-lapse GPR data sets. We tested and evaluated our attributes using synthetic data of different complexity. Afterward, we applied them to a field data example, in which subsurface flow was induced by an artificial rainfall event. For all examples, we identified our structural similarity attribute to be a robust measure for highlighting time-lapse changes also in data with low signal-to-noise ratios. We determined that our new attribute-based workflow is a promising tool to analyze time-lapse GPR data, especially for imaging subsurface hydrological processes.
Y1  - 2016
U6  - https://doi.org/10.1190/GEO2015-0171.1
SN  - 0016-8033
SN  - 1942-2156
VL  - 81
SP  - H1
EP  - H8
PB  - Society of Exploration Geophysicists
CY  - Tulsa
ER  - 
TY  - JOUR
A1  - Guillemoteau, Julien
A1  - Simon, Francois-Xavier
A1  - Lück, Erika
A1  - Tronicke, Jens
T1  - 1D sequential inversion of portable multi-configuration electromagnetic induction data
JF  - Near surface geophysics
N2  - We present an algorithm that performs sequentially one-dimensional inversion of subsurface magnetic permeability and electrical conductivity by using multi-configuration electromagnetic induction sensor data. The presented method is based on the conversion of the in-phase and out-of-phase data into effective magnetic permeability and electrical conductivity of the equivalent homogeneous half-space. In the case of small-offset systems, such as portable electromagnetic induction sensors, for which in-phase and out-of-phase data are moderately coupled, the effective half-space magnetic permeability and electrical conductivity can be inverted sequentially within an iterative scheme. We test and evaluate the proposed inversion strategy using synthetic and field examples. First, we apply it to synthetic data for some highly magnetic environments. Then, the method is tested on real field data acquired in a basaltic environment to image a formation of archaeological interest. These examples demonstrate that a joint interpretation of in-phase and out-of-phase data leads to a better characterisation of the subsurface in magnetic environments such as volcanic areas.
Y1  - 2016
U6  - https://doi.org/10.3997/1873-0604.2016029
SN  - 1569-4445
SN  - 1873-0604
VL  - 14
SP  - 423
EP  - 432
PB  - Wiley-VCH
CY  - Houten
ER  - 
TY  - JOUR
A1  - Beurskens, Rainer
A1  - Haeger, Matthias
A1  - Kliegl, Reinhold
A1  - Roecker, Kai
A1  - Granacher, Urs
T1  - Postural Control in Dual-Task Situations: Does Whole-Body Fatigue Matter?
JF  - PLoS one
N2  - Postural control is important to cope with demands of everyday life. It has been shown that both attentional demand (i.e., cognitive processing) and fatigue affect postural control in young adults. However, their combined effect is still unresolved. Therefore, we investigated the effects of fatigue on single-(ST) and dual-task (DT) postural control. Twenty young subjects (age: 23.7 +/- 2.7) performed an all-out incremental treadmill protocol. After each completed stage, one-legged-stance performance on a force platform under ST (i.e., one-legged-stance only) and DT conditions (i.e., one-legged-stance while subtracting serial 3s) was registered. On a second test day, subjects conducted the same balance tasks for the control condition (i.e., non-fatigued). Results showed that heart rate, lactate, and ventilation increased following fatigue (all p < 0.001; d = 4.2-21). Postural sway and sway velocity increased during DT compared to ST (all p < 0.001; d = 1.9-2.0) and fatigued compared to non-fatigued condition (all p < 0.001; d = 3.3-4.2). In addition, postural control deteriorated with each completed stage during the treadmill protocol (all p < 0.01; d = 1.9-3.3). The addition of an attention-demanding interference task did not further impede one-legged-stance performance. Although both additional attentional demand and physical fatigue affected postural control in healthy young adults, there was no evidence for an overadditive effect (i.e., fatigue-related performance decrements in postural control were similar under ST and DT conditions). Thus, attentional resources were sufficient to cope with the DT situations in the fatigue condition of this experiment.
Y1  - 2016
U6  - https://doi.org/10.1371/journal.pone.0147392
SN  - 1932-6203
VL  - 11
SP  - 1379
EP  - 1384
PB  - PLoS
CY  - San Fransisco
ER  - 
TY  - JOUR
A1  - Beurskens, Rainer
A1  - Mühlbauer, Thomas
A1  - Grabow, Lena
A1  - Kliegl, Reinhold
A1  - Granacher, Urs
T1  - Effects of Backpack Carriage on Dual-Task Performance in Children During Standing and Walking
JF  - Journal of motor behavior
KW  - attentional demand
KW  - cognitive performance
KW  - gait analysis
KW  - load carriage
KW  - postural control
Y1  - 2016
U6  - https://doi.org/10.1080/00222895.2016.1152137
SN  - 0022-2895
SN  - 1940-1027
VL  - 48
SP  - 500
EP  - 508
PB  - Wiley-VCH
CY  - Abingdon
ER  - 
TY  - JOUR
A1  - Lehmann, Andreas
A1  - Scheffler, Christiane
T1  - What does the mean menarcheal age mean?An analysis of temporal pattern in variability in a historical swiss population from the 19th and 20th centuries
JF  - American journal of human biology : the official journal of the Human Biology Council
N2  - ObjectivesAge at menarche is one of the most important factors when observing growth and development. The aim of this study was to assess the temporal pattern in variability of menarcheal age for a historic Swiss population from the 19th and 20th centuries. ResultsMean menarcheal age declined from 17.34 years (n=358) around 1830 to 13.80 years (n=141) around 1950. Within-cohort variance decreased from 7.5 to 2.1 year(2). Skewness was negatively correlated with birth year (r=-0.58). ConclusionThis study provided evidence for a secular trend in various statistical parameters for age at menarche since the 19th century. Furthermore, the results of the analysis of temporal pattern in variability revealed that the secular trend in menarcheal age happened in two phases. Am. J. Hum. Biol. 28:705-713, 2016. (c) 2016 Wiley Periodicals, Inc.
Y1  - 2016
U6  - https://doi.org/10.1002/ajhb.22854
SN  - 1042-0533
SN  - 1520-6300
VL  - 28
SP  - 705
EP  - 713
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Cui, Pin
A1  - Löber, Ulrike
A1  - Alquezar-Planas, David E.
A1  - Ishida, Yasuko
A1  - Courtiol, Alexandre
A1  - Timms, Peter
A1  - Johnson, Rebecca N.
A1  - Lenz, Dorina
A1  - Helgen, Kristofer M.
A1  - Roca, Alfred L.
A1  - Hartman, Stefanie
A1  - Greenwood, Alex D.
T1  - Comprehensive profiling of retroviral integration sites using target enrichment methods from historical koala samples without an assembled reference genome
JF  - PeerJ
N2  - Background. Retroviral integration into the host germline results in permanent viral colonization of vertebrate genomes. The koala retrovirus (KoRV) is currently invading the germline of the koala (Phascolarctos cinereus) and provides a unique opportunity for studying retroviral endogenization. Previous analysis of KoRV integration patterns in modern koalas demonstrate that they share integration sites primarily if they are related, indicating that the process is currently driven by vertical transmission rather than infection. However, due to methodological challenges, KoRV integrations have not been comprehensively characterized. Results. To overcome these challenges, we applied and compared three target enrichment techniques coupled with next generation sequencing (NGS) and a newly customized sequence-clustering based computational pipeline to determine the integration sites for 10 museum Queensland and New South Wales (NSW) koala samples collected between the 1870s and late 1980s. A secondary aim of this study sought to identify common integration sites across modern and historical specimens by comparing our dataset to previously published studies. Several million sequences were processed, and the KoRV integration sites in each koala were characterized. Conclusions. Although the three enrichment methods each exhibited bias in integration site retrieval, a combination of two methods, Primer Extension Capture and hybridization capture is recommended for future studies on historical samples. Moreover, identification of integration sites shows that the proportion of integration sites shared between any two koalas is quite small.
KW  - Integration sites
KW  - Retroviral endogenization
KW  - KoRV
KW  - Target enrichment
KW  - Clustering
Y1  - 2016
U6  - https://doi.org/10.7717/peerj.1847
SN  - 2167-8359
VL  - 4
PB  - PeerJ Inc.
CY  - London
ER  - 
TY  - JOUR
A1  - Iurchuk, V.
A1  - Schick, D.
A1  - Bran, J.
A1  - Colson, D.
A1  - Forget, A.
A1  - Halley, D.
A1  - Koc, Azize
A1  - Reinhardt, Mathias
A1  - Kwamen, C.
A1  - Morley, N. A.
A1  - Bargheer, Matias
A1  - Viret, M.
A1  - Gumeniuk, R.
A1  - Schmerber, G.
A1  - Doudin, B.
A1  - Kundys, B.
T1  - Optical Writing of Magnetic Properties by Remanent Photostriction
JF  - Physical review letters
N2  - We present an optically induced remanent photostriction in BiFeO3, resulting from the photovoltaic effect, which is used to modify the ferromagnetism of Ni film in a hybrid BiFeO3/Ni structure. The 75% change in coercivity in the Ni film is achieved via optical and nonvolatile control. This photoferromagnetic effect can be reversed by static or ac electric depolarization of BiFeO3. Hence, the strain dependent changes in magnetic properties are written optically, and erased electrically. Light-mediated straintronics is therefore a possible approach for low-power multistate control of magnetic elements relevant for memory and spintronic applications.
Y1  - 2016
U6  - https://doi.org/10.1103/PhysRevLett.117.107403
SN  - 0031-9007
SN  - 1079-7114
VL  - 117
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Reinhardt, Matthias
A1  - Koc, Azize
A1  - Leitenberger, Wolfram
A1  - Gaal, Peter
A1  - Bargheer, Matias
T1  - Optimized spatial overlap in optical pump-X-ray probe experiments with high repetition rate using laser-induced surface distortions
JF  - Journal of synchrotron radiation
N2  - Ultrafast X-ray diffraction experiments require careful adjustment of the spatial overlap between the optical excitation and the X-ray probe pulse. This is especially challenging at high laser repetition rates. Sample distortions caused by the large heat load on the sample and the relatively low optical energy per pulse lead to only tiny signal changes. In consequence, this results in small footprints of the optical excitation on the sample, which turns the adjustment of the overlap difficult. Here a method for reliable overlap adjustment based on reciprocal space mapping of a laser excited thin film is presented.
KW  - ultrafast X-ray diffraction
KW  - nanostructures
KW  - surface deformation
KW  - heat diffusion
KW  - optical pump
Y1  - 2016
U6  - https://doi.org/10.1107/S1600577515024443
SN  - 1600-5775
VL  - 23
SP  - 474
EP  - 479
PB  - International Union of Crystallography
CY  - Chester
ER  - 
TY  - JOUR
A1  - Czesnick, Hjördis
A1  - Lenhard, Michael
T1  - Antagonistic control of flowering time by functionally specialized poly(A) polymerases in Arabidopsis thaliana
JF  - The plant journal
N2  - Polyadenylation is a critical 3-end processing step during maturation of pre-mRNAs, and the length of the poly(A) tail affects mRNA stability, nuclear export and translation efficiency. The Arabidopsis thaliana genome encodes three canonical nuclear poly(A) polymerase (PAPS) isoforms fulfilling specialized functions, as reflected by their different mutant phenotypes. While PAPS1 affects several processes, such as the immune response, organ growth and male gametophyte development, the roles of PAPS2 and PAPS4 are largely unknown. Here we demonstrate that PAPS2 and PAPS4 promote flowering in a partially redundant manner. The enzymes act antagonistically to PAPS1, which delays the transition to flowering. The opposite flowering-time phenotypes in paps1 and paps2 paps4 mutants are at least partly due to decreased or increased FLC activity, respectively. In contrast to paps2 paps4 mutants, plants with increased PAPS4 activity flower earlier than the wild-type, concomitant with reduced FLC expression. Double mutant analyses suggest that PAPS2 and PAPS4 act independently of the autonomous pathway components FCA, FY and CstF64. The direct polyadenylation targets of the three PAPS isoforms that mediate their effects on flowering time do not include FLC sense mRNA and remain to be identified. Thus, our results uncover a role for canonical PAPS isoforms in flowering-time control, raising the possibility that modulating the balance of the isoform activities could be used to fine tune the transition to flowering. Significance Statement The length of the poly(A) tail affects mRNA stability, nuclear export and translation efficiency. Arabidopsis has three isoforms of nuclear poly(A) polymerase (PAPS): PAPS1 plays a major role in organ growth and plant defence. Here we show that PAPS2 and PAPS4 redundantly promote flowering and act antagonistically to PAPS1, which delays flowering. We suggest that modulating the activity of these isoforms fine-tunes the transition to flowering.
KW  - polyadenylation
KW  - 3-end processing
KW  - poly(A) polymerase
KW  - flowering time
KW  - autonomous pathway
KW  - Arabidopsis thaliana
Y1  - 2016
U6  - https://doi.org/10.1111/tpj.13280
SN  - 0960-7412
SN  - 1365-313X
VL  - 88
SP  - 570
EP  - 583
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Jöst, Moritz
A1  - Hensel, Goetz
A1  - Kappel, Christian
A1  - Druka, Arnis
A1  - Sicard, Adrien
A1  - Hohmann, Uwe
A1  - Beier, Sebastian
A1  - Himmelbach, Axel
A1  - Waugh, Robbie
A1  - Kumlehn, Jochen
A1  - Stein, Nils
A1  - Lenhard, Michael
T1  - The INDETERMINATE DOMAIN Protein BROAD LEAF1 Limits Barley Leaf Width by Restricting Lateral Proliferation
JF  - Current biology
N2  - Variation in the size, shape, and positioning of leaves as the major photosynthetic organs strongly impacts crop yield, and optimizing these aspects is a central aim of cereal breeding [1, 2]. Leaf growth in grasses is driven by cell proliferation and cell expansion in a basal growth zone [3]. Although several factors influencing final leaf size and shape have been identified from rice and maize [4-14], what limits grass leaf growth in the longitudinal or transverse directions during leaf development remains poorly understood. To identify factors involved in this process, we characterized the barley mutant broad leaf1 (blf1). Mutants form wider but slightly shorter leaves due to changes in the numbers of longitudinal cell files and of cells along the leaf length. These differences arise during primordia outgrowth because of more cell divisions in the width direction increasing the number of cell files. Positional cloning, analysis of independent alleles, and transgenic complementation confirm that BLF1 encodes a presumed transcriptional regulator of the INDETERMINATE DOMAIN family. In contrast to loss-of-function mutants, moderate overexpression of BLF1 decreases leaf width below wild-type levels. A functional BLF1-vYFP fusion protein expressed from the endogenous promoter shows a dynamic expression pattern in the shoot apical meristem and young leaf primordia. Thus, we propose that the BLF1 gene regulates barley leaf size by restricting cell proliferation in the leaf-width direction. Given the agronomic importance of canopy traits in cereals, identifying functionally different BLF1 alleles promises to allow for the generation of optimized cereal ideotypes.
Y1  - 2016
U6  - https://doi.org/10.1016/j.cub.2016.01.047
SN  - 0960-9822
SN  - 1879-0445
VL  - 26
SP  - 903
EP  - 909
PB  - Cell Press
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Sicard, Adrien
A1  - Kappel, Christian
A1  - Lee, Young Wha
A1  - Wozniak, Natalia Joanna
A1  - Marona, Cindy
A1  - Stinchcombe, John R.
A1  - Wright, Stephen I.
A1  - Lenhard, Michael
T1  - Standing genetic variation in a tissue-specific enhancer underlies
selfing-syndrome evolution in Capsella
JF  - Proceedings of the National Academy of Sciences of the United States of America
N2  - Mating system shifts recurrently drive specific changes in organ dimensions. The shift in mating system from out-breeding to selfing is one of the most frequent evolutionary transitions in flowering plants and is often associated with an organ-specific reduction in flower size. However, the evolutionary paths along which polygenic traits, such as size, evolve are poorly understood. In particular, it is unclear how natural selection can specifically modulate the size of one organ despite the pleiotropic action of most known growth regulators. Here, we demonstrate that allelic variation in the intron of a general growth regulator contributed to the specific reduction of petal size after the transition to selfing in the genus Capsella. Variation within this intron affects an organ-specific enhancer that regulates the level of STERILE APETALA (SAP) protein in the developing petals. The resulting decrease in SAP activity leads to a shortening of the cell proliferation period and reduced number of petal cells. The absence of private polymorphisms at the causal region in the selfing species suggests that the small-petal allele was captured from standing genetic variation in the ancestral out-crossing population. Petal-size variation in the current out-crossing population indicates that several small-effect mutations have contributed to reduce petal-size. These data demonstrate how tissue-specific regulatory elements in pleiotropic genes contribute to organ-specific evolution. In addition, they provide a plausible evolutionary explanation for the rapid evolution of flower size after the out-breeding-to-selfing transition based on additive effects of segregating alleles.
KW  - morphological evolution
KW  - growth control
KW  - standing variation;
 organ-specific evolution
KW  - intronic cis-regulatory element
Y1  - 2016
U6  - https://doi.org/10.1073/pnas.1613394113
SN  - 0027-8424
VL  - 113
SP  - 13911
EP  - 13916
PB  - National Acad. of Sciences
CY  - Washington
ER  - 
TY  - JOUR
A1  - Ronquillo, Cecinio C.
A1  - Hanke-Gogokhia, Christin
A1  - Revelo, Monica P.
A1  - Frederick, Jeanne M.
A1  - Jiang, Li
A1  - Baehr, Wolfgang
T1  - Ciliopathy-associated IQCB1/NPHP5 protein is required for mouse photoreceptor outer segment formation
JF  - The FASEB journal : the official journal of the Federation of American Societies for Experimental Biology
N2  - Null mutations in the human IQCB1/NPHP5 (nephrocystin-5) gene that encodes NPHP5 are the most frequent cause of Senior-LOken syndrome, a ciliopathy that is characterized by Leber congenital amaurosis and nephronophthisis. We generated germline Nphp5-knockout mice by placing a -Geo gene trap in intron 4, thereby truncating NPHP5 at Leu87 and removing all known functional domains. At eye opening, Nphp5(-/-) mice exhibited absence of scotopic and photopic electroretinogram responses, a phenotype that resembles Leber congenital amaurosis. Outer segment transmembrane protein accumulation in Nphp5(-/-) endoplasmic reticulum was evident as early as postnatal day (P)6. EGFP-CETN2, a centrosome and transition zone marker, identified basal bodies in Nphp5(-/-) photoreceptors, but without fully developed transition zones. Ultrastructure of P6 and 10 Nphp5(-/-) photoreceptors revealed aberrant transition zones of reduced diameter. Nphp5(-/-) photoreceptor degeneration was complete at 1 mo of age but was delayed significantly in Nphp5(-/-);Nrl(-/-) (cone only) retina. Nphp5(-/-) mouse embryonic fibroblast developed normal cilia, and Nphp5(-/-) kidney histology at 1 yr of age showed no significant pathology. Results establish that nephrocystin-5 is essential for photoreceptor outer segment formation but is dispensable for kidney and mouse embryonic fibroblast ciliary formation.
KW  - Senior-LOken syndrome
KW  - nephronophthisis
KW  - Leber congenital amaurosis
KW  - nephrocystins
Y1  - 2016
U6  - https://doi.org/10.1096/fj.201600511R
SN  - 0892-6638
SN  - 1530-6860
VL  - 30
SP  - 3400
EP  - 3412
PB  - Federation of American Societies for Experimental Biology
CY  - Bethesda
ER  - 
TY  - JOUR
A1  - Sas, Claudia
A1  - Mueller, Frank
A1  - Kappel, Christian
A1  - Kent, Tyler V.
A1  - Wright, Stephen I.
A1  - Hilker, Monika
A1  - Lenhard, Michael
T1  - Repeated Inactivation of the First Committed Enzyme Underlies the Loss of Benzaldehyde Emission after the Selfing Transition in Capsella
JF  - Current biology
N2  - The enormous species richness of flowering plants is at least partly due to floral diversification driven by interactions between plants and their animal pollinators [1, 2]. Specific pollinator attraction relies on visual and olfactory floral cues [3-5]; floral scent can not only attract pollinators but also attract or repel herbivorous insects [6-8]. However, despite its central role for plant-animal interactions, the genetic control of floral scent production and its evolutionary modification remain incompletely understood [9-13]. Benzenoids are an important class of floral scent compounds that are generated from phenylalanine via several enzymatic pathways [14-17]. Here we address the genetic basis of the loss of floral scent associated with the transition from outbreeding to selfing in the genus Capsella. While the outbreeding C. grandiflora emits benzaldehyde as a major constituent of its floral scent, this has been lost in the selfing C. rubella. We identify the Capsella CNL1 gene encoding cinnamate: CoA ligase as responsible for this variation. Population genetic analysis indicates that CNL1 has been inactivated twice independently in C. rubella via different novel mutations to its coding sequence. Together with a recent study in Petunia [18], this identifies cinnamate: CoA ligase as an evolutionary hotspot for mutations causing the loss of benzenoid scent compounds in association with a shift in the reproductive strategy of Capsella from pollination by insects to self-fertilization.
Y1  - 2016
U6  - https://doi.org/10.1016/j.cub.2016.10.026
SN  - 0960-9822
SN  - 1879-0445
VL  - 26
SP  - 3313
EP  - 3319
PB  - Cell Press
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Premke, Katrin
A1  - Attermeyer, Katrin
A1  - Augustin, Jürgen
A1  - Cabezas, Alvaro
A1  - Casper, Peter
A1  - Deumlich, Detlef
A1  - Gelbrecht, Jörg
A1  - Gerke, Horst H.
A1  - Gessler, Arthur
A1  - Grossart, Hans-Peter
A1  - Hilt, Sabine
A1  - Hupfer, Michael
A1  - Kalettka, Thomas
A1  - Kayler, Zachary
A1  - Lischeid, Gunnar
A1  - Sommer, Michael
A1  - Zak, Dominik
T1  - The importance of landscape diversity for carbon fluxes at the landscape level: small-scale heterogeneity matters
JF  - Wiley Interdisciplinary Reviews : Water
N2  - Landscapes can be viewed as spatially heterogeneous areas encompassing terrestrial and aquatic domains. To date, most landscape carbon (C) fluxes have been estimated by accounting for terrestrial ecosystems, while aquatic ecosystems have been largely neglected. However, a robust assessment of C fluxes on the landscape scale requires the estimation of fluxes within and between both landscape components. Here, we compiled data from the literature on C fluxes across the air–water interface from various landscape components. We simulated C emissions and uptake for five different scenarios which represent a gradient of increasing spatial heterogeneity within a temperate young moraine landscape: (I) a homogeneous landscape with only cropland and large lakes; (II) separation of the terrestrial domain into cropland and forest; (III) further separation into cropland, forest, and grassland; (IV) additional division of the aquatic area into large lakes and peatlands; and (V) further separation of the aquatic area into large lakes, peatlands, running waters, and small water bodies These simulations suggest that C fluxes at the landscape scale might depend on spatial heterogeneity and landscape diversity, among other factors. When we consider spatial heterogeneity and diversity alone, small inland waters appear to play a pivotal and previously underestimated role in landscape greenhouse gas emissions that may be regarded as C hot spots. Approaches focusing on the landscape scale will also enable improved projections of ecosystems’ responses to perturbations, e.g., due to global change and anthropogenic activities, and evaluations of the specific role individual landscape components play in regional C fluxes. WIREs Water 2016, 3:601–617. doi: 10.1002/wat2.1147
Y1  - 2016
U6  - https://doi.org/10.1002/wat2.1147
SN  - 2049-1948
SN  - 2049-1948
VL  - 3
SP  - 601
EP  - 617
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Wanner, Manfred
A1  - Seidl-Lampa, Barbara
A1  - Höhn, Axel
A1  - Puppe, Daniel
A1  - Meisterfeld, Ralf
A1  - Sommer, Michael
T1  - Culture growth of testate amoebae under different silicon concentrations
JF  - European journal of protistology
N2  - Testate amoebae with self-secreted siliceous shell platelets ("idiosomes") play an important role in terrestrial silicon (Si) cycles. In this context, Si-dependent culture growth dynamics of idiosomic testate amoebae are of interest. Clonal cultures of idiosomic testate amoebae were analyzed under three different Si concentrations: low (50 mu mol L-1), moderate/site-specific (150 mu mol L-1) and high Si supply (500 mu mol L-1). Food (Saccharomyces cerevisiae) was provided in surplus. (i) Shell size of four different clones of idiosomic testate amoebae either decreased (Trinema galeata, Euglypha filifera cf.), increased (E. rotunda cf.), or did not change (E. rotunda) under the lowest Si concentration (50 mu mol Si L-1). (ii) Culture growth of idiosomic Euglypha rotunda was dependent on Si concentration. The more Si available in the culture medium, the earlier the entry into exponential growth phase. (iii) Culture growth of idiosomic Euglypha rotunda was dependent on origin of inoculum. Amoebae previously cultured under a moderate Si concentration revealed highest sustainability in consecutive cultures. Amoebae derived from cultures with high Si concentrations showed rapid culture growth which finished early in consecutive cultures. (iv) Si (diluted in the culture medium) was absorbed by amoebae and fixed in the amoeba shells resulting in decreased Si concentrations. (C) 2016 Elsevier GmbH. All rights reserved.
KW  - Amoebal silicon
KW  - Sommer et al. 2006
KW  - Biosilicification
KW  - Consumption
KW  - Culture growth dynamics
KW  - Euglyphida
KW  - Terrestrial Si cycle
Y1  - 2016
U6  - https://doi.org/10.1016/j.ejop.2016.08.008
SN  - 0932-4739
SN  - 1618-0429
VL  - 56
SP  - 171
EP  - 179
PB  - Royal Society of Chemistry
CY  - Jena
ER  - 
TY  - JOUR
A1  - Puppe, Daniel
A1  - Höhn, Axel
A1  - Kaczorek, Danuta
A1  - Wanner, Manfred
A1  - Sommer, Michael
T1  - As time goes by-Spatiotemporal changes of biogenic Si pools in initial soils of an artificial catchment in NE Germany
JF  - Applied soil ecology : a section of agriculture, ecosystems & environment
KW  - Biogenic silica
KW  - Diatom frustule
KW  - Testate amoeba shell
KW  - Sponge spicule
KW  - Initial ecosystem
Y1  - 2016
U6  - https://doi.org/10.1016/j.apsoil.2016.01.020
SN  - 0929-1393
SN  - 1873-0272
VL  - 105
SP  - 9
EP  - 16
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Kaiser, Michael
A1  - Zederer, Dan P.
A1  - Ellerbrock, Ruth H.
A1  - Sommer, Michael
A1  - Ludwig, Bernard
T1  - Effects of mineral characteristics on content, composition, and stability of organic matter fractions separated from seven forest topsoils of different pedogenesis
JF  - Geoderma : an international journal of soil science
N2  - Mineral topsoils possess large organic carbon (OC) contents but there is only limited knowledge on the mechanisms controlling the preservation of organic matter (OM) against microbial decay. Samples were taken from the uppermost mineral topsoil horizon (0 to 5 cm) of seven sites under mature deciduous forest showing OC contents between 69 and 164 g kg(-1) and a wide range in mineral characteristics. At first, organic particles and the water-extractable OM were removed from the soil samples. Thereafter, Na-pyrophosphate extractable organic matter (OM(PY)), assumed to be indicative for OM bound via cation mediated interactions, and the OM remaining in the extraction residue (OM(ER)), supposed to be indicative for OM occluded in mechanically highly stable micro-aggregates, were sequentially separated and quantified. The composition of OM(PY) and OM(ER) was analyzed by FTIR and their stability by C-14 measurements. The OC remaining in the extraction residues accounted for 38 to 59% of the bulk soil OC (SOC) suggesting a much larger relevance of OM(ER) for the OM dynamic in the analyzed soils as compared with OM(PY) that accounted for 1.6 to 7.5% of the SOC. The FUR analyses revealed a lower relative proportion of C=O groups in OM(ER) compared to OM(PY) indicating differences in the degree of microbial processing between these fractions. Correlation analyses suggest an increase in the stability of OM(PY) with the soil pH and contents of Na-pyrophosphate soluble Fe, Al, and Mg and an increase in the stability of OM(ER) with the soil pH and the contents of clay and oxalate-soluble Fe and Al. Despite the detected influence of soil mineral characteristics on the turnover of OM(PY) and OM(ER), the Delta C-14 signatures indicated mean residence times less than 100 years. The presence of less stabilized OM in these fractions can be derived from methodological uncertainties and/or the fast cycling compartment of mineral-associated OM. (C) 2015 Elsevier B.V. All rights reserved.
KW  - Forest mineral topsoil
KW  - Organic matter stabilization
KW  - Na-pyrophosphate soluble organic matter
KW  - Micro-aggregates
KW  - Infrared spectroscopy
KW  - C-14 analyses
Y1  - 2016
U6  - https://doi.org/10.1016/j.geoderma.2015.08.029
SN  - 0016-7061
SN  - 1872-6259
VL  - 263
SP  - 1
EP  - 7
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Gerke, Horst H.
A1  - Rieckh, Helene
A1  - Sommer, Michael
T1  - Interactions between crop, water, and dissolved organic and inorganic carbon in a hummocky landscape with erosion-affected pedogenesis
JF  - Macromolecular rapid communications
N2  - Hummocky soil landscapes are characterized by 3D spatial patterns of soil types that result from erosion-affected pedogenesis. Due to tillage and water erosion, truncated profiles have been formed at steep and mid slopes and colluvial soils at hollows, while intact profiles remained at plateau positions. Pedogenetic variations in soil horizons lead to spatial differences in the soil water balance at hillslope positions. Here, possible interactions between erosion affected soil properties, the water balances, and the crop growth and feedback effects of erosion on the leaching rates were assumed. The hypothesis was tested by water balance simulations comparing uniform with hillslope position-specific crop and root growths for soils at plateau, flat mid slope, steep slope, and hollow using the Hydrus-1D program. The boundary condition data were monitored at the CarboZALF-D experimental field site, which was cropped with perennial lucerne (Medicago sativa L.) in 2013 and 2014. Crop and root growth at the four hillslope positions was assumed proportional to observed leaf area index (LAI). Fluxes of dissolved organic and inorganic carbon (DOC, DIC) were obtained from simulated water fluxes and measured DOC and DIC concentrations. For the colluvic soil at hollow, the crop growth was initially highest and later limited by an increasing water table; here the predominately upward flow led to a net input in DIC and DOC. For the truncated soils at steep slopes, simulations support the hypothesis that reduced crop growth caused an increase in percolation and DIC leaching from the subsoil horizons, which in turn led to accelerated soil development and more soil variations along eroding hillslopes in arable soil landscapes. (C) 2015 Elsevier B.V. All rights reserved.
KW  - Hydrus-1D
KW  - LAI
KW  - Eroded soil types
KW  - Hillslope pedosequence
KW  - Soil C leaching
KW  - DOC vs. DIC
KW  - Soil water balance simulation
KW  - Root water uptake
KW  - Rooting depth
Y1  - 2016
U6  - https://doi.org/10.1016/j.still.2015.09.003
SN  - 0167-1987
SN  - 1879-3444
VL  - 156
SP  - 230
EP  - 244
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Wehrhan, Marc
A1  - Rauneker, Philipp
A1  - Sommer, Michael
T1  - UAV-Based Estimation of Carbon Exports from Heterogeneous Soil Landscapes-A Case Study from the CarboZALF Experimental Area
JF  - SENSORS
N2  - The advantages of remote sensing using Unmanned Aerial Vehicles (UAVs) are a high spatial resolution of images, temporal flexibility and narrow-band spectral data from different wavelengths domains. This enables the detection of spatio-temporal dynamics of environmental variables, like plant-related carbon dynamics in agricultural landscapes. In this paper, we quantify spatial patterns of fresh phytomass and related carbon (C) export using imagery captured by a 12-band multispectral camera mounted on the fixed wing UAV Carolo P360. The study was performed in 2014 at the experimental area CarboZALF-D in NE Germany. From radiometrically corrected and calibrated images of lucerne (Medicago sativa), the performance of four commonly used vegetation indices (VIs) was tested using band combinations of six near-infrared bands. The highest correlation between ground-based measurements of fresh phytomass of lucerne and VIs was obtained for the Enhanced Vegetation Index (EVI) using near-infrared band b(899). The resulting map was transformed into dry phytomass and finally upscaled to total C export by harvest. The observed spatial variability at field- and plot-scale could be attributed to small-scale soil heterogeneity in part.
KW  - VI
KW  - soil landscape
KW  - carbon export
KW  - agriculture
KW  - multispectral
KW  - UAV
Y1  - 2016
U6  - https://doi.org/10.3390/s16020255
SN  - 1424-8220
VL  - 16
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Verma, Meetu
A1  - Denker, Carsten
A1  - Balthasar, H.
A1  - Kuckein, Christoph
A1  - González Manrique, Sergio Javier
A1  - Sobotka, M.
A1  - Gonzalez, N. Bello
A1  - Hoch, S.
A1  - Diercke, Andrea
A1  - Kummerow, Philipp
A1  - Berkefeld, T.
A1  - Collados Vera, M.
A1  - Feller, A.
A1  - Hofmann, A.
A1  - Kneer, F.
A1  - Lagg, A.
A1  - Löhner-Böttcher, J.
A1  - Nicklas, H.
A1  - Pastor Yabar, A.
A1  - Schlichenmaier, R.
A1  - Schmidt, D.
A1  - Schmidt, W.
A1  - Schubert, M.
A1  - Sigwarth, M.
A1  - Solanki, S. K.
A1  - Soltau, D.
A1  - Staude, J.
A1  - Strassmeier, Klaus G.
A1  - Volkmer, R.
A1  - von der Lühe, O.
A1  - Waldmann, T.
T1  - Horizontal flow fields in and around a small active region The transition period between flux emergence and decay
JF  - Polymers
N2  - Context. The solar magnetic field is responsible for all aspects of solar activity. Thus, emergence of magnetic flux at the surface is the first manifestation of the ensuing solar activity. Aims. Combining high-resolution and synoptic observations aims to provide a comprehensive description of flux emergence at photospheric level and of the growth process that eventually leads to a mature active region. Methods. The small active region NOAA 12118 emerged on 2014 July 17 and was observed one day later with the 1.5-m GREGOR solar telescope on 2014 July 18. High-resolution time-series of blue continuum and G-band images acquired in the blue imaging channel (BIC) of the GREGOR Fabry-Perot Interferometer (GFPI) were complemented by synoptic line-of-sight magnetograms and continuum images obtained with the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO). Horizontal proper motions and horizontal plasma velocities were computed with local correlation tracking (LCT) and the differential affine velocity estimator (DAVE), respectively. Morphological image processing was employed to measure the photometric and magnetic area, magnetic flux, and the separation profile of the emerging flux region during its evolution. Results. The computed growth rates for photometric area, magnetic area, and magnetic flux are about twice as high as the respective decay rates. The space-time diagram using HMI magnetograms of five days provides a comprehensive view of growth and decay. It traces a leaf-like structure, which is determined by the initial separation of the two polarities, a rapid expansion phase, a time when the spread stalls, and a period when the region slowly shrinks again. The separation rate of 0.26 km s(-1) is highest in the initial stage, and it decreases when the separation comes to a halt. Horizontal plasma velocities computed at four evolutionary stages indicate a changing pattern of inflows. In LCT maps we find persistent flow patterns such as outward motions in the outer part of the two major pores, a diverging feature near the trailing pore marking the site of upwelling plasma and flux emergence, and low velocities in the interior of dark pores. We detected many elongated rapidly expanding granules between the two major polarities, with dimensions twice as large as the normal granules.
KW  - Sun: photosphere
KW  - Sun: magnetic fields
KW  - techniques: image processing
KW  - methods: data analysis
Y1  - 2016
U6  - https://doi.org/10.1051/0004-6361/201628380
SN  - 1432-0746
VL  - 596
PB  - EDP Sciences
CY  - Les Ulis
ER  - 
TY  - JOUR
A1  - Gonzalez Manrique, Sergio Javier
A1  - Kuckein, Christoph
A1  - Pastor Yabar, A.
A1  - Collados Vera, M.
A1  - Denker, Carsten
A1  - Fischer, C. E.
A1  - Gömöry, P.
A1  - Diercke, Andrea
A1  - Gonzalez, N. Bello
A1  - Schlichenmaier, R.
A1  - Balthasar, H.
A1  - Berkefeld, T.
A1  - Feller, A.
A1  - Hoch, S.
A1  - Hofmann, A.
A1  - Kneer, F.
A1  - Lagg, A.
A1  - Nicklas, H.
A1  - Orozco Suarez, D.
A1  - Schmidt, D.
A1  - Schmidt, W.
A1  - Sigwarth, M.
A1  - Sobotka, M.
A1  - Solanki, S. K.
A1  - Soltau, D.
A1  - Staude, J.
A1  - Strassmeier, Klaus G.
A1  - Verma, Meetu
A1  - Volkmer, R.
A1  - von der Lühe, O.
A1  - Waldmann, T.
T1  - Fitting peculiar spectral profiles in He I 10830 angstrom absorption features
JF  - Astronomische Nachrichten = Astronomical notes
N2  - The new generation of solar instruments provides better spectral, spatial, and temporal resolution for a better understanding of the physical processes that take place on the Sun. Multiple-component profiles are more commonly observed with these instruments. Particularly, the He i 10830 triplet presents such peculiar spectral profiles, which give information on the velocity and magnetic fine structure of the upper chromosphere. The purpose of this investigation is to describe a technique to efficiently fit the two blended components of the He i 10830 triplet, which are commonly observed when two atmospheric components are located within the same resolution element. The observations used in this study were taken on 2015 April 17 with the very fast spectroscopic mode of the GREGOR Infrared Spectrograph (GRIS) attached to the 1.5-m GREGOR solar telescope, located at the Observatorio del Teide, Tenerife, Spain. We apply a double-Lorentzian fitting technique using Levenberg-Marquardt least-squares minimization. This technique is very simple and much faster than inversion codes. Line-of-sight Doppler velocities can be inferred for a whole map of pixels within just a few minutes. Our results show sub-and supersonic downflow velocities of up to 32 km s(-1) for the fast component in the vicinity of footpoints of filamentary structures. The slow component presents velocities close to rest. (C) 2016 WILEY-VCH Verlag GmbH& Co. KGaA, Weinheim
KW  - Sun: chromosphere
KW  - methods: data analysis
KW  - techniques: spectroscopic
KW  - line: profiles
Y1  - 2016
U6  - https://doi.org/10.1002/asna.201512433
SN  - 0004-6337
SN  - 1521-3994
VL  - 337
SP  - 1057
EP  - 1063
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Verma, Meetu
A1  - Denker, Carsten
A1  - Böhm, F.
A1  - Balthasar, H.
A1  - Fischer, C. E.
A1  - Kuckein, Christoph
A1  - Gonzalez, N. Bello
A1  - Berkefeld, T.
A1  - Collados Vera, M.
A1  - Diercke, Andrea
A1  - Feller, A.
A1  - Gonzalez Manrique, Sergio Javier
A1  - Hofmann, A.
A1  - Lagg, A.
A1  - Nicklas, H.
A1  - Orozco Suarez, D.
A1  - Pator Yabar, A.
A1  - Rezaei, R.
A1  - Schlichenmaier, R.
A1  - Schmidt, D.
A1  - Schmidt, W.
A1  - Sigwarth, M.
A1  - Sobotka, M.
A1  - Solanki, S. K.
A1  - Soltau, D.
A1  - Staude, J.
A1  - Strassmeier, Klaus G.
A1  - Volkmer, R.
A1  - von der Lühe, O.
A1  - Waldmann, T.
T1  - Flow and magnetic field properties in the trailing sunspots of active region NOAA 12396
JF  - Astronomische Nachrichten = Astronomical notes
N2  - Improved measurements of the photospheric and chromospheric three-dimensional magnetic and flow fields are crucial for a precise determination of the origin and evolution of active regions. We present an illustrative sample of multi-instrument data acquired during a two-week coordinated observing campaign in August 2015 involving, among others, the GREGOR solar telescope (imaging and near-infrared spectroscopy) and the space missions Solar Dynamics Observatory (SDO) and Interface Region Imaging Spectrograph (IRIS). The observations focused on the trailing part of active region NOAA 12396 with complex polarity inversion lines and strong intrusions of opposite polarity flux. The GREGOR Infrared Spectrograph (GRIS) provided Stokes IQUV spectral profiles in the photospheric Si i.1082.7 nm line, the chromospheric He I lambda 1083.0 nm triplet, and the photospheric Ca I lambda 1083.9 nm line. Carefully calibrated GRIS scans of the active region provided maps of Doppler velocity and magnetic field at different atmospheric heights. We compare quick-look maps with those obtained with the " Stokes Inversions based on Response functions" (SIR) code, which furnishes deeper insight into the magnetic properties of the region. We find supporting evidence that newly emerging flux and intruding opposite polarity flux are hampering the formation of penumbrae, i.e., a penumbra fully surrounding a sunspot is only expected after cessation of flux emergence in proximity to the sunspots. (C) 2016 WILEY-VCH Verlag GmbH& Co.KGaA, Weinheim
KW  - Sun: magnetic fields
KW  - sunspots
KW  - methods: data analysis
KW  - techniques: polarimetric
KW  - techniques: spectroscopic
Y1  - 2016
U6  - https://doi.org/10.1002/asna.201612447
SN  - 0004-6337
SN  - 1521-3994
VL  - 337
SP  - 1090
EP  - 1098
PB  - Wiley-VCH
CY  - Weinheim
ER  -