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Showing papers by "Leibniz Association published in 2010"


Journal ArticleDOI
TL;DR: MassBank is the first public repository of mass spectra of small chemical compounds for life sciences and provides a merged spectrum for each compound prepared by merging the analyzed ESI-MS(2) data on an identical compound under different collision-induced dissociation conditions.
Abstract: MassBank is the first public repository of mass spectra of small chemical compounds for life sciences (<3000 Da). The database contains 605 electron-ionization mass spectrometry (EI-MS), 137 fast atom bombardment MS and 9276 electrospray ionization (ESI)-MS(n) data of 2337 authentic compounds of metabolites, 11 545 EI-MS and 834 other-MS data of 10,286 volatile natural and synthetic compounds, and 3045 ESI-MS(2) data of 679 synthetic drugs contributed by 16 research groups (January 2010). ESI-MS(2) data were analyzed under nonstandardized, independent experimental conditions. MassBank is a distributed database. Each research group provides data from its own MassBank data servers distributed on the Internet. MassBank users can access either all of the MassBank data or a subset of the data by specifying one or more experimental conditions. In a spectral search to retrieve mass spectra similar to a query mass spectrum, the similarity score is calculated by a weighted cosine correlation in which weighting exponents on peak intensity and the mass-to-charge ratio are optimized to the ESI-MS(2) data. MassBank also provides a merged spectrum for each compound prepared by merging the analyzed ESI-MS(2) data on an identical compound under different collision-induced dissociation conditions. Data merging has significantly improved the precision of the identification of a chemical compound by 21-23% at a similarity score of 0.6. Thus, MassBank is useful for the identification of chemical compounds and the publication of experimental data.

1,689 citations


Journal ArticleDOI
TL;DR: The rationale, potential and flexibility of tumor spheroid mono- and cocultures for implementation into state of the art anti-cancer therapy test platforms are highlighted and the relevance of the cancer stem cell hypothesis for cancer cure is highlighted.

1,430 citations


Journal ArticleDOI
10 Dec 2010-Science
TL;DR: Though the threat of extinction is increasing, overall declines would have been worse in the absence of conservation, and current conservation efforts remain insufficient to offset the main drivers of biodiversity loss in these groups.
Abstract: Using data for 25,780 species categorized on the International Union for Conservation of Nature Red List, we present an assessment of the status of the world's vertebrates. One-fifth of species are classified as Threatened, and we show that this figure is increasing: On average, 52 species of mammals, birds, and amphibians move one category closer to extinction each year. However, this overall pattern conceals the impact of conservation successes, and we show that the rate of deterioration would have been at least one-fifth again as much in the absence of these. Nonetheless, current conservation efforts remain insufficient to offset the main drivers of biodiversity loss in these groups: agricultural expansion, logging, overexploitation, and invasive alien species.

1,333 citations


Journal ArticleDOI
12 Feb 2010-Science
TL;DR: Precision agriculture comprises a set of technologies that combines sensors, information systems, enhanced machinery, and informed management to optimize production by accounting for variability and uncertainties within agricultural systems.
Abstract: Precision agriculture comprises a set of technologies that combines sensors, information systems, enhanced machinery, and informed management to optimize production by accounting for variability and uncertainties within agricultural systems. Adapting production inputs site-specifically within a field and individually for each animal allows better use of resources to maintain the quality of the environment while improving the sustainability of the food supply. Precision agriculture provides a means to monitor the food production chain and manage both the quantity and quality of agricultural produce.

875 citations


Journal ArticleDOI
TL;DR: Results underline the need of genetic screening for all susceptibility factors as part of clinical management of aHUS and for identification of patients who could safely benefit from kidney transplant.
Abstract: Background and objectives: Hemolytic uremic syndrome (HUS) is characterized by microangiopathic hemolytic anemia, thrombocytopenia, and renal impairment. Most childhood cases are caused by Shiga toxin–producing bacteria. The other form, atypical HUS (aHUS), accounts for 10% of cases and has a poor prognosis. Genetic complement abnormalities have been found in aHUS. Design, setting, participants, and measurements: We screened 273 consecutive patients with aHUS for complement abnormalities and studied their role in predicting clinical phenotype and response to treatment. We compared mutation frequencies and localization and clinical outcome in familial (82) and sporadic (191) cases. Results: In >70% of sporadic and familial cases, gene mutations, disease-associated factor H ( CFH ) polymorphisms, or anti-CFH autoantibodies were found. Either mutations or CFH polymorphisms were also found in the majority of patients with secondary aHUS, suggesting a genetic predisposition. Familial cases showed a higher prevalence of mutations in SCR20 of CFH and more severe disease than sporadic cases. Patients with CFH or THBD (thrombomodulin) mutations had the earliest onset and highest mortality. Membrane-cofactor protein ( MCP ) mutations were associated with the best prognosis. Plasma therapy induced remission in 55 to 80% of episodes in patients with CFH , C3, or THBD mutations or autoantibodies, whereas patients with CFI (factor I) mutations were poor responders. aHUS recurred frequently after kidney transplantation except for patients with MCP mutations. Conclusions: Results underline the need of genetic screening for all susceptibility factors as part of clinical management of aHUS and for identification of patients who could safely benefit from kidney transplant.

845 citations


Journal ArticleDOI
TL;DR: It is proposed that two pathological hits, namely nuclear import defects and cellular stress, are involved in the pathogenesis of FUS‐opathies.
Abstract: Mutations in fused in sarcoma (FUS) are a cause of familial amyotrophic lateral sclerosis (fALS). Patients carrying point mutations in the C-terminus of FUS show neuronal cytoplasmic FUS-positive inclusions, whereas in healthy controls, FUS is predominantly nuclear. Cytoplasmic FUS inclusions have also been identified in a subset of frontotemporal lobar degeneration (FTLD-FUS). We show that a non-classical PY nuclear localization signal (NLS) in the C-terminus of FUS is necessary for nuclear import. The majority of fALS-associated mutations occur within the NLS and impair nuclear import to a degree that correlates with the age of disease onset. This presents the first case of disease-causing mutations within a PY-NLS. Nuclear import of FUS is dependent on Transportin, and interference with this transport pathway leads to cytoplasmic redistribution and recruitment of FUS into stress granules. Moreover, proteins known to be stress granule markers co-deposit with inclusions in fALS and FTLD-FUS patients, implicating stress granule formation in the pathogenesis of these diseases. We propose that two pathological hits, namely nuclear import defects and cellular stress, are involved in the pathogenesis of FUS-opathies.

728 citations


Journal ArticleDOI
TL;DR: It is shown that the accumulation in barley and wheat of double-stranded or antisense RNA targeting fungal transcripts affects the development of the powdery mildew fungus Blumeria graminis, and this may lead to an RNAi-based crop protection strategy against fungal pathogens.
Abstract: Powdery mildew fungi are obligate biotrophic pathogens that only grow on living hosts and cause damage in thousands of plant species. Despite their agronomical importance, little direct functional evidence for genes of pathogenicity and virulence is currently available because mutagenesis and transformation protocols are lacking. Here, we show that the accumulation in barley (Hordeum vulgare) and wheat (Triticum aestivum) of double-stranded or antisense RNA targeting fungal transcripts affects the development of the powdery mildew fungus Blumeria graminis. Proof of concept for host-induced gene silencing was obtained by silencing the effector gene Avra10, which resulted in reduced fungal development in the absence, but not in the presence, of the matching resistance gene Mla10. The fungus could be rescued from the silencing of Avra10 by the transient expression of a synthetic gene that was resistant to RNA interference (RNAi) due to silent point mutations. The results suggest traffic of RNA molecules from host plants into B. graminis and may lead to an RNAi-based crop protection strategy against fungal pathogens.

595 citations


Journal ArticleDOI
TL;DR: Measurements of pH, nitrate, and nitrite concentrations after DBD plasma or NO gas treatment lead to the conclusion that nitric acid formation from plasma-generated reactive nitrogen species are the main source of liquid acidification.
Abstract: Water disinfection by indirect plasma treatment was investigated using a surface dielectric barrier discharge (DBD). Liquid was neither part of the discharge electrode configuration nor stirred during plasma treatment. High concentrations (106–108 cfu·mL−1) of Escherichia coli and Staphylococcus aureus have been completely inactivated within 5–15 min, depending on liquid sample volume. Inactivation occurred in non-buffered liquids, only, where pH decrease was found. Measurements of pH, nitrate, and nitrite concentrations after DBD plasma or NO gas treatment lead to the conclusion that nitric acid formation from plasma-generated reactive nitrogen species are the main source of liquid acidification. Incubation of bacteria in nitric acid alone did not result in comparable inactivation effects. Increase of H2O2 concentration was found as a result of plasma treatment of liquids but not after treatment by NO gas. Therefore, synergistic action of both reactive oxygen and nitrogen species are discussed to be responsible for antimicrobial plasma effects.

588 citations


Journal ArticleDOI
TL;DR: In this article, the authors present three conceptual models that address spatial and temporal patterns in temporary-river biodiversity and biogeochemistry, and predict that aggregations of local communities in isolated water bodies of temporary rivers function as metacommunities.
Abstract: SUMMARY 1. Temporary rivers and streams are among the most common and most hydrologically dynamic freshwater ecosystems. The number of temporary rivers and the severity of flow intermittence may be increasing in regions affected by climatic drying trends or water abstraction. Despite their abundance, temporary rivers have been historically neglected by ecologists. A recent increase in temporary-river research needs to be supported by new models that generate hypotheses and stimulate further research. In this article, we present three conceptual models that address spatial and temporal patterns in temporary-river biodiversity and biogeochemistry. 2. Temporary rivers are characterised by the repeated onset and cessation of flow, and by complex hydrological dynamics in the longitudinal dimension. Longitudinal dynamics, such as advancing and retreating wetted fronts, hydrological connections and discon- nections, and gradients in flow permanence, influence biotic communities and nutrient and organic matter processing. 3. The first conceptual model concerns connectivity between habitat patches. Variable connectivity suggests that the metacommunity and metapopulation concepts are applicable in temporary rivers. We predict that aggregations of local communities in the isolated water bodies of temporary rivers function as metacommunities. These metacom- munities may become longitudinally nested due to interspecific differences in dispersal and mortality. The metapopulation concept applies to some temporary river species, but not all. In stable metapopulations, rates of local extinction are balanced by recolonisation. However, extinction and recolonisation in many temporary-river species are decoupled by frequent disturbances, and populations of these species are usually expanding or contracting. 4. The second conceptual model predicts that large-scale biodiversity varies as a function of aquatic and terrestrial patch dynamics and water-level fluctuations. Habitat mosaics in temporary rivers change in composition and configuration in response to inundation and drying, and these changes elicit a range of biotic responses. In the model, aquatic biodiversity initially increases directly with water level due to increasing abundance of aquatic patches. When most of the channel is inundated and most aquatic patches are connected, further increases in aquatic habitat and connectivity cause aquatic biodiversity to decline due to community homogenisation and reduced habitat diversity. The

582 citations


Journal ArticleDOI
TL;DR: A method that is able to identify small molecules from tandem MS measurements, even without spectral reference data or a large set of fragmentation rules is presented.
Abstract: Mass spectrometry has become the analytical method of choice in metabolomics research. The identification of unknown compounds is the main bottleneck. In addition to the precursor mass, tandem MS spectra carry informative fragment peaks, but the coverage of spectral libraries of measured reference compounds are far from covering the complete chemical space. Compound libraries such as PubChem or KEGG describe a larger number of compounds, which can be used to compare their in silico fragmentation with spectra of unknown metabolites. We created the MetFrag suite to obtain a candidate list from compound libraries based on the precursor mass, subsequently ranked by the agreement between measured and in silico fragments. In the evaluation MetFrag was able to rank most of the correct compounds within the top 3 candidates returned by an exact mass query in KEGG. Compared to a previously published study, MetFrag obtained better results than the commercial MassFrontier software. Especially for large compound libraries, the candidates with a good score show a high structural similarity or just different stereochemistry, a subsequent clustering based on chemical distances reduces this redundancy. The in silico fragmentation requires less than a second to process a molecule, and MetFrag performs a search in KEGG or PubChem on average within 30 to 300 seconds, respectively, on an average desktop PC. We presented a method that is able to identify small molecules from tandem MS measurements, even without spectral reference data or a large set of fragmentation rules. With today's massive general purpose compound libraries we obtain dozens of very similar candidates, which still allows a confident estimate of the correct compound class. Our tool MetFrag improves the identification of unknown substances from tandem MS spectra and delivers better results than comparable commercial software. MetFrag is available through a web application, web services and as java library. The web frontend allows the end-user to analyse single spectra and browse the results, whereas the web service and console application are aimed to perform batch searches and evaluation.

577 citations


Journal ArticleDOI
TL;DR: In a recent TREE article, Sutherland and colleagues used horizon scanning to identify fifteen emerging issues in biodiversity conservation, including invasive species, synthetic meat, nanosilver and microplastic pollution, but feel they overlooked an emerging problem of great importance and urgency, namely light pollution.
Abstract: In a recent TREE article, Sutherland and colleagues [1] used horizon scanning to identify fifteen emerging issues in biodiversity conservation. They discussed both threats and opportunities for a broad range of issues, including invasive species, synthetic meat, nanosilver and microplastic pollution. We recognize that the article was not intended to be comprehensive, but feel they overlooked an emerging problem of great importance and urgency, namely that of light pollution. Although the widespread use of artificial light at night has enhanced the quality of human life and is positively associated with security, wealth and modernity, the rapid global increase of artificial light has fundamentally transformed nightscapes over the past six decades, both in quantity (6% increase per year, range: 0–20%) and quality (i.e.

Journal ArticleDOI
TL;DR: In this article, the authors synthesize data on aerosol (particulate matter, PM) physical and chemical characteristics, which were obtained over the past decade in aerosol research and monitoring activities.

Journal ArticleDOI
TL;DR: In this paper, the authors identify study objectives that are consistent with the use of resistance surfaces and critically review the various approaches that have been used to parameterize resist surfaces and select optimal models in landscape genetics.
Abstract: Measures of genetic structure among individuals or populations collected at different spatial locations across a landscape are commonly used as surrogate measures of functional (i.e. demographic or genetic) connectivity. In order to understand how landscape characteristics influence functional connectivity, resistance surfaces are typically created in a raster GIS environment. These resistance surfaces represent hypothesized relationships between landscape features and gene flow, and are based on underlying biological functions such as relative abundance or movement probabilities in different land cover types. The biggest challenge for calculating resistance surfaces is assignment of resistance values to different landscape features. Here, we first identify study objectives that are consistent with the use of resistance surfaces and critically review the various approaches that have been used to parameterize resistance surfaces and select optimal models in landscape genetics. We then discuss the biological assumptions and considerations that influence analyses using resistance surfaces, such as the relationship between gene flow and dispersal, how habitat suitability may influence animal movement, and how resistance surfaces can be translated into estimates of functional landscape connectivity. Finally, we outline novel approaches for creating optimal resistance surfaces using either simulation or computational methods, as well as alternatives to resistance surfaces (e.g. network and buffered paths). These approaches have the potential to improve landscape genetic analyses, but they also create new challenges. We conclude that no single way of using resistance surfaces is appropriate for every situation. We suggest that researchers carefully consider objectives, important biological assumptions and available parameterization and validation techniques when planning landscape genetic studies.

Journal ArticleDOI
TL;DR: An intuitive and rapid procedure for analyzing experimental data by nonlinear least-squares fitting (NLSF) in the most widely used spreadsheet program, using the well-known Michaelis–Menten equation characterizing simple enzyme kinetics.
Abstract: We describe an intuitive and rapid procedure for analyzing experimental data by nonlinear least-squares fitting (NLSF) in the most widely used spreadsheet program. Experimental data in x/y form and data calculated from a regression equation are inputted and plotted in a Microsoft Excel worksheet, and the sum of squared residuals is computed and minimized using the Solver add-in to obtain the set of parameter values that best describes the experimental data. The confidence of best-fit values is then visualized and assessed in a generally applicable and easily comprehensible way. Every user familiar with the most basic functions of Excel will be able to implement this protocol, without previous experience in data fitting or programming and without additional costs for specialist software. The application of this tool is exemplified using the well-known Michaelis-Menten equation characterizing simple enzyme kinetics. Only slight modifications are required to adapt the protocol to virtually any other kind of dataset or regression equation. The entire protocol takes approximately 1 h.

Journal ArticleDOI
TL;DR: This article reviews the fabrication approaches used so far for the creation of micro- and nanostructured fibrillar surfaces with adhesive properties and first responsive systems that allow thermal switching between nonadhesive and adhesive states are described.
Abstract: The amazing adhesion of gecko pads to almost any kind of surfaces has inspired a very active research direction over the last decade: the investigation of how geckos achieve this feat and how this knowledge can be turned into new strategies to reversibly join surfaces. This article reviews the fabrication approaches used so far for the creation of micro- and nanostructured fibrillar surfaces with adhesive properties. In the light of the pertinent contact mechanics, the adhesive properties are presented and discussed. The decisive design parameters are fiber radius and aspect ratio, tilt angle, hierarchical arrangement and the effect of the backing layer. Also first responsive systems that allow thermal switching between nonadhesive and adhesive states are described. These structures show a high potential of application, providing the remaining issues of robustness, reliability, and large-area manufacture can be solved.

Journal ArticleDOI
TL;DR: It is established that NET formation occurs in vivo during host defence against A. fumigatus, but it is suggested that it does not play a major role in killing this fungus and may have a fungistatic effect and may prevent further spreading.
Abstract: Aspergillus fumigatus is the most important airborne fungal pathogen causing life-threatening infections in immunocompromised patients. Macrophages and neutrophils are known to kill conidia, whereas hyphae are killed mainly by neutrophils. Since hyphae are too large to be engulfed, neutrophils possess an array of extracellular killing mechanisms including the formation of neutrophil extracellular traps (NETs) consisting of nuclear DNA decorated with fungicidal proteins. However, until now NET formation in response to A. fumigatus has only been demonstrated in vitro, the importance of neutrophils for their production in vivo is unclear and the molecular mechanisms of the fungus to defend against NET formation are unknown. Here, we show that human neutrophils produce NETs in vitro when encountering A. fumigatus. In time-lapse movies NET production was a highly dynamic process which, however, was only exhibited by a sub-population of cells. NETosis was maximal against hyphae, but reduced against resting and swollen conidia. In a newly developed mouse model we could then demonstrate the existence and measure the kinetics of NET formation in vivo by 2-photon microscopy of Aspergillus-infected lungs. We also observed the enormous dynamics of neutrophils within the lung and their ability to interact with and phagocytose fungal elements in situ. Furthermore, systemic neutrophil depletion in mice almost completely inhibited NET formation in lungs, thus directly linking the immigration of neutrophils with NET formation in vivo. By using fungal mutants and purified proteins we demonstrate that hydrophobin RodA, a surface protein making conidia immunologically inert, led to reduced NET formation of neutrophils encountering Aspergillus fungal elements. NET-dependent killing of Aspergillus-hyphae could be demonstrated at later time-points, but was only moderate. Thus, these data establish that NET formation occurs in vivo during host defence against A. fumigatus, but suggest that it does not play a major role in killing this fungus. Instead, NETs may have a fungistatic effect and may prevent further spreading.

Journal ArticleDOI
TL;DR: An overview on plasma sources for therapeutic applications in plasma medicine and selected specific plasma sources that are used for the investigation of various biological effects are presented and discussed.
Abstract: Plasma-based treatment of chronic wounds or skin diseases as well as tissue engi- neering or tumor treatment is an extremely promising field. First practical studies are prom- ising, and plasma medicine as an independent medical field is emerging worldwide. While during the last years the basics of sterilizing effects of plasmas were well studied, concepts of tailor-made plasma sources which meet the technical requirements of medical instrumen- tation are still less developed. Indeed, studies on the verification of selective antiseptic effects of plasmas are required, but the development of advanced plasma sources for biomedical ap- plications and a profound knowledge of their physics, chemistry, and parameters must be contributed by physical research. Considering atmospheric-pressure plasma sources, the de- termination of discharge development and plasma parameters is a great challenge, due to the high complexity and limited diagnostic approaches. This contribution gives an overview on plasma sources for therapeutic applications in plasma medicine. Selected specific plasma sources that are used for the investigation of various biological effects are presented and dis- cussed. Furthermore, the needs, prospects, and approaches for its characterization from the fundamental plasma physical point of view will be discussed.

Journal ArticleDOI
TL;DR: In this paper, the authors provide spatially explicit information on multiple stressors; a key prerequisite for setting priorities in conservation and management planning, based on the European Catchment Data Base.
Abstract: SUMMARY 1. Riverine floodplains are highly complex, dynamic and diverse ecosystems. At the same time they are among the world’s most threatened ecosystems because of the pervasiveness of dams, levees and other factors such as rapid spreading of non-native species. Hence, floodplains are ideal systems to study ecological impacts of multiple stressors at the local, regional and catchment scale. 2. Concepts such as the subsidy-stress hypothesis and the stress-induced community tolerance concept have been formulated to study the effect of stressors on aquatic and terrestrial ecosystems, as well as on their functional linkages. 3. Riverine floodplains are pulsed ecosystems with distinct flow, sediment, resource and thermal pulses – thereby creating distinct ‘windows of ecological opportunity’. Human modifications that truncate or amplify theses pulses will have cascading effects on river– floodplain interactions by shifting the thresholds of connectivity, resilience or resistance – causing drastic regime shifts. 4. Most aquatic insects and pond-breeding amphibians have complex life cycles with aquatic and terrestrial stages. They are exposed to different stressors in their aquatic and terrestrial realm. Because most life history functions of aquatic insects are restricted to a short terrestrial period, we need to fully integrate the ‘airscape’ into the future management of river–floodplain ecosystems. 5. Riverine floodplains integrate and accumulate multiple stressors at the catchment level, as reflected by distinct catchment fingerprints. Based on the European Catchment Data Base we provide spatially explicit information on multiple stressors; a key prerequisite for setting priorities in conservation and management planning. 6. Thematic implications: the management of stressed river and floodplain ecosystems is a major challenge for the near future and water managers worldwide. Management approaches need to be adaptive and embedded within a catchment-wide concept to cope with upcoming pressures originating from global change.

Journal ArticleDOI
16 Dec 2010-Nature
TL;DR: The PHD-Bromo of TRIM24 provides a structural rationale for chromatin activation through a non-canonical histone signature, establishing a new route by which chromatin readers may influence cancer pathogenesis.
Abstract: Recognition of modified histone species by distinct structural domains within 'reader' proteins plays a critical role in the regulation of gene expression. Readers that simultaneously recognize histones with multiple marks allow transduction of complex chromatin modification patterns into specific biological outcomes. Here we report that chromatin regulator tripartite motif-containing 24 (TRIM24) functions in humans as a reader of dual histone marks by means of tandem plant homeodomain (PHD) and bromodomain (Bromo) regions. The three-dimensional structure of the PHD-Bromo region of TRIM24 revealed a single functional unit for combinatorial recognition of unmodified H3K4 (that is, histone H3 unmodified at lysine 4, H3K4me0) and acetylated H3K23 (histone H3 acetylated at lysine 23, H3K23ac) within the same histone tail. TRIM24 binds chromatin and oestrogen receptor to activate oestrogen-dependent genes associated with cellular proliferation and tumour development. Aberrant expression of TRIM24 negatively correlates with survival of breast cancer patients. The PHD-Bromo of TRIM24 provides a structural rationale for chromatin activation through a non-canonical histone signature, establishing a new route by which chromatin readers may influence cancer pathogenesis.

Journal ArticleDOI
29 Jan 2010-Immunity
TL;DR: Functional reprogramming of unfavorably differentiated Th2 cells may facilitate the establishment of protective immune responses and provide a molecular concept for the long-term coexistence of Th2 and Th1 cell lineage characteristics in single memory T cells.

Journal ArticleDOI
19 Jan 2010-PLOS ONE
TL;DR: Yasuní has outstanding global conservation significance due to its extraordinary biodiversity and potential to sustain this biodiversity in the long term because of its large size and wilderness character, and likelihood of maintaining wet, rainforest conditions while anticipated climate change-induced drought intensifies in the eastern Amazon.
Abstract: The Blue Moon Fund, the Conservation; Food & Health Foundation; the Forrest and Frances Lattner Foundation; The US National Science Foundation (Graduate Research Fellowship Program); Texas State University-Department of Biology; TADPOLE; The US National Science Foundation; the L.S.B. Leakey Foundation; the Wenner-Gren Foundation for Anthropological Research; Primate Conservation, Inc.; US National Science Foundation (DBI-0434875)

Journal ArticleDOI
TL;DR: An improved understanding of the complex mechanisms underlying gluconeogenesis may further improve options to enhance the postpartum health status of dairy cows.
Abstract: Gluconeogenesis is a crucial process to support glucose homeostasis when nutritional supply with glucose is insufficient. Because ingested carbohydrates are efficiently fermented to short-chain fatty acids in the rumen, ruminants are required to meet the largest part of their glucose demand by de novo genesis after weaning. The qualitative difference to nonruminant species is that propionate originating from ruminal metabolism is the major substrate for gluconeogenesis. Disposal of propionate into gluconeogenesis via propionyl-CoA carboxylase, methylmalonyl-CoA mutase, and the cytosolic form of phosphoenolpyruvate carboxykinase (PEPCK) has a high metabolic priority and continues even if glucose is exogenously supplied. Gluconeogenesis is regulated at the transcriptional and several posttranscriptional levels and is under hormonal control (primarily insulin, glucagon, and growth hormone). Transcriptional regulation is relevant for regulating precursor entry into gluconeogenesis (propionate, alanine and other amino acids, lactate, and glycerol). Promoters of the bovine pyruvate carboxylase (PC) and PEPCK genes are directly controlled by metabolic products. The final steps decisive for glucose release (fructose 1,6-bisphosphatase and glucose 6-phosphatase) appear to be highly dependent on posttranscriptional regulation according to actual glucose status. Glucogenic precursor entry, together with hepatic glycogen dynamics, is mostly sufficient to meet the needs for hepatic glucose output except in high-producing dairy cows during the transition from the dry period to peak lactation. Lactating cows adapt to the increased glucose requirement for lactose production by mobilization of endogenous glucogenic substrates and increased hepatic PC expression. If these adaptations fail, lipid metabolism may be altered leading to fatty liver and ketosis. Increasing feed intake and provision of glucogenic precursors from the diet are important to ameliorate these disturbances. An improved understanding of the complex mechanisms underlying gluconeogenesis may further improve our options to enhance the postpartum health status of dairy cows.


Journal ArticleDOI
TL;DR: In this article, a conceptual model of the overall aerosol iron solubility is presented, in which they liken the various controls on iron insolubility to sets of parallel electrical resistors.

Journal ArticleDOI
TL;DR: In this paper, the authors employ a transcriptomic approach to get insight into potential shifts in metabolic activity and symbiotic signalling, and in the defence status of plants exposed to high exogenous phosphate levels.
Abstract: Most terrestrial plants form arbuscular mycorrhiza (AM), mutualistic associations with soil fungi of the order Glomeromycota. The obligate biotrophic fungi trade mineral nutrients, mainly phosphate (P(i) ), for carbohydrates from the plants. Under conditions of high exogenous phosphate supply, when the plant can meet its own P requirements without the fungus, AM are suppressed, an effect which could be interpreted as an active strategy of the plant to limit carbohydrate consumption of the fungus by inhibiting its proliferation in the roots. However, the mechanisms involved in fungal inhibition are poorly understood. Here, we employ a transcriptomic approach to get insight into potential shifts in metabolic activity and symbiotic signalling, and in the defence status of plants exposed to high P(i) levels. We show that in mycorrhizal roots of petunia, a similar set of symbiosis-related genes is expressed as in mycorrhizal roots of Medicago, Lotus and rice. P(i) acts systemically to repress symbiotic gene expression and AM colonization in the root. In established mycorrhizal roots, P(i) repressed symbiotic gene expression rapidly, whereas the inhibition of colonization followed with a lag of more than a week. Taken together, these results suggest that P(i) acts by repressing essential symbiotic genes, in particular genes encoding enzymes of carotenoid and strigolactone biosynthesis, and symbiosis-associated phosphate transporters. The role of these effects in the suppression of symbiosis under high P(i) conditions is discussed.

Journal ArticleDOI
TL;DR: Approaches from seemingly disparate areas are tied together by means of a general definition of SI to unite SI work on both animal and human groups and propose areas in which further progress with SI research can be made.
Abstract: Electronic media have unlocked a hitherto largely untapped potential for swarm intelligence (SI; generally, the realisation that group living can facilitate solving cognitive problems that go beyond the capacity of single animals) in humans with relevance for areas such as company management, prediction of elections, product development and the entertainment industry. SI is a rapidly developing topic that has become a hotbed for both innovative research and wild speculation. Here, we tie together approaches from seemingly disparate areas by means of a general definition of SI to unite SI work on both animal and human groups. Furthermore, we identify criteria that are important for SI to operate and propose areas in which further progress with SI research can be made.

Journal ArticleDOI
TL;DR: The complementary action of all symbiont-produced antibiotics confers a potent antimicrobial defense for the wasp larvae that parallels the 'combination prophylaxis' known from human medicine.
Abstract: Beewolf digger wasps cultivate specific symbiotic bacteria (Streptomyces spp.) that are incorporated into the larval cocoon for protection against pathogens. We identified the molecular basis of this protective symbiosis in the natural context and demonstrate that the bacteria produce a 'cocktail' of nine antibiotic substances. The complementary action of all symbiont-produced antibiotics confers a potent antimicrobial defense for the wasp larvae that parallels the 'combination prophylaxis' known from human medicine.

Journal ArticleDOI
TL;DR: This review provides an overview on the structural diversity, biological activities, biosynthesis and synthesis of cytochalasans (or cy tochalasins) up to the end of 2009.

Journal ArticleDOI
TL;DR: An overview of the recent literature on the effects of grafting on fruit vegetable (Solanaceae and Cucurbitaceae) quality including physical properties, flavor and health-related compounds of the product is given.

Journal ArticleDOI
TL;DR: The multiple effects of GCs on major immune cells, dendritic cells, myeloid cells and B- and T-lymphocytes are reviewed and a summary of studies using conditional GR knockout mice is given.