TY - JOUR A1 - Milewski, Robert A1 - Chabrillat, Sabine A1 - Behling, Robert T1 - Analyses of Recent Sediment Surface Dynamic of a Namibian Kalahari Salt Pan Based on Multitemporal Landsat and Hyperspectral Hyperion Data JF - Remote Sensing N2 - This study combines spaceborne multitemporal and hyperspectral data to analyze the spatial distribution of surface evaporite minerals and changes in a semi-arid depositional environment associated with episodic flooding events, the Omongwa salt pan (Kalahari, Namibia). The dynamic of the surface crust is evaluated by a change-detection approach using the Iterative-reweighted Multivariate Alteration Detection (IR-MAD) based on the Landsat archive imagery from 1984 to 2015. The results show that the salt pan is a highly dynamic and heterogeneous landform. A change gradient is observed from very stable pan border to a highly dynamic central pan. On the basis of hyperspectral EO-1 Hyperion images, the current distribution of surface evaporite minerals is characterized using Spectral Mixture Analysis (SMA). Assessment of field and image endmembers revealed that the pan surface can be categorized into three major crust types based on diagnostic absorption features and mineralogical ground truth data. The mineralogical crust types are related to different zones of surface change as well as pan morphology that influences brine flow during the pan inundation and desiccation cycles. These combined information are used to spatially map depositional environments where the more dynamic halite crust concentrates in lower areas although stable gypsum and calcite/sepiolite crusts appear in higher elevated areas. KW - salt pan KW - playa KW - hyperspectral KW - multitemporal KW - change detection KW - evaporite minerals Y1 - 2016 U6 - https://doi.org/10.3390/rs9020170 SN - 2072-4292 VL - 9 IS - 2 PB - MDPI CY - Basel ER - TY - JOUR A1 - Schinköth, Michaela A1 - Brand, Ralf T1 - Automatic associations and the affective valuation of exercise BT - disentangling the type-1 process of the affective–reflective theory of physical inactivity and exercise JF - German Journal of Exercise and Sport Research N2 - The decision to exercise is not only bound to rational considerations but also automatic affective processes. The affective–reflective theory of physical inactivity and exercise (ART) proposes a theoretical framework for explaining how the automatic affective process (type‑1 process) will influence exercise behavior, i.e., through the automatic activation of exercise-related associations and a subsequent affective valuation of exercise. This study aimed to empirically test this assumption of the ART with data from 69 study participants. A single-measurement study, including within-subject experimental variation, was conducted. Automatic associations with exercise were first measured with a single-target implicit association test. The somato-affective core of the participants’ automatic valuation of exercise-related pictures was then assessed via heart rate variability (HRV) analysis, and the affective valence of the valuation was tested with a facial expression (FE; smile and frown) task. Exercise behavior was assessed via self-report. Multiple regression (path) analysis revealed that automatic associations predicted HRV reactivity (β = −0.24, p = .044); the signs of the correlation between automatic associations and the smile FE score was in the expected direction but remained nonsignificant (β = −0.21, p = .078). HRV reactivity predicted self-reported exercise behavior (β = −0.28, p = .013) (the same pattern of results was achieved for the frown FE score). The HRV-related results illustrate the potential role of automatic negative affective reactions to the thought of exercise as a restraining force in exercise motivation. For better empirical distinction between the two ART type‑1 process components, automatic associations and the affective valuation should perhaps be measured separately in the future. The results support the notion that automatic and affective processes should be regarded as essential aspects of the motivation to exercise. KW - Heart rate variability KW - Facial expression KW - Somatic KW - Dual-process KW - Motivation Y1 - 2019 U6 - https://doi.org/10.1007/s12662-020-00664-9 SN - 2509-3150 SN - 2509-3142 VL - 50 IS - 654 SP - 366 EP - 376 PB - Springer CY - Berlin ; Heidelberg ER - TY - JOUR A1 - Mardoukhi, Yousof A1 - Chechkin, Aleksei V. A1 - Metzler, Ralf T1 - Spurious ergodicity breaking in normal and fractional Ornstein–Uhlenbeck process JF - New Journal of Physics N2 - The Ornstein–Uhlenbeck process is a stationary and ergodic Gaussian process, that is fully determined by its covariance function and mean. We show here that the generic definitions of the ensemble- and time-averaged mean squared displacements fail to capture these properties consistently, leading to a spurious ergodicity breaking. We propose to remedy this failure by redefining the mean squared displacements such that they reflect unambiguously the statistical properties of any stochastic process. In particular we study the effect of the initial condition in the Ornstein–Uhlenbeck process and its fractional extension. For the fractional Ornstein–Uhlenbeck process representing typical experimental situations in crowded environments such as living biological cells, we show that the stationarity of the process delicately depends on the initial condition. KW - Ornstein–Uhlenbeck process KW - stationary stochastic process KW - ensemble and time averaged mean squared displacement Y1 - 2020 U6 - https://doi.org/10.1088/1367-2630/ab950b SN - 1367-2630 VL - 22 PB - IOP CY - London ER - TY - JOUR A1 - Lonsdorf, Tina B. A1 - Klingelhöfer-Jens, Maren A1 - Andreatta, Marta A1 - Beckers, Tom A1 - Chalkia, Anastasia A1 - Gerlicher, Anna A1 - Jentsch, Valerie L. A1 - Drexler, Shira Meir A1 - Mertens, Gaetan A1 - Richter, Jan A1 - Sjouwerman, Rachel A1 - Wendt, Julia A1 - Merz, Christian J. T1 - Navigating the garden of forking paths for data exclusions in fear conditioning research JF - eLife N2 - In this report, we illustrate the considerable impact of researcher degrees of freedom with respect to exclusion of participants in paradigms with a learning element. We illustrate this empirically through case examples from human fear conditioning research, in which the exclusion of ‘non-learners’ and ‘non-responders’ is common – despite a lack of consensus on how to define these groups. We illustrate the substantial heterogeneity in exclusion criteria identified in a systematic literature search and highlight the potential problems and pitfalls of different definitions through case examples based on re-analyses of existing data sets. On the basis of these studies, we propose a consensus on evidence-based rather than idiosyncratic criteria, including clear guidelines on reporting details. Taken together, we illustrate how flexibility in data collection and analysis can be avoided, which will benefit the robustness and replicability of research findings and can be expected to be applicable to other fields of research that involve a learning element. Y1 - 2019 U6 - https://doi.org/10.7554/eLife.52465 SN - 2050-084X VL - 8 PB - eLife Sciences Publications CY - Cambridge ER - TY - JOUR A1 - Lonsdorf, Tina B. A1 - Klingelhöfer-Jens, Maren A1 - Andreatta, Marta A1 - Beckers, Tom A1 - Chalkia, Anastasia A1 - Gerlicher, Anna Maria Veronika A1 - Jentsch, Valerie L. A1 - Drexler, Shira Meir A1 - Mertens, Gaetan A1 - Richter, Jan A1 - Sjouwerman, Rachel A1 - Wendt, Julia A1 - Merz, Christian J. T1 - Navigating the garden of forking paths for data exclusions in fear conditioning research JF - eLife Y1 - 2019 U6 - https://doi.org/10.7554/eLife.52465 SN - 2050-084X VL - 8 PB - eLife Sciences Publications CY - Cambridge ER - TY - JOUR A1 - Günther, Erika A1 - Klauß, André A1 - Toro-Nahuelpan, Mauricio A1 - Schüler, Dirk A1 - Hille, Carsten A1 - Faivre, Damien T1 - The in vivo mechanics of the magnetotactic backbone as revealed by correlative FLIM-FRET and STED microscopy JF - Scientific reports N2 - Protein interaction and protein imaging strongly benefit from the advancements in time-resolved and superresolution fluorescence microscopic techniques. However, the techniques were typically applied separately and ex vivo because of technical challenges and the absence of suitable fluorescent protein pairs. Here, we show correlative in vivo fluorescence lifetime imaging microscopy Forster resonance energy transfer (FLIM-FRET) and stimulated emission depletion (STED) microscopy to unravel protein mechanics and structure in living cells. We use magnetotactic bacteria as a model system where two proteins, MamJ and MamK, are used to assemble magnetic particles called magnetosomes. The filament polymerizes out of MamK and the magnetosomes are connected via the linker MamJ. Our system reveals that bacterial filamentous structures are more fragile than the connection of biomineralized particles to this filament. More importantly, we anticipate the technique to find wide applicability for the study and quantification of biological processes in living cells and at high resolution. Y1 - 2019 U6 - https://doi.org/10.1038/s41598-019-55804-5 SN - 2045-2322 VL - 9 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Thomas, Jessica E. A1 - Carvalho, Gary R. A1 - Haile, James A1 - Rawlence, Nicolas J. A1 - Martin, Michael D. A1 - Ho, Simon Y. W. A1 - Sigfusson, Arnor P. A1 - Josefsson, Vigfus A. A1 - Frederiksen, Morten A1 - Linnebjerg, Jannie F. A1 - Castruita, Jose A. Samaniego A1 - Niemann, Jonas A1 - Sinding, Mikkel-Holger S. A1 - Sandoval-Velasco, Marcela A1 - Soares, Andre E. R. A1 - Lacy, Robert A1 - Barilaro, Christina A1 - Best, Juila A1 - Brandis, Dirk A1 - Cavallo, Chiara A1 - Elorza, Mikelo A1 - Garrett, Kimball L. A1 - Groot, Maaike A1 - Johansson, Friederike A1 - Lifjeld, Jan T. A1 - Nilson, Goran A1 - Serjeanston, Dale A1 - Sweet, Paul A1 - Fuller, Errol A1 - Hufthammer, Anne Karin A1 - Meldgaard, Morten A1 - Fjeldsa, Jon A1 - Shapiro, Beth A1 - Hofreiter, Michael A1 - Stewart, John R. A1 - Gilbert, M. Thomas P. A1 - Knapp, Michael T1 - Demographic reconstruction from ancient DNA supports rapid extinction of the great auk JF - eLife N2 - The great auk was once abundant and distributed across the North Atlantic. It is now extinct, having been heavily exploited for its eggs, meat, and feathers. We investigated the impact of human hunting on its demise by integrating genetic data, GPS-based ocean current data, and analyses of population viability. We sequenced complete mitochondrial genomes of 41 individuals from across the species' geographic range and reconstructed population structure and population dynamics throughout the Holocene. Taken together, our data do not provide any evidence that great auks were at risk of extinction prior to the onset of intensive human hunting in the early 16th century. In addition, our population viability analyses reveal that even if the great auk had not been under threat by environmental change, human hunting alone could have been sufficient to cause its extinction. Our results emphasise the vulnerability of even abundant and widespread species to intense and localised exploitation. Y1 - 2019 U6 - https://doi.org/10.7554/eLife.47509 SN - 2050-084X VL - 8 PB - eLife Sciences Publications CY - Cambridge ER - TY - JOUR A1 - Bröker, Katharine A1 - Sinelnikov, Evgeny A1 - Gustavus, Dirk A1 - Schumacher, Udo A1 - Pörtner, Ralf A1 - Hoffmeister, Hans A1 - Lüth, Stefan A1 - Dammermann, Werner T1 - Mass Production of Highly Active NK Cells for Cancer Immunotherapy in a GMP Conform Perfusion Bioreactor JF - Frontiers in Bioengineering and Biotechnology N2 - NK cells have emerged as promising candidates for cancer immunotherapy, especially due to their ability to fight circulating tumor cells thereby preventing metastases formation. Hence several studies have been performed to generate and expand highly cytotoxic NK cells ex vivo, e.g., by using specific cytokines to upregulate both their proliferation and surface expression of distinct activating receptors. Apart from an enhanced activity, application of NK cells as immunotherapeutic agent further requires sufficient cell numbers and a high purity. All these parameters depend on a variety of different factors including the starting material, additives like cytokines as well as the culture system. Here we analyzed PBMC-derived NK cells of five anonymized healthy donors expanded under specific conditions in an innovative perfusion bioreactor system with respect to their phenotype, IFN gamma production, and cytotoxicity in vitro. Important features of the meander type bioreactors used here are a directed laminar flow of medium and control of relevant process parameters. Cells are cultivated under "steady state" conditions in perfusion mode. Our data demonstrate that expansion of CD3(+) T cell depleted PBMCs in our standardized system generates massive amounts of highly pure (>85%) and potent anticancer active NK cells. These cells express a variety of important receptors driving NK cell recruitment, adhesion as well as activation. More specifically, they express the chemokine receptors CXCR3, CXCR4, and CCR7, the adhesion molecules L-selectin, LFA-1, and VLA-4, the activating receptors NKp30, NKp44, NKp46, NKG2D, DNAM1, and CD16 as well as the death ligands TRAIL and Fas-L. Moreover, the generated NK cells show a strong IFN gamma expression upon cultivation with K562 tumor cells and demonstrate a high cytotoxicity toward leukemic as well as solid tumor cell lines in vitro. Altogether, these characteristics promise a high clinical potency of thus produced NK cells awaiting further evaluation. KW - natural killer cells (NK cells) KW - cytotoxicity KW - tumor immunity KW - immunotherapy KW - perfusion bioreactor KW - GMP KW - mass production process Y1 - 2019 U6 - https://doi.org/10.3389/fbioe.2019.00194 SN - 2296-4185 VL - 7 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Löpfe, Moira A1 - Duss, Anja A1 - Zafeiropoulou, Katerina-Alexandra A1 - Bjoergvinsdottir, Oddny A1 - Eglin, David A1 - Fortunato, Giuseppino A1 - Klasen, Jürgen A1 - Ferguson, Stephen J. A1 - Würtz-Kozak, Karin A1 - Krupkova, Olga T1 - Electrospray-Based Microencapsulation of Epigallocatechin 3-Gallate for Local Delivery into the Intervertebral Disc JF - Pharmaceutics N2 - Locally delivered anti-inflammatory compounds can restore the homeostasis of the degenerated intervertebral disc (IVD). With beneficial effects on IVD cells, epigallocatechin 3-gallate (EGCG) is a promising therapeutic candidate. However, EGCG is prone to rapid degradation and/or depletion. Therefore, the purpose of this study was to develop a method for controlled EGCG delivery in the degenerated IVD. Primary IVD cells were isolated from human donors undergoing IVD surgeries. EGCG was encapsulated into microparticles by electrospraying of glutaraldehyde-crosslinked gelatin. The resulting particles were characterized in terms of cytocompatibility and anti-inflammatory activity, and combined with a thermoresponsive carrier to produce an injectable EGCG delivery system. Subsequently, electrospraying was scaled up using the industrial NANOSPIDER (TM) technology. The produced EGCG microparticles reduced the expression of inflammatory (IL-6, IL-8, COX-2) and catabolic (MMP1, MMP3, MMP13) mediators in pro-inflammatory 3D cell cultures. Combining the EGCG microparticles with the carrier showed a trend towards modulating EGCG activity/release. Electrospray upscaling was achieved, leading to particles with homogenous spherical morphologies. In conclusion, electrospray-based encapsulation of EGCG resulted in cytocompatible microparticles that preserved the activity of EGCG and showed the potential to control EGCG release, thus favoring IVD health by downregulating local inflammation. Future studies will focus on further exploring the biological activity of the developed delivery system for potential clinical use. KW - degenerative disc disease KW - inflammation KW - drug delivery KW - EGCG KW - microparticles KW - injectable biomaterial KW - electrospraying Y1 - 2019 U6 - https://doi.org/10.3390/pharmaceutics11090435 SN - 1999-4923 VL - 11 IS - 9 PB - MDPI CY - Basel ER - TY - JOUR A1 - Miele, Vincent A1 - Guill, Christian A1 - Ramos-Jiliberto, Rodrigo A1 - Kéfi, Sonia T1 - Non-trophic interactions strengthen the diversity-functioning relationship in an ecological bioenergetic network model JF - PLoS Computational Biology : a new community journal N2 - Ecological communities are undeniably diverse, both in terms of the species that compose them as well as the type of interactions that link species to each other. Despite this long recognition of the coexistence of multiple interaction types in nature, little is known about the consequences of this diversity for community functioning. In the ongoing context of global change and increasing species extinction rates, it seems crucial to improve our understanding of the drivers of the relationship between species diversity and ecosystem functioning. Here, using a multispecies dynamical model of ecological communities including various interaction types (e.g. competition for space, predator interference, recruitment facilitation in addition to feeding), we studied the role of the presence and the intensity of these interactions for species diversity, community functioning (biomass and production) and the relationship between diversity and functioning. Taken jointly, the diverse interactions have significant effects on species diversity, whose amplitude and sign depend on the type of interactions involved and their relative abundance. They however consistently increase the slope of the relationship between diversity and functioning, suggesting that species losses might have stronger effects on community functioning than expected when ignoring the diversity of interaction types and focusing on feeding interactions only. Y1 - 2020 U6 - https://doi.org/10.1371/journal.pcbi.1007269 SN - 1553-7358 VL - 15 IS - 8 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Koetz, Joachim T1 - The Effect of Surface Modification of Gold Nanotriangles for Surface-Enhanced Raman Scattering Performance JF - Nanomaterials N2 - A surface modification of ultraflat gold nanotriangles (AuNTs) with different shaped nanoparticles is of special relevance for surface-enhanced Raman scattering (SERS) and the photo-catalytic activity of plasmonic substrates. Therefore, different approaches are used to verify the flat platelet morphology of the AuNTs by oriented overgrowth with metal nanoparticles. The most important part for the morphological transformation of the AuNTs is the coating layer, containing surfactants or polymers. By using well established AuNTs stabilized by a dioctyl sodium sulfosuccinate (AOT) bilayer, different strategies of surface modification with noble metal nanoparticles are possible. On the one hand undulated superstructures were synthesized by in situ growth of hemispherical gold nanoparticles in the polyethyleneimine (PEI)-coated AOT bilayer of the AuNTs. On the other hand spiked AuNTs were obtained by a direct reduction of Au³⁺ ions in the AOT double layer in presence of silver ions and ascorbic acid as reducing agent. Additionally, crumble topping of the smooth AuNTs can be realized after an exchange of the AOT bilayer by hyaluronic acid, followed by a silver-ion mediated reduction with ascorbic acid. Furthermore, a decoration with silver nanoparticles after coating the AOT bilayer with the cationic surfactant benzylhexadecyldimethylammonium chloride (BDAC) can be realized. In that case the ultraviolet (UV)-absorption of the undulated Au@Ag nanoplatelets can be tuned depending on the degree of decoration with silver nanoparticles. Comparing the Raman scattering data for the plasmon driven dimerization of 4-nitrothiophenol (4-NTP) to 4,4′-dimercaptoazobenzene (DMAB) one can conclude that the most important effect of surface modification with a 75 times higher enhancement factor in SERS experiments becomes available by decoration with gold spikes. KW - undulated KW - spiked and crumble gold nanotriangles KW - SERS enhancement factor KW - dimerization of 4-nitrothiophenol KW - AOT bilayer KW - PEI coating Y1 - 2020 U6 - https://doi.org/10.3390/nano10112187 SN - 2079-4991 VL - 10 IS - 11 PB - MDPI CY - Basel ER - TY - JOUR A1 - Rieck, Christoph Paul Kurt A1 - Geiger, Daniel A1 - Munkert, Jennifer A1 - Messerschmidt, Katrin A1 - Petersen, Jan A1 - Strasser, Juliane A1 - Meitinger, Nadine A1 - Kreis, Wolfgang T1 - Biosynthetic approach to combine the first steps of cardenolide formation in Saccharomyces cerevisiae JF - Microbiologyopen N2 - A yeast expression plasmid was constructed containing a cardenolide biosynthetic module, referred to as CARD II, using the AssemblX toolkit, which enables the assembly of large DNA constructs. The genes cloned into the vector were (a) a Δ5‐3β‐hydroxysteroid dehydrogenase gene from Digitalis lanata, (b) a steroid Δ5‐isomerase gene from Comamonas testosteronii, (c) a mutated steroid‐5β‐reductase gene from Arabidopsis thaliana, and (d) a steroid 21‐hydroxylase gene from Mus musculus. A second plasmid bearing an ADR/ADX fusion gene from Bos taurus was also constructed. A Saccharomyces cerevisiae strain bearing these two plasmids was generated. This strain, termed “CARD II yeast”, was capable of producing 5β‐pregnane‐3β,21‐diol‐20‐one, a central intermediate in 5β‐cardenolide biosynthesis, starting from pregnenolone which was added to the culture medium. Using this approach, five consecutive steps in cardenolide biosynthesis were realized in baker's yeast. Y1 - 2019 U6 - https://doi.org/10.1002/mbo3.925 SN - 2045-8827 VL - 8 IS - 12 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Werger, Luise A1 - Bergmann, Joana A1 - Weber, Ewald A1 - Heinze, Johannes T1 - Wind intensity affects fine root morphological traits with consequences for plant-soil feedback effects JF - Annals of Botany Plants N2 - Wind influences the development, architecture and morphology of plant roots and may modify subsequent interactions between plants and soil (plant–soil feedbacks—PSFs). However, information on wind effects on fine root morphology is scarce and the extent to which wind changes plant–soil interactions remains unclear. Therefore, we investigated the effects of two wind intensity levels by manipulating surrounding vegetation height in a grassland PSF field experiment. We grew four common plant species (two grasses and two non-leguminous forbs) with soil biota either previously conditioned by these or other species and tested the effect of wind on root:shoot ratio, fine root morphological traits as well as the outcome for PSFs. Wind intensity did not affect biomass allocation (i.e. root:shoot ratio) in any species. However, fine-root morphology of all species changed under high wind intensity. High wind intensity increased specific root length and surface area and decreased root tissue density, especially in the two grasses. Similarly, the direction of PSFs changed under high wind intensity in all four species, but differences in biomass production on the different soils between high and low wind intensity were marginal and most pronounced when comparing grasses with forbs. Because soils did not differ in plant-available nor total nutrient content, the results suggest that wind-induced changes in root morphology have the potential to influence plant–soil interactions. Linking wind-induced changes in fine-root morphology to effects on PSF improves our understanding of plant–soil interactions under changing environmental conditions. KW - Wind KW - root traits KW - root morphology KW - specific root length KW - plant–soil feedback Y1 - 2020 U6 - https://doi.org/10.1093/aobpla/plaa050 SN - 2041-2851 VL - 12 IS - 5 PB - Oxford University Press CY - Oxford ER - TY - JOUR A1 - Knudsen, Erlend Moster A1 - Heinold, Bernd A1 - Dahlke, Sandro A1 - Bozem, Heiko A1 - Crewell, Susanne A1 - Gorodetskaya, Irina V. A1 - Heygster, Georg A1 - Kunkel, Daniel A1 - Maturilli, Marion A1 - Mech, Mario A1 - Viceto, Carolina A1 - Rinke, Annette A1 - Schmithusen, Holger A1 - Ehrlich, Andre A1 - Macke, Andreas A1 - Lüpkes, Christof A1 - Wendisch, Manfred T1 - Meteorological conditions during the ACLOUD/PASCAL field campaign near Svalbard in early summer 2017 JF - Atmospheric chemistry and physics N2 - The two concerted field campaigns, Arctic CLoud Observations Using airborne measurements during polar Day (ACLOUD) and the Physical feedbacks of Arctic planetary boundary level Sea ice, Cloud and AerosoL (PASCAL), took place near Svalbard from 23 May to 26 June 2017. They were focused on studying Arctic mixed-phase clouds and involved observations from two airplanes (ACLOUD), an icebreaker (PASCAL) and a tethered balloon, as well as ground-based stations. Here, we present the synoptic development during the 35-day period of the campaigns, using near-surface and upper-air meteorological observations, as well as operational satellite, analysis, and reanalysis data. Over the campaign period, short-term synoptic variability was substantial, dominating over the seasonal cycle. During the first campaign week, cold and dry Arctic air from the north persisted, with a distinct but seasonally unusual cold air outbreak. Cloudy conditions with mostly low-level clouds prevailed. The subsequent 2 weeks were characterized by warm and moist maritime air from the south and east, which included two events of warm air advection. These synoptical disturbances caused lower cloud cover fractions and higher-reaching cloud systems. In the final 2 weeks, adiabatically warmed air from the west dominated, with cloud properties strongly varying within the range of the two other periods. Results presented here provide synoptic information needed to analyze and interpret data of upcoming studies from ACLOUD/PASCAL, while also offering unprecedented measurements in a sparsely observed region. Y1 - 2018 U6 - https://doi.org/10.5194/acp-18-17995-2018 SN - 1680-7316 SN - 1680-7324 VL - 18 IS - 24 SP - 17995 EP - 18022 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Runge, Alexandra A1 - Grosse, Guido T1 - Mosaicking Landsat and Sentinel-2 Data to Enhance LandTrendr Time Series Analysis in Northern High Latitude Permafrost Regions JF - Remote Sensing N2 - Permafrost is warming in the northern high latitudes, inducing highly dynamic thaw-related permafrost disturbances across the terrestrial Arctic. Monitoring and tracking of permafrost disturbances is important as they impact surrounding landscapes, ecosystems and infrastructure. Remote sensing provides the means to detect, map, and quantify these changes homogeneously across large regions and time scales. Existing Landsat-based algorithms assess different types of disturbances with similar spatiotemporal requirements. However, Landsat-based analyses are restricted in northern high latitudes due to the long repeat interval and frequent clouds, in particular at Arctic coastal sites. We therefore propose to combine Landsat and Sentinel-2 data for enhanced data coverage and present a combined annual mosaic workflow, expanding currently available algorithms, such as LandTrendr, to achieve more reliable time series analysis. We exemplary test the workflow for twelve sites across the northern high latitudes in Siberia. We assessed the number of images and cloud-free pixels, the spatial mosaic coverage and the mosaic quality with spectral comparisons. The number of available images increased steadily from 1999 to 2019 but especially from 2016 onward with the addition of Sentinel-2 images. Consequently, we have an increased number of cloud-free pixels even under challenging environmental conditions, which then serve as the input to the mosaicking process. In a comparison of annual mosaics, the Landsat+Sentinel-2 mosaics always fully covered the study areas (99.9–100 %), while Landsat-only mosaics contained data-gaps in the same years, only reaching coverage percentages of 27.2 %, 58.1 %, and 69.7 % for Sobo Sise, East Taymyr, and Kurungnakh in 2017, respectively. The spectral comparison of Landsat image, Sentinel-2 image, and Landsat+Sentinel-2 mosaic showed high correlation between the input images and mosaic bands (e.g., for Kurungnakh 0.91–0.97 between Landsat and Landsat+Sentinel-2 mosaic and 0.92–0.98 between Sentinel-2 and Landsat+Sentinel-2 mosaic) across all twelve study sites, testifying good quality mosaic results. Our results show that especially the results for northern, coastal areas was substantially improved with the Landsat+Sentinel-2 mosaics. By combining Landsat and Sentinel-2 data we accomplished to create reliably high spatial resolution input mosaics for time series analyses. Our approach allows to apply a high temporal continuous time series analysis to northern high latitude permafrost regions for the first time, overcoming substantial data gaps, and assess permafrost disturbance dynamics on an annual scale across large regions with algorithms such as LandTrendr by deriving the location, timing and progression of permafrost thaw disturbances KW - time series analysis KW - data fusion KW - disturbance tracking KW - permafrost KW - permafrost thaw Y1 - 2020 U6 - https://doi.org/10.3390/rs12152471 SN - 2072-4292 VL - 12 IS - 15 PB - MDPI CY - Basel ER - TY - JOUR A1 - He, Hai A1 - Höper, Rune A1 - Dodenhöft, Moritz A1 - Marlière, Philippe A1 - Bar-Even, Arren T1 - An optimized methanol assimilation pathway relying on promiscuous formaldehyde-condensing aldolases in E. coli JF - Metabolic Engineering N2 - Engineering biotechnological microorganisms to use methanol as a feedstock for bioproduction is a major goal for the synthetic metabolism community. Here, we aim to redesign the natural serine cycle for implementation in E. coli. We propose the homoserine cycle, relying on two promiscuous formaldehyde aldolase reactions, as a superior pathway design. The homoserine cycle is expected to outperform the serine cycle and its variants with respect to biomass yield, thermodynamic favorability, and integration with host endogenous metabolism. Even as compared to the RuMP cycle, the most efficient naturally occurring methanol assimilation route, the homoserine cycle is expected to support higher yields of a wide array of products. We test the in vivo feasibility of the homoserine cycle by constructing several E. coli gene deletion strains whose growth is coupled to the activity of different pathway segments. Using this approach, we demonstrate that all required promiscuous enzymes are active enough to enable growth of the auxotrophic strains. Our findings thus identify a novel metabolic solution that opens the way to an optimized methylotrophic platform. KW - Pathway design KW - Promiscuous enzymes KW - Formaldehyde assimilation KW - Serine cycle KW - Growth selection Y1 - 2020 U6 - https://doi.org/10.1016/j.ymben.2020.03.002 SN - 1096-7176 SN - 1096-7184 VL - 60 SP - 1 EP - 13 PB - Elsevier CY - Amsterdam [u.a.] ER - TY - JOUR A1 - He, Hai A1 - Noor, Elad A1 - Ramos-Parra, Perla A. A1 - García-Valencia, Liliana E. A1 - Patterson, Jenelle A. A1 - Díaz de la Garza, Rocío I. A1 - Hanson, Andrew D. A1 - Bar-Even, Arren T1 - In Vivo Rate of Formaldehyde Condensation with Tetrahydrofolate JF - Metabolites N2 - Formaldehyde is a highly reactive compound that participates in multiple spontaneous reactions, but these are mostly deleterious and damage cellular components. In contrast, the spontaneous condensation of formaldehyde with tetrahydrofolate (THF) has been proposed to contribute to the assimilation of this intermediate during growth on C1 carbon sources such as methanol. However, the in vivo rate of this condensation reaction is unknown and its possible contribution to growth remains elusive. Here, we used microbial platforms to assess the rate of this condensation in the cellular environment. We constructed Escherichia coli strains lacking the enzymes that naturally produce 5,10-methylene-THF. These strains were able to grow on minimal medium only when equipped with a sarcosine (N-methyl-glycine) oxidation pathway that sustained a high cellular concentration of formaldehyde, which spontaneously reacts with THF to produce 5,10-methylene-THF. We used flux balance analysis to derive the rate of the spontaneous condensation from the observed growth rate. According to this, we calculated that a microorganism obtaining its entire biomass via the spontaneous condensation of formaldehyde with THF would have a doubling time of more than three weeks. Hence, this spontaneous reaction is unlikely to serve as an effective route for formaldehyde assimilation. KW - one-carbon metabolism KW - spontaneous reaction KW - auxotrophy KW - serine cycle KW - phenotypic phase plane Y1 - 2019 U6 - https://doi.org/10.3390/metabo10020065 SN - 2218-1989 VL - 10 IS - 65 PB - MDPI CY - Basel ER - TY - JOUR A1 - Shcherbakov, Robert A1 - Zhuang, Jiancang A1 - Zöller, Gert A1 - Ogata, Yosihiko T1 - Forecasting the magnitude of the largest expected earthquake JF - Nature Communications N2 - The majority of earthquakes occur unexpectedly and can trigger subsequent sequences of events that can culminate in more powerful earthquakes. This self-exciting nature of seismicity generates complex clustering of earthquakes in space and time. Therefore, the problem of constraining the magnitude of the largest expected earthquake during a future time interval is of critical importance in mitigating earthquake hazard. We address this problem by developing a methodology to compute the probabilities for such extreme earthquakes to be above certain magnitudes. We combine the Bayesian methods with the extreme value theory and assume that the occurrence of earthquakes can be described by the Epidemic Type Aftershock Sequence process. We analyze in detail the application of this methodology to the 2016 Kumamoto, Japan, earthquake sequence. We are able to estimate retrospectively the probabilities of having large subsequent earthquakes during several stages of the evolution of this sequence. Y1 - 2019 U6 - https://doi.org/10.1038/s41467-019-11958-4 SN - 2041-1723 VL - 10 PB - Nature Publishing Group CY - London ER - TY - JOUR A1 - Figueroa Campos, Gustavo A. A1 - Sagu Tchewonpi, Sorel A1 - Saravia Celis, Pedro A1 - Rawel, Harshadrai Manilal T1 - Comparison of batch and continuous wet-processing of coffee BT - changes in the main compounds in beans, by-products and wastewater JF - Foods N2 - Many technical challenges still need to be overcome to improve the quality of the green coffee beans. In this work, the wet Arabica coffee processing in batch and continuous modus were investigated. Coffee beans samples as well as by-products and wastewaters collected at different production steps were analyzed in terms of their content in total phenols, antioxidant capacity, caffeine content, organic acids, reducing sugars, free amino group and protein content. The results showed that 40% of caffeine was removed with pulp. Green coffee beans showed highest concentration of organic acids and sucrose (4.96 ± 0.25 and 5.07 ± 0.39 g/100 g DW for the batch and continuous processing). Batch green coffee beans contained higher amount of phenols. 5-caffeoylquinic Acid (5-CQA) was the main constituent (67.1 and 66.0% for the batch and continuous processing, respectively). Protein content was 15 and 13% in the green coffee bean in batch and continuous processing, respectively. A decrease of 50 to 64% for free amino groups during processing was observed resulting in final amounts of 0.8 to 1.4% in the processed beans. Finally, the batch processing still revealed by-products and wastewater with high nutrient content encouraging a better concept for valorization. KW - Arabica coffee beans KW - coffee by-products KW - batch process KW - continuous process KW - nutritional characteristics Y1 - 2020 U6 - https://doi.org/10.3390/foods9081135 SN - 2304-8158 VL - 9 IS - 8 PB - MDPI CY - Basel ER - TY - JOUR A1 - Schiro, Gabriele A1 - Colangeli, Pierluigi A1 - Müller, Marina E. H. T1 - A Metabarcoding Analysis of the Mycobiome of Wheat Ears Across a Topographically Heterogeneous Field JF - Frontiers in microbiology KW - Fusarium KW - microclimate KW - canopy KW - fungal community KW - Alternaria KW - spatially induced variance Y1 - 2019 U6 - https://doi.org/10.3389/fmicb.2019.02095 SN - 1664-302X VL - 10 PB - Frontiers Research Foundation CY - Lausanne ER -