Recent Submissions

  • Journal Article

    Mycotoxigenic Fungi and Mycotoxins in Agricultural Crop Commodities in the Philippines: A Review 

    Balendres, Mark Angelo O.; Karlovsky, Petr; Cumagun,Christian Joseph R.
    Foods 2019; 8(7): Art. 249
    The tropical, warm, and humid conditions that are favorable to the growth and development of mycotoxigenic fungi put the Philippines at a high risk of mycotoxin contamination. To date, seven mycotoxigenic Aspergillus species, four Fusarium species, and one Penicillium species have been isolated from various agricultural crop commodities in the country. There are five mycotoxin groups (aflatoxin, fumonisin, ochratoxin, nivalenol, and zearalenone) that have been detected in both the raw form and the by-products of major crops grown in the country. Since the first scientific report of aflatoxin contamination in the Philippines in 1972, new information has been generated on mycotoxins and mycotoxigenic fungi, but little has been known of other mycotoxins until the last two decades. Further, despite the increase in the understanding of mycotoxigenic fungi and mycotoxins in the country, very limited knowledge exists on practices and measures that control both the fungi and the toxins. This paper reviews the current literature on mycotoxigenic fungi and mycotoxins in the Philippines with emphasis on the last two decades and on other mycotoxins.
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  • Journal Article

    Bis-naphthopyrone pigments protect filamentous ascomycetes from a wide range of predators 

    Xu, Yang; Vinas, Maria; Alsarrag, Albatol; Su, Ling; Pfohl, Katharina; Rohlfs, Marko; Schäfer, Wilhelm; Chen, Wei; Karlovsky, Petr
    Nature Communications 2019; 10(1): Art. 3579
    It is thought that fungi protect themselves from predation by the production of compounds that are toxic to soil-dwelling animals. Here, we show that a nontoxic pigment, the bisnaphthopyrone aurofusarin, protects Fusarium fungi from a wide range of animal predators. We find that springtails (primitive hexapods), woodlice (crustaceans), and mealworms (insects) prefer feeding on fungi with disrupted aurofusarin synthesis, and mealworms and springtails are repelled by wheat flour amended with the fungal bis-naphthopyrones aurofusarin, viomellein, or xanthomegnin. Predation stimulates aurofusarin synthesis in several Fusarium species and viomellein synthesis in Aspergillus ochraceus. Aurofusarin displays low toxicity in mealworms, springtails, isopods, Drosophila, and insect cells, contradicting the common view that fungal defence metabolites are toxic. Our results indicate that bisnaphthopyrones are defence compounds that protect filamentous ascomycetes from predators through a mechanism that does not involve toxicity.
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  • Journal Article

    Leaf mechanisms involved in the response of Cydonia oblonga trees to water stress and recovery 

    Griñán, I.; Rodríguez, P.; Nouri, H.; Wang, R.; Huang, G.; Morales, D.; Corell, M.; Pérez-López, D.; Centeno, A.; Martin-Palomo, M.J.; et al.
    Hernández, F.Torrecillas, A.Galindo, A.
    Agricultural Water Management 2019; 221 p.66-72
    Quince tree (Cydonia oblonga Mill.) is known for bearing fruits that are rich in nutrients and health-promoting compounds while requiring low inputs of agrochemicals, and maintenance, but no information exists on the mechanisms developed at the level of leaf water relations to confront water stress and recovery. For this reason, the purpose of the present study was to identify the strategy (isohydric or anisohydric) by which quince plants cope with water stress and to further elucidate the resistance mechanisms developed in response to water stress and during recovery. In summer 2016, field-grown own rooted 17-years old quince trees (cv. BA-29) were subjected to two irrigation treatments. Control (T0) plants were drip irrigated (105% ETo) to ensure non-limiting soil water conditions, while T1 plants were irrigated at the same level as used in T0, except that irrigation was withheld for 42 days during the linear fruit growth phase, after which irrigation returned to the levels of T0 (recovery period). During the experimental period, T0 and T1 received a total of 374 and 143 mm water, respectively, including rain water. The quince trees exhibited extreme anisohydric behaviour under the experimental conditions. As water stress developed and during the recovery period, the plants exhibited high hydraulic conductivity, probably the result of resistance to cavitation. From the beginning of water stress to the time of maximum water stress, leaf turgor was maintained, possibly due to active osmotic adjustment (stress tolerance mechanism). This leaf turgor maintenance may have contributed to the high leaf conductance, and, therefore, good leaf productivity. The low quince leaf apoplastic water fraction under water stress could be considered as another drought tolerance characteristic because if the accumulation of water in the apoplasm is avoided a steeper gradient in water potential between the leaf and the soil can take place under water stress, thus favouring water absorption.
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  • Journal Article

    Effects of root and leaf litter identity and diversity on oribatid mite abundance, species richness and community composition 

    Bluhm, Christian; Butenschoen, Olaf; Maraun, Mark; Scheu, Stefan
    PLOS ONE 2019; 14(7): Art. e0219166
    Habitat heterogeneity is an important driver of aboveground species diversity but few studies have investigated effects on soil communities. Trees shape their surrounding by both leaf litter and roots generating small scale heterogeneity and potentially governing community patterns of soil organisms. To assess the role of vegetation for the soil fauna, we studied whether tree species (Fagus sylvatica L., Acer pseudoplatanus L., Fraxinus excelsior L., Tilia cordata Mill.), markedly differing in leaf litter quality and root associated mycorrhizal symbionts, affect oribatid mite communities by shaping below- and aboveground resources and habitat complexity and availability. Oribatid mite abundance, species richness, community structure and the proportion of litter living and parthenogenetic individuals were analyzed and related to microbial biomass and the amount of remaining litter mass. Although leaf litter species with higher nutritional values decomposed considerably faster, microbial biomass only slightly differed between leaf litter species. Neither root species nor leaf litter species affected abundance, species richness or community structure of oribatid mites. However, root species had an effect on the proportion of parthenogenetic individuals with increased proportions in the presence of beech roots. Overall, the results suggest that identity and diversity of vegetation via leaf litter or roots are of minor importance for structuring oribatid mite communities of a temperate forest ecosystem.
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  • Journal Article

    Small-Scale Bioreactor for Sterile Hydroponics and Hairy Roots: Metabolic Diversity and Salicylic Acid Exudation by Hairy Roots of Hyoscyamus niger 

    Kareem, Zana Jamal; Su, Ling; Rathgeb, Anna; Sirrenberg, Anke; Hadacek, Franz; Rashid, Ahmad Hama Ameen H.; Karlovsky, Petr
    Applied Sciences 2019; 9(15): Art. 3044
    The volume and complexity of commercial bioreactors for sterile hydroponics and hairy roots are too large for comparative analysis of many cultures. Here a small-scale bioreactor fabricated from standard glass materials and suitable for both airlift and bubble aeration mode is described. The performance of the bioreactor was tested by growing oilseed rape (Brassica napus L.) and rose plants (Rosa canina L.) in sterile hydroponics and by cultivating hairy roots of henbane (Hyoscyamus niger L.) and sesame (Hyoscyamus niger L.). Plants grown in hydroponics for up to six weeks did not show chloroses or necroses. Hairy roots grew faster or comparably fast in bioreactors as compared to shaking flasks. Root exudates of roses and exudates of hairy roots of henbane were subjected to targeted and nontargeted analysis by HPLC coupled with optical and mass spectrometric detectors. The diversity and concentration of hairy root exudates were higher in bioreactors than in shaking flasks. The composition of hairy root exudates of three accessions of H. niger did not match the genetic relatedness among the accessions. Hairy roots of Hyoscyamus niger exuded salicylic acid in amounts varying among plant accessions and between bioreactors and shaking flask cultures.
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  • Journal Article

    Sustainability Matters: Consumer Acceptance of Different Vertical Farming Systems 

    Jürkenbeck, Kristin; Heumann, Andreas; Spiller, Achim
    Sustainability 2019; 11(15): Art. 4052
    Fresh produce within vertical farming systems grows vertically in different layers stacked atop each other, thus allowing for the efficient use of space. As the environment in vertical farming systems is completely controlled, neither sunlight nor soil is necessary. On the one hand, vertical farming may help to provide a healthy diet for the growing global population because it has a greater crop yield per square meter used than conventional farming; moreover, it can offer the opportunity to grow food in climatically disadvantaged areas. On the other hand, growth conditions may be perceived as unnatural and the entire vertical farming system as unsustainable. Therefore, understanding the consumers’ acceptance of vertical farming systems is important. This study is the first work to provide insights into consumers’ acceptance of three different vertical farming systems. Data are collected through an online survey of 482 consumers in Germany in February 2018. Drivers of consumer acceptance of vertical farming systems are identified through structural equation modelling. The results indicate that perceived sustainability is the major driver of consumer acceptance of vertical farming systems. The larger the system, the higher the likelihood that it will be considered as sustainable. Obviously, consumers perceive something like ecologies of scale.
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  • Journal Article

    Opportunities for the Adoption of Health-Based Sustainable Dietary Patterns: A Review on Consumer Research of Meat Substitutes 

    Weinrich, Ramona
    Sustainability 2019; 11(15): Art. 4028
    This article reviews empirical research on consumers’ adoption of meat substitutes published up to spring 2018. Recent meat substitutes often have sustainable characteristics in line with consumers’ concerns over aspects of healthy food and the environmental impact of food production. However, changing lifestyles with less time for cooking, any transition from a strongly meat-based to a more plant-based diet depends on the successful establishment of convenient meat substitutes. This article reviews the growing body of research on meat substitutes. These research articles were classified into five different stages in line with the innovation-decision process of: knowledge, persuasion, decision, implementation and confirmation. The research was analysed both quantitatively and qualitatively, with results suggesting that although health, environmental and animal welfare aspects can persuade consumers and influence their decision to try a meat substitute, the appearance and taste of those meat substitutes are crucial factors for their consumption on a regular basis. However, there still remains a gap in research articles focusing on the regular consumption of meat substitutes.
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  • Journal Article

    Determinants of the Use of Certified Seed Potato among Smallholder Farmers: The Case of Potato Growers in Central and Eastern Kenya 

    Okello, Julius; Zhou, Yuan; Kwikiriza, Norman; Ogutu, Sylvester; Barker, Ian; Schulte-Geldermann, Elmar; Atieno, Elly; Ahmed, Justin
    Agriculture 2016; 6(4): Art. 55
    Potato yields in sub-Saharan Africa remain very low compared with those of developed countries. Yet potato is major food staple and source of income to the predominantly smallholder growing households in the tropical highlands of this region. A major cause of the low potato yields is the use of poor quality seed potato. This paper examines the factors determining the decision to use certified seed potato (CSP), as well as the intensity of its use, among potato growers with access to it. We focused on potato growers in the central highlands of Kenya and used regression analysis to test hypotheses relating to potential impediments of CSP use. The study found that the distance to the market (a proxy for transaction costs), household food insecurity, and asset endowment affect the decision to use CSP. However, the effect of the intensity of use of CSP depends on how the intensity variable is defined. Several other control variables also affect the decision and extent of CSP use. The study concludes that transaction costs, asset endowment, and household food insecurity play a major role in the decision by smallholder potato farmers to use CSP and the extent to which they do so. We also discuss the policy implications of the findings.
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  • Journal Article

    Productivity and food security effects of using of certified seed potato: the case of Kenya’s potato farmers 

    Okello, Julius Juma; Zhou, Yuan; Kwikiriza, Norman; Ogutu, Sylvester; Barker, Ian; Schulte-Geldermann, Elmar; Atieno, Elly; Ahmed, Justin Taj
    Agriculture & Food Security 2017; 6(1): Art. 25
    Background: Potato is a major food crop in the tropical regions of Africa. However, potato yields continue to remain very low in these regions mainly due to use of poor quality seed. The recent development of rapid seed multiplication technique has helped to shorten the duration of certified seed potato (CSP) production and increase the supply of seed. This study assessed the effect of using CSP on yield, input use, and food security among smallholder farmers. It focused on potato growers in central highlands of Kenya, who were in close proximity to a private seed multiplier that uses these new techniques. The study used the propensity score matching technique and data collected from 408 smallholder farmers through personal interviews. The farmers were stratified by use of CSP. Results: The study found positive effect of using certified seed on both yield and food security. There was also a slight increase in input usage, apparently due to pursuit by farmers to optimize the gains from CSP. Conclusion: The study concludes that using CSP has positive effect on smallholder farm households.
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  • Journal Article

    How to make farming and agricultural extension more nutrition-sensitive: evidence from a randomised controlled trial in Kenya 

    Ogutu, Sylvester Ochieng; Fongar, Andrea; Gödecke, Theda; Jäckering, Lisa; Mwololo, Henry; Njuguna, Michael; Wollni, Meike; Qaim, Matin
    European Review of Agricultural Economics p.1-24: Art. jby049
    We analyse how agricultural extension can be made more effective in terms of increasing farmers’ adoption of pro-nutrition technologies, such as biofortified crops. In a randomised controlled trial with farmers in Kenya, we implemented several extension treatments and evaluated their effects on the adoption of beans biofortified with iron and zinc. Difference-in-difference estimates show that intensive agricultural training can increase technology adoption considerably. Additional nutrition training helps farmers to better appreciate the technology’s nutritional benefits and thus further increases adoption. This study is among the first to analyse how improved extension designs can help to make smallholder farming more nutrition-sensitive.
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  • Journal Article

    WNT Signaling in Neuroblastoma 

    Becker, Juergen; Wilting, Joerg
    Cancers 2019; 11(7): Art. 1013
    The term WNT (wingless-type MMTV integration site family) signaling comprises a complex molecular pathway consisting of ligands, receptors, coreceptors, signal transducers and transcriptional modulators with crucial functions during embryonic development, including all aspects of proliferation, morphogenesis and di erentiation. Its involvement in cancer biology is well documented. Even though WNT signaling has been divided into mainly three distinct branches in the past, increasing evidence shows that some molecular hubs can act in various branches by exchanging interaction partners. Here we discuss developmental and clinical aspects of WNT signaling in neuroblastoma (NB), an embryonic tumor with an extremely broad clinical spectrum, ranging from spontaneous di erentiation to fatal outcome. We discuss implications of WNT molecules in NB onset, progression, and relapse due to chemoresistance. In the light of the still too high number of NB deaths, new pathways must be considered.
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  • Journal Article

    Development of Rapid Extraction Method of Mycobacterium avium Subspecies paratuberculosis DNA from Bovine Stool Samples 

    Hansen, Sören; Roller, Marco; Alslim, Lamia; Böhlken-Fascher, Susanne; Fechner, Kim; Czerny, Claus-Peter; Abd El Wahed, Ahmed
    Diagnostics 2019; 9(2): Art. 36
    The rapid identification of Mycobacterium avium subspecies paratuberculosis (MAP) infected animals within the herd is essential for preventing the spread of the disease as well as avoiding human exposure. Although culture is seen as the gold standard, there are various molecular assays available i.e., polymerase chain reaction (PCR) or isothermal amplification technique (recombinase polymerase amplification (RPA)) for the detection of MAP. The accuracy of the molecular assays is highly dependent on the DNA extraction method. In order to establish a rapid point of need system for the detection of MAP DNA from stool samples, we developed a rapid DNA extraction protocol (MAP DNA SpeedXtract) specified for use in combination with the RPA. The whole procedure from “sample in” to “result out” was conducted in a mobile suitcase laboratory. The DNA extraction is based on reverse purification by magnetic beads, which reduces the required technical demand. The MAP DNA SpeedXtract was performed within 25 min and only three pipetting steps were needed. The amplification and detection time were 20 min in RPA. The sensitivity and specificity of the developed protocol in comparison with the lab-based silica membrane column extraction and real-time PCR were 90.9% (n = 22) and 100% (n = 23), respectively. In conclusion, we established a rapid and reliable protocol for the extraction and detection of MAP DNA. All reagents are cold chain independent. The entire setup is ideal for point of need identification of MAP infected cases.
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  • Journal Article

    Dairy Supply Chain in Southern Brazil: Barriers to Competitiveness 

    Beber, C.L.; Ruales Carpio, A. F.; Almadani, M. I.
    2018 Conference, July 28-August 2, 2018, Vancouver, British Columbia; International Association of Agricultural Economists p.1-23
    Different from other sectors in the Brazilian agriculture, the dairy is still immature, especially regarding external markets competition, and therefore is facing difficult challenges. This study identifies the main factors affecting the competitiveness in one of the most promising and dynamic dairy production areas in the world, the mesoregion Grande Fronteira do Mercosul in Southern Brazil. It is based on the perceptions of supply chain leaders about the challenges to improve the competitiveness. Missing professionalism, formal agreements, investments in marketing and research, technology, development and innovation, technical assistance, high transport and transaction costs, idle capacities and frauds are among the main factors retarding the modernization of this supply chain. It also present different strategies already implemented by some actors to overcome such competitiveness barriers. Therefore these problems and strategies must be the target of managers and authorities in a sustainable common project of development for the benefit of the whole chain. Acknowledgement : We would like to acknowledge the CAPES from the Brazilian Ministry of Education for the financing as well as the interviewees participants of this study for their time and dedication.
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  • Journal Article

    Microhydrological Niches in Soils: How Mucilage and EPS Alter the Biophysical Properties of the Rhizosphere and Other Biological Hotspots 

    Benard, Pascal; Zarebanadkouki, Mohsen; Brax, Mathilde; Kaltenbach, Robin; Jerjen, Iwan; Marone, Federica; Couradeau, Estelle; Felde, Vincent J. M. N. L.; Kaestner, Anders; Carminati, Andrea
    Vadose Zone Journal 2019; 18(1)
    Plant roots and bacteria are capable of buffering erratic fluctuations of water content in their local soil environment by releasing a diverse, highly polymeric blend of substances (e.g. extracellular polymeric substances [EPS] and mucilage). Although this concept is well accepted, the physical mechanisms by which EPS and mucilage interact with the soil matrix and determine the soil water dynamics remain unclear. High-resolution X-ray computed tomography revealed that upon drying in porous media, mucilage (from maize [Zea mays L.] roots) and EPS (from intact biocrusts) form filaments and two-dimensional interconnected structures spanning across multiple pores. Unlike water, these mucilage and EPS structures connecting soil particles did not break up upon drying, which is explained by the high viscosity and low surface tension of EPS and mucilage. Measurements of water retention and evaporation with soils mixed with seed mucilage show how these one- and two-dimensional pore-scale structures affect macroscopic hydraulic properties (i.e., they enhance water retention, preserve the continuity of the liquid phase in drying soils, and decrease vapor diffusivity and local drying rates). In conclusion, we propose that the release of viscous polymeric substances and the consequent creation of a network bridging the soil pore space represent a universal strategy of plants and bacteria to engineer their own soil microhydrological niches where stable conditions for life are preserved.
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  • Journal Article

    Animal Ethics and Eating Animals: Consumer Segmentation Based on Domain-Specific Values 

    Hölker, Sarah; von Meyer-Höfer, Marie; Spiller, Achim
    Sustainability 2019; 11(14): Art. 3907
    For a sustainable diet, especially with regard to animal welfare, human health, and environmental issues, a significant reduction in the consumption of animal source foods is essential. The most frequently reported motivations for a meat-reduced or meat-free diet are ethical concerns about animal welfare. This study realizes one of the first consumer segmentations in the context of the human–animal relationship based on domain-specific values; animal ethics. Such a consumer segmentation is relatively stable over time and encompasses the issue of the human–animal relationship in its entirety without limiting itself to a specific question. Based on a comprehensive consumer survey in Germany and by means of a three-step cluster analysis, five consumer segments characterized by di erent animal-ethical value profiles were defined. A subsequent analysis revealed a link between animal ethics and diet. As a key result, relationism as an animal-ethical position seems to play a key role in the choice of a sustainable diet. About a quarter of the population is characterized by a combination of animal welfare-oriented ethical positions with a clear rejection of relationism, i.e., they do not distinguish between farm animals and companion animals. This specific combination of animal-ethical values is associated with a significantly above-average proportion of flexitarians and vegetarians. Thus, the study contributes to a deeper understanding of existing animal-ethical values and their link to the choice of diet.
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  • Journal Article

    Genetics of adaptation in modern chicken 

    Qanbari, Saber; Rubin, Carl-Johan; Maqbool, Khurram; Weigend, Steffen; Weigend, Annett; Geibel, Johannes; Kerje, Susanne; Wurmser, Christine; Peterson, Andrew Townsend; Brisbin, I. Lehr; et al.
    Preisinger, RuediFries, RuediSimianer, HennerAndersson, Leif
    PLOS Genetics 2019; 15(4): Art. e1007989
    We carried out whole genome resequencing of 127 chicken including red jungle fowl and multiple populations of commercial broilers and layers to perform a systematic screening of adaptive changes in modern chicken (Gallus gallus domesticus). We uncovered >21 million high quality SNPs of which 34% are newly detected variants. This panel comprises >115,000 predicted amino-acid altering substitutions as well as 1,100 SNPs predicted to be stop-gain or -loss, several of which reach high frequencies. Signatures of selection were investigated both through analyses of fixation and differentiation to reveal selective sweeps that may have had prominent roles during domestication and breed development. Contrasting wild and domestic chicken we confirmed selection at the BCO2 and TSHR loci and identified 34 putative sweeps co-localized with ALX1, KITLG, EPGR, IGF1, DLK1, JPT2, CRAMP1, and GLI3, among others. Analysis of enrichment between groups of wild vs. commercials and broilers vs. layers revealed a further panel of candidate genes including CORIN, SKIV2L2 implicated in pigmentation and LEPR, MEGF10 and SPEF2, suggestive of production-oriented selection. SNPs with marked allele frequency differences between wild and domestic chicken showed a highly significant deficiency in the proportion of amino-acid altering mutations (P<2.5×10-6). The results contribute to the understanding of major genetic changes that took place during the evolution of modern chickens and in poultry breeding.
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  • Journal Article

    Integrating Aquatic and Terrestrial Perspectives to Improve Insights Into Organic Matter Cycling at the Landscape Scale 

    Kayler, Zachary E.; Premke, Katrin; Gessler, Arthur; Gessner, Mark O.; Griebler, Christian; Hilt, Sabine; Klemedtsson, Leif; Kuzyakov, Yakov; Reichstein, Markus; Siemens, Jan; et al.
    Totsche, Kai-UweTranvik, LarsWagner, AnnekatrinWeitere, MarkusGrossart, Hans-Peter
    Frontiers in Earth Science 2019; 7: Art. 127
    Across a landscape, aquatic-terrestrial interfaces within and between ecosystems are hotspots of organic matter (OM) mineralization. These interfaces are characterized by sharp spatio-temporal changes in environmental conditions, which affect OM properties and thus control OM mineralization and other transformation processes. Consequently, the extent of OM movement at and across aquatic-terrestrial interfaces is crucial in determining OM turnover and carbon (C) cycling at the landscape scale. Here, we propose expanding current concepts in aquatic and terrestrial ecosystem sciences to comprehensively evaluate OM turnover at the landscape scale. We focus on three main concepts toward explaining OM turnover at the landscape scale: the landscape spatiotemporal context, OM turnover described by priming and ecological stoichiometry, and anthropogenic effects as a disruptor of natural OM transfer magnitudes and pathways. A conceptual framework is introduced that allows for discussing the disparities in spatial and temporal scales of OM transfer, changes in environmental conditions, ecosystem connectivity, and microbial–substrate interactions. The potential relevance of priming effects in both terrestrial and aquatic systems is addressed. For terrestrial systems, we hypothesize that the interplay between the influx of OM, its corresponding elemental composition, and the elemental demand of the microbial communities may alleviate spatial and metabolic thresholds. In comparison, substrate level OM dynamics may be substantially different in aquatic systems due to matrix effects that accentuate the role of abiotic conditions, substrate quality, and microbial community dynamics. We highlight the disproportionate impact anthropogenic activities can have on OM cycling across the landscape. This includes reversing natural OM flows through the landscape, disrupting ecosystem connectivity, and nutrient additions that cascade across the landscape. This knowledge is crucial for a better understanding of OM cycling in a landscape context, in particular since terrestrial and aquatic compartments may respond differently to the ongoing changes in climate, land use, and other anthropogenic interferences.
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  • Journal Article

    Conversion of monoculture cropland and open grassland to agroforestry alters the abundance of soil bacteria, fungi and soil-N-cycling genes 

    Beule, Lukas; Corre, Marife D.; Schmidt, Marcus; Göbel, Leonie; Veldkamp, Edzo; Karlovsky, Petr
    PLOS ONE 2019; 14(6): Art. e0218779
    Integration of trees in agroforestry systems can increase the system sustainability compared to monocultures. The resulting increase in system complexity is likely to affect soil-N cycling by altering soil microbial community structure and functions. Our study aimed to assess the abundance of genes encoding enzymes involved in soil-N cycling in paired monoculture and agroforestry cropland in a Phaeozem soil, and paired open grassland and agroforestry grassland in Histosol and Anthrosol soils. The soil fungi-to-bacteria ratio was greater in the tree row than in the crop or grass rows of the monoculture cropland and open grassland in all soil types, possibly due to increased input of tree residues and the absence of tillage in the Phaeozem (cropland) soil. In the Phaeozem (cropland) soil, gene abundances of amoA indicated a niche differentiation between archaeal and bacterial ammonia oxidizers that distinctly separated the influence of the tree row from the crop row and monoculture system. Abundances of nitrate (napA and narG), nitrite (nirK and nirS) and nitrous oxide reductase genes (nosZ clade I) were largely influenced by soil type rather than management system. The soil types' effects were associated with their differences in soil organic C, total N and pH. Our findings show that in temperate regions, conversion of monoculture cropland and open grassland to agroforestry systems can alter the abundance of soil bacteria and fungi and soil-N-cycling genes, particularly genes involved in ammonium oxidation.
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  • Journal Article

    Species-Specific Conservation of Linear Antigenic Sites on Vaccinia Virus A27 Protein Homologs of Orthopoxviruses 

    Ahsendorf, Henrike; Gan, Li; Eltom, Kamal; Abd El Wahed, Ahmed; Hotop, Sven-Kevin; Roper, Rachel; Beutling, Ulrike; Broenstrup, Mark; Stahl-Hennig, Christiane; Hoelzle, Ludwig; et al.
    Czerny, Claus-Peter
    Viruses 2019; 11(6): Art. 493
    The vaccinia virus (VACV) A27 protein and its homologs, which are found in a large number of members of the genus Orthopoxvirus (OPXV), are targets of viral neutralization by host antibodies. We have mapped six binding sites (epitopes #1A: aa 32-39, #1B: aa 28-33, #1C: aa 26-31, #1D: 28-34, #4: aa 9-14, and #5: aa 68-71) of A27 specific monoclonal antibodies (mAbs) using peptide arrays. MAbs recognizing epitopes #1A-D and #4 neutralized VACV Elstree in a complement dependent way (50% plaque-reduction: 12.5-200 µg/mL). Fusion of VACV at low pH was blocked through inhibition of epitope #1A. To determine the sequence variability of the six antigenic sites, 391 sequences of A27 protein homologs available were compared. Epitopes #4 and #5 were conserved among most of the OPXVs, while the sequential epitope complex #1A-D was more variable and, therefore, responsible for species-specific epitope characteristics. The accurate and reliable mapping of defined epitopes on immuno-protective proteins such as the A27 of VACV enables phylogenetic studies and insights into OPXV evolution as well as to pave the way to the development of safer vaccines and chemical or biological antivirals.
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  • Journal Article

    Conventionalization of Organic Farms in Germany: An Empirical Investigation Based on a Composite Indicator Approach 

    Seidel, Claudia; Heckelei, Thomas; Lakner, Sebastian
    Sustainability 2019; 11(10): Art. 2934
    The term “conventionalization” of organic agriculture was created to depict the controversially discussed phenomenon that organic agriculture departs from the core organic principles on which it is based. We present an empirical, index-based approach to investigate developments of organic farming practices towards conventionalization. An index of conventionalization can be used as a monitoring tool to support policymakers to further develop agricultural regulations. We calculate composite indicators for three farm types: farms specialized on crop production, farms specialized on animal husbandry, and mixed farms. Principal component analysis serves to derive objective weights based on the correlations between indicators which then allow a linear aggregation to the composite indicator. Results show that developments towards conventionalization of the whole organic farming sector cannot be detected for German farms between 2000 and 2009. Therefore, we do not see the necessity for changes in regulation of the organic sector with regard to conventionalization.
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