Items 1-20 of 311

    • Journal Article

      Mortality of Different Populus Genotypes in Recently Established Mixed Short Rotation Coppice with Robinia pseudoacacia L. 

      Rebola-Lichtenberg, Jessica; Schall, Peter; Annighöfer, Peter; Ammer, Christian; Leinemann, Ludger; Polle, Andrea; Euring, Dejuan
      Forests 2019; 10(5): Art. 410
      Short rotation coppices play an increasing role in providing wooden biomass for energy. Mixing fast-growing tree species in short rotation coppices may result in complementary e ects and increased yield. The aim of this study was to analyze the e ect on mortality of eight di erent poplar genotypes (Populus sp.) in mixed short rotation coppices with three di erent provenances of the N-fixing tree species black locust (Robinia pseudoacacia L.). Pure and mixed stands were established at two sites of contrasting fertility. Survival of poplar was assessed for each tree two times a year, for a period of three years. In the first two years, high variation in mortality was observed between the genotypes, but no significant di erences between pure and mixed stands were identified. However, three years after planting, higher mortality rates were observed in the mixtures across all poplar genotypes in comparison to pure stands. The expected advantage on growth of combining an N-fixing tree with an N-demanding tree species, such as poplar, was overshadowed by the Robinia’s dominance and competitiveness.
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    • Journal Article

      Biodiversity data integration—the significance of data resolution and domain 

      König, Christian; Weigelt, Patrick; Schrader, Julian; Taylor, Amanda; Kattge, Jens; Kreft, Holger
      PLOS Biology 2019; 17(3): Art. e3000183
      ecent years have seen an explosion in the availability of biodiversity data describing the distribution, function, and evolutionary history of life on earth. Integrating these heterogeneous data remains a challenge due to large variations in observational scales, collection purposes, and terminologies. Here, we conceptualize widely used biodiversity data types according to their domain (what aspect of biodiversity is described?) and informational resolution (how specific is the description?). Applying this framework to major data providers in biodiversity research reveals a strong focus on the disaggregated end of the data spectrum, whereas aggregated data types remain largely underutilized. We discuss the implications of this imbalance for the scope and representativeness of current macroecological research and highlight the synergies arising from a tighter integration of biodiversity data across domains and resolutions. We lay out effective strategies for data collection, mobilization, imputation, and sharing and summarize existing frameworks for scalable and integrative biodiversity research. Finally, we use two case studies to demonstrate how the explicit consideration of data domain and resolution helps to identify biases and gaps in global data sets and achieve unprecedented taxonomic and geographical data coverage in macroecological analyses.
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    • Journal Article

      A Theoretical Framework to Derive Simple, Firing-Rate-Dependent Mathematical Models of Synaptic Plasticity 

      Lappalainen, Janne; Herpich, Juliane; Tetzlaff, Christian
      Frontiers in Computational Neuroscience 2019; 13: Art. 26
      Synaptic plasticity serves as an essential mechanism underlying cognitive processes as learning and memory. For a better understanding detailed theoretical models combine experimental underpinnings of synaptic plasticity and match experimental results. However, these models are mathematically complex impeding the comprehensive investigation of their link to cognitive processes generally executed on the neuronal network level. Here, we derive a mathematical framework enabling the simplification of such detailed models of synaptic plasticity facilitating further mathematical analyses. By this framework we obtain a compact, firing-rate-dependent mathematical formulation, which includes the essential dynamics of the detailed model and, thus, of experimentally verified properties of synaptic plasticity. Amongst others, by testing our framework by abstracting the dynamics of two well-established calcium-dependent synaptic plasticity models, we derived that the synaptic changes depend on the square of the presynaptic firing rate, which is in contrast to previous assumptions. Thus, the here-presented framework enables the derivation of biologically plausible but simple mathematical models of synaptic plasticity allowing to analyze the underlying dependencies of synaptic dynamics from neuronal properties such as the firing rate and to investigate their implications in complex neuronal networks.
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    • Journal Article

      Signal peptide peptidase activity connects the unfolded protein response to plant defense suppression by Ustilago maydis 

      Pinter, Niko; Hach, Christina Andrea; Hampel, Martin; Rekhter, Dmitrij; Zienkiewicz, Krzysztof; Feussner, Ivo; Poehlein, Anja; Daniel, Rolf; Finkernagel, Florian; Heimel, Kai
      PLOS Pathogens 2019; 15(4): Art. e1007734
      The corn smut fungus Ustilago maydis requires the unfolded protein response (UPR) to maintain homeostasis of the endoplasmic reticulum (ER) during the biotrophic interaction with its host plant Zea mays (maize). Crosstalk between the UPR and pathways controlling pathogenic development is mediated by protein-protein interactions between the UPR regulator Cib1 and the developmental regulator Clp1. Cib1/Clp1 complex formation results in mutual modification of the connected regulatory networks thereby aligning fungal proliferation in planta, efficient effector secretion with increased ER stress tolerance and long-term UPR activation in planta. Here we address UPR-dependent gene expression and its modulation by Clp1 using combinatorial RNAseq/ChIPseq analyses. We show that increased ER stress resistance is connected to Clp1-dependent alterations of Cib1 phosphorylation, protein stability and UPR gene expression. Importantly, we identify by deletion screening of UPR core genes the signal peptide peptidase Spp1 as a novel key factor that is required for establishing a compatible biotrophic interaction between U. maydis and its host plant maize. Spp1 is dispensable for ER stress resistance and vegetative growth but requires catalytic activity to interfere with the plant defense, revealing a novel virulence specific function for signal peptide peptidases in a biotrophic fungal/plant interaction.
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    • Journal Article

      Hypertension screening, awareness, treatment, and control in India: A nationally representative cross-sectional study among individuals aged 15 to 49 years 

      Prenissl, Jonas; Manne-Goehler, Jennifer; Jaacks, Lindsay M.; Prabhakaran, Dorairaj; Awasthi, Ashish; Bischops, Anne Christine; Atun, Rifat; Bärnighausen, Till; Davies, Justine I.; Vollmer, Sebastian; et al.
      Geldsetzer, Pascal
      PLOS Medicine 2019; 16(5): Art. e1002801
      BACKGROUND: Evidence on where in the hypertension care process individuals are lost to care, and how this varies among states and population groups in a country as large as India, is essential for the design of targeted interventions and to monitor progress. Yet, to our knowledge, there has not yet been a nationally representative analysis of the proportion of adults who reach each step of the hypertension care process in India. This study aimed to determine (i) the proportion of adults with hypertension who have been screened, are aware of their diagnosis, take antihypertensive treatment, and have achieved control and (ii) the variation of these care indicators among states and sociodemographic groups. METHODS AND FINDINGS: We used data from a nationally representative household survey carried out from 20 January 2015 to 4 December 2016 among individuals aged 15-49 years in all states and union territories (hereafter "states") of the country. The stages of the care process-computed among those with hypertension at the time of the survey-were (i) having ever had one's blood pressure (BP) measured before the survey ("screened"), (ii) having been diagnosed ("aware"), (iii) currently taking BP-lowering medication ("treated"), and (iv) reporting being treated and not having a raised BP ("controlled"). We disaggregated these stages by state, rural-urban residence, sex, age group, body mass index, tobacco consumption, household wealth quintile, education, and marital status. In total, 731,864 participants were included in the analysis. Hypertension prevalence was 18.1% (95% CI 17.8%-18.4%). Among those with hypertension, 76.1% (95% CI 75.3%-76.8%) had ever received a BP measurement, 44.7% (95% CI 43.6%-45.8%) were aware of their diagnosis, 13.3% (95% CI 12.9%-13.8%) were treated, and 7.9% (95% CI 7.6%-8.3%) had achieved control. Male sex, rural location, lower household wealth, and not being married were associated with greater losses at each step of the care process. Between states, control among individuals with hypertension varied from 2.4% (95% CI 1.7%-3.3%) in Nagaland to 21.0% (95% CI 9.8%-39.6%) in Daman and Diu. At 38.0% (95% CI 36.3%-39.0%), 28.8% (95% CI 28.5%-29.2%), 28.4% (95% CI 27.7%-29.0%), and 28.4% (95% CI 27.8%-29.0%), respectively, Puducherry, Tamil Nadu, Sikkim, and Haryana had the highest proportion of all adults (irrespective of hypertension status) in the sampled age range who had hypertension but did not achieve control. The main limitation of this study is that its results cannot be generalized to adults aged 50 years and older-the population group in which hypertension is most common. CONCLUSIONS: Hypertension prevalence in India is high, but the proportion of adults with hypertension who are aware of their diagnosis, are treated, and achieve control is low. Even after adjusting for states' economic development, there is large variation among states in health system performance in the management of hypertension. Improvements in access to hypertension diagnosis and treatment are especially important among men, in rural areas, and in populations with lower household wealth.
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    • Journal Article

      Linking Arable Crop Occurrence with Site Conditions by the Use of Highly Resolved Spatial Data 

      Stein, Susanne; Steinmann, Horst-Henning; Isselstein, Johannes
      Land 2019; 8(4): Art. 65
      Agricultural land use is influenced in different ways by local factors such as soil conditions, water supply, and socioeconomic structure. We investigated at regional and field scale how strong the relationship of arable crop patterns and specific local site conditions is. At field scale, a logistic regression analysis for the main crops and selected site variables detected, for each of the analyzed crops, its own specific character of crop–site relationship. Some crops have diverging site relations such as maize and wheat, while other crops show similar probabilities under comparable site conditions, e.g., oilseed rape and winter barley. At the regional scale, the spatial comparison of clustered variables and clustered crop pattern showed a slightly stronger relationship of crop combination and specific combinations of site variables compared to the view of the single crop–site relationship. View Full-Text
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    • Journal Article

      Dementia with Lewy bodies: an update and outlook 

      Outeiro, Tiago Fleming; Koss, David J.; Erskine, Daniel; Walker, Lauren; Kurzawa-Akanbi, Marzena; Burn, David; Donaghy, Paul; Morris, Christopher; Taylor, John-Paul; Thomas, Alan; et al.
      Attems, JohannesMcKeith, Ian
      Molecular Neurodegeneration 2019; 14(1): Art. 5
      Dementia with Lewy bodies (DLB) is an age-associated neurodegenerative disorder producing progressive cognitive decline that interferes with normal life and daily activities. Neuropathologically, DLB is characterised by the accumulation of aggregated α-synuclein protein in Lewy bodies and Lewy neurites, similar to Parkinson's disease (PD). Extrapyramidal motor features characteristic of PD, are common in DLB patients, but are not essential for the clinical diagnosis of DLB. Since many PD patients develop dementia as disease progresses, there has been controversy about the separation of DLB from PD dementia (PDD) and consensus reports have put forward guidelines to assist clinicians in the identification and management of both syndromes. Here, we present basic concepts and definitions, based on our current understanding, that should guide the community to address open questions that will, hopefully, lead us towards improved diagnosis and novel therapeutic strategies for DLB and other synucleinopathies.
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    • Journal Article

      Peri-hand space expands beyond reach in the context of walk-and-reach movements 

      Berger, Michael; Neumann, Peter; Gail, Alexander
      Scientific Reports 2019; 9(1): Art. 3013
      The brain incorporates sensory information across modalities to be able to interact with our environment. The peripersonal space (PPS), defined by a high level of crossmodal interaction, is centered on the relevant body part, e.g. the hand, but can spatially expand to encompass tools or reach targets during goal-directed behavior. Previous studies considered expansion of the PPS towards goals within immediate or tool-mediated reach, but not the translocation of the body as during walking. Here, we used the crossmodal congruency effect (CCE) to quantify the extension of the PPS and test if PPS can also expand further to include far located walk-and-reach targets accessible only by translocation of the body. We tested for orientation specificity of the hand-centered reference frame, asking if the CCE inverts with inversion of the hand orientation during reach. We show a high CCE with onset of the movement not only towards reach targets but also walk-and-reach targets. When participants must change hand orientation, the CCE decreases, if not vanishes, and does not simply invert. We conclude that the PPS can expand to the action space beyond immediate or tool-mediated reaching distance but is not purely hand-centered with respect to orientation.
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    • Journal Article

      Technical challenges of quantitative chest MRI data analysis in a large cohort pediatric study 

      Nguyen, Anh H.; Perez-Rovira, Adria; Wielopolski, Piotr A.; Hernandez Tamames, Juan A.; Duijts, Liesbeth; de Bruijne, Marleen; Aliverti, Andrea; Pennati, Francesca; Ivanovska, Tetyana; Tiddens, Harm A. W. M.; et al.
      Ciet, Pierluigi
      European Radiology
      OBJECTIVES: This study was conducted in order to evaluate the effect of geometric distortion (GD) on MRI lung volume quantification and evaluate available manual, semi-automated, and fully automated methods for lung segmentation. METHODS: A phantom was scanned with MRI and CT. GD was quantified as the difference in phantom's volume between MRI and CT, with CT as gold standard. Dice scores were used to measure overlap in shapes. Furthermore, 11 subjects from a prospective population-based cohort study each underwent four chest MRI acquisitions. The resulting 44 MRI scans with 2D and 3D Gradwarp were used to test five segmentation methods. Intraclass correlation coefficient, Bland-Altman plots, Wilcoxon, Mann-Whitney U, and paired t tests were used for statistics. RESULTS: Using phantoms, volume differences between CT and MRI varied according to MRI positions and 2D and 3D Gradwarp correction. With the phantom located at the isocenter, MRI overestimated the volume relative to CT by 5.56 ± 1.16 to 6.99 ± 0.22% with body and torso coils, respectively. Higher Dice scores and smaller intraobject differences were found for 3D Gradwarp MR images. In subjects, semi-automated and fully automated segmentation tools showed high agreement with manual segmentations (ICC = 0.971-0.993 for end-inspiratory scans; ICC = 0.992-0.995 for end-expiratory scans). Manual segmentation time per scan was approximately 3-4 h and 2-3 min for fully automated methods. CONCLUSIONS: Volume overestimation of MRI due to GD can be quantified. Semi-automated and fully automated segmentation methods allow accurate, reproducible, and fast lung volume quantification. Chest MRI can be a valid radiation-free imaging modality for lung segmentation and volume quantification in large cohort studies. KEY POINTS: • Geometric distortion varies according to MRI setting and patient positioning. • Automated segmentation methods allow fast and accurate lung volume quantification. • MRI is a valid radiation-free alternative to CT for quantitative data analysis.
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    • Journal Article

      Collembola interact with mycorrhizal fungi in modifying oak morphology, C and N incorporation and transcriptomics 

      Graf, Marcel; Bönn, Markus; Feldhahn, Lasse; Kurth, Florence; Grams, Thorsten E. E.; Herrmann, Sylvie; Tarkka, Mika; Buscot, Francois; Scheu, Stefan
      Royal Society Open Science 2019; 6(3): Art. 181869
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    • Journal Article

      Rocks rock: the importance of rock formations as resting sites of the Eurasian lynx Lynx lynx 

      Signer, Johannes; Filla, Marc; Schoneberg, Sebastian; Kneib, Thomas; Bufka, Ludek; Belotti, Elisa; Heurich, Marco
      Wildlife Biology 2019; 2019(1)
      Eurasian lynx Lynx lynx L. are recolonizing parts of their former range in Europe. Not only are lynx strictly protected as a species, but also their habitat and in particular their resting sites are protected. As the known characteristics of lynx resting sites are restricted to vegetation structure, it is difficult to take resting sites into account in planning processes. Here, we show the importance of rock formations for potential resting sites selection and analyzed the frequencies at which GPS-collared lynx returned to potential resting sites in the Bohemian Forest Ecosystem at the border between the Czech Republic and Germany. Lynx showed a strong selection for proximity of rocks for resting site selection, and the distance of potential resting sites to rocks was an important predictor for determining whether lynx return to the resting site or not. Furthermore, the frequency of returns to the resting site was positively influenced by the distance to roads and geomorphology. Our findings highlight the importance of rock formations as resting sites for lynx, which can help with the implementation of concrete protection measures.
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    • Working Paper

      Biopolitics and Displaced Bodies 

      Ince, Güler
      Göttinger Centrum für Geschlechterforschung, 2018
      For a geographic “place” to become a “homeland” or “home”, a community sharing a common cultural background has to take root there. The acquired place then forms part of the “body” of that community. Displacement turns individuals and communities into fragile entities by cutting their connection with their “place” and depriving them of their histories and bodies. The concepts of “borders” and “biopolitics” have gained prominence in the context of liberal nation states. In the view of persistent banishment, forced displacement, and population exchange in many parts of the world, contemporary border enforcement based on biopolitics serves to maintain control over bodies. This article will analyse depictions of the phenomena of exile, migration, immigration, and refuge/asylum in modern art with reference to the concept of biopolitics.
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    • Working Paper

      Song of My Mother 

      Yilmaz, Tebessüm
      Göttinger Centrum für Geschlechterforschung, 2018
      In the 1990s, Bakur (also known as ‘Turkish Kurdistan’) was exposed to mass state-inflicted violence. To supress the Kurdish insurgence and cut off the logistic support of the PKK (the Kurdistan Workers’ Party; Kurdish: Partiya Karkerên Kurdistanê), the Turkish state introduced new war strategies, such as forced disappearances and village evacuations executed by its security forces (TSK) and state- fostered counter-paramilitary forces (JİTEM, Hizbullah), leading to the displacement of three million people. Within a couple of years, thousands of Kurdish people were tortured, mutilated and forcibly disappeared. Their whereabouts remain unknown. This article investigates how state violence in the 1990s is depicted, represented, and recreated via cinematic narration. Erol Mintaş’s first feature film Song of My Mother (Annemin Şarkısı/2014) serves as a case study to analyse how forced displacement and resettlement of Kurds are visualised. Further, this account focuses on how the violence is remembered, represented, and recreated and which emotions are revealed while dealing with the traumatic events of the past and, finally, how the past is imagined and commemorated in the present. The visualisation and memorialisation of the 1990s in Kurdish culture contrast with the official Turkish discourse on memory and also provide a basis for collective societal confrontation.
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    • Working Paper

      National Belonging and Violent Norms of Gendered Migrant Citizenship 

      Dinkelaker, Samia
      Göttinger Centrum für Geschlechterforschung, 2018
      This article takes into view negotiations over the behaviour of Hong Kong-based Indonesian domes-tic workers as morally upright and respectable citizens. In collaboration with private agencies, the Indonesian government has actively promoted the temporary outmigration of female workers into low-waged and precarious employment arrangements as a strategy to combat unemployment and generate remittances, foreign exchange and development. The Indonesian labour migration program is, however, faced with the public’s anxieties and indignation over migrant domestic workers’ experi-ences of gender-based violence abroad and concerns over national dignity. As pointed out by a num-ber of feminist studies, “labor brokerage states” (Rodriguez 2010) meet the gendered contradictions of their labour migration programmes with appeals to migrant domestic workers’ morality. This arti-cle makes use of Judith Butler’s notion of “normative violence” (Butler 1999, 2004) to frame these appeals as subtle forms of discipline that police and regulate Indonesian migrant domestic workers. It addresses the strong role of female morality in defining which workers deserve protection and which workers can adequately represent the Indonesian nation on the international stage. By taking the case of Hong Kong-based Indonesian domestic workers’ self-organised and distinct enactment of a na-tional ritual on Independence Day 2014, I discuss how they appropriate norms of national belonging and how at the same time they challenge the subtle forms of violence inherent in moralising notions of gendered “migrant citizenship” (Rodriguez 2010).
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    • Working Paper

      Introduction to the Special Issue Gender and Violence in Contexts of Migration and Displacement 

      Hofmann, Susanne; Senoguz, Hatice Pinar
      Göttinger Centrum für Geschlechterforschung, 2018
      This special issue originates from the Summer Symposium Reconsidering gender-based violence in the context of displacement and migration held at the Georg-August University of Göttingen on 6-7th July 2017. The working papers explore different forms of gender violence, avoiding the pitfalls of a mainstream feminism that reproduces stereotypes of victimhood and marginalisation. Instead, the authors emphasise the role of power in relation to various kinds of gender violence, paying attention to the intricate inequalities that structure victims’ lives. The authors contribute to intersectional and actor-focused understandings of gender violence in conditions of mobility within or across borders of nation states.
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    • Anthology

      Gender and Violence in Contexts of Migration and Displacement 

      Hofmann, Susanne; Senoguz, Hatice Pinar
      Göttinger Centrum für Geschlechterforschung, 2018
      This special issue originates from the Summer Symposium Reconsidering gender-based violence in the context of displacement and migration held at the Georg-August University of Göttingen on 6-7th July 2017. The working papers explore different forms of gender violence, avoiding the pitfalls of a mainstream feminism that reproduces stereotypes of victimhood and marginalisation. Instead, the authors emphasise the role of power in relation to various kinds of gender violence, paying attention to the intricate inequalities that structure victims’ lives. The authors contribute to intersectional and actor-focused understandings of gender violence in conditions of mobility within or across borders of nation states.
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    • Journal Article

      Activity Correlations between Direction-Selective Retinal Ganglion Cells Synergistically Enhance Motion Decoding from Complex Visual Scenes 

      Kühn, Norma Krystyna; Gollisch, Tim
      Neuron 2019; 101(5): Art. 976.e7
      Neurons in sensory systems are often tuned to particular stimulus features. During complex naturalistic stimulation, however, multiple features may simultaneously affect neuronal responses, which complicates the readout of individual features. To investigate feature representation under complex stimulation, we studied how direction-selective ganglion cells in salamander retina respond to texture motion where direction, velocity, and spatial pattern inside the receptive field continuously change. We found that the cells preserve their direction preference under this stimulation, yet their direction encoding becomes ambiguous due to simultaneous activation by luminance changes. The ambiguities can be resolved by considering populations of direction-selective cells with different preferred directions. This gives rise to synergistic motion decoding, yielding more information from the population than the summed information from single-cell responses. Strong positive response correlations between cells with different preferred directions amplify this synergy. Our results show how correlated population activity can enhance feature extraction in complex visual scenes.
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    • Journal Article

      Screening of Barley Resistance Against Powdery Mildew by Simultaneous High-Throughput Enzyme Activity Signature Profiling and Multispectral Imaging 

      Kuska, Matheus T.; Behmann, Jan; Großkinsky, Dominik K.; Roitsch, Thomas; Mahlein, Anne-Katrin
      Frontiers in Plant Science 2018; 9 p.1074-1074
      Molecular marker analysis allow for a rapid and advanced pre-selection and resistance screenings in plant breeding processes. During the phenotyping process, optical sensors have proved their potential to determine and assess the function of the genotype of the breeding material. Thereby, biomarkers for specific disease resistance traits provide valuable information for calibrating optical sensor approaches during early plant-pathogen interactions. In this context, the combination of physiological, metabolic phenotyping and phenomic profiles could establish efficient identification and quantification of relevant genotypes within breeding processes. Experiments were conducted with near-isogenic lines of H. vulgare (susceptible, mildew locus o (mlo) and Mildew locus a (Mla) resistant). Multispectral imaging of barley plants was daily conducted 0-8 days after inoculation (dai) in a high-throughput facility with 10 wavelength bands from 400 to 1,000 nm. In parallel, the temporal dynamics of the activities of invertase isoenzymes, as key sink specific enzymes that irreversibly cleave the transport sugar sucrose into the hexose monomers, were profiled in a semi high-throughput approach. The activities of cell wall, cytosolic and vacuole invertase revealed specific dynamics of the activity signatures for susceptible genotypes and genotypes with mlo and Mla based resistances 0-120 hours after inoculation (hai). These patterns could be used to differentiate between interaction types and revealed an early influence of Blumeria graminis f.sp. hordei (Bgh) conidia on the specific invertase activity already 0.5 hai. During this early powdery mildew pathogenesis, the reflectance intensity increased in the blue bands and at 690 nm. The Mla resistant plants showed an increased reflectance at 680 and 710 nm and a decreased reflectance in the near infrared bands from 3 dai. Applying a Support Vector Machine classification as a supervised machine learning approach, the pixelwise identification and quantification of powdery mildew diseased barley tissue and hypersensitive response spots were established. This enables an automatic identification of the barley-powdery mildew interaction. The study established a proof-of-concept for plant resistance phenotyping with multispectral imaging in high-throughput. The combination of invertase analysis and multispectral imaging showed to be a complementing validation system. This will provide a deeper understanding of optical data and its implementation into disease resistance screening.
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    • Journal Article

      Crop Rotational Effects on Yield Formation in Current Sugar Beet Production - Results From a Farm Survey and Field Trials 

      Koch, Heinz-Josef; Trimpler, Kerrin; Jacobs, Anna; Stockfisch, Nicol
      Frontiers in plant science 2018; 9: Art. 231
      In Europe, the framework for sugar beet (Beta vulgaris L.) production was subject to considerable changes and for the future it is expected that sugar beet cultivation might concentrate around the sugar factories for economic reasons. Based on data from a national sugar beet farmers' survey and multi-year crop rotation trials, the effects of cropping interval (number of years in between two subsequent sugar beet crops) and of preceding crops on sugar yield were elucidated under current Central European management conditions. The dominating sugar beet cropping interval was ≥4 years in the farm survey with pronounced differences between regions. However, the cropping intervals 2, 3, and ≥4 years did not affect the sugar yield. Therefore, significant differences in sugar yield between regions were assumed to be caused by multiple interactions between year, site, and farmers' skills. Throughout Germany, the dominating preceding crops in sugar beet cultivation were winter wheat (Triticum aestivum L.) and winter barley (Hordeum vulgare L.). In the field trials, the sugar yield was 5% higher after pea (Pisum sativum L.) compared to maize (Zea mays L.) as preceding crop, while differences between the preceding crops pea and winter wheat, and wheat and maize were not significant. Repeated measurements of canopy development and leaf color during the growing season revealed a higher N-availability after pea as preceding crop. However, decreased growth after maize was not completely compensated for by high N-fertilizer doses. Overall, the causes for the differences in sugar yield between the preceding crops remained open. The results do not support concerns about substantial yield losses in sugar beet production due to a reduction in the cropping interval from 3 to 2 years. Nevertheless, short rotations with maize and sugar beet might increase the risk of Rhizoctonia solani crown and root rot infestation. Leguminous crops such as pea offer the potential for higher sugar beet yield with lower N-fertilizer doses.
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    • Journal Article

      Yield Potential of Sugar Beet - Have We Hit the Ceiling? 

      Hoffmann, Christa M.; Kenter, Christine
      Frontiers in Plant Science 2018; 9: Art. 289
      The yield of sugar beet has continuously increased in the past decades. The question arises, whether this progress will continue in the future. A key factor for increasing yield potential of the crop is breeding progress. It was related to a shift in assimilate partitioning in the plant toward more storage carbohydrates (sucrose), whereas structural carbohydrates (leaves, cell wall compounds) unintendedly declined. The yield potential of sugar beet was estimated at 24 t sugar ha-1. For maximum yield, sufficient growth factors have to be available and the crop has to be able to fully utilize them. In sugar beet, limitations result from the lacking coincidence of maximum irradiation rates and full canopy cover, sink strength for carbon assimilation and high water demand, which cannot be met by rainfall alone. After harvest, sugar losses during storage occur. The paper discusses options for a further increase in yield potential, like autumn sowing of sugar beet, increasing sink strength and related constraints. It is prospected that yield increase by further widening the ratio of storage and structural carbohydrates will come to its natural limit as a certain cell wall stability is necessary. New challenges caused by climate change and by prolonged processing campaigns will occur. Thus breeding for improved pathogen resistance and storage properties will be even more important for successful sugar beet production than a further increase in yield potential itself.
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