WorldWideScience

Sample records for model organism aspergillus

  1. An accurate description of Aspergillus niger organic acid batch fermentation through dynamic metabolic modelling.

    Science.gov (United States)

    Upton, Daniel J; McQueen-Mason, Simon J; Wood, A Jamie

    2017-01-01

    Aspergillus niger fermentation has provided the chief source of industrial citric acid for over 50 years. Traditional strain development of this organism was achieved through random mutagenesis, but advances in genomics have enabled the development of genome-scale metabolic modelling that can be used to make predictive improvements in fermentation performance. The parent citric acid-producing strain of A. niger , ATCC 1015, has been described previously by a genome-scale metabolic model that encapsulates its response to ambient pH. Here, we report the development of a novel double optimisation modelling approach that generates time-dependent citric acid fermentation using dynamic flux balance analysis. The output from this model shows a good match with empirical fermentation data. Our studies suggest that citric acid production commences upon a switch to phosphate-limited growth and this is validated by fitting to empirical data, which confirms the diauxic growth behaviour and the role of phosphate storage as polyphosphate. The calibrated time-course model reflects observed metabolic events and generates reliable in silico data for industrially relevant fermentative time series, and for the behaviour of engineered strains suggesting that our approach can be used as a powerful tool for predictive metabolic engineering.

  2. Organic acid production in Aspergillus niger and other filamentous fungi

    NARCIS (Netherlands)

    Odoni, Dorett I.

    2017-01-01

    The aim of the thesis was to increase the understanding of organic acid production in Aspergillus niger and other filamentous fungi, with the ultimate purpose to improve A. niger as biotechnological production host.

    In Chapter 1, the use of microbial

  3. Organic acid production by Aspergillus niger

    DEFF Research Database (Denmark)

    Jongh, Wian de

    2006-01-01

    . Specielt Aspergillus niger er interessant i forbindelse med produktion af organiske syrer, idet denne organisme tolerer lavt pH, kan give høje produktudbytter, og kan give høje produktiviteter som allerede illustreret i anvendelsen af denne organisme i produktionen af citronsyre. Disse faktorer gør A....... niger til en ideel kandidat for metabolic engineering, men anvendelsen af metabolic engineering til at udvikle en A. niger cellefabrik der producerer forskellige organiske syrer har været begrænset af vores kendskab til metabolismen og dens regulering i denne organisme. Formålet med dette Ph.D. stadium...... intracellulære metabolitter samt kontinuert fermentering af A. niger. Ved anvendelse af metabolic engieering lykkedes det at udvikle nogle stammer af A. niger der havde forbedret produktion af citrat. Mekanismerne bag de forbedrede produktiviteter blev undersøgt og resultaterne heraf er diskuteret i afhandlingen...

  4. Uranium leaching using mixed organic acids produced by Aspergillus niger

    International Nuclear Information System (INIS)

    Yong-dong Wang; Guang-yue Li; De-xin Ding; Zhi-xiang Zhou; Qin-wen Deng; Nan Hu; Yan Tan

    2013-01-01

    Both of culture temperature and pH value had impacts on the degree of uranium extraction through changing types and concentrations of mixed organic acids produced by Aspergillus niger, and significant interactions existed between them though pH value played a leading role. And with the change of pH value of mixed organic acids, the types and contents of mixed organic acids changed and impacted on the degree of uranium extraction, especially oxalic acid, citric acid and malic acid. The mean degree of uranium extraction rose to peak when the culture temperature was 25 deg C (76.14 %) and pH value of mixed organic acids was 2.3 (82.40 %) respectively. And the highest one was 83.09 %. The optimal culture temperature (25 deg C) of A. niger for uranium leaching was different from the most appropriate growing temperature (37 deg C). (author)

  5. Profiling of volatile organic compounds produced by clinical Aspergillus isolates using gas chromatography-mass spectrometry

    NARCIS (Netherlands)

    Gerritsen, M G; Brinkman, P; Escobar Salazar, Natalia; Bos, L D; de Heer, K; Meijer, M; Janssen, H-G; de Cock, H; Wösten, H A B; Visser, C.E.; van Oers, M H J; Sterk, P J

    Volatile organic compounds (VOCs) in exhaled breath may identify the presence of invasive pulmonary aspergillosis. We aimed to detect VOC profiles emitted by in vitro cultured, clinical Aspergillus isolates using gas chromatography-mass spectrometry (GC-MS). Three clinical Aspergillus isolates and a

  6. Profiling of volatile organic compounds produced by clinical Aspergillus isolates using gas chromatography-mass spectrometry

    NARCIS (Netherlands)

    Gerritsen, M. G.; Brinkman, P.; Escobar, N.; Bos, L. D.; de Heer, K.; Meijer, M.; Janssen, H.-G.; de Cock, H.; Wösten, H. A. B.; Visser, C. E.; van Oers, M. H. J.; Sterk, P. J.

    2018-01-01

    Volatile organic compounds (VOCs) in exhaled breath may identify the presence of invasive pulmonary aspergillosis. We aimed to detect VOC profiles emitted by in vitro cultured, clinical Aspergillus isolates using gas chromatography-mass spectrometry (GC-MS). Three clinical Aspergillus isolates and a

  7. Antifungal activity of some marine organisms from India, against food spoilage Aspergillus strains

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosale, S.H.; Jagtap, T.G.; Naik, C.G.

    Crude aqueous methanol extracts obtained from 31 species of various marine organisms (including floral and faunal), were screened for their antifungal activity against food poisoning strains of Aspergillus. Seventeen species exhibited mild (+ = zone...

  8. Gene deletion of cytosolic ATP: citrate lyase leads to altered organic acid production in Aspergillus niger

    DEFF Research Database (Denmark)

    Meijer, Susan Lisette; Nielsen, Michael Lynge; Olsson, Lisbeth

    2009-01-01

    With the availability of the genome sequence of the filamentous fungus Aspergillus niger, the use of targeted genetic modifications has become feasible. This, together with the fact that A. niger is well established industrially, makes this fungus an attractive micro-organism for creating a cell...... factory platform for production of chemicals. Using molecular biology techniques, this study focused on metabolic engineering of A. niger to manipulate its organic acid production in the direction of succinic acid. The gene target for complete gene deletion was cytosolic ATP: citrate lyase (acl), which...... the acl gene. Additionally, the total amount of organic acids produced in the deletion strain was significantly increased. Genome-scale stoichiometric metabolic model predictions can be used for identifying gene targets. Deletion of the acl led to increased succinic acid production by A. niger....

  9. Mathematical model of gluconic acid fermentation by Aspergillus niger

    Energy Technology Data Exchange (ETDEWEB)

    Takamatsu, T.; Shioya, S.; Furuya, T.

    1981-11-01

    A mathematical model for the study of gluconic acid fermentation by Aspergillus niger has been developed. The model has been deduced from the basic biological concept of multicellular filamentous microorganisms, i.e. cell population balance. It can be used to explain the behaviour of both batch and continuous cultures, even when in a lag phase. A new characteristic, involving the existence of dual equilibrium stages during fermentation, has been predicted using this mathematical model. (Refs. 6).

  10. Switching from a unicellular to multicellular organization in an Aspergillus niger hypha.

    Science.gov (United States)

    Bleichrodt, Robert-Jan; Hulsman, Marc; Wösten, Han A B; Reinders, Marcel J T

    2015-03-03

    Pores in fungal septa enable cytoplasmic streaming between hyphae and their compartments. Consequently, the mycelium can be considered unicellular. However, we show here that Woronin bodies close ~50% of the three most apical septa of growing hyphae of Aspergillus niger. The incidence of closure of the 9th and 10th septa was even ≥94%. Intercompartmental streaming of photoactivatable green fluorescent protein (PA-GFP) was not observed when the septa were closed, but open septa acted as a barrier, reducing the mobility rate of PA-GFP ~500 times. This mobility rate decreased with increasing septal age and under stress conditions, likely reflecting a regulatory mechanism affecting septal pore diameter. Modeling revealed that such regulation offers effective control of compound concentration between compartments. Modeling also showed that the incidence of septal closure in A. niger had an even stronger impact on cytoplasmic continuity. Cytoplasm of hyphal compartments was shown not to be in physical contact when separated by more than 4 septa. Together, data show that apical compartments of growing hyphae behave unicellularly, while older compartments have a multicellular organization. The hyphae of higher fungi are compartmentalized by porous septa that enable cytosolic streaming. Therefore, it is believed that the mycelium shares cytoplasm. However, it is shown here that the septa of Aspergillus niger are always closed in the oldest part of the hyphae, and therefore, these compartments are physically isolated from each other. In contrast, only part of the septa is closed in the youngest part of the hyphae. Still, compartments in this hyphal part are physically isolated when separated by more than 4 septa. Even open septa act as a barrier for cytoplasmic mixing. The mobility rate through such septa reduces with increasing septal age and under stress conditions. Modeling shows that the septal pore width is set such that its regulation offers maximal control of

  11. Aspergillus: a rare primary organism in soft-tissue infections.

    Science.gov (United States)

    Johnson, M A; Lyle, G; Hanly, M; Yeh, K A

    1998-02-01

    Nonclostridial necrotizing soft-tissue infections are usually polymicrobial, with greater than 90 per cent involving beta-hemolytic streptococci or coagulase-positive staphylococci. The remaining 10 per cent are usually due to Gram-negative enteric pathogens. We describe the case of a 46-year-old woman with bilateral lower extremity fungal soft tissue infections. She underwent multiple surgical debridements of extensive gangrenous necrosis of the skin and subcutaneous fat associated with severe acute arteritis. Histopathological examination revealed Aspergillus niger as the sole initial pathogen. Despite aggressive surgical debridement, allografts, and intravenous amphotericin B, her condition clinically deteriorated and she ultimately died of overwhelming infection. Treatment for soft-tissue infections include surgical debridement and intravenous antibiotics. More specifically, Aspergillus can be treated with intravenous amphotericin B, 5-fluorocytosine, and rifampin. Despite these treatment modalities, necrotizing fascitis is associated with a 60 per cent mortality rate. Primary fungal pathogens should be included in the differential diagnosis of soft-tissue infections.

  12. Linking secondary metabolites to gene clusters through genome sequencing of six diverse Aspergillus species

    DEFF Research Database (Denmark)

    Kjærbølling, Inge; Vesth, Tammi C.; Frisvad, Jens C.

    2018-01-01

    The fungal genus of Aspergillus is highly interesting, containing everything from industrial cell factories, model organisms, and human pathogens. In particular, this group has a prolific production of bioactive secondary metabolites (SMs). In this work, four diverse Aspergillus species (A...

  13. Pharmacodynamics of isavuconazole in an Aspergillus fumigatus mouse infection model

    NARCIS (Netherlands)

    Seyedmousavi, S.; Bruggemann, R.J.; Meis, J.F.G.M.; Melchers, W.J.G.; Verweij, P.E.; Mouton, J.W.

    2015-01-01

    Azole resistance is an emerging problem in Aspergillus fumigatus which translates into treatment failure. Alternative treatments with new azoles may improve therapeutic outcome in invasive aspergillosis (IA) even for strains with decreased susceptibility to current azoles. The in vivo efficacy of

  14. Aspergillus in chronic lung disease: Modeling what goes on in the airways.

    Science.gov (United States)

    Takazono, Takahiro; Sheppard, Donald C

    2017-01-01

    Aspergillus species cause a range of respiratory diseases in humans. While immunocompromised patients are at risk for the development of invasive infection with these opportunistic molds, patients with underlying pulmonary disease can develop chronic airway infection with Aspergillus species. These conditions span a range of inflammatory and allergic diseases including Aspergillus bronchitis, allergic bronchopulmonary aspergillosis, and severe asthma with fungal sensitization. Animal models are invaluable tools for the study of the molecular mechanism underlying the colonization of airways by Aspergillus and the host response to these non-invasive infections. In this review we summarize the state-of-the-art with respect to the available animal models of noninvasive and allergic Aspergillus airway disease; the key findings of host-pathogen interaction studies using these models; and the limitations and future directions that should guide the development and use of models for the study of these important pulmonary conditions. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. Cloning and Genomic Organization of a Rhamnogalacturonase Gene from Locally Isolated Strain of Aspergillus niger.

    Science.gov (United States)

    Damak, Naourez; Abdeljalil, Salma; Taeib, Noomen Hadj; Gargouri, Ali

    2015-08-01

    The rhg gene encoding a rhamnogalacturonase was isolated from the novel strain A1 of Aspergillus niger. It consists of an ORF of 1.505 kb encoding a putative protein of 446 amino acids with a predicted molecular mass of 47 kDa, belonging to the family 28 of glycosyl hydrolases. The nature and position of amino acids comprising the active site as well as the three-dimensional structure were well conserved between the A. niger CTM10548 and fungal rhamnogalacturonases. The coding region of the rhg gene is interrupted by three short introns of 56 (introns 1 and 3) and 52 (intron 2) bp in length. The comparison of the peptide sequence with A. niger rhg sequences revealed that the A1 rhg should be an endo-rhamnogalacturonases, more homologous to rhg A than rhg B A. niger known enzymes. The comparison of rhg nucleotide sequence from A. niger A1 with rhg A from A. niger shows several base changes. Most of these changes (59 %) are located at the third base of codons suggesting maintaining the same enzyme function. We used the rhamnogalacturonase A from Aspergillus aculeatus as a template to build a structural model of rhg A1 that adopted a right-handed parallel β-helix.

  16. Quantifying the importance of galactofuranose in Aspergillus nidulans hyphal wall surface organization by atomic force microscopy.

    Science.gov (United States)

    Paul, Biplab C; El-Ganiny, Amira M; Abbas, Mariam; Kaminskyj, Susan G W; Dahms, Tanya E S

    2011-05-01

    The fungal wall mediates cell-environment interactions. Galactofuranose (Galf), the five-member ring form of galactose, has a relatively low abundance in Aspergillus walls yet is important for fungal growth and fitness. Aspergillus nidulans strains deleted for Galf biosynthesis enzymes UgeA (UDP-glucose-4-epimerase) and UgmA (UDP-galactopyranose mutase) lacked immunolocalizable Galf, had growth and sporulation defects, and had abnormal wall architecture. We used atomic force microscopy and force spectroscopy to image and quantify cell wall viscoelasticity and surface adhesion of ugeAΔ and ugmAΔ strains. We compared the results for ugeAΔ and ugmAΔ strains with the results for a wild-type strain (AAE1) and the ugeB deletion strain, which has wild-type growth and sporulation. Our results suggest that UgeA and UgmA are important for cell wall surface subunit organization and wall viscoelasticity. The ugeAΔ and ugmAΔ strains had significantly larger surface subunits and lower cell wall viscoelastic moduli than those of AAE1 or ugeBΔ hyphae. Double deletion strains (ugeAΔ ugeBΔ and ugeAΔ ugmAΔ) had more-disorganized surface subunits than single deletion strains. Changes in wall surface structure correlated with changes in its viscoelastic modulus for both fixed and living hyphae. Wild-type walls had the largest viscoelastic modulus, while the walls of the double deletion strains had the smallest. The ugmAΔ strain and particularly the ugeAΔ ugmAΔ double deletion strain were more adhesive to hydrophilic surfaces than the wild type, consistent with changes in wall viscoelasticity and surface organization. We propose that Galf is necessary for full maturation of A. nidulans walls during hyphal extension.

  17. Antifungal Activity of Culture Filtrates and Organic Extracts of Aspergillus spp. against Pythium ultimum

    OpenAIRE

    Rania Aydi-Ben Abdallah; Marwa Hassine; Hayfa Jabnoun-Khiareddine; Rabiaa Haouala; Mejda Daami-Remadi

    2014-01-01

    Culture filtrates, chloroform and ethyl acetate extracts of nine isolates of Aspergillus spp. (A. niger, A. terreus, A. flavus and Aspergillus sp.), isolated from soil and compost, were tested for antifungal activity against Pythium ultimum the causal agent of the potato Pythium leak. Culture filtrates showed a significant antifungal activity at the different tested concentrations. Total inhibition of the pathogen was induced by the filtrate of CH8 of Aspergillus sp., used at 10% ...

  18. Aspergillus infection monitored by multimodal imaging in a rat model.

    Science.gov (United States)

    Pluhacek, Tomas; Petrik, Milos; Luptakova, Dominika; Benada, Oldrich; Palyzova, Andrea; Lemr, Karel; Havlicek, Vladimir

    2016-06-01

    Although myriads of experimental approaches have been published in the field of fungal infection diagnostics, interestingly, in 21st century there is no satisfactory early noninvasive tool for Aspergillus diagnostics with good sensitivity and specificity. In this work, we for the first time described the fungal burden in rat lungs by multimodal imaging approach. The Aspergillus infection was monitored by positron emission tomography and light microscopy employing modified Grocott's methenamine silver staining and eosin counterstaining. Laser ablation inductively coupled plasma mass spectrometry imaging has revealed a dramatic iron increase in fungi-affected areas, which can be presumably attributed to microbial siderophores. Quantitative elemental data were inferred from matrix-matched standards prepared from rat lungs. The iron, silver, and gold MS images collected with variable laser foci revealed that particularly silver or gold can be used as excellent elements useful for sensitively tracking the Aspergillus infection. The limit of detection was determined for both (107) Ag and (197) Au as 0.03 μg/g (5 μm laser focus). The selective incorporation of (107) Ag and (197) Au into fungal cell bodies and low background noise from both elements were confirmed by energy dispersive X-ray scattering utilizing the submicron lateral resolving power of scanning electron microscopy. The low limits of detection and quantitation of both gold and silver make ICP-MS imaging monitoring a viable alternative to standard optical evaluation used in current clinical settings. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Exploiting proteomic data for genome annotation and gene model validation in Aspergillus niger

    OpenAIRE

    Wright, James C.; Sugden, Deana; Francis-McIntyre, Sue; Riba Garcia, Isabel; Gaskell, Simon J.; Grigoriev, Igor V.; Baker, Scott E.; Beynon, Robert J.; Hubbard, Simon J.

    2009-01-01

    Abstract Background Proteomic data is a potentially rich, but arguably unexploited, data source for genome annotation. Peptide identifications from tandem mass spectrometry provide prima facie evidence for gene predictions and can discriminate over a set of candidate gene models. Here we apply this to the recently sequenced Aspergillus niger fungal genome from the Joint Genome Institutes (JGI) and another predicted protein set from another A.niger sequence. Tandem mass spectra (MS/MS) were ac...

  20. The effect of cocoa fermentation and weak organic acids on growth and ochratoxin A production by Aspergillus species

    DEFF Research Database (Denmark)

    Copetti, Marina V.; Iamanaka, Beatriz T.; Mororó, Raimundo C.

    2012-01-01

    The acidic characteristics of cocoa beans have influence on flavor development in chocolate. Cocoa cotyledons are not naturally acidic, the acidity comes from organic acids produced by the fermentative microorganisms which grow during the processing of cocoa. Different concentrations of these met...... by Aspergillus carbonarius in cocoa, and the effect of weak organic acids such as acetic, lactic and citric at different pH values on growth and ochratoxin A production by A. carbonarius and Aspergillus niger in culture media. A statistical difference (ρ......The acidic characteristics of cocoa beans have influence on flavor development in chocolate. Cocoa cotyledons are not naturally acidic, the acidity comes from organic acids produced by the fermentative microorganisms which grow during the processing of cocoa. Different concentrations...... of these metabolites can be produced according to the fermentation practices adopted in the farms, which could affect the growth and ochratoxin A production by fungi. This work presents two independent experiments carried out to investigate the effect of some fermentation practices on ochratoxin A production...

  1. Proteomics of eukaryotic microorganisms: The medically and biotechnologically important fungal genus Aspergillus.

    Science.gov (United States)

    Kniemeyer, Olaf

    2011-08-01

    Fungal species of the genus Aspergillus play significant roles as model organisms in basic research, as "cell factories" for the production of organic acids, pharmaceuticals or industrially important enzymes and as pathogens causing superficial and invasive infections in animals and humans. The release of the genome sequences of several Aspergillus sp. has paved the way for global analyses of protein expression in Aspergilli including the characterisation of proteins, which have not designated any function. With the application of proteomic methods, particularly 2-D gel and LC-MS/MS-based methods, first insights into the composition of the proteome of Aspergilli under different growth and stress conditions could be gained. Putative targets of global regulators led to the improvement of industrially relevant Aspergillus strains and so far not described Aspergillus antigens have already been discovered. Here, I review the recent proteome data generated for the species Aspergillus nidulans, Aspergillus fumigatus, Aspergillus niger, Aspergillus terreus, Aspergillus flavus and Aspergillus oryzae. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Bimolecular Rate Constants for FAD-Dependent Glucose Dehydrogenase from Aspergillus terreus and Organic Electron Acceptors.

    Science.gov (United States)

    Tsuruoka, Nozomu; Sadakane, Takuya; Hayashi, Rika; Tsujimura, Seiya

    2017-03-10

    The flavin adenine dinucleotide-dependent glucose dehydrogenase (FAD-GDH) from Aspergillus species require suitable redox mediators to transfer electrons from the enzyme to the electrode surface for the application of bioelectrical devices. Although several mediators for FAD-GDH are already in use, they are still far from optimum in view of potential, kinetics, sustainability, and cost-effectiveness. Herein, we investigated the efficiency of various phenothiazines and quinones in the electrochemical oxidation of FAD-GDH from Aspergillus terreus . At pH 7.0, the logarithm of the bimolecular oxidation rate constants appeared to depend on the redox potentials of all the mediators tested. Notably, the rate constant of each molecule for FAD-GDH was approximately 2.5 orders of magnitude higher than that for glucose oxidase from Aspergillus sp. The results suggest that the electron transfer kinetics is mainly determined by the formal potential of the mediator, the driving force of electron transfer, and the electron transfer distance between the redox active site of the mediator and the FAD, affected by the steric or chemical interactions. Higher k ₂ values were found for ortho-quinones than for para-quinones in the reactions with FAD-GDH and glucose oxidase, which was likely due to less steric hindrance in the active site in the case of the ortho-quinones.

  3. Bimolecular Rate Constants for FAD-Dependent Glucose Dehydrogenase from Aspergillus terreus and Organic Electron Acceptors

    Directory of Open Access Journals (Sweden)

    Nozomu Tsuruoka

    2017-03-01

    Full Text Available The flavin adenine dinucleotide-dependent glucose dehydrogenase (FAD-GDH from Aspergillus species require suitable redox mediators to transfer electrons from the enzyme to the electrode surface for the application of bioelectrical devices. Although several mediators for FAD-GDH are already in use, they are still far from optimum in view of potential, kinetics, sustainability, and cost-effectiveness. Herein, we investigated the efficiency of various phenothiazines and quinones in the electrochemical oxidation of FAD-GDH from Aspergillus terreus. At pH 7.0, the logarithm of the bimolecular oxidation rate constants appeared to depend on the redox potentials of all the mediators tested. Notably, the rate constant of each molecule for FAD-GDH was approximately 2.5 orders of magnitude higher than that for glucose oxidase from Aspergillus sp. The results suggest that the electron transfer kinetics is mainly determined by the formal potential of the mediator, the driving force of electron transfer, and the electron transfer distance between the redox active site of the mediator and the FAD, affected by the steric or chemical interactions. Higher k2 values were found for ortho-quinones than for para-quinones in the reactions with FAD-GDH and glucose oxidase, which was likely due to less steric hindrance in the active site in the case of the ortho-quinones.

  4. Aspergillus: introduction

    Science.gov (United States)

    Species in the genus Aspergillus possess versatile metabolic activities that impact our daily life both positively and negatively. Aspergillus flavus and Aspergillus oryzae are closely related fungi. While the former is able to produce carcinogenic aflatoxins and is an etiological agent of aspergill...

  5. Aspergillus infection monitored by multimodal imaging in a rat model

    Czech Academy of Sciences Publication Activity Database

    Pluháček, Tomáš; Petrík, M.; Luptáková, Dominika; Benada, Oldřich; Palyzová, Andrea; Lemr, Karel; Havlíček, Vladimír

    2016-01-01

    Roč. 16, 11-12 (2016), s. 1785-1792 ISSN 1615-9853 R&D Projects: GA MŠk LO1509; GA ČR GAP206/12/1150 Institutional support: RVO:61388971 Keywords : Animal model * Aspergillosis * Biomedicine Subject RIV: CE - Biochemistry Impact factor: 4.041, year: 2016

  6. Improved annotation through genome-scale metabolic modeling of Aspergillus oryzae

    DEFF Research Database (Denmark)

    Vongsangnak, Wanwipa; Olsen, Peter; Hansen, Kim

    2008-01-01

    Background: Since ancient times the filamentous fungus Aspergillus oryzae has been used in the fermentation industry for the production of fermented sauces and the production of industrial enzymes. Recently, the genome sequence of A. oryzae with 12,074 annotated genes was released but the number...... to a genome scale metabolic model of A. oryzae. Results: Our assembled EST sequences we identified 1,046 newly predicted genes in the A. oryzae genome. Furthermore, it was possible to assign putative protein functions to 398 of the newly predicted genes. Noteworthy, our annotation strategy resulted...... model was validated and shown to correctly describe the phenotypic behavior of A. oryzae grown on different carbon sources. Conclusion: A much enhanced annotation of the A. oryzae genome was performed and a genomescale metabolic model of A. oryzae was reconstructed. The model accurately predicted...

  7. Elevated Serum Beta-D-Glucan with Pseudomonas, Aspergillus, and a Partially Acid-Fast Organism in Respiratory Cultures: A Case of Hickam's Dictum Over Occam's Razor.

    Science.gov (United States)

    Khan, Salman; Hamula, Camille; Rana, Meenakshi; Sullivan, Timothy; Dunn, Dallas; Patel, Pinki; Mishkin, Aaron; Huprikar, Shirish

    2017-10-01

    We describe a case of a man with ectopic Cushing's syndrome, elevated serum beta-D-glucan, and respiratory cultures with Pseudomonas, Aspergillus, and a partially acid-fast organism. Our case highlights challenges in diagnosis and management of coinfection in an immunocompromised host.

  8. The Cell Wall of the Human Fungal Pathogen Aspergillus fumigatus: Biosynthesis, Organization, Immune Response, and Virulence.

    Science.gov (United States)

    Latgé, Jean-Paul; Beauvais, Anne; Chamilos, Georgios

    2017-09-08

    More than 90% of the cell wall of the filamentous fungus Aspergillus fumigatus comprises polysaccharides. Biosynthesis of the cell wall polysaccharides is under the control of three types of enzymes: transmembrane synthases, which are anchored to the plasma membrane and use nucleotide sugars as substrates, and cell wall-associated transglycosidases and glycosyl hydrolases, which are responsible for remodeling the de novo synthesized polysaccharides and establishing the three-dimensional structure of the cell wall. For years, the cell wall was considered an inert exoskeleton of the fungal cell. The cell wall is now recognized as a living organelle, since the composition and cellular localization of the different constitutive cell wall components (especially of the outer layers) vary when the fungus senses changes in the external environment. The cell wall plays a major role during infection. The recognition of the fungal cell wall by the host is essential in the initiation of the immune response. The interactions between the different pattern-recognition receptors (PRRs) and cell wall pathogen-associated molecular patterns (PAMPs) orientate the host response toward either fungal death or growth, which would then lead to disease development. Understanding the molecular determinants of the interplay between the cell wall and host immunity is fundamental to combatting Aspergillus diseases.

  9. Modeling enzyme production with Aspergillus oryzae in pilot scale vessels with different agitation, aeration, and agitator types

    DEFF Research Database (Denmark)

    Albæk, Mads Orla; Gernaey, Krist; Hansen, Morten S.

    2011-01-01

    The purpose of this article is to demonstrate how a model can be constructed such that the progress of a submerged fed‐batch fermentation of a filamentous fungus can be predicted with acceptable accuracy. The studied process was enzyme production with Aspergillus oryzae in 550 L pilot plant stirred...

  10. Identification of a Transcription Factor Controlling pH-Dependent Organic Acid Response in Aspergillus niger

    DEFF Research Database (Denmark)

    Poulsen, Lars; Andersen, Mikael Rørdam; Lantz, Anna Eliasson

    2012-01-01

    exhibiting an oxalate overproducing phenotype were identified. The yield of oxalate was increased up to 158% compared to the wild type and the corresponding transcription factor was therefore entitled Oxalic Acid repression Factor, OafA. Detailed physiological characterization of one of the ΔoafA mutants......, compared to the wild type, showed that both strains produced substantial amounts of gluconic acid, but the mutant strain was more efficient in re-uptake of gluconic acid and converting it to oxalic acid, particularly at high pH (pH 5.0). Transcriptional profiles showed that 241 genes were differentially......Acid formation in Aspergillus niger is known to be subjected to tight regulation, and the acid production profiles are fine-tuned to respond to the ambient pH. Based on transcriptome data, putative trans-acting pH responding transcription factors were listed and through knock out studies, mutants...

  11. Effects of inclusion Aspergillus niger fermented shrimp waste meal in broiler diets on live performance and digestive organ weight

    Directory of Open Access Journals (Sweden)

    Irfan H. Djunaidi

    2009-06-01

    Full Text Available An experiment was conducted to evaluate the effect of the inclusion of different levels of shrimp waste meal fermented with Aspergillus niger (LUF in diets on growth performance and digestive organ weight of broilers. A total of 75 d-old chicks were randomly allocated to 5 (five treatments in 3 replication pens of 5 birds each. Treatments consisted of LUF inclusion of 0 (control, and 5, 7.5, 10 and 12,5% (P0, P1, P2, P3 and P4 in the diets. Birds were raised under standard condition and provided with feed and water ad-libitum. Feed and birds were weighed weekly up to 35 days to determine body weight, feed intake and feed conversion. At the end of experimental period, the birds were slaughatered and dressed up to determine carcass percentage and digestive organ weight. There was a significant negative linear response in body weight, feed consumption and feed conversion with increase of LUF more than 7.5% in the diets until 35 days of age, but % carcass was almost the same for all treatment. There was no significant response in digestive organ weight with increasing levels of LUF. The present result indicated that LUF could be considered as a potential feed ingredient as protein source of broiler but its inclusion should be limited until 7.5% of the diet to maintain growth performance and digestive organ weight.

  12. Advances in citric acid fermentation by Aspergillus niger: biochemical aspects, membrane transport and modeling.

    Science.gov (United States)

    Papagianni, Maria

    2007-01-01

    Citric acid is regarded as a metabolite of energy metabolism, of which the concentration will rise to appreciable amounts only under conditions of substantive metabolic imbalances. Citric acid fermentation conditions were established during the 1930s and 1940s, when the effects of various medium components were evaluated. The biochemical mechanism by which Aspergillus niger accumulates citric acid has continued to attract interest even though its commercial production by fermentation has been established for decades. Although extensive basic biochemical research has been carried out with A. niger, the understanding of the events relevant for citric acid accumulation is not completely understood. This review is focused on citric acid fermentation by A. niger. Emphasis is given to aspects of fermentation biochemistry, membrane transport in A. niger and modeling of the production process.

  13. A study of organic acid production in contrasts between two phosphate solubilizing fungi: Penicillium oxalicum and Aspergillus niger

    Science.gov (United States)

    Li, Zhen; Bai, Tongshuo; Dai, Letian; Wang, Fuwei; Tao, Jinjin; Meng, Shiting; Hu, Yunxiao; Wang, Shimei; Hu, Shuijin

    2016-04-01

    Phosphate solubilizing fungi (PSF) have huge potentials in enhancing release of phosphorus from fertilizer. Two PSF (NJDL-03 and NJDL-12) were isolated and identified as Penicillium oxalicum and Aspergillus niger respectively in this study. The quantification and identification of organic acids were performed by HPLC. Total concentrations of organic acids secreted by NJDL-03 and NJDL-12 are ~4000 and ~10,000 mg/L with pH values of 3.6 and 2.4 respectively after five-days culture. Oxalic acid dominates acidity in the medium due to its high concentration and high acidity constant. The two fungi were also cultured for five days with the initial pH values of the medium varied from 6.5 to 1.5. The biomass reached the maximum when the initial pH values are 4.5 for NJDL-03 and 2.5 for NJDL-12. The organic acids for NJDL-12 reach the maximum at the initial pH = 5.5. However, the acids by NJDL-03 continue to decrease and proliferation of the fungus terminates at pH = 2.5. The citric acid production increases significantly for NJDL-12 at acidic environment, whereas formic and oxalic acids decrease sharply for both two fungi. This study shows that NJDL-12 has higher ability in acid production and has stronger adaptability to acidic environment than NJDL-03.

  14. Exploiting proteomic data for genome annotation and gene model validation in Aspergillus niger.

    Science.gov (United States)

    Wright, James C; Sugden, Deana; Francis-McIntyre, Sue; Riba-Garcia, Isabel; Gaskell, Simon J; Grigoriev, Igor V; Baker, Scott E; Beynon, Robert J; Hubbard, Simon J

    2009-02-04

    Proteomic data is a potentially rich, but arguably unexploited, data source for genome annotation. Peptide identifications from tandem mass spectrometry provide prima facie evidence for gene predictions and can discriminate over a set of candidate gene models. Here we apply this to the recently sequenced Aspergillus niger fungal genome from the Joint Genome Institutes (JGI) and another predicted protein set from another A.niger sequence. Tandem mass spectra (MS/MS) were acquired from 1d gel electrophoresis bands and searched against all available gene models using Average Peptide Scoring (APS) and reverse database searching to produce confident identifications at an acceptable false discovery rate (FDR). 405 identified peptide sequences were mapped to 214 different A.niger genomic loci to which 4093 predicted gene models clustered, 2872 of which contained the mapped peptides. Interestingly, 13 (6%) of these loci either had no preferred predicted gene model or the genome annotators' chosen "best" model for that genomic locus was not found to be the most parsimonious match to the identified peptides. The peptides identified also boosted confidence in predicted gene structures spanning 54 introns from different gene models. This work highlights the potential of integrating experimental proteomics data into genomic annotation pipelines much as expressed sequence tag (EST) data has been. A comparison of the published genome from another strain of A.niger sequenced by DSM showed that a number of the gene models or proteins with proteomics evidence did not occur in both genomes, further highlighting the utility of the method.

  15. Mycotoxin production and predictive modelling kinetics on the growth of Aspergillus flavus and Aspergillus parasiticus isolates in whole black peppercorns (Piper nigrum L).

    Science.gov (United States)

    Yogendrarajah, Pratheeba; Vermeulen, An; Jacxsens, Liesbeth; Mavromichali, Evangelia; De Saeger, Sarah; De Meulenaer, Bruno; Devlieghere, Frank

    2016-07-02

    The growth and mycotoxin production of three Aspergillus flavus isolates and an Aspergillus parasiticus isolate were studied in whole black peppercorns (Piper nigrum L.) using a full factorial design with seven water activity (aw) (0.826-0.984) levels and three temperatures (22, 30 and 37°C). Growth rates and lag phases were estimated using linear regression. Diverse secondary models were assessed for their ability to describe the radial growth rate as a function of individual and combined effect of aw and temperature. Optimum radial growth rate ranged from 0.75±0.04 to 2.65±0.02mm/day for A. flavus and 1.77±0.10 to 2.50±0.10mm/day for A. parasiticus based on the Rosso cardinal estimations. Despite the growth failure of some isolates at marginal conditions, all the studied models showed good performance to predict the growth rates. Validation of the models was performed on independently derived data. The bias factors (0.73-1.03), accuracy factors (0.97-1.36) and root mean square error (0.050-0.278) show that the examined models are conservative predictors of the colony growth rate of both fungal species in black peppers. The Rosso cardinal model can be recommended to describe the individual aw effect while the extended Gibson model was the best model for describing the combined effect of aw and temperature on the growth rate of both fungal species in peppercorns. Temperature optimum ranged from 30 to 33°C, while aw optimum was 0.87-0.92 as estimated by multi-factorial cardinal model for both species. The estimated minimum temperature and aw for A. flavus and A. parasiticus for growth were 11-16°C and 0.73-0.76, respectively, hence, achieving these conditions should be considered during storage to prevent the growth of these mycotoxigenic fungal species in black peppercorns. Following the growth study, production of mycotoxins (aflatoxins B1, B2, G1, G2, sterigmatocystin and O-methyl sterigmatocystin (OMST)) was quantified using LC-MS/MS. Very small

  16. Identification of a transcription factor controlling pH-dependent organic acid response in Aspergillus niger.

    Directory of Open Access Journals (Sweden)

    Lars Poulsen

    Full Text Available Acid formation in Aspergillus niger is known to be subjected to tight regulation, and the acid production profiles are fine-tuned to respond to the ambient pH. Based on transcriptome data, putative trans-acting pH responding transcription factors were listed and through knock out studies, mutants exhibiting an oxalate overproducing phenotype were identified. The yield of oxalate was increased up to 158% compared to the wild type and the corresponding transcription factor was therefore entitled Oxalic Acid repression Factor, OafA. Detailed physiological characterization of one of the ΔoafA mutants, compared to the wild type, showed that both strains produced substantial amounts of gluconic acid, but the mutant strain was more efficient in re-uptake of gluconic acid and converting it to oxalic acid, particularly at high pH (pH 5.0. Transcriptional profiles showed that 241 genes were differentially expressed due to the deletion of oafA and this supported the argument of OafA being a trans-acting transcription factor. Furthermore, expression of two phosphoketolases was down-regulated in the ΔoafA mutant, one of which has not previously been described in fungi. It was argued that the observed oxalate overproducing phenotype was a consequence of the efficient re-uptake of gluconic acid and thereby a higher flux through glycolysis. This results in a lower flux through the pentose phosphate pathway, demonstrated by the down-regulation of the phosphoketolases. Finally, the physiological data, in terms of the specific oxygen consumption, indicated a connection between the oxidative phosphorylation and oxalate production and this was further substantiated through transcription analysis.

  17. Exploiting proteomic data for genome annotation and gene model validation in Aspergillus niger

    Directory of Open Access Journals (Sweden)

    Grigoriev Igor V

    2009-02-01

    Full Text Available Abstract Background Proteomic data is a potentially rich, but arguably unexploited, data source for genome annotation. Peptide identifications from tandem mass spectrometry provide prima facie evidence for gene predictions and can discriminate over a set of candidate gene models. Here we apply this to the recently sequenced Aspergillus niger fungal genome from the Joint Genome Institutes (JGI and another predicted protein set from another A.niger sequence. Tandem mass spectra (MS/MS were acquired from 1d gel electrophoresis bands and searched against all available gene models using Average Peptide Scoring (APS and reverse database searching to produce confident identifications at an acceptable false discovery rate (FDR. Results 405 identified peptide sequences were mapped to 214 different A.niger genomic loci to which 4093 predicted gene models clustered, 2872 of which contained the mapped peptides. Interestingly, 13 (6% of these loci either had no preferred predicted gene model or the genome annotators' chosen "best" model for that genomic locus was not found to be the most parsimonious match to the identified peptides. The peptides identified also boosted confidence in predicted gene structures spanning 54 introns from different gene models. Conclusion This work highlights the potential of integrating experimental proteomics data into genomic annotation pipelines much as expressed sequence tag (EST data has been. A comparison of the published genome from another strain of A.niger sequenced by DSM showed that a number of the gene models or proteins with proteomics evidence did not occur in both genomes, further highlighting the utility of the method.

  18. Comprehensive reconstruction and in silico analysis of Aspergillus niger genome-scale metabolic network model that accounts for 1210 ORFs.

    Science.gov (United States)

    Lu, Hongzhong; Cao, Weiqiang; Ouyang, Liming; Xia, Jianye; Huang, Mingzhi; Chu, Ju; Zhuang, Yingping; Zhang, Siliang; Noorman, Henk

    2017-03-01

    Aspergillus niger is one of the most important cell factories for industrial enzymes and organic acids production. A comprehensive genome-scale metabolic network model (GSMM) with high quality is crucial for efficient strain improvement and process optimization. The lack of accurate reaction equations and gene-protein-reaction associations (GPRs) in the current best model of A. niger named GSMM iMA871, however, limits its application scope. To overcome these limitations, we updated the A. niger GSMM by combining the latest genome annotation and literature mining technology. Compared with iMA871, the number of reactions in iHL1210 was increased from 1,380 to 1,764, and the number of unique ORFs from 871 to 1,210. With the aid of our transcriptomics analysis, the existence of 63% ORFs and 68% reactions in iHL1210 can be verified when glucose was used as the only carbon source. Physiological data from chemostat cultivations, 13 C-labeled and molecular experiments from the published literature were further used to check the performance of iHL1210. The average correlation coefficients between the predicted fluxes and estimated fluxes from 13 C-labeling data were sufficiently high (above 0.89) and the prediction of cell growth on most of the reported carbon and nitrogen sources was consistent. Using the updated genome-scale model, we evaluated gene essentiality on synthetic and yeast extract medium, as well as the effects of NADPH supply on glucoamylase production in A. niger. In summary, the new A. niger GSMM iHL1210 contains significant improvements with respect to the metabolic coverage and prediction performance, which paves the way for systematic metabolic engineering of A. niger. Biotechnol. Bioeng. 2017;114: 685-695. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  19. Aspergillus contaminans

    Science.gov (United States)

    Aspergillus contaminans is described as a new species from the fingernail of a patient with an infected nail. Phylogenetic analysis of four loci (ITS, calmodulin, beta tubulin and RNA polymerase beta, second largest subunit) showed that this species is most closely related to A. carlsbadensis from A...

  20. ASPERGILLUS NIGER ASPERGILLUS NIGER

    African Journals Online (AJOL)

    eobe

    ABSTRACT. Additives such as low molecular weight alcohols, trace metals, phytate, lipids etc have been reported to stimulate ... The results of analysis of variance (ANOVA) carried out on the model showed that .... the data points all clustered around the 45o diagonal .... C.O. “Dynamic modelling and simulation of citric acid.

  1. Growth and product formation of Aspergillus oryzae during submerged cultivations: Verification of a morphologically structured model using fluorescent probes

    DEFF Research Database (Denmark)

    Agger, Teit; Spohr, Anders Bendsen; Carlsen, Morten

    1998-01-01

    of Aspergillus oryzae. The model is based on a division of the fungal hyphae into three different regions: an extension zone, representing the tips of the hyphae; an active region, which is responsible for growth and product formation; and an inactive hyphal region. Two metamorphosis reactions describing...... and automated image analysis, has been developed for measuring the fraction of active cells. The method employs the fluorescent dye 3,3'-dihexyloxocarbocyanin to stain organelles inside the hyphae and Calcoflour White to stain the cell wall. The ratio between the projected areas of the organelles...

  2. Biosorption of Cu (II onto chemically modified waste mycelium of Aspergillus awamori: Equilibrium, kinetics and modeling studies

    Directory of Open Access Journals (Sweden)

    ZDRAVKA VELKOVA

    2012-01-01

    Full Text Available The biosorption potential of chemically modified waste mycelium of industrial xylanase-producing strain Aspergillus awamori for Cu (II removal from aqueous solutions was evaluated. The influence of pH, contact time and initial Cu (II concentration on the removal efficiency was evaluated. Maximum biosorption capacity was reached by sodium hydroxide treated waste fungal mycelium at pH 5.0. The Langmuir adsorption equation matched very well the adsorption equilibrium data in the studied conditions. The process kinetic followed the pseudo-firs order model.

  3. Expression of the protein serum amyloid A in response to Aspergillus fumigatus in murine models of allergic airway inflammation.

    Science.gov (United States)

    Moran, Gabriel; Carcamo, Carolina; Concha, Margarita; Folch, Hugo

    2015-01-01

    Serum amyloid A (SAA) is an acute phase protein that is elevated in blood during inflammation. The role of this protein in allergic diseases of airways remains unclear. The objective of this study was to evaluate the SAA in blood, lung and bronchial cells in a murine model of bronchial hypersensitivity to Aspergillus fumigatus. To achieve this purpose, different groups of 5-month-old mice were housed in cages containing hay bedding that was contaminated with A. fumigatus and were kept in an isolation room for 16 days to allow for the induction of allergic airway inflammation. Subsequently, the mice were then exposed once again to Aspergillus spores at 0, 2, 8, 24 and 72 h, and they were bled to acquire serum and sacrificed to obtain bronchoalveolar lavage fluid (BALF) or lung tissues for analysis. SAA levels were measured in lung, serum and BALF by dot blot assay and RT-PCR (reverse transcription polymerase chain reaction). The results indicated that SAA protein levels increased in both serum and lung within 2-24h after mice were exposed to Aspergillus spores. Moreover, the SAA mRNA expression levels in the lungs and BALF cells demonstrated the same trend that was observed for the protein levels through the dot blot assay; in particular, SAA mRNA levels increased within the first hour after mice were exposed to A. fumigatus. In this allergic airway model, we conclude that A. fumigatus can induce an acute inflammatory response in the airways through the stimulation of the SAA protein, increasing its levels in serum, lung tissue and BALF samples during the early hours of exposure of mice that have been sensitised for this fungus. Copyright © 2012 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  4. Modelling growth of Penicillium expansum and Aspergillus niger at constant and fluctuating temperature conditions.

    Science.gov (United States)

    Gougouli, Maria; Koutsoumanis, Konstantinos P

    2010-06-15

    The growth of Penicillium expansum and Aspergillus niger, isolated from yogurt production environment, was investigated on malt extract agar with pH=4.2 and a(w)=0.997, simulating yogurt, at isothermal conditions ranging from -1.3 to 35 degrees C and from 5 to 42.3 degrees C, respectively. The growth rate (mu) and (apparent) lag time (lambda) of the mycelium growth were modelled as a function of temperature using a Cardinal Model with Inflection (CMI). The results showed that the CMI can describe successfully the effect of temperature on fungal growth within the entire biokinetic range for both isolates. The estimated values of the CMI for mu were T(min)=-5.74 degrees C, T(max)=30.97 degrees C, T(opt)=22.08 degrees C and mu(opt)=0.221 mm/h for P. expansum and T(min)=10.13 degrees C, T(max)=43.13 degrees C, T(opt)=31.44 degrees C, and mu(opt)=0.840 mm/h for A. niger. The cardinal values for lambda were very close to the respective values for mu indicating similar temperature dependence of the growth rate and the lag time of the mycelium growth. The developed models were further validated under fluctuating temperature conditions using various dynamic temperature scenarios. The time-temperature conditions studied included single temperature shifts before or after the end of the lag time and continuous periodic temperature fluctuations. The prediction of growth at changing temperature was based on the assumption that after a temperature shift the growth rate is adopted instantaneously to the new temperature, while the lag time was predicted using a cumulative lag approach. The results showed that when the temperature shifts occurred before the end of the lag, they did not cause any significant additional lag and the observed total lag was very close to the cumulative lag predicted by the model. In experiments with temperature shifts after the end of the lag time, accurate predictions were obtained when the temperature profile included temperatures which were inside the

  5. Assessment of Aspergillus niger biofilm growth kinetics in ...

    African Journals Online (AJOL)

    Jane

    2011-10-12

    Oct 12, 2011 ... other hand, A. niger biofilm growth followed a logistic model having higher maximal specific growth rate than ...... Growth estimation of Aspergillus oryzae cultured on ... Initial intracellular proteome profile of Aspergillus niger.

  6. Biomarkers of Aspergillus spores

    Science.gov (United States)

    Sulc, Miroslav; Peslova, Katerina; Zabka, Martin; Hajduch, Marian; Havlicek, Vladimir

    2009-02-01

    We applied both matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometric and 1D sodium dodecylsulfate polyacrylamide gel electrophoretic (1D-PAGE) approaches for direct analysis of intact fungal spores of twenty four Aspergillus species. In parallel, we optimized various protocols for protein extraction from Aspergillus spores using acidic conditions, step organic gradient and variable sonication treatment. The MALDI-TOF mass spectra obtained from optimally prepared samples provided a reproducible fingerprint demonstrating the capability of the MALDI-TOF approach to type and characterize different fungal strains within the Aspergillus genus. Mass spectra of intact fungal spores provided signals mostly below 20 kDa. The minimum material amount represented 0.3 [mu]g (10,000 spores). Proteins with higher molecular weight were detected by 1D-PAGEE Eleven proteins were identified from three selected strains in the range 5-25 kDa by the proteomic approach. Hemolysin and hydrophobin have the highest relevance in host-pathogen interactions.

  7. Virtual Organizations: Trends and Models

    Science.gov (United States)

    Nami, Mohammad Reza; Malekpour, Abbaas

    The Use of ICT in business has changed views about traditional business. With VO, organizations with out physical, geographical, or structural constraint can collaborate with together in order to fulfill customer requests in a networked environment. This idea improves resource utilization, reduces development process and costs, and saves time. Virtual Organization (VO) is always a form of partnership and managing partners and handling partnerships are crucial. Virtual organizations are defined as a temporary collection of enterprises that cooperate and share resources, knowledge, and competencies to better respond to business opportunities. This paper presents an overview of virtual organizations and main issues in collaboration such as security and management. It also presents a number of different model approaches according to their purpose and applications.

  8. Mapping of polyketide biosynthesis pathways in Aspergillus nidulans using a genome wide PKS gene deletion library

    DEFF Research Database (Denmark)

    Larsen, Thomas Ostenfeld; Rank, Christian; Klejnstrup, Marie Louise

    In order to map new links between PKS genes and their products in Aspergillus nidulans we have systematically deleted all thirty-two individual genes predicted to encode polyketide synthases in this model organism. This number greatly exceeds the number of currently known PKs calling for new appr...

  9. Systems Analysis Unfolds the Relationship between the Phosphoketolase Pathway and Growth in Aspergillus nidulans

    DEFF Research Database (Denmark)

    Panagiotou, Gianni; Andersen, Mikael Rørdam; Grotkjær, Thomas

    2008-01-01

    Background: Aspergillus nidulans is an important model organism for studies on fundamental eukaryotic cell biology and on industrial processes due to its close relation to A. niger and A. oryzae. Here we identified the gene coding for a novel metabolic pathway in A. nidulans, namely...

  10. Abundance, genetic diversity and sensitivity to demethylation inhibitor fungicides of Aspergillus fumigatus isolates from organic substrates with special emphasis on compost.

    Science.gov (United States)

    Santoro, Karin; Matić, Slavica; Gisi, Ulrich; Spadaro, Davide; Pugliese, Massimo; Gullino, Maria L

    2017-12-01

    Aspergillus fumigatus is a widespread fungus that colonizes dead organic substrates but it can also cause fatal human diseases. Aspergilloses are treated with demethylation inhibitor (DMI) fungicides; however, resistant isolates appeared recently in the medical and also environmental area. The present study aims at molecular characterizing and quantifying A. fumigatus in major environmental habitats and determining its sensitivity to medical and agricultural DMI fungicides. A. fumigatus was isolated only rarely from soil and meadow/forest organic matter but high concentrations (10 3 to 10 7  cfu/g) were detected in substrates subjected to elevated temperatures, such as compost and silage. High genetic diversity of A. fumigatus from compost was found based on SSR markers, distinguishing among fungal isolates even when coming from the same substrate sample, while subclustering was observed based on mutations in cyp51A gene. Several cyp51A amino acid substitutions were found in 15 isolates, although all isolates were fully sensitive to the tested DMI fungicides, with exception of one isolate in combination with one fungicide. This study suggests that the tested A. fumigatus isolates collected in Italy, Spain and Hungary from the fungus' major living habitats (compost) and commercial growing substrates are not potential carriers for DMI resistance in the environment. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  11. Simulations of CYP51A from Aspergillus fumigatus in a model bilayer provide insights into triazole drug resistance.

    Science.gov (United States)

    Nash, Anthony; Rhodes, Johanna

    2018-04-01

    Azole antifungal drugs target CYP51A in Aspergillus fumigatus by binding with the active site of the protein, blocking ergosterol biosynthesis. Resistance to azole antifungal drugs is now common, with a leucine to histidine amino acid substitution at position 98 the most frequent, predominantly conferring resistance to itraconazole, although cross-resistance has been reported in conjunction with other mutations. In this study, we create a homology model of CYP51A using a recently published crystal structure of the paralog protein CYP51B. The derived structures, wild type, and L98H mutant are positioned within a lipid membrane bilayer and subjected to molecular dynamics simulations in order improve the accuracy of both models. The structural analysis from our simulations suggests a decrease in active site surface from the formation of hydrogen bonds between the histidine substitution and neighboring polar side chains, potentially preventing the binding of azole drugs. This study yields a biologically relevant structure and set of dynamics of the A. fumigatus Lanosterol 14 alpha-demethylase enzyme and provides further insight into azole antifungal drug resistance.

  12. A novel biocatalytic approach to acetylation of 1-β-D-arabinofuranosylcytosine by Aspergillus oryzae whole cell in organic solvents.

    Science.gov (United States)

    Li, Xiao-Feng; Zhu, Zhen; Zhao, Guang-Lei; Yu, Yi-Gang; Lai, Fu-Rao; Wu, Hui

    2012-01-01

    Biocatalytic acylation of 1-β-D-arabinofuranosylcytosine (ara-C) was developed using whole cell of Aspergillus oryzae as a novel catalyst. (13)C nuclear magnetic resonance (NMR) analysis indicated that the whole-cell biocatalyst had more specific activity toward the 3'-hydroxyl group than 5'-hydroxyl group among the available hydroxyl groups in sugar moiety of ara-C. Except for glucose and maltose, 11 carbon sources supplemented to basal media, including Spans, Tweens, olive oil and oleic acid, exhibited notable enhancement effects on both the cell growth and the acylation reactions. It was suggested that the carbon sources containing controlled-release oleic acid were the important substrates for the production of fungal cell-bound lipase with specific activity, partially due to a gradual induction effect of their released oleic acid on the cell-bound lipase production. Despite the low initial reaction rate and substrate conversion, the addition of 2.0 g/l Span 80 resulted in a higher 3'-regioselectivity of the cells than 81%. By using Tween 85 at its optimum concentration of 5.0 g/l, however, the highest initial rates (3.2 mmol/l h) and substrate conversion (76%) of the whole-cell catalyzed acylation of ara-C can be achieved. It was also found that the 3'-regioselectivity of the cells showed observable increase by extending the culture time. And the activity of cell-bound lipase drastically increased in the early stage of cell growth and then declined in the late culture stage, whatever the culture media used. Our results thus indicated that A. oryzae whole cell was a promising green tool for biosynthesis of nucleoside esters with potential bioactivities.

  13. Model of organ dose combination

    International Nuclear Information System (INIS)

    Valley, J.-F.; Lerch, P.

    1977-01-01

    The ICRP recommendations are based on the limitation of the dose to each organ. In the application and for a unique source the critical organ concept allows to limit the calculation and represents the irradiation status of an individuum. When several sources of radiation are involved the derivation of the dose contribution of each source to each organ is necessary. In order to represent the irradiation status a new parameter is to be defined. Propositions have been made by some authors, in particular by Jacobi introducing at this level biological parameters like the incidence rate of detriment and its severity. The new concept is certainly richer than a simple dose notion. However, in the actual situation of knowledge about radiation effects an intermediate parameter, using only physical concepts and the maximum permissible doses to the organs, seems more appropriate. The model, which is a generalization of the critical organ concept and shall be extended in the future to take the biological effects into account, will be presented [fr

  14. Innate and adaptive immune response to chronic pulmonary infection of hyphae of Aspergillus fumigatus in a new murine model.

    Science.gov (United States)

    Wang, Fengyuan; Zhang, Caiyun; Jiang, Yuan; Kou, Caixia; Kong, Qingtao; Long, Nanbiao; Lu, Ling; Sang, Hong

    2017-10-01

    The pathogenesis of chronic pulmonary aspergillosis (CPA) has seldom been studied due partly to a lack of animal models. Since hypha is the main morphology colonizing the airway in CPA, it's critical to study the immune reaction to chronic pulmonary infection of hyphae of Aspergillus fumigatus, which also has seldom been studied in vivo before. We established a novel murine model of chronic pulmonary infection of hyphae by challenging immunocompetent mice with tightly-structured hyphae balls intratracheally, and described the ensuing immunoreaction to hyphae and conidia, and the pathogenesis of CPA. Our experiment proved that the hyphae balls could induce a chronic pulmonary infection for 28 days with a considerable recrudescence at day 28 post-infection. Lungs infected with hyphae balls were remarkable for the many neutrophils and macrophages that flooded into airway lumens, with peribronchiolar infiltration of leukocytes. There was a transient increase of Th2 cells and Th17 cells at day 7 post-infection in the lung tissue. In contrast, lungs infected with conidia showed no peribronchiolar infiltration of leukocytes, but an influx of a great number of macrophages, and a much less number of neutrophils in the lumen. Besides, conidia activated the co-response of Th1, Th2 and Th17 cells with an increase of Treg cells in the lung tissue (quite different from most previous studies). We established a new murine model of chronic infection of hyphae to mimic the formation of CPA, and provide a new marker for different immune responses to hyphae and conidia.

  15. Regulatory processes in Aspergillus niger

    OpenAIRE

    Poulsen, Lars; Thykær, Jette; Eliasson Lantz, Anna

    2012-01-01

    Filamentous fungi are extensively used in the fermentation industry for synthesis of numerous products. One of the most important, is the fungus Aspergillus niger, used industrially for production of organic acids, and homologous as well as heterologous enzymes. This fungus has numerous of advantages, including tolerance for low pH, which is important for acid production. Furthermore, it has the capability of metabolizing a wide variety of carbon sources, possesses an exceptional efficient pr...

  16. A genomics based discovery of secondary metabolite biosynthetic gene clusters in Aspergillus ustus.

    Directory of Open Access Journals (Sweden)

    Borui Pi

    Full Text Available Secondary metabolites (SMs produced by Aspergillus have been extensively studied for their crucial roles in human health, medicine and industrial production. However, the resulting information is almost exclusively derived from a few model organisms, including A. nidulans and A. fumigatus, but little is known about rare pathogens. In this study, we performed a genomics based discovery of SM biosynthetic gene clusters in Aspergillus ustus, a rare human pathogen. A total of 52 gene clusters were identified in the draft genome of A. ustus 3.3904, such as the sterigmatocystin biosynthesis pathway that was commonly found in Aspergillus species. In addition, several SM biosynthetic gene clusters were firstly identified in Aspergillus that were possibly acquired by horizontal gene transfer, including the vrt cluster that is responsible for viridicatumtoxin production. Comparative genomics revealed that A. ustus shared the largest number of SM biosynthetic gene clusters with A. nidulans, but much fewer with other Aspergilli like A. niger and A. oryzae. These findings would help to understand the diversity and evolution of SM biosynthesis pathways in genus Aspergillus, and we hope they will also promote the development of fungal identification methodology in clinic.

  17. A Genomics Based Discovery of Secondary Metabolite Biosynthetic Gene Clusters in Aspergillus ustus

    Science.gov (United States)

    Pi, Borui; Yu, Dongliang; Dai, Fangwei; Song, Xiaoming; Zhu, Congyi; Li, Hongye; Yu, Yunsong

    2015-01-01

    Secondary metabolites (SMs) produced by Aspergillus have been extensively studied for their crucial roles in human health, medicine and industrial production. However, the resulting information is almost exclusively derived from a few model organisms, including A. nidulans and A. fumigatus, but little is known about rare pathogens. In this study, we performed a genomics based discovery of SM biosynthetic gene clusters in Aspergillus ustus, a rare human pathogen. A total of 52 gene clusters were identified in the draft genome of A. ustus 3.3904, such as the sterigmatocystin biosynthesis pathway that was commonly found in Aspergillus species. In addition, several SM biosynthetic gene clusters were firstly identified in Aspergillus that were possibly acquired by horizontal gene transfer, including the vrt cluster that is responsible for viridicatumtoxin production. Comparative genomics revealed that A. ustus shared the largest number of SM biosynthetic gene clusters with A. nidulans, but much fewer with other Aspergilli like A. niger and A. oryzae. These findings would help to understand the diversity and evolution of SM biosynthesis pathways in genus Aspergillus, and we hope they will also promote the development of fungal identification methodology in clinic. PMID:25706180

  18. Aspergillus fumigatus in Poultry

    Directory of Open Access Journals (Sweden)

    Pascal Arné

    2011-01-01

    Full Text Available Aspergillus fumigatus remains a major respiratory pathogen in birds. In poultry, infection by A. fumigatus may induce significant economic losses particularly in turkey production. A. fumigatus develops and sporulates easily in poor quality bedding or contaminated feedstuffs in indoor farm environments. Inadequate ventilation and dusty conditions increase the risk of bird exposure to aerosolized spores. Acute cases are seen in young animals following inhalation of spores, causing high morbidity and mortality. The chronic form affects older birds and looks more sporadic. The respiratory tract is the primary site of A. fumigatus development leading to severe respiratory distress and associated granulomatous airsacculitis and pneumonia. Treatments for infected poultry are nonexistent; therefore, prevention is the only way to protect poultry. Development of avian models of aspergillosis may improve our understanding of its pathogenesis, which remains poorly understood.

  19. SCRINING IN SILICO ACTIVE COMPOUND OF Pachyrrhizus erosus AS ANTITIROSINASE ON Aspergillus oryzae (COMPUTATTIONAL STUDY WITH HOMOLOGY MODELING AND MOLECULAR DOCKING

    Directory of Open Access Journals (Sweden)

    Endang Lukitaningsih

    2015-11-01

    Full Text Available Bengkoang telah banyak digunakan dalam industri kosmetika sebagai whitening agent. Berdasarkan penelitian Lukitaningsih (2009, bengkoang mengandung 6 senyawa aktif yang mampu berperan sebagai whitening agent dengan menghambat aktivitas enzim tirosinase dari jamur Aspergillus oryzae (TyrAo. Namun interaksi senyawa aktif bengkoang dalam menghambat enzim tirosinase belum dapat diketahui. Interaksi senyawa-senyawa aktif bengkoang dengan enzim TyrAo dapat diketahui dengan studi komputasional (in silico. Pemodelan interaksi senyawa aktif bengkoang dengan enzim TyrAo dilakukan dengan metode homology modeling dan molecular docking. Homology modeling dilakukan untuk memodelkan struktur tiga dimensi (3D enzim tirosinase Aspergillus oryzae (TyrAo melalui template berupa protein homolog yang sudah diketahui struktur 3D-nya yaitu enzim TyrAb (PDBID: 2Y9X. Model TyrAo digunakan sebagai target makromolekul dalam metode molecular docking. Metode molecular docking merupakan metode untuk menggambarkan posisi ligan (senyawa-senyawa aktif bengkoang pada sisi aktif reseptor (model TyrAo. Berdasarkan docking yang dilakukan diketahui bahwa residu-residu yang banyak berpengaruh pada interaksi ligan pada sisi aktif adalah residu Thr275 yang berinteraksi secara ikatan hidrogen dengan ligan dan residu His294 yang berinteraksi secara hidrofobik pada cincin aromatik ligan. Penelitian in silico dan in vitro yang telah dilakukan memiliki korelasi (R2 sebesar -0,8366. Korelasi ini menandakan bahwa aktivitas senyawa-senyawa aktif pada bengkoang dalam menghambat enzim TyrAo memiliki hasil yang serupa pada penelitian yang  dilakukan secara in silico dan in vitro.

  20. Germination of Aspergillus niger conidia

    OpenAIRE

    Hayer, Kimran

    2014-01-01

    Aspergillus niger is a black-spored filamentous fungus that forms asexual spores called conidospores (‘conidia’). Germination of conidia, leading to the formation of hyphae, is initiated by conidial swelling and mobilisation of endogenous carbon and energy stores, followed by polarisation and emergence of a hyphal germ tube. These morphological and biochemical changes which define the model of germination have been studied with the aim of understanding how conidia sense and utilise different...

  1. Modeling the degradation of Portland cement pastes by biogenic organic acids

    International Nuclear Information System (INIS)

    De Windt, Laurent; Devillers, Philippe

    2010-01-01

    Reactive transport models can be used to assess the long-term performance of cement-based materials subjected to biodegradation. A bioleaching test (with Aspergillus niger fungi) applied to ordinary Portland cement pastes during 15 months is modeled with HYTEC. Modeling indicates that the biogenic organic acids (acetic, butyric, lactic and oxalic) strongly accelerate hydrate dissolution by acidic hydrolysis whilst their complexation of aluminum has an effect on the secondary gel stability only. The deepest degradation front corresponds to portlandite dissolution and decalcification of calcium silicate hydrates. A complex pattern of sulfate phases dissolution and precipitation takes place in an intermediate zone. The outermost degraded zone consists of alumina and silica gels. The modeling accurateness of calcium leaching, pH evolution and degradation thickness is consistently enhanced whilst considering increase of diffusivity in the degraded zones. Precipitation of calcium oxalate is predicted by modeling but was hindered in the bioleaching reactor.

  2. [Progress in omics research of Aspergillus niger].

    Science.gov (United States)

    Sui, Yufei; Ouyang, Liming; Lu, Hongzhong; Zhuang, Yingping; Zhang, Siliang

    2016-08-25

    Aspergillus niger, as an important industrial fermentation strain, is widely applied in the production of organic acids and industrial enzymes. With the development of diverse omics technologies, the data of genome, transcriptome, proteome and metabolome of A. niger are increasing continuously, which declared the coming era of big data for the research in fermentation process of A. niger. The data analysis from single omics and the comparison of multi-omics, to the integrations of multi-omics based on the genome-scale metabolic network model largely extends the intensive and systematic understanding of the efficient production mechanism of A. niger. It also provides possibilities for the reasonable global optimization of strain performance by genetic modification and process regulation. We reviewed and summarized progress in omics research of A. niger, and proposed the development direction of omics research on this cell factory.

  3. using stereochemistry models in teaching organic compounds

    African Journals Online (AJOL)

    Preferred Customer

    The purpose of the study was to find out the effect of stereochemistry models on students' ... consistent with the names given to organic compounds. Some of ... Considering class level, what is the performance of the students in naming organic.

  4. Effects of organic solvent, water activity, and salt hydrate pair on the sn-1,3 selectivity and activity of whole-cell lipase from Aspergillus niger GZUF36.

    Science.gov (United States)

    Li, Cuiqin; Zhang, Fuhao; Gao, Zexin; He, Laping; Zeng, Xuefeng; Zhu, Qiujin; Yu, Lijuan

    2018-01-01

    We previously screened a whole-cell lipase EC 3.1.1.3 from the novel strain Aspergillus niger GZUF36, which exhibited 1,3-selectivity in the synthesis of 1,3-diacylglycerol via glycerolysis. However, the mechanism of lipase selectively in catalyzing the sn-1,3 position remains ambiguous. This work was performed to investigate the 1,3-selective mechanism of lipase using glycerolysis to synthesize 1,3-diacylglycerol (1,3-DG) as a model reaction by changing solvent(s) and water activity (a w ), and addition of salt hydrate pair. The measured diacylglycerol yield was also used to examine lipase activity. Results indicated that not only organic solvent and a w have strong effect on the sn-1,3 selectivity, but also ions of salt hydrate pair also affected selectivity. Lipase conformation was altered by hydrophobic interactions of the solvent, a w , or ions of salt hydrate, resulting in distinct sn-1,3 selectivity of the lipase. The salt hydrate pair changed the lipase conformation and selectivity not only by a w but also by static interactions, which was rarely reported. These parameters also affected lipase activity. The lipase displayed the highest selectivity (about 88%) and activity in solvents of t-butanol and n-hexane (1:29, v/v) at a w 0.43. The results demonstrated that the sn-1,3 selectivity and activity of the lipase from A. niger GZUF36 may be improved by control of some crucial factors. This work laid a foundation for the application of lipase in the synthesis of 1,3-DG and other structural and functional lipids.

  5. Tree-Structured Digital Organisms Model

    Science.gov (United States)

    Suzuki, Teruhiko; Nobesawa, Shiho; Tahara, Ikuo

    Tierra and Avida are well-known models of digital organisms. They describe a life process as a sequence of computation codes. A linear sequence model may not be the only way to describe a digital organism, though it is very simple for a computer-based model. Thus we propose a new digital organism model based on a tree structure, which is rather similar to the generic programming. With our model, a life process is a combination of various functions, as if life in the real world is. This implies that our model can easily describe the hierarchical structure of life, and it can simulate evolutionary computation through mutual interaction of functions. We verified our model by simulations that our model can be regarded as a digital organism model according to its definitions. Our model even succeeded in creating species such as viruses and parasites.

  6. Transcriptional regulation of the xylanolytic enzyme system of Aspergillus

    NARCIS (Netherlands)

    Peij, van N.N.M.E.

    1999-01-01

    Filamentous fungi, such as Aspergillus niger , produce high levels of polysaccharide degrading enzymes and are frequently used as production organisms for industrial enzyme preparations. The application of these polysaccharidases as xylanases and cellulases comprises

  7. Metabolic control analysis of Aspergillus niger L-arabinose catabolism

    DEFF Research Database (Denmark)

    de Groot, M.J.L.; Prathumpai, Wai; Visser, J.

    2005-01-01

    A mathematical model of the L-arabinose/D-xylose catabolic pathway of Aspergillus niger was constructed based on the kinetic properties of the enzymes. For this purpose L-arabinose reductase, L-arabitol dehydrogenase and D-xylose reductase were purified using dye-affinity chromatography...... aiming at either flux or metabolite level optimization of the L-arabinose catabolic pathway of A. niger. Faster L-arabinose utilization may enhance utilization of readily available organic waste containing hemicelluloses to be converted into industrially interesting metabolites or valuable enzymes...

  8. Modelling the effect of temperature, water activity and carbon dioxide on the growth of Aspergillus niger and Alternaria alternata isolated from fresh date fruit.

    Science.gov (United States)

    Belbahi, A; Leguerinel, I; Méot, J-M; Loiseau, G; Madani, K; Bohuon, P

    2016-12-01

    To quantify and model the combined effects of temperature (T) (10-40°C), water activity (a w ) (0·993-0·818) and CO 2 concentration (9·4-55·1%, v/v) on the growth rate of Aspergillus niger and Alternaria alternata that cause spoilage during the storage and packaging of dates. The effects of environmental factors were studied using the γ-concept. Cardinal models were used to quantify the effect of studied environmental factors on the growth rates. Firstly, the cardinal parameters were estimated independently from experiments carried out on potato dextrose agar using a monofactorial design. Secondly, model performance evaluation was conducted on pasteurized date paste. The boundary between growth and no-growth was predicted using a deterministic approach. Aspergillus niger displayed a faster growth rate and higher tolerance to low a w than Al. alternata, which in turn proved more resistant to CO 2 concentration. Minimal cardinal parameters of T and a w were lower than those reported in the literature. The combination of the a w and CO 2 effects significantly affected As. niger and Al. alternata growth. The γ-concept model overestimated growth rates, however, it is optimistic and provides somewhat conservative predictions. The developed model provides a decision support tool for the choice of the date fruit conservation mode (refrigeration, drying, modified atmospheric packaging or their combination) using T, a w and CO 2 as environmental factors. © 2016 The Society for Applied Microbiology.

  9. Modelling organic particles in the atmosphere

    International Nuclear Information System (INIS)

    Couvidat, Florian

    2012-01-01

    Organic aerosol formation in the atmosphere is investigated via the development of a new model named H 2 O (Hydrophilic/Hydrophobic Organics). First, a parameterization is developed to take into account secondary organic aerosol formation from isoprene oxidation. It takes into account the effect of nitrogen oxides on organic aerosol formation and the hydrophilic properties of the aerosols. This parameterization is then implemented in H 2 O along with some other developments and the results of the model are compared to organic carbon measurements over Europe. Model performance is greatly improved by taking into account emissions of primary semi-volatile compounds, which can form secondary organic aerosols after oxidation or can condense when temperature decreases. If those emissions are not taken into account, a significant underestimation of organic aerosol concentrations occurs in winter. The formation of organic aerosols over an urban area was also studied by simulating organic aerosols concentration over the Paris area during the summer campaign of Megapoli (July 2009). H 2 O gives satisfactory results over the Paris area, although a peak of organic aerosol concentrations from traffic, which does not appear in the measurements, appears in the model simulation during rush hours. It could be due to an underestimation of the volatility of organic aerosols. It is also possible that primary and secondary organic compounds do not mix well together and that primary semi volatile compounds do not condense on an organic aerosol that is mostly secondary and highly oxidized. Finally, the impact of aqueous-phase chemistry was studied. The mechanism for the formation of secondary organic aerosol includes in-cloud oxidation of glyoxal, methylglyoxal, methacrolein and methylvinylketone, formation of methyltetrols in the aqueous phase of particles and cloud droplets, and the in-cloud aging of organic aerosols. The impact of wet deposition is also studied to better estimate the

  10. A rare case of bilateral aspergillus endophthalmitis

    Directory of Open Access Journals (Sweden)

    Saurabh Gupta

    2015-12-01

    Full Text Available Aspergillus endophthalmitis is a devastating inflammatory condition of the intraocular cavities that may result in irreparable loss of vision and rapid destruction of the eye. Almost all cases in the literature have shown an identified source causing aspergillus endophthalmitis as a result of direct extension of disease. We present a rare case of bilateral aspergillus endophthalmitis. A 72-year-old woman with a history of diabetes mellitus, congenital Hirschsprung disease, and recent culture-positive candida pyelonephritis with hydronephrosis status post-surgical stent placement presented with difficulty opening her eyes. She complained of decreased vision (20/200 with pain and redness in both eyes – right worse then left. Examination demonstrated multiple white fungal balls in both retinas consistent with bilateral fungal endophthalmitis. Bilateral vitreous taps for cultures and staining were performed. Patient was given intravitreal injections of amphotericin B, vancomycin, ceftazidime, and started on oral fluconazole. Patient was scheduled for vitrectomy to decrease organism burden and to remove loculated areas of infection that would not respond to systemic antifungal agents. Four weeks after initial presentation, the fungal cultures revealed mold growth consistent with aspergillus. Patient was subsequently started on voriconazole and fluconazole was discontinued due to poor efficacy against aspergillus. Further workup was conducted to evaluate for the source of infection and seeding. Transthoracic cardiogram was unremarkable for any vegetation or valvular abnormalities. MRI of the orbits and sinuses did not reveal any mass lesions or bony destruction. CT of the chest was unremarkable for infection. Aspergillus endophthalmitis may occur because of one of these several mechanisms: hematogenous dissemination, direct inoculation by trauma, and contamination during surgery. Our patient's cause of bilateral endophthalmitis was through an

  11. Aspergillus baeticus sp. nov. and Aspergillus thesauricus sp. nov., two species in section Usti from Spanish caves.

    Science.gov (United States)

    Nováková, Alena; Hubka, Vit; Saiz-Jimenez, Cesareo; Kolarik, Miroslav

    2012-11-01

    Two novel species of Aspergillus that are clearly distinct from all known species in section Usti were revealed during a study of microfungal communities in Spanish caves. The novel species identified in this study and additional species of Aspergillus section Usti are associated with places and substrates related to human activities in caves. Novel species are described using data from four loci (ITS, benA, caM and rpb2), morphology and basic chemical and physiological analyses. Members of the species Aspergillus thesauricus sp. nov. were isolated from various substrates, including decaying organic matter, cave air and cave sediment of the Cueva del Tesoro Cave (the Treasure cave); the species is represented by twelve isolates and is most closely related to the recently described Aspergillus germanicus. Members of the species Aspergillus baeticus sp. nov. were isolated from cave sediment in the Gruta de las Maravillas Cave (the Grotto of the Marvels); the species is represented by two isolates. An additional isolate was found in the Cueva del Tesoro Cave and in the Demänovská Peace Cave (Slovakia), suggesting a potentially wide distribution of this micro-organism. The species is related to Aspergillus ustus and Aspergillus pseudoustus. Both species were unable to grow at 37 °C, and a weakly positive, light greenish yellow Ehrlich reaction was observed in A. thesauricus. Unique morphological features alone are sufficient to distinguish both species from related taxa.

  12. 76 FR 16297 - Aspergillus flavus

    Science.gov (United States)

    2011-03-23

    ... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 180 [EPA-HQ-OPP-2010-0101; FRL-8868-7] Aspergillus... for residues of the microbial pesticide, Aspergillus flavus AF36, in or on corn food and feed... to the existing exemption from the requirement of a tolerance for Aspergillus flavus AF36. This...

  13. Aspergillus Species and Their Associated Mycotoxins.

    Science.gov (United States)

    Perrone, Giancarlo; Gallo, Antonia

    2017-01-01

    The genus Aspergillus is among the most abundant and widely distributed organism on earth, and at the moment comprises 339 known species. It is one of the most important economically fungal genus and the biotechnological use of Aspergillus species is related to production of soy sauce, of different hydrolytic enzymes (amylases, lipases) and organic acid (citric acid, gluconic acid), as well as biologically active metabolites such as lovastatin. Although they are not considered to be major cause of plant diseases, Aspergillus species are responsible for several disorders in various plants and plant products, especially as opportunistic storage moulds. The notable consequence of their presence is contamination of foods and feeds by mycotoxins, among which the most important are aflatoxins, ochratoxin A, and, at a less extent, fumonisins. Aflatoxins B 1 , B 2 , G 1 , G 2 are the most toxic and carcinogenic mycotoxins, due to their extreme hepatocarcinogenicity; ochratoxin A is a potent nephrotoxin, it is also carcinogenic, teratogenic, and immunotoxic in rats and possibly in humans; fumonisins are hepatotoxic and nephrotoxic with potential carcinogenic effects on rat and mice. In this chapter we summarize the main aspects of morphology, ecology, epidemiology, and toxigenicity of Aspergillus foodborne pathogens which belong to sections Flavi, Circumdati, and Nigri, occurring in several agricultural products and responsible of aflatoxin, ochratoxin A, and fumonisins contamination of food and feed.

  14. Organic production in a dynamic CGE model

    DEFF Research Database (Denmark)

    Jacobsen, Lars Bo

    2004-01-01

    for conventional production into land for organic production, a period of two years must pass before the land being transformed can be used for organic production. During that time, the land is counted as land of the organic industry, but it can only produce the conventional product. To handle this rule, we make......Concerns about the impact of modern agriculture on the environment have in recent years led to an interest in supporting the development of organic farming. In addition to environmental benefits, the aim is to encourage the provision of other “multifunctional” properties of organic farming...... such as rural amenities and rural development that are spillover benefit additional to the supply of food. In this paper we further develop an existing dynamic general equilibrium model of the Danish economy to specifically incorporate organic farming. In the model and input-output data each primary...

  15. Cardiac Electromechanical Models: From Cell to Organ

    Directory of Open Access Journals (Sweden)

    Natalia A Trayanova

    2011-08-01

    Full Text Available The heart is a multiphysics and multiscale system that has driven the development of the most sophisticated mathematical models at the frontiers of computation physiology and medicine. This review focuses on electromechanical (EM models of the heart from the molecular level of myofilaments to anatomical models of the organ. Because of the coupling in terms of function and emergent behaviors at each level of biological hierarchy, separation of behaviors at a given scale is difficult. Here, a separation is drawn at the cell level so that the first half addresses subcellular/single cell models and the second half addresses organ models. At the subcelluar level, myofilament models represent actin-myosin interaction and Ca-based activation. Myofilament models and their refinements represent an overview of the development in the field. The discussion of specific models emphasizes the roles of cooperative mechanisms and sarcomere length dependence of contraction force, considered the cellular basis of the Frank-Starling law. A model of electrophysiology and Ca handling can be coupled to a myofilament model to produce an EM cell model, and representative examples are summarized to provide an overview of the progression of field. The second half of the review covers organ-level models that require solution of the electrical component as a reaction-diffusion system and the mechanical component, in which active tension generated by the myocytes produces deformation of the organ as described by the equations of continuum mechanics. As outlined in the review, different organ-level models have chosen to use different ionic and myofilament models depending on the specific application; this choice has been largely dictated by compromises between model complexity and computational tractability. The review also addresses application areas of EM models such as cardiac resynchronization therapy and the role of mechano-electric coupling in arrhythmias and

  16. Project-matrix models of marketing organization

    Directory of Open Access Journals (Sweden)

    Gutić Dragutin

    2009-01-01

    Full Text Available Unlike theory and practice of corporation organization, in marketing organization numerous forms and contents at its disposal are not reached until this day. It can be well estimated that marketing organization today in most of our companies and in almost all its parts, noticeably gets behind corporation organization. Marketing managers have always been occupied by basic, narrow marketing activities as: sales growth, market analysis, market growth and market share, marketing research, introduction of new products, modification of products, promotion, distribution etc. They rarely found it necessary to focus a bit more to different aspects of marketing management, for example: marketing planning and marketing control, marketing organization and leading. This paper deals with aspects of project - matrix marketing organization management. Two-dimensional and more-dimensional models are presented. Among two-dimensional, these models are analyzed: Market management/products management model; Products management/management of product lifecycle phases on market model; Customers management/marketing functions management model; Demand management/marketing functions management model; Market positions management/marketing functions management model. .

  17. The Zebrafish Model Organism Database (ZFIN)

    Data.gov (United States)

    U.S. Department of Health & Human Services — ZFIN serves as the zebrafish model organism database. It aims to: a) be the community database resource for the laboratory use of zebrafish, b) develop and support...

  18. Complex Systems and Self-organization Modelling

    CERN Document Server

    Bertelle, Cyrille; Kadri-Dahmani, Hakima

    2009-01-01

    The concern of this book is the use of emergent computing and self-organization modelling within various applications of complex systems. The authors focus their attention both on the innovative concepts and implementations in order to model self-organizations, but also on the relevant applicative domains in which they can be used efficiently. This book is the outcome of a workshop meeting within ESM 2006 (Eurosis), held in Toulouse, France in October 2006.

  19. Aspergillus Section Fumigati Typing by PCR-Restriction Fragment Polymorphism▿

    OpenAIRE

    Staab, Janet F.; Balajee, S. Arunmozhi; Marr, Kieren A.

    2009-01-01

    Recent studies have shown that there are multiple clinically important members of the Aspergillus section Fumigati that are difficult to distinguish on the basis of morphological features (e.g., Aspergillus fumigatus, A. lentulus, and Neosartorya udagawae). Identification of these organisms may be clinically important, as some species vary in their susceptibilities to antifungal agents. In a prior study, we utilized multilocus sequence typing to describe A. lentulus as a species distinct from...

  20. Aspergillus fumigatus and Related Species

    Science.gov (United States)

    Sugui, Janyce A.; Kwon-Chung, Kyung J.; Juvvadi, Praveen R.; Latgé, Jean-Paul; Steinbach, William J.

    2015-01-01

    The genus Aspergillus contains etiologic agents of aspergillosis. The clinical manifestations of the disease range from allergic reaction to invasive pulmonary infection. Among the pathogenic aspergilli, Aspergillus fumigatus is most ubiquitous in the environment and is the major cause of the disease, followed by Aspergillus flavus, Aspergillus niger, Aspergillus terreus, Aspergillus nidulans, and several species in the section Fumigati that morphologically resemble A. fumigatus. Patients that are at risk for acquiring aspergillosis are those with an altered immune system. Early diagnosis, species identification, and adequate antifungal therapy are key elements for treatment of the disease, especially in cases of pulmonary invasive aspergillosis that often advance very rapidly. Incorporating knowledge of the basic biology of Aspergillus species to that of the diseases that they cause is fundamental for further progress in the field. PMID:25377144

  1. Self-affine fractal growth front of Aspergillus oryzae

    Science.gov (United States)

    Matsuura, Shu; Miyazima, Sasuke

    1992-12-01

    Aspergillus oryzae have been grown in various environmental conditions and analyzed from the viewpoint of self-affinity. The growth behavior can be described by the Eden model in favorable conditions, and by DLA in unfavorable conditions.

  2. Development and application of a predictive model of Aspergillus candidus growth as a tool to improve shelf life of bakery products.

    Science.gov (United States)

    Huchet, V; Pavan, S; Lochardet, A; Divanac'h, M L; Postollec, F; Thuault, D

    2013-12-01

    Molds are responsible for spoilage of bakery products during storage. A modeling approach to predict the effect of water activity (aw) and temperature on the appearance time of Aspergillus candidus was developed and validated on cakes. The gamma concept of Zwietering was adapted to model fungal growth, taking into account the impact of temperature and aw. We hypothesized that the same model could be used to calculate the time for mycelium to become visible (tv), by substituting the matrix parameter by tv. Cardinal values of A. candidus were determined on potato dextrose agar, and predicted tv were further validated by challenge-tests run on 51 pastries. Taking into account the aw dynamics recorded in pastries during reasonable conditions of storage, high correlation was shown between predicted and observed tv when the aw at equilibrium (after 14 days of storage) was used for modeling (Af = 1.072, Bf = 0.979). Validation studies on industrial cakes confirmed the experimental results and demonstrated the suitability of the model to predict tv in food as a function of aw and temperature. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. As a Rare Site of Invasive Fungal Infection, Chronic Granulomatous Aspergillus Synovitis: A Case Report

    Directory of Open Access Journals (Sweden)

    Aylin Canbolat Ayhan

    2013-06-01

    Full Text Available Aspergillus can causes invasive disease of various organs especially in patients with weakened immune systems. Aspergillus synovitis and arthritis are uncommon types of involvement due to this infection. Approches to fungal osteoarticular infections are based on only case reports. This paper presents a rare case of chronic granulomatous Aspergillus synovitis in an immunocompromised 5-year old girl who was treated for acute lymphoblastic leukemia.

  4. Modeling self-organization of novel organic materials

    Science.gov (United States)

    Sayar, Mehmet

    In this thesis, the structural organization of oligomeric multi-block molecules is analyzed by computational analysis of coarse-grained models. These molecules form nanostructures with different dimensionalities, and the nanostructured nature of these materials leads to novel structural properties at different length scales. Previously, a number of oligomeric triblock rodcoil molecules have been shown to self-organize into mushroom shaped noncentrosymmetric nanostructures. Interestingly, thin films of these molecules contain polar domains and a finite macroscopic polarization. However, the fully polarized state is not the equilibrium state. In the first chapter, by solving a model with dipolar and Ising-like short range interactions, we show that polar domains are stable in films composed of aggregates as opposed to isolated molecules. Unlike classical molecular systems, these nanoaggregates have large intralayer spacings (a ≈ 6 nm), leading to a reduction in the repulsive dipolar interactions that oppose polar order within layers. This enables the formation of a striped pattern with polar domains of alternating directions. The energies of the possible structures at zero temperature are computed exactly and results of Monte Carlo simulations are provided at non-zero temperatures. In the second chapter, the macroscopic polarization of such nanostructured films is analyzed in the presence of a short range surface interaction. The surface interaction leads to a periodic domain structure where the balance between the up and down domains is broken, and therefore films of finite thickness have a net macroscopic polarization. The polarization per unit volume is a function of film thickness and strength of the surface interaction. Finally, in chapter three, self-organization of organic molecules into a network of one dimensional objects is analyzed. Multi-block organic dendron rodcoil molecules were found to self-organize into supramolecular nanoribbons (threads) and

  5. (+)-Geodin from Aspergillus terreus

    DEFF Research Database (Denmark)

    Rønnest, Mads Holger; Nielsen, Morten Thrane; Leber, Blanka

    2011-01-01

    The fungal metabolite (+)-geodin [systematic name: (2R)-methyl 5,7-dichloro-4-hydroxy-6'-methoxy-6-methyl-3,4'-dioxospiro[benzofuran-2,1'-cyclohexa-2',5'-diene]-2'-carboxylate], C(17)H(12)Cl(2)O(7), was isolated from Aspergillus terreus. The crystal structure contains two independent molecules...

  6. Genetics of Polyketide Metabolism in Aspergillus nidulans

    Directory of Open Access Journals (Sweden)

    Marie L. Klejnstrup

    2012-01-01

    Full Text Available Secondary metabolites are small molecules that show large structural diversity and a broad range of bioactivities. Some metabolites are attractive as drugs or pigments while others act as harmful mycotoxins. Filamentous fungi have the capacity to produce a wide array of secondary metabolites including polyketides. The majority of genes required for production of these metabolites are mostly organized in gene clusters, which often are silent or barely expressed under laboratory conditions, making discovery and analysis difficult. Fortunately, the genome sequences of several filamentous fungi are publicly available, greatly facilitating the establishment of links between genes and metabolites. This review covers the attempts being made to trigger the activation of polyketide metabolism in the fungal model organism Aspergillus nidulans. Moreover, it will provide an overview of the pathways where ten polyketide synthase genes have been coupled to polyketide products. Therefore, the proposed biosynthesis of the following metabolites will be presented; naphthopyrone, sterigmatocystin, aspyridones, emericellamides, asperthecin, asperfuranone, monodictyphenone/emodin, orsellinic acid, and the austinols.

  7. Septic arthritis due to tubercular and Aspergillus co-infection

    Directory of Open Access Journals (Sweden)

    Mukesh Kumar

    2016-01-01

    Full Text Available Aspergillus septic arthritis is a rare and serious medical and surgical problem. It occurs mainly in immunocompromised patients. Aspergillus fumigatus is the most common causative organism followed by Aspergillus flavus. The most common site affected is knee followed by shoulder, ankle, wrist, hip and sacroiliac joint. Debridement and voriconazole are primary treatment of articular aspergilosis. To the best of our knowledge, there are no reported cases of co-infection of tuberculosis (TB and Aspergillus infecting joints. We report a case of co-infection of TB and A. flavus of hip and knee of a 60-year-old male, with type 2 diabetes mellitus. He was treated with debridement, intravenous voriconazole, and antitubercular drugs.

  8. Septic arthritis due to tubercular and Aspergillus co-infection.

    Science.gov (United States)

    Kumar, Mukesh; Thilak, Jai; Zahoor, Adnan; Jyothi, Arun

    2016-01-01

    Aspergillus septic arthritis is a rare and serious medical and surgical problem. It occurs mainly in immunocompromised patients. Aspergillus fumigatus is the most common causative organism followed by Aspergillus flavus. The most common site affected is knee followed by shoulder, ankle, wrist, hip and sacroiliac joint. Debridement and voriconazole are primary treatment of articular aspergilosis. To the best of our knowledge, there are no reported cases of co-infection of tuberculosis (TB) and Aspergillus infecting joints. We report a case of co-infection of TB and A. flavus of hip and knee of a 60-year-old male, with type 2 diabetes mellitus. He was treated with debridement, intravenous voriconazole, and antitubercular drugs.

  9. Aspergillus otitis in small animals--a retrospective study of 17 cases.

    Science.gov (United States)

    Goodale, Elizabeth C; Outerbridge, Catherine A; White, Stephen D

    2016-02-01

    Aspergillus spp. are saprophytic opportunistic fungal organisms and are a common cause of otomycosis in humans. Although there have been case reports of Aspergillus otitis externa in dogs, to the best of the authors' knowledge, this is the first retrospective case series describing Aspergillus otitis in dogs and cats. To characterize signalment, putative risk factors, treatments and outcomes of a case series of dogs and cats with Aspergillus otitis. Eight dogs and nine cats diagnosed with Aspergillus otitis. A retrospective review of medical records from 1989 to 2014 identified animals diagnosed with Aspergillus otitis based on culture. All dogs weighed greater than 23 kg. The most common putative risk factors identified in this study were concurrent diseases, therapy causing immunosuppression or a history of an otic foreign body. Aspergillus otitis was unilateral in all study dogs and most cats. Concurrent otitis media was confirmed in three dogs and one cat, and suspected in two additional cats. Aspergillus fumigatus was the most common isolate overall and was the dominant isolate in cats. Aspergillus niger and A. terreus were more commonly isolated from dogs. Animals received various topical and systemic antifungal medications; however, otic lavage under anaesthesia and/or surgical intervention increased the likelihood of resolution of the fungal infection. Aspergillus otitis is uncommon, typically seen as unilateral otitis externa in cats and larger breed dogs with possible risk factors that include immunosuppression and otic foreign bodies; previous antibiotic usage was common. © 2015 ESVD and ACVD.

  10. The conceptual model of organization social responsibility

    OpenAIRE

    LUO, Lan; WEI, Jingfu

    2014-01-01

    With the developing of the research of CSR, people more and more deeply noticethat the corporate should take responsibility. Whether other organizations besides corporatesshould not take responsibilities beyond their field? This paper puts forward theconcept of organization social responsibility on the basis of the concept of corporate socialresponsibility and other theories. And the conceptual models are built based on theconception, introducing the OSR from three angles: the types of organi...

  11. Putting "Organizations" into an Organization Theory Course: A Hybrid CAO Model for Teaching Organization Theory

    Science.gov (United States)

    Hannah, David R.; Venkatachary, Ranga

    2010-01-01

    In this article, the authors present a retrospective analysis of an instructor's multiyear redesign of a course on organization theory into what is called a hybrid Classroom-as-Organization model. It is suggested that this new course design served to apprentice students to function in quasi-real organizational structures. The authors further argue…

  12. Effect of low shear modeled microgravity on phenotypic and central chitin metabolism in the filamentous fungi Aspergillus niger and Penicillium chrysogenum.

    Science.gov (United States)

    Sathishkumar, Yesupatham; Velmurugan, Natarajan; Lee, Hyun Mi; Rajagopal, Kalyanaraman; Im, Chan Ki; Lee, Yang Soo

    2014-08-01

    Phenotypic and genotypic changes in Aspergillus niger and Penicillium chrysogenum, spore forming filamentous fungi, with respect to central chitin metabolism were studied under low shear modeled microgravity, normal gravity and static conditions. Low shear modeled microgravity (LSMMG) response showed a similar spore germination rate with normal gravity and static conditions. Interestingly, high ratio of multiple germ tube formation of A. niger in LSMMG condition was observed. Confocal laser scanning microscopy images of calcofluor flurophore stained A. niger and P. chrysogenum showed no significant variations between different conditions tested. Transmission electron microscopy images revealed number of mitochondria increased in P. chrysogenum in low shear modeled microgravity condition but no stress related-woronin bodies in fungal hyphae were observed. To gain additional insight into the cell wall integrity under different conditions, transcription level of a key gene involved in cell wall integrity gfaA, encoding the glutamine: fructose-6-phosphate amidotransferase enzyme, was evaluated using qRT-PCR. The transcription level showed no variation among different conditions. Overall, the results collectively indicate that the LSMMG has shown no significant stress on spore germination, mycelial growth, cell wall integrity of potentially pathogenic fungi, A. niger and P. chrysogenum.

  13. An attempt to model the probability of growth and aflatoxin B1 production of Aspergillus flavus under non-isothermal conditions in pistachio nuts.

    Science.gov (United States)

    Aldars-García, Laila; Ramos, Antonio J; Sanchis, Vicente; Marín, Sonia

    2015-10-01

    Human exposure to aflatoxins in foods is of great concern. The aim of this work was to use predictive mycology as a strategy to mitigate the aflatoxin burden in pistachio nuts postharvest. The probability of growth and aflatoxin B1 (AFB1) production of aflatoxigenic Aspergillus flavus, isolated from pistachio nuts, under static and non-isothermal conditions was studied. Four theoretical temperature scenarios, including temperature levels observed in pistachio nuts during shipping and storage, were used. Two types of inoculum were included: a cocktail of 25 A. flavus isolates and a single isolate inoculum. Initial water activity was adjusted to 0.87. Logistic models, with temperature and time as explanatory variables, were fitted to the probability of growth and AFB1 production under a constant temperature. Subsequently, they were used to predict probabilities under non-isothermal scenarios, with levels of concordance from 90 to 100% in most of the cases. Furthermore, the presence of AFB1 in pistachio nuts could be correctly predicted in 70-81 % of the cases from a growth model developed in pistachio nuts, and in 67-81% of the cases from an AFB1 model developed in pistachio agar. The information obtained in the present work could be used by producers and processors to predict the time for AFB1 production by A. flavus on pistachio nuts during transport and storage. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. A controlled study to determine the efficacy of Loxostylis alata (Anacardiaceae in the treatment of aspergillus in a chicken (Gallus domesticus model in comparison to ketoconazole

    Directory of Open Access Journals (Sweden)

    Suleiman Mohammed M

    2012-10-01

    Full Text Available Abstract Background The poultry industry due to intensive methods of farming is burdened with losses from numerous infectious agents, of which one is the fungus Aspergillus fumigatus. In a preliminary study, the extracts of Loxostylis alata A. Spreng, ex Rchb. showed good activity in vitro against A. fumigatus with a minimum inhibitory concentration of 0.07 mg/ml. For this study crude, a crude acetone extract of L. alata leaves was evaluated for its acute toxicity in a healthy chicken model and for efficacy in an infectious model of aspergillosis (A. fumigatus. Results At a dose of 300 mg/kg, the extract induced some toxicity characterised by decreased feed intake and weight loss. Consequently, 100 and 200 mg/kg were used to ascertain efficacy in the infectious model. The plant extract significantly reduced clinical disease in comparison to the control in a dose dependant manner. The extract was as effective as the positive control ketoconazole dosed at 60 mg/kg. Conclusions The results indicate that a crude extract of L. alata leaves has potential as an antifungal agent to protect poultry against avian aspergillosis.

  15. Transcriptome-Based Modeling Reveals that Oxidative Stress Induces Modulation of the AtfA-Dependent Signaling Networks in Aspergillus nidulans

    Directory of Open Access Journals (Sweden)

    Erzsébet Orosz

    2017-01-01

    Full Text Available To better understand the molecular functions of the master stress-response regulator AtfA in Aspergillus nidulans, transcriptomic analyses of the atfA null mutant and the appropriate control strains exposed to menadione sodium bisulfite- (MSB-, t-butylhydroperoxide- and diamide-induced oxidative stresses were performed. Several elements of oxidative stress response were differentially expressed. Many of them, including the downregulation of the mitotic cell cycle, as the MSB stress-specific upregulation of FeS cluster assembly and the MSB stress-specific downregulation of nitrate reduction, tricarboxylic acid cycle, and ER to Golgi vesicle-mediated transport, showed AtfA dependence. To elucidate the potential global regulatory role of AtfA governing expression of a high number of genes with very versatile biological functions, we devised a model based on the comprehensive transcriptomic data. Our model suggests that an important function of AtfA is to modulate the transduction of stress signals. Although it may regulate directly only a limited number of genes, these include elements of the signaling network, for example, members of the two-component signal transduction systems. AtfA acts in a stress-specific manner, which may increase further the number and diversity of AtfA-dependent genes. Our model sheds light on the versatility of the physiological functions of AtfA and its orthologs in fungi.

  16. Tannase Production by Aspergillus niger

    Directory of Open Access Journals (Sweden)

    N. Lokeswari

    2007-01-01

    Full Text Available A method for assay of microbial tannase (Tannin acyl hydrolase based on the formation of chromogen between gallic acid and rhodanine is reported. Maximum Tannase production occurred in the culture broth containing 1-2% (w/v tannic acid and 0.05 – 0.1% (w/v glucose. The pH, incubation period, temperature and Glucose concentration optima of Tannase production was found at 5.5, 36 h, 35°C and 0.5% respectively. These properties make the enzyme suitable for pollution control and bioprocess industry. This assay is very simple, reproducible, and very convenient, and with it Tannase activity can be measured in relation to the growth of the organism. Aspergillus niger exhibited higher enzyme activity showing about 65 mole percent conversion respectively after a 36 h incubation period. The assay is complete in a short time, very convenient and reproducible.

  17. Modelling and mutational analysis of Aspergillus nidulans UreA, a member of the subfamily of urea/H+ transporters in fungi and plants

    Science.gov (United States)

    Sanguinetti, Manuel; Amillis, Sotiris; Pantano, Sergio; Scazzocchio, Claudio; Ramón, Ana

    2014-01-01

    We present the first account of the structure–function relationships of a protein of the subfamily of urea/H+ membrane transporters of fungi and plants, using Aspergillus nidulans UreA as a study model. Based on the crystal structures of the Vibrio parahaemolyticus sodium/galactose symporter (vSGLT) and of the Nucleobase-Cation-Symport-1 benzylhydantoin transporter from Microbacterium liquefaciens (Mhp1), we constructed a three-dimensional model of UreA which, combined with site-directed and classical random mutagenesis, led to the identification of amino acids important for UreA function. Our approach allowed us to suggest roles for these residues in the binding, recognition and translocation of urea, and in the sorting of UreA to the membrane. Residues W82, Y106, A110, T133, N275, D286, Y388, Y437 and S446, located in transmembrane helixes 2, 3, 7 and 11, were found to be involved in the binding, recognition and/or translocation of urea and the sorting of UreA to the membrane. Y106, A110, T133 and Y437 seem to play a role in substrate selectivity, while S446 is necessary for proper sorting of UreA to the membrane. Other amino acids identified by random classical mutagenesis (G99, R141, A163, G168 and P639) may be important for the basic transporter's structure, its proper folding or its correct traffic to the membrane. PMID:24966243

  18. Modeling and verification of process parameters for the production of tannase by Aspergillus oryzae under submerged fermentation using agro-wastes.

    Science.gov (United States)

    Varadharajan, Venkatramanan; Vadivel, Sudhan Shanmuga; Ramaswamy, Arulvel; Sundharamurthy, Venkatesaprabhu; Chandrasekar, Priyadharshini

    2017-01-01

    Tannase production by Aspergillus oryzae using various agro-wastes as substrates by submerged fermentation was studied in this research. The microbe was isolated from degrading corn kernel obtained from the corn fields at Tiruchengode, India. The microbial identification was done using 18S rRNA gene analysis. The agro-wastes chosen for the study were pomegranate rind, Cassia auriculata flower, black gram husk, and tea dust. The process parameters chosen for optimization study were substrate concentration, pH, temperature, and incubation period. During one variable at a time optimization, the pomegranate rind extract produced maximum tannase activity of 138.12 IU/mL and it was chosen as the best substrate for further experiments. The quadratic model was found to be the effective model for prediction of tannase production by A. oryzae. The optimized conditions predicted by response surface methodology (RSM) with genetic algorithm (GA) were 1.996% substrate concentration, pH of 4.89, temperature of 34.91 °C, and an incubation time of 70.65 H with maximum tannase activity of 138.363 IU/mL. The confirmatory experiment under optimized conditions showed tannase activity of 139.22 IU/mL. Hence, RSM-GA pair was successfully used in this study to optimize the process parameters required for the production of tannase using pomegranate rind. © 2015 International Union of Biochemistry and Molecular Biology, Inc.

  19. Comparative Reannotation of 21 Aspergillus Genomes

    Energy Technology Data Exchange (ETDEWEB)

    Salamov, Asaf; Riley, Robert; Kuo, Alan; Grigoriev, Igor

    2013-03-08

    We used comparative gene modeling to reannotate 21 Aspergillus genomes. Initial automatic annotation of individual genomes may contain some errors of different nature, e.g. missing genes, incorrect exon-intron structures, 'chimeras', which fuse 2 or more real genes or alternatively splitting some real genes into 2 or more models. The main premise behind the comparative modeling approach is that for closely related genomes most orthologous families have the same conserved gene structure. The algorithm maps all gene models predicted in each individual Aspergillus genome to the other genomes and, for each locus, selects from potentially many competing models, the one which most closely resembles the orthologous genes from other genomes. This procedure is iterated until no further change in gene models is observed. For Aspergillus genomes we predicted in total 4503 new gene models ( ~;;2percent per genome), supported by comparative analysis, additionally correcting ~;;18percent of old gene models. This resulted in a total of 4065 more genes with annotated PFAM domains (~;;3percent increase per genome). Analysis of a few genomes with EST/transcriptomics data shows that the new annotation sets also have a higher number of EST-supported splice sites at exon-intron boundaries.

  20. Safety Cultural Competency Modeling in Nuclear Organizations

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sa Kil; Oh, Yeon Ju; Luo, Meiling; Lee, Yong Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    The nuclear safety cultural competency model should be supplemented through a bottom-up approach such as behavioral event interview. The developed model, however, is meaningful for determining what should be dealt for enhancing safety cultural competency of nuclear organizations. The more details of the developing process, results, and applications will be introduced later. Organizational culture include safety culture in terms of its organizational characteristics.

  1. A STRATEGIC MANAGEMENT MODEL FOR SERVICE ORGANIZATIONS

    OpenAIRE

    Andreea ZAMFIR

    2013-01-01

    This paper provides a knowledge-based strategic management of services model, with a view to emphasise an approach to gaining competitive advantage through knowledge, people and networking. The long-term evolution of the service organization is associated with the way in which the strategic management is practised.

  2. Expanding on Successful Concepts, Models, and Organization

    Science.gov (United States)

    If the goal of the AEP framework was to replace existing exposure models or databases for organizing exposure data with a concept, we would share Dr. von Göetz concerns. Instead, the outcome we promote is broader use of an organizational framework for exposure science. The f...

  3. Chemodiversity in the genus Aspergillus

    DEFF Research Database (Denmark)

    Frisvad, Jens Christian; Larsen, Thomas Ostenfeld

    2015-01-01

    to be characterized. The genus Aspergillus is cladistically holophyletic but phenotypically polythetic and very diverse and is associated to quite different sexual states. Following the one fungus one name system, the genus Aspergillus is restricted to a holophyletic clade that include the morphologically different...... biosynthetic family isoextrolites. However, it appears that secondary metabolites from one Aspergillus section have analogous metabolites in other sections (here also called heteroisoextrolites). In this review, we give a genus-wide overview of secondary metabolite production in Aspergillus species. Extrolites...

  4. Studies on Aspergillus flavus

    International Nuclear Information System (INIS)

    Padwal-Desai, S.R.; Ghanekar, A.S.; Sreenivasan, A.

    1976-01-01

    In vitro studies were conducted on conidia of Aspergillus flavus Link (aflatoxin producing) and Aspergillus flavus oryzae (non-toxigenic) strains isolated and identified in this laboratory. These strains differed in resistance to heat and gamma radiation, the toxigenic strain being more resistant to both treatments. Results of tests on dose-modifying factors indicated that composition, temperature and pH of suspending media affected radiation resistance. On the other hand, the size of the initial population and the age of the conidia did not influence the radiation resistance of either strain. Studies on thermal inactivation of the conidia suggested that the temperature employed was more important than the time of heat treatment. Conidia of both strains showed a synergistic effect of combined heat and radiation treatments, although a heat-radiation sequence was more effective than a radiation-heat sequence. (author)

  5. Aspergillus Galactomannan Enzyme Immunoassay and Quantitative PCR for Diagnosis of Invasive Aspergillosis with Bronchoalveolar Lavage Fluid

    OpenAIRE

    Musher, Benjamin; Fredricks, David; Leisenring, Wendy; Balajee, S. Arunmozhi; Smith, Caitlin; Marr, Kieren A.

    2004-01-01

    Invasive pulmonary aspergillosis (IPA) is frequent and often fatal in hematopoietic stem cell transplant patients. Diagnosis requires microbiological or histopathologic demonstration of the organism in tissues; however, cultivation of Aspergillus species from respiratory secretions has low diagnostic sensitivity. Assays to detect Aspergillus antigen or DNA in bronchoalveolar lavage (BAL) fluid could facilitate earlier diagnosis, thereby guiding optimal therapy and obviating the need for addit...

  6. Emergent organization in a model market

    Science.gov (United States)

    Yadav, Avinash Chand; Manchanda, Kaustubh; Ramaswamy, Ramakrishna

    2017-09-01

    We study the collective behaviour of interacting agents in a simple model of market economics that was originally introduced by Nørrelykke and Bak. A general theoretical framework for interacting traders on an arbitrary network is presented, with the interaction consisting of buying (namely consumption) and selling (namely production) of commodities. Extremal dynamics is introduced by having the agent with least profit in the market readjust prices, causing the market to self-organize. In addition to examining this model market on regular lattices in two-dimensions, we also study the cases of random complex networks both with and without community structures. Fluctuations in an activity signal exhibit properties that are characteristic of avalanches observed in models of self-organized criticality, and these can be described by power-law distributions when the system is in the critical state.

  7. A trispecies Aspergillus microarray: Comparative transcriptomics of three Aspergillus species

    DEFF Research Database (Denmark)

    Andersen, Mikael Rørdam; Vongsangnak, Wanwipa; Panagiotou, Gianni

    2008-01-01

    The full-genome sequencing of the filamentous fungi Aspergillus nidulans, Aspergillus niger, and Aspergillus oryzae has opened possibilities for studying the cellular physiology of these fungi on a systemic level. As a tool to explore this, we are making available an Affymetrix GeneChip developed...... data identified 23 genes to be a conserved response across Aspergillus sp., including the xylose transcriptional activator XlnR. A promoter analysis of the up-regulated genes in all three species indicates the conserved XInR-binding site to be 5'-GGNTAAA-3'. The composition of the conserved gene......-set suggests that xylose acts as a molecule, indicating the presence of complex carbohydrates such as hemicellulose, and triggers an array of degrading enzymes. With this case example, we present a validated tool for transcriptome analysis of three Aspergillus species and a methodology for conducting cross...

  8. Gene expression profiles of human dendritic cells interacting with Aspergillus fumigatus in a bilayer model of the alveolar epithelium/endothelium interface.

    Directory of Open Access Journals (Sweden)

    Charles Oliver Morton

    Full Text Available The initial stages of the interaction between the host and Aspergillus fumigatus at the alveolar surface of the human lung are critical in the establishment of aspergillosis. Using an in vitro bilayer model of the alveolus, including both the epithelium (human lung adenocarcinoma epithelial cell line, A549 and endothelium (human pulmonary artery epithelial cells, HPAEC on transwell membranes, it was possible to closely replicate the in vivo conditions. Two distinct sub-groups of dendritic cells (DC, monocyte-derived DC (moDC and myeloid DC (mDC, were included in the model to examine immune responses to fungal infection at the alveolar surface. RNA in high quantity and quality was extracted from the cell layers on the transwell membrane to allow gene expression analysis using tailored custom-made microarrays, containing probes for 117 immune-relevant genes. This microarray data indicated minimal induction of immune gene expression in A549 alveolar epithelial cells in response to germ tubes of A. fumigatus. In contrast, the addition of DC to the system greatly increased the number of differentially expressed immune genes. moDC exhibited increased expression of genes including CLEC7A, CD209 and CCL18 in the absence of A. fumigatus compared to mDC. In the presence of A. fumigatus, both DC subgroups exhibited up-regulation of genes identified in previous studies as being associated with the exposure of DC to A. fumigatus and exhibiting chemotactic properties for neutrophils, including CXCL2, CXCL5, CCL20, and IL1B. This model closely approximated the human alveolus allowing for an analysis of the host pathogen interface that complements existing animal models of IA.

  9. Integrated modelling of two xenobiotic organic compounds

    DEFF Research Database (Denmark)

    Lindblom, Erik Ulfson; Gernaey, K.V.; Henze, Mogens

    2006-01-01

    This paper presents a dynamic mathematical model that describes the fate and transport of two selected xenobiotic organic compounds (XOCs) in a simplified representation. of an integrated urban wastewater system. A simulation study, where the xenobiotics bisphenol A and pyrene are used as reference...... compounds, is carried out. Sorption and specific biological degradation processes are integrated with standardised water process models to model the fate of both compounds. Simulated mass flows of the two compounds during one dry weather day and one wet weather day are compared for realistic influent flow...... rate and concentration profiles. The wet weather day induces resuspension of stored sediments, which increases the pollutant load on the downstream system. The potential of the model to elucidate important phenomena related to origin and fate of the model compounds is demonstrated....

  10. Modelling the behaviour of organic degradation products

    International Nuclear Information System (INIS)

    Cross, J.E.; Ewart, F.T.; Greenfield, B.F.

    1989-03-01

    Results are presented from recent studies at Harwell which show that the degradation products which are formed when certain organic waste materials are exposed to the alkaline conditions typical of a cementitious environment, can enhance the solubility of plutonium, even at pH values as high as 12, by significant factors. Characterisation of the degradation products has been undertaken but the solubility enhancement does not appear to be related to the concentration of any of the major organic species that have been identified in the solutions. While it has not been possible to identify by analysis the organic ligand responsible for the increased solubility of plutonium, the behaviour of D-Saccharic acid does approach the behaviour of the degradation products. The PHREEQE code has been used to simulate the solubility of plutonium in the presence of D-Saccharic acid and other model degradation products, in order to explain the solubility enhancement. The extrapolation of the experimental conditions to the repository is the major objective, but in this work the ability of a model to predict the behaviour of plutonium over a range of experimental conditions has been tested. (author)

  11. Aspergillus saccharolyticus sp. nov., a new black Aspergillus species isolated in Denmark

    DEFF Research Database (Denmark)

    Sørensen, Annette; Lübeck, Peter S.; Lübeck, Mette

    2011-01-01

    A novel species, Aspergillus saccharolyticus sp. nov., belonging to the Aspergillus section Nigri group is described. This species was isolated in Denmark from treated hardwood. Its taxonomic status was determined using a polyphasic taxonomic approach including phenotypic (morphology and extrolite...... Aspergillus species that is morphologically similar to Aspergillus japonicus and Aspergillus aculeatus, but has a totally different extrolite profile compared to any known Aspergillus species. The type strain of A. saccharolyticus sp. nov. is CBS 127449T ( = IBT 28509T)....

  12. Growth Modeling of Aspergillus niger Strains Isolated from Citrus Fruit as a Function of Temperature on a Synthetic Medium from Lime (Citrus latifolia T.) Pericarp.

    Science.gov (United States)

    Sandoval-Contreras, T; Marín, S; Villarruel-López, A; Gschaedler, A; Garrido-Sánchez, L; Ascencio, F

    2017-07-01

    Molds are responsible for postharvest spoilage of citrus fruits. The objective of this study was to evaluate the effect of temperature on growth rate and the time to visible growth of Aspergillus niger strains isolated from citrus fruits. The growth of these strains was studied on agar lime medium (AL) at different temperatures, and growth rate was estimated using the Baranyi and Roberts model (Int. J. Food Microbiol. 23:277-294, 1994). The Rosso et al. cardinal model with inflexion (L. Rosso, J. R. Lobry, S. Bajard, and J. P. Flandrois, J. Theor. Biol. 162:447-463, 1993) was used as a secondary model to describe the effect of temperature on growth rate and the lag phase. We hypothesized that the same model could be used to calculate the time for the mycelium to become visible (t v ) by substituting the lag phase (1/λ and 1/λ opt ) with the time to visible colony (1/t v -opt and 1/t v ), respectively, in the Rosso et al. High variability was observed at suboptimal conditions. Extremes of temperature of growth for A. niger seem to have a normal variability. For the growth rate and time t v , the model was satisfactorily compared with results of previous studies. An external validation was performed in lime fruits; the bias and accuracy factors were 1.3 and 1.5, respectively, for growth rate and 0.24 and 3.72, respectively, for the appearance time. The discrepancy may be due to the influence of external factors. A. niger grows significantly more slowly on lime fruit than in culture medium, probably because the nutrients are more easily available in medium than in fruits, where the peel consistency may be a physical barrier. These findings will help researchers understand the postharvest behavior of mold on lime fruits, host-pathogen interactions, and environmental conditions infecting fruit and also help them develop guidelines for future work in the field of predictive mycology to improve models for control of postharvest fungi.

  13. AFM images of complexes between amylose and Aspergillus niger glucoamylase mutants, native and mutant starch binding domains: a model for the action of glucoamylase

    DEFF Research Database (Denmark)

    Morris, V. M.; Gunning, A. P.; Faults, C. B.

    2005-01-01

    Atomic force microscopy has been used to investigate the complexes formed between high molecular weight amylose chains and Aspergillus niger glucoamylase mutants (E400Q and W52F), wild-type A. niger starch binding domains (SBDS), and mutant SBDs (W563K and W590K) lacking either of the two starch...

  14. Effect of low oxygen concentrations on growth and alpha-amylase production of Aspergillus oryzae in model solid-state fermentation systems

    NARCIS (Netherlands)

    Rahardjo, Y.S.P.; Sie, S.; Weber, F.J.; Tramper, J.; Rinzema, A.

    2005-01-01

    Oxygen transfer in the fungal mat is a major concern in solid-state fermentation (SSF). Oxygen supply into the mycelial layers is hampered by diffusion limitation. For aerobic fungi, like Aspergillus oryzae, this oxygen depletion can be a severely limiting factor for growth and metabolite

  15. Previously unknown species of Aspergillus.

    Science.gov (United States)

    Gautier, M; Normand, A-C; Ranque, S

    2016-08-01

    The use of multi-locus DNA sequence analysis has led to the description of previously unknown 'cryptic' Aspergillus species, whereas classical morphology-based identification of Aspergillus remains limited to the section or species-complex level. The current literature highlights two main features concerning these 'cryptic' Aspergillus species. First, the prevalence of such species in clinical samples is relatively high compared with emergent filamentous fungal taxa such as Mucorales, Scedosporium or Fusarium. Second, it is clearly important to identify these species in the clinical laboratory because of the high frequency of antifungal drug-resistant isolates of such Aspergillus species. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) has recently been shown to enable the identification of filamentous fungi with an accuracy similar to that of DNA sequence-based methods. As MALDI-TOF MS is well suited to the routine clinical laboratory workflow, it facilitates the identification of these 'cryptic' Aspergillus species at the routine mycology bench. The rapid establishment of enhanced filamentous fungi identification facilities will lead to a better understanding of the epidemiology and clinical importance of these emerging Aspergillus species. Based on routine MALDI-TOF MS-based identification results, we provide original insights into the key interpretation issues of a positive Aspergillus culture from a clinical sample. Which ubiquitous species that are frequently isolated from air samples are rarely involved in human invasive disease? Can both the species and the type of biological sample indicate Aspergillus carriage, colonization or infection in a patient? Highly accurate routine filamentous fungi identification is central to enhance the understanding of these previously unknown Aspergillus species, with a vital impact on further improved patient care. Copyright © 2016 European Society of Clinical Microbiology and

  16. Virtuous organization: A structural equation modeling approach

    Directory of Open Access Journals (Sweden)

    Majid Zamahani

    2013-02-01

    Full Text Available For years, the idea of virtue was unfavorable among researchers and virtues were traditionally considered as culture-specific, relativistic and they were supposed to be associated with social conservatism, religious or moral dogmatism, and scientific irrelevance. Virtue and virtuousness have been recently considered seriously among organizational researchers. The proposed study of this paper examines the relationships between leadership, organizational culture, human resource, structure and processes, care for community and virtuous organization. Structural equation modeling is employed to investigate the effects of each variable on other components. The data used in this study consists of questionnaire responses from employees in Payam e Noor University in Yazd province. A total of 250 questionnaires were sent out and a total of 211 valid responses were received. Our results have revealed that all the five variables have positive and significant impacts on virtuous organization. Among the five variables, organizational culture has the most direct impact (0.80 and human resource has the most total impact (0.844 on virtuous organization.

  17. cellulase and pectinase production potentials of aspergillus niger

    African Journals Online (AJOL)

    Prof Oyeleke

    Production of pectinase and cellulase by Aspergillus niger from corn cob was examined. ... organism was screened for enzymatic activity using Carboxyl Methyl ... preparation of denim fabrics in textile industries, ... exploitation of cellulase is its high cost of production ... catabolite repression influence economics of cellulase.

  18. Nutrient effects on production of cellulolytic enzymes by Aspergillus ...

    African Journals Online (AJOL)

    glucosidase) by Aspergillus niger on three media in liquid shake culture was compared. The culture filtrate of this organism exhibited relatively highest activity of all three enzymes and extracellular protein content at 7-day interval during the course of its ...

  19. Oxidant and solvent stable alkaline protease from Aspergillus flavus ...

    African Journals Online (AJOL)

    The increase in agricultural practices has necessitated the judicious use of agricultural wastes into value added products. In this study, an extracellular, organic solvent and oxidant stable, serine protease was produced by Aspergillus flavus MTCC 9952 under solid state fermentation. Maximum protease yield was obtained ...

  20. SACCHAROMYCES CEREVISIAE AND ASPERGILLUS NIGER

    African Journals Online (AJOL)

    DR. AMINU

    increase in ethanol production and cell growth increased with time of fermentation. ... fuel for automobiles. ... growth was determined by measuring the cell density .... Direct fermentation of potato starch to ethanol by co-cultures of Aspergillus.

  1. An Organization's Extended (Soft) Competencies Model

    Science.gov (United States)

    Rosas, João; Macedo, Patrícia; Camarinha-Matos, Luis M.

    One of the steps usually undertaken in partnerships formation is the assessment of organizations’ competencies. Typically considered competencies of a functional or technical nature, which provide specific outcomes can be considered as hard competencies. Yet, the very act of collaboration has its specific requirements, for which the involved organizations must be apt to exercise other type of competencies that affect their own performance and the partnership success. These competencies are more of a behavioral nature, and can be named as soft-competencies. This research aims at addressing the effects of the soft competencies on the performance of the hard ones. An extended competencies model is thus proposed, allowing the construction of adjusted competencies profiles, in which the competency levels are adjusted dynamically according to the requirements of collaboration opportunities.

  2. Modeling photocurrent transients in organic solar cells

    International Nuclear Information System (INIS)

    Hwang, I; Greenham, N C

    2008-01-01

    We investigate the transient photocurrents of organic photovoltaic devices in response to a sharp turn-on of illumination, by numerical modeling of the drift-diffusion equations. We show that the photocurrent turn-on dynamics are determined not only by the transport dynamics of free charges, but also by the time required for the population of geminate charge pairs to reach its steady-state value. The dissociation probability of a geminate charge pair is found to be a key parameter in determining the device performance, not only by controlling the efficiency at low intensities, but also in determining the fate of charge pairs formed by bimolecular recombination at high intensities. Bimolecular recombination is shown to reduce the turn-on time at high intensities, since the typical distance traveled by a charge pair is reduced.

  3. Computational modeling of Metal-Organic Frameworks

    Science.gov (United States)

    Sung, Jeffrey Chuen-Fai

    In this work, the metal-organic frameworks MIL-53(Cr), DMOF-2,3-NH 2Cl, DMOF-2,5-NH2Cl, and HKUST-1 were modeled using molecular mechanics and electronic structure. The effect of electronic polarization on the adsorption of water in MIL-53(Cr) was studied using molecular dynamics simulations of water-loaded MIL-53 systems with both polarizable and non-polarizable force fields. Molecular dynamics simulations of the full systems and DFT calculations on representative framework clusters were utilized to study the difference in nitrogen adsorption between DMOF-2,3-NH2Cl and DMOF-2,5-NH 2Cl. Finally, the control of proton conduction in HKUST-1 by complexation of molecules to the Cu open metal site was investigated using the MS-EVB methodology.

  4. Aspergillus asper sp. nov. and Aspergillus collinsii sp. nov., from Aspergillus section Usti.

    Science.gov (United States)

    Jurjevic, Zeljko; Peterson, Stephen W

    2016-07-01

    In sampling fungi from the built environment, two isolates that could not confidently be placed in described species were encountered. Phenotypic analysis suggested that they belonged in Aspergillus sect. Usti. In order to verify the sectional placement and to assure that they were undescribed rather than phenotypically aberrant isolates, DNA was isolated and sequenced at the beta-tubulin, calmodulin, internal transcribed spacer and RNA polymerase II loci and sequences compared with those from other species in the genus Aspergillus. At each locus, each new isolate was distant from existing species. Phylogenetic trees calculated from these data and GenBank data for species of the section Usti excluded the placement of these isolates in existing species, with statistical support. Because they were excluded from existing taxa, the distinct species Aspergillus asper (type strain NRRL 35910 T ) and Aspergillus collinsii (type strain NRRL 66196 T ) in sect. Usti are proposed to accommodate these strains.

  5. Blood, carcass and organ measurements as influenced by ...

    African Journals Online (AJOL)

    Effects of feeding Aspergillus treated cassava wastes on haematological values, organs and carcass measurements of West African dwarf goats (WAD) were determined. Twelve West African dwarf goats (weighing between 2.8 and 5.4kg) in a completely randomized design (CRD) model with 56d periods consumed diets A ...

  6. Model for Railway Infrastructure Management Organization

    Directory of Open Access Journals (Sweden)

    Gordan Stojić

    2012-03-01

    Full Text Available The provision of appropriate quality rail services has an important role in terms of railway infrastructure: quality of infrastructure maintenance, regulation of railway traffic, line capacity, speed, safety, train station organization, the allowable lines load and other infrastructure parameters.The analysis of experiences in transforming the railway systems points to the conclusion that there is no unique solution in terms of choice for institutional rail infrastructure management modes, although more than nineteen years have passed from the beginning of the implementation of the Directive 91/440/EEC. Depending on the approach to the process of restructuring the national railway company, adopted regulations and caution in its implementation, the existence or absence of a clearly defined transport strategy, the willingness to liberalize the transport market, there are several different ways for institutional management of railway infrastructure.A hybrid model for selection of modes of institutional rail infrastructure management was developed based on the theory of artificial intelligence, theory of fuzzy sets and theory of multicriteria optimization.KEY WORDSmanagement, railway infrastructure, organizational structure, hybrid model

  7. Metabolic control analysis of xylose catabolism in Aspergillus

    NARCIS (Netherlands)

    Prathumpai, W.; Gabelgaard, J.B.; Wanchanthuek, P.; Vondervoort, van de P.J.I.; Groot, de M.J.L.; McIntyre, M.; Nielsen, J.

    2003-01-01

    A kinetic model for xylose catabolism in Aspergillus is proposed. From a thermodynamic analysis it was found that the intermediate xylitol will accumulate during xylose catabolism. Use of the kinetic model allowed metabolic control analysis (MCA) of the xylose catabolic pathway to be carried out,

  8. The effectiveness of arbuscular-mycorrhizal fungi and Aspergillus niger or Phanerochaete chrysosporium treated organic amendments from olive residues upon plant growth in a semi-arid degraded soil.

    Science.gov (United States)

    Medina, A; Roldán, A; Azcón, R

    2010-12-01

    Arbuscular mycorrhizal (AM) fungi and a residue from dry olive cake (DOC) supplemented with rock phosphate (RP) and treated with either Aspergillus niger (DOC-A) or Phanerochaete chrysosporium (DOC-P), were assayed in a natural, semi-arid soil using Trifolium repens or Dorycnium pentaphyllum plants. The effects of the AM fungi and/or DOC-A were compared with P-fertilisation (P) over eleven successive harvests to evaluate the persistence of the effectiveness of the treatments. The biomass of dually-treated plants after four successive harvests was greater than that obtained for non-treated plants or those receiving the AM inoculum or DOC-A treatments after eleven yields. The AM inoculation was critical for obtaining plant growth benefit from the application of fermented DOC-A residue. The abilities of the treatments to prevent plant drought stress were also assayed. Drought-alleviating effects were evaluated in terms of plant growth, proline and total sugars concentration under alternative drought and re-watering conditions (8th and 9th harvests). The concentrations of both compounds in plant biomass increased under drought when DOC-A amendment and AM inoculation were employed together: they reinforced the plant drought-avoidance capabilities and anti-oxidative defence. Water stress was less compensated in P-fertilised than in DOC-A-treated plants. DOC-P increased D. pentaphyllum biomass, shoot P content, nodule number and AM colonisation, indicating the greater DOC-transforming ability of P. chrysosporium compared to A. niger. The lack of AM colonisation and nodulation in this soil was compensated by the application of DOC-P, particularly with AM inoculum. The management of natural resources (organic amendments and soil microorganisms) represents an important strategy that assured the growth, nutrition and plant establishment in arid, degraded soils, preventing the damage that arises from limited water and nutrient supply. Copyright © 2010 Elsevier Ltd. All rights

  9. Project-matrix models of marketing organization

    OpenAIRE

    Gutić Dragutin; Rudelj Siniša

    2009-01-01

    Unlike theory and practice of corporation organization, in marketing organization numerous forms and contents at its disposal are not reached until this day. It can be well estimated that marketing organization today in most of our companies and in almost all its parts, noticeably gets behind corporation organization. Marketing managers have always been occupied by basic, narrow marketing activities as: sales growth, market analysis, market growth and market share, marketing research, introdu...

  10. Analytical modeling and numerical optimization of the biosurfactants production in solid-state fermentation by Aspergillus fumigatus - doi: 10.4025/actascitechnol.v36i1.17818

    Directory of Open Access Journals (Sweden)

    Gabriel Castiglioni

    2014-01-01

    Full Text Available This is an experimental, analytical and numerical study to optimize the biosurfactants production in solid-state fermentation of a medium containing rice straw and minced rice bran inoculated with Aspergillus fumigatus. The goal of this work was to analytically model the biosurfactants production in solid-state fermentation into a column fixed bed bioreactor. The Least-Squares Method was used to adjust the emulsification activity experimental values to a quadratic function semi-empirical model. Control variables were nutritional conditions, the fermentation time and the aeration. The mathematical model is validated against experimental results and then used to predict the maximum emulsification activity for different nutritional conditions and aerations. Based on the semi-empirical model the maximum emulsification activity with no additional hydrocarbon sources was 8.16 UE·g-1 for 112 hours. When diesel oil was used the predicted maximum emulsification activity was 8.10 UE·g-1 for 108 hours.

  11. A novel fungal fruiting structure formed by Aspergillus niger and Aspergillus carbonarius in grape berries.

    Science.gov (United States)

    Pisani, Cristina; Nguyen, Trang Thoaivan; Gubler, Walter Douglas

    2015-09-01

    Sour rot, is a pre-harvest disease that affects many grape varieties. Sour rot symptoms include initial berry cracking and breakdown of berry tissue. This is a disease complex with many filamentous fungi and bacteria involved, but is usually initiated by Aspergillus niger or Aspergillus carbonarius. Usually, by the time one sees the rot there are many other organisms involved and it is difficult to attribute the disease to one species. In this study two species of Aspergillus were shown to produce a previously unknown fruiting structure in infected berries. The nodulous morphology, bearing conidia, suggests them to be an 'everted polymorphic stroma'. This structure forms freely inside the berry pulp and assumes multiple shapes and sizes, sometimes sclerotium-like in form. It is composed of a mass of vegetative hyphae with or without tissue of the host containing spores or fruiting bodies bearing spores. Artificially inoculated berries placed in soil in winter showed the possible overwintering function of the fruiting body. Inoculated berry clusters on standing vines produced fruiting structures within 21 d post inoculation when wounds were made at veraison or after (July-September). Histological studies confirmed that the fruiting structure was indeed fungal tissue. Copyright © 2015 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  12. Analysis and prediction of gene splice sites in four Aspergillus genomes

    DEFF Research Database (Denmark)

    Wang, Kai; Ussery, David; Brunak, Søren

    2009-01-01

    Several Aspergillus fungal genomic sequences have been published, with many more in progress. Obviously, it is essential to have high-quality, consistently annotated sets of proteins from each of the genomes, in order to make meaningful comparisons. We have developed a dedicated, publicly available......, splice site prediction program called NetAspGene, for the genus Aspergillus. Gene sequences from Aspergillus fumigatus, the most common mould pathogen, were used to build and test our model. Compared to many animals and plants, Aspergillus contains smaller introns; thus we have applied a larger window...... better splice site prediction than other available tools. NetAspGene will be very helpful for the study in Aspergillus splice sites and especially in alternative splicing. A webpage for NetAspGene is publicly available at http://www.cbs.dtu.dk/services/NetAspGene....

  13. The Time Is Right to Focus on Model Organism Metabolomes

    Directory of Open Access Journals (Sweden)

    Arthur S. Edison

    2016-02-01

    Full Text Available Model organisms are an essential component of biological and biomedical research that can be used to study specific biological processes. These organisms are in part selected for facile experimental study. However, just as importantly, intensive study of a small number of model organisms yields important synergies as discoveries in one area of science for a given organism shed light on biological processes in other areas, even for other organisms. Furthermore, the extensive knowledge bases compiled for each model organism enable systems-level understandings of these species, which enhance the overall biological and biomedical knowledge for all organisms, including humans. Building upon extensive genomics research, we argue that the time is now right to focus intensively on model organism metabolomes. We propose a grand challenge for metabolomics studies of model organisms: to identify and map all metabolites onto metabolic pathways, to develop quantitative metabolic models for model organisms, and to relate organism metabolic pathways within the context of evolutionary metabolomics, i.e., phylometabolomics. These efforts should focus on a series of established model organisms in microbial, animal and plant research.

  14. Models of care and organization of services.

    Science.gov (United States)

    Markova, Alina; Xiong, Michael; Lester, Jenna; Burnside, Nancy J

    2012-01-01

    This article examines the overall organization of services and delivery of health care in the United States. Health maintenance organization, fee-for-service, preferred provider organizations, and the Veterans Health Administration are discussed, with a focus on structure, outcomes, and areas for improvement. An overview of wait times, malpractice, telemedicine, and the growing population of physician extenders in dermatology is also provided. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Allergens/Antigens, Toxins and Polyketides of Important Aspergillus Species

    OpenAIRE

    Bhetariya, Preetida J.; Madan, Taruna; Basir, Seemi Farhat; Varma, Anupam; Usha, Sarma P.

    2011-01-01

    The medical, agricultural and biotechnological importance of the primitive eukaryotic microorganisms, the Fungi was recognized way back in 1920. Among various groups of fungi, the Aspergillus species are studied in great detail using advances in genomics and proteomics to unravel biological and molecular mechanisms in these fungi. Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger, Aspergillus parasiticus, Aspergillus nidulans and Aspergillus terreus are some of the important specie...

  16. Organization model and formalized description of nuclear enterprise information system

    International Nuclear Information System (INIS)

    Yuan Feng; Song Yafeng; Li Xudong

    2012-01-01

    Organization model is one of the most important models of Nuclear Enterprise Information System (NEIS). Scientific and reasonable organization model is the prerequisite that NEIS has robustness and extendibility, and is also the foundation of the integration of heterogeneous system. Firstly, the paper describes the conceptual model of the NEIS on ontology chart, which provides a consistent semantic framework of organization. Then it discusses the relations between the concepts in detail. Finally, it gives the formalized description of the organization model of NEIS based on six-tuple array. (authors)

  17. Aspergillus--classification and antifungal susceptibilities.

    Science.gov (United States)

    Buzina, Walter

    2013-01-01

    Aspergillus is one of the most important fungal genera for the man, for its industrial use, its ability to spoil food and not least its medical impact as cause of a variety of diseases. Currently hundreds of species of Aspergillus are known; nearly fifty of them are able to cause infections in humans and animals. Recently, the genus Aspergillus is subdivided into 8 subgenera and 22 sections. The spectrum of diseases caused by Aspergillus species varies from superficial cutaneous to invasive and systemic infections. All species of Aspergillus investigated so far are resistant against the antifungals fluconazole and 5-fluorocytosine, the range of susceptibilities to currently available antifungals is discussed in this paper.

  18. 3D Bioprinting of Tissue/Organ Models.

    Science.gov (United States)

    Pati, Falguni; Gantelius, Jesper; Svahn, Helene Andersson

    2016-04-04

    In vitro tissue/organ models are useful platforms that can facilitate systematic, repetitive, and quantitative investigations of drugs/chemicals. The primary objective when developing tissue/organ models is to reproduce physiologically relevant functions that typically require complex culture systems. Bioprinting offers exciting prospects for constructing 3D tissue/organ models, as it enables the reproducible, automated production of complex living tissues. Bioprinted tissues/organs may prove useful for screening novel compounds or predicting toxicity, as the spatial and chemical complexity inherent to native tissues/organs can be recreated. In this Review, we highlight the importance of developing 3D in vitro tissue/organ models by 3D bioprinting techniques, characterization of these models for evaluating their resemblance to native tissue, and their application in the prioritization of lead candidates, toxicity testing, and as disease/tumor models. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Metabolic control analysis of Aspergillus niger L-arabinose catabolism

    NARCIS (Netherlands)

    Groot, de M.J.L.; Prathumpai, W.; Visser, J.; Ruijter, G.J.G.

    2005-01-01

    A mathematical model of the L-arabinose/D-xylose catabolic pathway of Aspergillus niger was constructed based on the kinetic properties of the enzymes. For this purpose L-arabinose reductase, L-arabitol dehydrogenase and D-xylose reductase were purified using dye-affinity chromatography, and their

  20. Authentication in Virtual Organizations: A Reputation Based PKI Interconnection Model

    Science.gov (United States)

    Wazan, Ahmad Samer; Laborde, Romain; Barrere, Francois; Benzekri, Abdelmalek

    Authentication mechanism constitutes a central part of the virtual organization work. The PKI technology is used to provide the authentication in each organization involved in the virtual organization. Different trust models are proposed to interconnect the different PKIs in order to propagate the trust between them. While the existing trust models contain many drawbacks, we propose a new trust model based on the reputation of PKIs.

  1. Cyclopiazonic Acid Biosynthesis of Aspergillus flavus and Aspergillus oryzae

    Science.gov (United States)

    Cyclopiazonic acid (CPA) is an indole-tetramic acid neurotoxin produced by some of the same strains of A. flavus that produce aflatoxins and by some Aspergillus oryzae strains. Despite its discovery 40 years ago, few reviews of its toxicity and biosynthesis have been reported. This review examines w...

  2. EFFECT OF GAMMA IRRADIATION AND ENVIRONMENTAL FACTORS ON -AMYLASE PRODUCTION BY ASPERGILLUS NIGER AND ASPERGILLUS ORYZAE FROM SOME AGRICULTURAL WASTES

    International Nuclear Information System (INIS)

    MATTAR, Z.A.

    2008-01-01

    Amylases are one of the most important and oldest industrial enzymes. The optimization of production of α -amylase from Aspergillus niger and Aspergillus oryzae fungi, using different agro-wastes as sole carbon sources, was performed. The highest productivity of α -amylase by the two organisms was recorded at pH 6 and incubation temperature at 30 0C when the two organisms were grown on potato peels (PPs) and/or wheat straw (Ws) after days of cultivation. Pre-treated PPs and Ws with 20 kGy gave the best enzyme productivity by the two organisms compared with untreated ones. Also, exposing the inoculums of A. niger and A.oryzae to 0.5 and 0.75 kGy, respectively, led to enhancement of α-amylase to 48 and 46 μ/ml, respectively

  3. Aspergillus section Fumigati typing by PCR-restriction fragment polymorphism.

    Science.gov (United States)

    Staab, Janet F; Balajee, S Arunmozhi; Marr, Kieren A

    2009-07-01

    Recent studies have shown that there are multiple clinically important members of the Aspergillus section Fumigati that are difficult to distinguish on the basis of morphological features (e.g., Aspergillus fumigatus, A. lentulus, and Neosartorya udagawae). Identification of these organisms may be clinically important, as some species vary in their susceptibilities to antifungal agents. In a prior study, we utilized multilocus sequence typing to describe A. lentulus as a species distinct from A. fumigatus. The sequence data show that the gene encoding beta-tubulin, benA, has high interspecies variability at intronic regions but is conserved among isolates of the same species. These data were used to develop a PCR-restriction fragment length polymorphism (PCR-RFLP) method that rapidly and accurately distinguishes A. fumigatus, A. lentulus, and N. udagawae, three major species within the section Fumigati that have previously been implicated in disease. Digestion of the benA amplicon with BccI generated unique banding patterns; the results were validated by screening a collection of clinical strains and by in silico analysis of the benA sequences of Aspergillus spp. deposited in the GenBank database. PCR-RFLP of benA is a simple method for the identification of clinically important, similar morphotypes of Aspergillus spp. within the section Fumigati.

  4. Aspergillus Section Fumigati Typing by PCR-Restriction Fragment Polymorphism▿

    Science.gov (United States)

    Staab, Janet F.; Balajee, S. Arunmozhi; Marr, Kieren A.

    2009-01-01

    Recent studies have shown that there are multiple clinically important members of the Aspergillus section Fumigati that are difficult to distinguish on the basis of morphological features (e.g., Aspergillus fumigatus, A. lentulus, and Neosartorya udagawae). Identification of these organisms may be clinically important, as some species vary in their susceptibilities to antifungal agents. In a prior study, we utilized multilocus sequence typing to describe A. lentulus as a species distinct from A. fumigatus. The sequence data show that the gene encoding β-tubulin, benA, has high interspecies variability at intronic regions but is conserved among isolates of the same species. These data were used to develop a PCR-restriction fragment length polymorphism (PCR-RFLP) method that rapidly and accurately distinguishes A. fumigatus, A. lentulus, and N. udagawae, three major species within the section Fumigati that have previously been implicated in disease. Digestion of the benA amplicon with BccI generated unique banding patterns; the results were validated by screening a collection of clinical strains and by in silico analysis of the benA sequences of Aspergillus spp. deposited in the GenBank database. PCR-RFLP of benA is a simple method for the identification of clinically important, similar morphotypes of Aspergillus spp. within the section Fumigati. PMID:19403766

  5. Variability of Germinative Potential among Pathogenic Species of Aspergillus

    OpenAIRE

    Araujo, Ricardo; Rodrigues, Acacio Gonçalves

    2004-01-01

    The objective of our study was to evaluate parameters influencing the germination of Aspergillus conidia. Inoculum concentration and age significantly influenced germination. Different incubation temperatures revealed significant differences among Aspergillus species. The internal human milieu provides the ideal conditions for the development of invasive disease by Aspergillus fumigatus but restricts invasion by Aspergillus flavus and Aspergillus niger.

  6. MODELING OF MANAGEMENT PROCESSES IN AN ORGANIZATION

    Directory of Open Access Journals (Sweden)

    Stefan Iovan

    2016-05-01

    Full Text Available When driving any major change within an organization, strategy and execution are intrinsic to a project’s success. Nevertheless, closing the gap between strategy and execution remains a challenge for many organizations [1]. Companies tend to focus more on execution than strategy for quick results, instead of taking the time needed to understand the parts that make up the whole, so the right execution plan can be put in place to deliver the best outcomes. A large part of this understands that business operations don’t fit neatly within the traditional organizational hierarchy. Business processes are often messy, collaborative efforts that cross teams, departments and systems, making them difficult to manage within a hierarchical structure [2]. Business process management (BPM fills this gap by redefining an organization according to its end-to-end processes, so opportunities for improvement can be identified and processes streamlined for growth, revenue and transformation. This white paper provides guidelines on what to consider when using business process applications to solve your BPM initiatives, and the unique capabilities software systems provides that can help ensure both your project’s success and the success of your organization as a whole. majority of medium and small businesses, big companies and even some guvermental organizations [2].

  7. Self-Organizing Map Models of Language Acquisition

    Directory of Open Access Journals (Sweden)

    Ping eLi

    2013-11-01

    Full Text Available Connectionist models have had a profound impact on theories of language. While most early models were inspired by the classic PDP architecture, recent models of language have explored various other types of models, including self-organizing models for language acquisition. In this paper we aim at providing a review of the latter type of models, and highlight a number of simulation experiments that we have conducted based on these models. We show that self-organizing connectionist models can provide significant insights into long-standing debates in both monolingual and bilingual language development.

  8. Selection arena in Aspergillus nidulans

    NARCIS (Netherlands)

    Bruggeman, J.; Debets, A.J.M.; Hoekstra, R.F.

    2004-01-01

    The selection arena hypothesis states that overproduction of zygotes-a widespread phenomenon in animals and plants-can be explained as a mechanism of progeny choice. As a similar mechanism, the ascomycetous fungus Aspergillus nidulans may overproduce dikaryotic fruit initials, hereafter called

  9. Aspergillus mediastinitis after cardiac surgery

    Directory of Open Access Journals (Sweden)

    Marie-Josée Caballero

    2016-03-01

    Conclusion: The clinical features of postoperative Aspergillus mediastinitis may be paucisymptomatic, emphasizing the need for a low index of suspicion in cases of culture-negative mediastinitis or in indolent wound infections. In addition to surgical debridement, the central component of antifungal therapy should include amphotericin B or voriconazole.

  10. Nitrile biotransformation by Aspergillus niger

    Czech Academy of Sciences Publication Activity Database

    Šnajdrová, Radka; Kristová, Veronika; Crestia, D.; Nikolaou, K.; Kuzma, Marek; Lemaire, M.; Gallienne, E.; Bolte, J.; Bezouška, K.; Křen, Vladimír; Martínková, Ludmila

    2004-01-01

    Roč. 29, - (2004), s. 227-232 ISSN 1381-1177 R&D Projects: GA MŠk OC D25.002; GA AV ČR IAA4020213 Institutional research plan: CEZ:AV0Z5020903 Keywords : aspergillus niger * nitrile-converting enzymes * nitrile hydratase Subject RIV: EE - Microbiology, Virology Impact factor: 1.547, year: 2004

  11. The initiative on Model Organism Proteomes (iMOP) Session

    DEFF Research Database (Denmark)

    Schrimpf, Sabine P; Mering, Christian von; Bendixen, Emøke

    2012-01-01

    iMOP – the Initiative on Model Organism Proteomes – was accepted as a new HUPO initiative at the Ninth HUPO meeting in Sydney in 2010. A goal of iMOP is to integrate research groups working on a great diversity of species into a model organism community. At the Tenth HUPO meeting in Geneva...

  12. Modeling the Explicit Chemistry of Anthropogenic and Biogenic Organic Aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Madronich, Sasha [Univ. Corporation for Atmospheric Research, Boulder, CO (United States)

    2015-12-09

    The atmospheric burden of Secondary Organic Aerosols (SOA) remains one of the most important yet uncertain aspects of the radiative forcing of climate. This grant focused on improving our quantitative understanding of SOA formation and evolution, by developing, applying, and improving a highly detailed model of atmospheric organic chemistry, the Generation of Explicit Chemistry and Kinetics of Organics in the Atmosphere (GECKO-A) model. Eleven (11) publications have resulted from this grant.

  13. Physiological characterisation of acuB deletion in Aspergillus niger

    DEFF Research Database (Denmark)

    Meijer, Susan Lisette; De Jongh, Willem Adriaan; Olsson, Lisbeth

    2009-01-01

    The acuB gene of Aspergillus niger is an ortholog of facB in Aspergillus nidulans. Under carbon-repression conditions, facB is repressed, thereby preventing acetate metabolism when the repressing carbon source is present. Even though facB is reported to be repressed directly by CreA, it is believed...... that a basal level of FacB activity exists under glucose-repressive conditions. In the present study, the effect of deletion of acuB on the physiology of A. niger was assessed. Differences in organic acid and acetate production, enzyme activities and extracellular amino and non-amino organic acid production...... were determined under glucose-repressing and -derepressing conditions. Furthermore, consumption of alternative carbon sources (e.g. xylose, citrate, lactate and succinate) was investigated. It was shown that AcuB has pleiotropic effects on the physiology of A. niger. The results indicate that metabolic...

  14. Two novel aflatoxin-producing Aspergillus species from Argentinean peanuts

    DEFF Research Database (Denmark)

    Pildain, M.B.; Frisvad, Jens Christian; Vaamonde, G.

    2008-01-01

    Two novel species from Aspergillus section Flavi from different species of Arachis (peanuts) in Argentina are described as Aspergillus arachidicola sp. nov. and Aspergillus minisclerotigenes sp. nov. Their novel taxonomic status was determined using a polyphasic taxonomic approach with phenotypic...

  15. Effect of nutrient components for phytase production by Aspergillus niger

    OpenAIRE

    KALIYEVA AIGUL; SULEIMENOVA ZHANARA; AKHMETSADYKOV NURLAN; SADUYEVA ZHAZIRA

    2015-01-01

    In present study the effect of carbon sources, glucose, sucrose, lactose, maltose, fructose, xylose and nitrogen sources such as ammonium sulfate, ammonium phosphate, ammonium nitrate, potassium nitrate, yeast extract, peptone on the phytase production has been studied. Maximal phytase activity of Aspergillus niger was detected in media with 1.0% sucrose as a carbon source. All other monosaccharides and disaccharides used had less effect on phytase production. Among the inorganic and organic ...

  16. Aspergillus niger: an unusual cause of invasive pulmonary aspergillosis

    Science.gov (United States)

    Person, A. K.; Chudgar, S. M.; Norton, B. L.; Tong, B. C.; Stout, J. E.

    2010-01-01

    Infections due to Aspergillus species cause significant morbidity and mortality. Most are attributed to Aspergillus fumigatus, followed by Aspergillus flavus and Aspergillus terreus. Aspergillus niger is a mould that is rarely reported as a cause of pneumonia. A 72-year-old female with chronic obstructive pulmonary disease and temporal arteritis being treated with steroids long term presented with haemoptysis and pleuritic chest pain. Chest radiography revealed areas of heterogeneous consolidation with cavitation in the right upper lobe of the lung. Induced bacterial sputum cultures, and acid-fast smears and cultures were negative. Fungal sputum cultures grew A. niger. The patient clinically improved on a combination therapy of empiric antibacterials and voriconazole, followed by voriconazole monotherapy. After 4 weeks of voriconazole therapy, however, repeat chest computed tomography scanning showed a significant progression of the infection and near-complete necrosis of the right upper lobe of the lung. Serum voriconazole levels were low–normal (1.0 μg ml−1, normal range for the assay 0.5–6.0 μg ml−1). A. niger was again recovered from bronchoalveolar lavage specimens. A right upper lobectomy was performed, and lung tissue cultures grew A. niger. Furthermore, the lung histopathology showed acute and organizing pneumonia, fungal hyphae and oxalate crystallosis, confirming the diagnosis of invasive A. niger infection. A. niger, unlike A. fumigatus and A. flavus, is less commonly considered a cause of invasive aspergillosis (IA). The finding of calcium oxalate crystals in histopathology specimens is classic for A. niger infection and can be helpful in making a diagnosis even in the absence of conidia. Therapeutic drug monitoring may be useful in optimizing the treatment of IA given the wide variations in the oral bioavailability of voriconazole. PMID:20299503

  17. Saccharomyces cerevisiae as a model organism: a comparative study.

    Directory of Open Access Journals (Sweden)

    Hiren Karathia

    Full Text Available BACKGROUND: Model organisms are used for research because they provide a framework on which to develop and optimize methods that facilitate and standardize analysis. Such organisms should be representative of the living beings for which they are to serve as proxy. However, in practice, a model organism is often selected ad hoc, and without considering its representativeness, because a systematic and rational method to include this consideration in the selection process is still lacking. METHODOLOGY/PRINCIPAL FINDINGS: In this work we propose such a method and apply it in a pilot study of strengths and limitations of Saccharomyces cerevisiae as a model organism. The method relies on the functional classification of proteins into different biological pathways and processes and on full proteome comparisons between the putative model organism and other organisms for which we would like to extrapolate results. Here we compare S. cerevisiae to 704 other organisms from various phyla. For each organism, our results identify the pathways and processes for which S. cerevisiae is predicted to be a good model to extrapolate from. We find that animals in general and Homo sapiens in particular are some of the non-fungal organisms for which S. cerevisiae is likely to be a good model in which to study a significant fraction of common biological processes. We validate our approach by correctly predicting which organisms are phenotypically more distant from S. cerevisiae with respect to several different biological processes. CONCLUSIONS/SIGNIFICANCE: The method we propose could be used to choose appropriate substitute model organisms for the study of biological processes in other species that are harder to study. For example, one could identify appropriate models to study either pathologies in humans or specific biological processes in species with a long development time, such as plants.

  18. The System Dynamics Model for Development of Organic Agriculture

    Science.gov (United States)

    Rozman, Črtomir; Škraba, Andrej; Kljajić, Miroljub; Pažek, Karmen; Bavec, Martina; Bavec, Franci

    2008-10-01

    Organic agriculture is the highest environmentally valuable agricultural system, and has strategic importance at national level that goes beyond the interests of agricultural sector. In this paper we address development of organic farming simulation model based on a system dynamics methodology (SD). The system incorporates relevant variables, which affect the development of the organic farming. The group decision support system (GDSS) was used in order to identify most relevant variables for construction of causal loop diagram and further model development. The model seeks answers to strategic questions related to the level of organically utilized area, levels of production and crop selection in a long term dynamic context and will be used for simulation of different policy scenarios for organic farming and their impact on economic and environmental parameters of organic production at an aggregate level.

  19. Kinetics of cellobiose hydrolysis using cellobiase composites from Trichoderma reesei and Aspergillus niger

    Energy Technology Data Exchange (ETDEWEB)

    Grous, W.; Converse, A.; Grethlein, H.; Lynd, L.

    1985-01-01

    The enzymatic hydrolysis of cellulose to glucose involves the formation of cellobiose as an intermediate. It has been found necessary to add cellobiase from Aspergillus niger (NOVO) to the cellobiase component of Trichoderma reesei mutant Rut C-30 (Natick) cellulase enzymes in order to obtain after 48 h complete conversion of the cellobiose formed in the enzymatic hydrolysis of biomass. This study of the cellobiase activity of these two enzyme sources was undertaken as a first step in the formation of a kinetic model for cellulose hydrolysis that can be used in process design. In order to cover the full range of cellobiose concentrations, it was necessary to develop separate kinetic parameters for high- and low-concentration ranges of cellobiose for the enzymes from each organism. Competitive glucose inhibition was observed with the enzymes from both organisms. Substrate inhibition was observed only with the A. niger enzymes.

  20. A linear solvation energy relationship model of organic chemical partitioning to dissolved organic carbon.

    Science.gov (United States)

    Kipka, Undine; Di Toro, Dominic M

    2011-09-01

    Predicting the association of contaminants with both particulate and dissolved organic matter is critical in determining the fate and bioavailability of chemicals in environmental risk assessment. To date, the association of a contaminant to particulate organic matter is considered in many multimedia transport models, but the effect of dissolved organic matter is typically ignored due to a lack of either reliable models or experimental data. The partition coefficient to dissolved organic carbon (K(DOC)) may be used to estimate the fraction of a contaminant that is associated with dissolved organic matter. Models relating K(DOC) to the octanol-water partition coefficient (K(OW)) have not been successful for many types of dissolved organic carbon in the environment. Instead, linear solvation energy relationships are proposed to model the association of chemicals with dissolved organic matter. However, more chemically diverse K(DOC) data are needed to produce a more robust model. For humic acid dissolved organic carbon, the linear solvation energy relationship predicts log K(DOC) with a root mean square error of 0.43. Copyright © 2011 SETAC.

  1. Atypical Aspergillus parasiticus isolates from pistachio with aflR gene nucleotide insertion identical to Aspergillus sojae

    Science.gov (United States)

    Aflatoxins are the most toxic and carcinogenic secondary metabolites produced primarily by the filamentous fungi Aspergillus flavus and Aspergillus parasiticus. The toxins cause devastating economic losses because of strict regulations on distribution of contaminated products. Aspergillus sojae are...

  2. What Does Genetic Diversity of Aspergillus flavus Tell Us About Aspergillus oryzae?

    Science.gov (United States)

    Aspergillus flavus and Aspergillus oryzae belong to Aspergillus section Flavi. They are closely related and are of significant economic importance. The former species has the ability to produce harmful aflatoxins while the latter is widely used in food fermentation and industrial enzyme production. ...

  3. Modeling the influence of organic acids on soil weathering

    Science.gov (United States)

    Lawrence, Corey R.; Harden, Jennifer W.; Maher, Kate

    2014-01-01

    Biological inputs and organic matter cycling have long been regarded as important factors in the physical and chemical development of soils. In particular, the extent to which low molecular weight organic acids, such as oxalate, influence geochemical reactions has been widely studied. Although the effects of organic acids are diverse, there is strong evidence that organic acids accelerate the dissolution of some minerals. However, the influence of organic acids at the field-scale and over the timescales of soil development has not been evaluated in detail. In this study, a reactive-transport model of soil chemical weathering and pedogenic development was used to quantify the extent to which organic acid cycling controls mineral dissolution rates and long-term patterns of chemical weathering. Specifically, oxalic acid was added to simulations of soil development to investigate a well-studied chronosequence of soils near Santa Cruz, CA. The model formulation includes organic acid input, transport, decomposition, organic-metal aqueous complexation and mineral surface complexation in various combinations. Results suggest that although organic acid reactions accelerate mineral dissolution rates near the soil surface, the net response is an overall decrease in chemical weathering. Model results demonstrate the importance of organic acid input concentrations, fluid flow, decomposition and secondary mineral precipitation rates on the evolution of mineral weathering fronts. In particular, model soil profile evolution is sensitive to kaolinite precipitation and oxalate decomposition rates. The soil profile-scale modeling presented here provides insights into the influence of organic carbon cycling on soil weathering and pedogenesis and supports the need for further field-scale measurements of the flux and speciation of reactive organic compounds.

  4. Daphnia as an Emerging Epigenetic Model Organism

    Directory of Open Access Journals (Sweden)

    Kami D. M. Harris

    2012-01-01

    Full Text Available Daphnia offer a variety of benefits for the study of epigenetics. Daphnia’s parthenogenetic life cycle allows the study of epigenetic effects in the absence of confounding genetic differences. Sex determination and sexual reproduction are epigenetically determined as are several other well-studied alternate phenotypes that arise in response to environmental stressors. Additionally, there is a large body of ecological literature available, recently complemented by the genome sequence of one species and transgenic technology. DNA methylation has been shown to be altered in response to toxicants and heavy metals, although investigation of other epigenetic mechanisms is only beginning. More thorough studies on DNA methylation as well as investigation of histone modifications and RNAi in sex determination and predator-induced defenses using this ecologically and evolutionarily important organism will contribute to our understanding of epigenetics.

  5. Nematodes: Model Organisms in High School Biology

    Science.gov (United States)

    Bliss, TJ; Anderson, Margery; Dillman, Adler; Yourick, Debra; Jett, Marti; Adams, Byron J.; Russell, RevaBeth

    2007-01-01

    In a collaborative effort between university researchers and high school science teachers, an inquiry-based laboratory module was designed using two species of insecticidal nematodes to help students apply scientific inquiry and elements of thoughtful experimental design. The learning experience and model are described in this article. (Contains 4…

  6. Transcriptional profiling of Aspergillus niger

    OpenAIRE

    Veen, van der, D.

    2009-01-01

    The industrially important fungus Aspergillus niger feeds naturally on decomposing plant material, of which a significant proportion is lipid. Examination of the A. niger genome sequence suggested that all proteins required for metabolic conversion of lipids are present, including 63 predicted lipases. In contrast to polysaccharide-degrading enzyme networks, not much is known about the signaling and regulatory processes that control lipase expression and activity in fungi. This project was ai...

  7. Hyphal heterogeneity in Aspergillus niger

    OpenAIRE

    de Bekker, A.M.

    2011-01-01

    Mycelial fungi use hyphae to colonize substrates. These hyphae secrete enzymes that convert complex polymers into breakdown products that can be taken up to serve as nutrients. Using GFP as a reporter it has been shown that exploring hyphae of Aspergillus niger are heterogenic with respect to expression of the glucoamylase gene glaA; some hyphae strongly express the glucoamylase gene glaA, while others express it lowly. This was a surprising finding considering the fact that all hyphae were e...

  8. Self-organized quantum rings : Physical characterization and theoretical modeling

    NARCIS (Netherlands)

    Fomin, V.M.; Gladilin, V.N.; Devreese, J.T.; Koenraad, P.M.; Fomin, V.M.

    2014-01-01

    An adequate modeling of the self-organized quantum rings is possible only on the basis of the modern characterization of those nanostructures.We discuss an atomic-scale analysis of the indium distribution of self-organized InGaAs quantum rings (QRs). The analysis of the shape, size and composition

  9. Resilient organizations: matrix model and service line management.

    Science.gov (United States)

    Westphal, Judith A

    2005-09-01

    Resilient organizations modify structures to meet the demands of the marketplace. The author describes a structure that enables multihospital organizations to innovate and rapidly adapt to changes. Service line management within a matrix model is an evolving organizational structure for complex systems in which nurses are pivotal members.

  10. (Tropical) soil organic matter modelling: problems and prospects

    NARCIS (Netherlands)

    Keulen, van H.

    2001-01-01

    Soil organic matter plays an important role in many physical, chemical and biological processes. However, the quantitative relations between the mineral and organic components of the soil and the relations with the vegetation are poorly understood. In such situations, the use of models is an

  11. Systemic analysis of the response of Aspergillus niger to ambient pH

    DEFF Research Database (Denmark)

    Andersen, Mikael Rørdam; Lehmann, Linda Olkjær; Nielsen, Jens

    2009-01-01

    Background: The filamentous fungus Aspergillus niger is an exceptionally efficient producer of organic acids, which is one of the reasons for its relevance to industrial processes and commercial importance. While it is known that the mechanisms regulating this production are tied to the levels...... of ambient pH, the reasons and mechanisms for this are poorly understood. Methods: To cast light on the connection between extracellular pH and acid production, we integrate results from two genome-based strategies: A novel method of genome-scale modeling of the response, and transcriptome analysis across...... three levels of pH. Results: With genome scale modeling with an optimization for extracellular proton-production, it was possible to reproduce the preferred pH levels for citrate and oxalate. Transcriptome analysis and clustering expanded upon these results and allowed the identification of 162 clusters...

  12. Investigating ecological speciation in non-model organisms

    DEFF Research Database (Denmark)

    Foote, Andrew David

    2012-01-01

    Background: Studies of ecological speciation tend to focus on a few model biological systems. In contrast, few studies on non-model organisms have been able to infer ecological speciation as the underlying mechanism of evolutionary divergence. Questions: What are the pitfalls in studying ecological...... speciation in non-model organisms that lead to this bias? What alternative approaches might redress the balance? Organism: Genetically differentiated types of the killer whale (Orcinus orca) exhibiting differences in prey preference, habitat use, morphology, and behaviour. Methods: Review of the literature...... on killer whale evolutionary ecology in search of any difficulty in demonstrating causal links between variation in phenotype, ecology, and reproductive isolation in this non-model organism. Results: At present, we do not have enough evidence to conclude that adaptive phenotype traits linked to ecological...

  13. Modelling the self-organization and collapse of complex networks

    Indian Academy of Sciences (India)

    Modelling the self-organization and collapse of complex networks. Sanjay Jain Department of Physics and Astrophysics, University of Delhi Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore Santa Fe Institute, Santa Fe, New Mexico.

  14. Self-organizing map models of language acquisition

    Science.gov (United States)

    Li, Ping; Zhao, Xiaowei

    2013-01-01

    Connectionist models have had a profound impact on theories of language. While most early models were inspired by the classic parallel distributed processing architecture, recent models of language have explored various other types of models, including self-organizing models for language acquisition. In this paper, we aim at providing a review of the latter type of models, and highlight a number of simulation experiments that we have conducted based on these models. We show that self-organizing connectionist models can provide significant insights into long-standing debates in both monolingual and bilingual language development. We suggest future directions in which these models can be extended, to better connect with behavioral and neural data, and to make clear predictions in testing relevant psycholinguistic theories. PMID:24312061

  15. Ortholog prediction of the Aspergillus genus applicable for synthetic biology

    DEFF Research Database (Denmark)

    Rasmussen, Jane Lind Nybo; Vesth, Tammi Camilla; Theobald, Sebastian

    of genotype-to-phenotype. To achieve this, we have developed orthologous protein prediction software that utilizes genus-wide genetic diversity. The approach is optimized for large data sets, based on BLASTp considering protein identity and alignment coverage, and clustering using single linkage of bi......The Aspergillus genus contains leading industrial microorganisms, excelling in producing bioactive compounds and enzymes. Using synthetic biology and bioinformatics, we aim to re-engineer these organisms for applications within human health, pharmaceuticals, environmental engineering, and food......-directional hits. The result is orthologous protein families describing the genomic and functional features of individual species, clades and the core/pan genome of Aspergillus; and applicable to genotype-to-phenotype analyses in other microbial genera....

  16. Aspergillus and Penicillium in the Post-genomic Era

    DEFF Research Database (Denmark)

    and a whole genus genome sequencing project in progress for Aspergillus. This book highlights some of the changes in the studies into these fungi, since the availability of genome sequences. The contributions vary from insights in the taxonomy of these genera, use of genomics for forward genetics and genomic......Genome sequencing has affected studies into the biology of all classes of organisms and this is certainly true for filamentous fungi. The level with which biological systems can be studied since the availability of genomes and post-genomic technologies is beyond what most people could have imagined...... previously. The fungal genera Aspergillus and Penicillium contain some species that are amongst the most widely used industrial microorganisms and others that are serious pathogens of plants, animals and humans. These genera are also at the forefront of fungal genomics with many genome sequences available...

  17. Aspergillus candidus: a respiratory hazard associated with grain dust.

    Science.gov (United States)

    Krysinska-Traczyk, E; Dutkiewicz, J

    2000-01-01

    The concentration of Aspergillus candidus in samples of grain dust and of air polluted with grain dust was found to be large (respectively 3.0 x 10(5) - 3.0 x 10(9) cfu/g and 5.0 x 10(3) - 6.47 x 10(5) cfu/m(3)) and proved to be significantly greater compared to samples of other organic dusts (pgrain workers reacted significantly more frequently to extract of A. candidus in the leukocyte migration inhibition test (pdusts. It was concluded that Aspergillus candidus, because of its common occurrence and strong immunomodulating properties, poses an important occupational hazard for grain handling workers

  18. Discovery of novel secondary metabolites in Aspergillus aculeatus

    DEFF Research Database (Denmark)

    Petersen, Lene Maj; Holm, Dorte Koefoed; Gotfredsen, Charlotte Held

    2012-01-01

    , whereby several novel secondary metabolites have been discovered. A. aculeatus has recently been genome-sequenced; however no genetic approaches have so far been described to facilitate genetic engineering. We here present a system for non-integrated (AMA1-based) gene expression in A. aculeatus based...... on the USERTM cloning technique. The AMA-1 based gene expression has successfully been applied to express genes in A. aculeatus and by this approach the function of a PKS gene has been established. Furthermore the technique was used to activate a silent cluster by expression of a transcription factor, leading...... of the industrially important black Aspergillus Aspergillus aculeatus by UHPLC-DAD-HRMS has identified several SMs already known from this organism. However, several compounds could not be unambiguously dereplicated wherefore some have been selected, purified and structure elucidated by 1D and 2D NMR spectroscopy...

  19. Labour Quality Model for Organic Farming Food Chains

    OpenAIRE

    Gassner, B.; Freyer, B.; Leitner, H.

    2008-01-01

    The debate on labour quality in science is controversial as well as in the organic agriculture community. Therefore, we reviewed literature on different labour quality models and definitions, and had key informant interviews on labour quality issues with stakeholders in a regional oriented organic agriculture bread food chain. We developed a labour quality model with nine quality categories and discussed linkages to labour satisfaction, ethical values and IFOAM principles.

  20. Xanthusbase: adapting wikipedia principles to a model organism database

    OpenAIRE

    Arshinoff, Bradley I.; Suen, Garret; Just, Eric M.; Merchant, Sohel M.; Kibbe, Warren A.; Chisholm, Rex L.; Welch, Roy D.

    2006-01-01

    xanthusBase () is the official model organism database (MOD) for the social bacterium Myxococcus xanthus. In many respects, M.xanthus represents the pioneer model organism (MO) for studying the genetic, biochemical, and mechanistic basis of prokaryotic multicellularity, a topic that has garnered considerable attention due to the significance of biofilms in both basic and applied microbiology research. To facilitate its utility, the design of xanthusBase incorporates open-source software, leve...

  1. Knowledge Loss: A Defensive Model In Nuclear Research Organization Memory

    International Nuclear Information System (INIS)

    Mohamad Safuan Bin Sulaiman; Muhd Noor Muhd Yunus

    2013-01-01

    Knowledge is an essential part of research based organization. It should be properly managed to ensure that any pitfalls of knowledge retention due to knowledge loss of both tacit and explicit is mitigated. Audit of the knowledge entities exist in the organization is important to identify the size of critical knowledge. It is very much related to how much know-what, know-how and know-why experts exist in the organization. This study conceptually proposed a defensive model for Nuclear Malaysia's organization memory and application of Knowledge Loss Risk Assessment (KLRA) as an important tool for critical knowledge identification. (author)

  2. NEW MODEL FOR QUANTIFICATION OF ICT DEPENDABLE ORGANIZATIONS RESILIENCE

    Directory of Open Access Journals (Sweden)

    Zora Arsovski

    2011-03-01

    Full Text Available Business environment today demands high reliable organizations in every segment to be competitive on the global market. Beside that, ICT sector is becoming irreplaceable in many fields of business, from the communication to the complex systems for process control and production. To fulfill those requirements and to develop further, many organizations worldwide are implementing business paradigm called - organizations resilience. Although resilience is well known term in many science fields, it is not well studied due to its complex nature. This paper is dealing with developing the new model for assessment and quantification of ICT dependable organizations resilience.

  3. A model to accumulate fractionated dose in a deforming organ

    International Nuclear Information System (INIS)

    Yan Di; Jaffray, D.A.; Wong, J.W.

    1999-01-01

    Purpose: Measurements of internal organ motion have demonstrated that daily organ deformation exists throughout the course of radiation treatment. However, a method of constructing the resultant dose delivered to the organ volume remains a difficult challenge. In this study, a model to quantify internal organ motion and a method to construct a cumulative dose in a deforming organ are introduced. Methods and Materials: A biomechanical model of an elastic body is used to quantify patient organ motion in the process of radiation therapy. Intertreatment displacements of volume elements in an organ of interest is calculated by applying an finite element method with boundary conditions, obtained from multiple daily computed tomography (CT) measurements. Therefore, by incorporating also the measurements of daily setup error, daily dose delivered to a deforming organ can be accumulated by tracking the position of volume elements in the organ. Furthermore, distribution of patient-specific organ motion is also predicted during the early phase of treatment delivery using the daily measurements, and the cumulative dose distribution in the organ can then be estimated. This dose distribution will be updated whenever a new measurement becomes available, and used to reoptimize the ongoing treatment. Results: An integrated process to accumulate dosage in a daily deforming organ was implemented. In this process, intertreatment organ motion and setup error were systematically quantified, and incorporated in the calculation of the cumulative dose. An example of the rectal wall motion in a prostate treatment was applied to test the model. The displacements of volume elements in the rectal wall, as well as the resultant doses, were calculated. Conclusion: This study is intended to provide a systematic framework to incorporate daily patient-specific organ motion and setup error in the reconstruction of the cumulative dose distribution in an organ of interest. The realistic dose

  4. Charge carrier relaxation model in disordered organic semiconductors

    International Nuclear Information System (INIS)

    Lu, Nianduan; Li, Ling; Sun, Pengxiao; Liu, Ming

    2013-01-01

    The relaxation phenomena of charge carrier in disordered organic semiconductors have been demonstrated and investigated theoretically. An analytical model describing the charge carrier relaxation is proposed based on the pure hopping transport theory. The relation between the material disorder, electric field and temperature and the relaxation phenomena has been discussed in detail, respectively. The calculated results reveal that the increase of electric field and temperature can promote the relaxation effect in disordered organic semiconductors, while the increase of material disorder will weaken the relaxation. The proposed model can explain well the stretched-exponential law by adopting the appropriate parameters. The calculation shows a good agreement with the experimental data for organic semiconductors

  5. Ecophysiological characterization of Aspergillus carbonarius, Aspergillus tubingensis and Aspergillus niger isolated from grapes in Spanish vineyards.

    Science.gov (United States)

    García-Cela, E; Crespo-Sempere, A; Ramos, A J; Sanchis, V; Marin, S

    2014-03-03

    The aim of this study was to evaluate the diversity of black aspergilli isolated from berries from different agroclimatic regions of Spain. Growth characterization (in terms of temperature and water activity requirements) of Aspergillus carbonarius, Aspergillus tubingensis and Aspergillus niger was carried out on synthetic grape medium. A. tubingensis and A. niger showed higher maximum temperatures for growth (>45 °C versus 40-42 °C), and lower minimum aw requirements (0.83 aw versus 0.87 aw) than A. carbonarius. No differences in growth boundaries due to their geographical origin were found within A. niger aggregate isolates. Conversely, A. carbonarius isolates from the hotter and drier region grew and produced OTA at lower aw than other isolates. However, little genetic diversity in A. carbonarius was observed for the microsatellites tested and the same sequence of β-tubulin gene was observed; therefore intraspecific variability did not correlate with the geographical origin of the isolates or with their ability to produce OTA. Climatic change prediction points to drier and hotter climatic scenarios where A. tubingensis and A. niger could be even more prevalent over A. carbonarius, since they are better adapted to extreme high temperature and drier conditions. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Modelling the fate of organic micropollutants in stormwater ponds

    DEFF Research Database (Denmark)

    Vezzaro, Luca; Eriksson, Eva; Ledin, Anna

    2011-01-01

    ). The four simulated organic stormwater MP (iodopropynyl butylcarbamate — IPBC, benzene, glyphosate and pyrene) were selected according to their different urban sources and environmental fate. This ensures that the results can be extended to other relevant stormwater pollutants. All three models use......Urban water managers need to estimate the potential removal of organic micropollutants (MP) in stormwater treatment systems to support MP pollution control strategies. This study documents how the potential removal of organic MP in stormwater treatment systems can be quantified by using multimedia...... models. The fate of four different MP in a stormwater retention pond was simulated by applying two steady-state multimedia fate models (EPI Suite and SimpleBox) commonly applied in chemical risk assessment and a dynamic multimedia fate model (Stormwater Treatment Unit Model for Micro Pollutants — STUMP...

  7. Modelling the fate of oxidisable organic contaminants in groundwater

    DEFF Research Database (Denmark)

    Barry, D.A.; Prommer, H.; Miller, C.T.

    2002-01-01

    modelling framework is illustrated by pertinent examples, showing the degradation of dissolved organics by microbial activity limited by the availability of nutrients or electron acceptors (i.e., changing redox states), as well as concomitant secondary reactions. Two field-scale modelling examples......Subsurface contamination by organic chemicals is a pervasive environmental problem, susceptible to remediation by natural or enhanced attenuation approaches or more highly engineered methods such as pump-and-treat, amongst others. Such remediation approaches, along with risk assessment...... are discussed, the Vejen landfill (Denmark) and an example where metal contamination is remediated by redox changes wrought by injection of a dissolved organic compound. A summary is provided of current and likely future challenges to modelling of oxidisable organics in the subsurface. (C) 2002 Elsevier Science...

  8. Drosophila melanogaster as a model organism to study nanotoxicity.

    Science.gov (United States)

    Ong, Cynthia; Yung, Lin-Yue Lanry; Cai, Yu; Bay, Boon-Huat; Baeg, Gyeong-Hun

    2015-05-01

    Drosophila melanogaster has been used as an in vivo model organism for the study of genetics and development since 100 years ago. Recently, the fruit fly Drosophila was also developed as an in vivo model organism for toxicology studies, in particular, the field of nanotoxicity. The incorporation of nanomaterials into consumer and biomedical products is a cause for concern as nanomaterials are often associated with toxicity in many in vitro studies. In vivo animal studies of the toxicity of nanomaterials with rodents and other mammals are, however, limited due to high operational cost and ethical objections. Hence, Drosophila, a genetically tractable organism with distinct developmental stages and short life cycle, serves as an ideal organism to study nanomaterial-mediated toxicity. This review discusses the basic biology of Drosophila, the toxicity of nanomaterials, as well as how the Drosophila model can be used to study the toxicity of various types of nanomaterials.

  9. Liver injury in invasive aspergillus. Echographic findings

    International Nuclear Information System (INIS)

    Otero Fernandez, R.; Garcia Revillo, J.; Paez Moreno, J.; Zurera Tendero, L.J.

    1994-01-01

    Aspergillus is the second most common mycoses in immuno compromised patients. The invasive form is associated with a mortality of approximately 100%. We present a case of invasive aspergillus in a heart transplant recipient in whom ultrasound disclosed the presence of liver injury which was later confirmed by necropsy. We review the available literature. (Author) 15 refs

  10. Characterization of Aspergillus species associated with ...

    African Journals Online (AJOL)

    About 82 triphala powder samples were analyzed for the association of different fungi. Results reveal the predominance of Aspergillus as the major genera with six predominant species namely, A. niger, A. flavus, A. fumigatus, A. terreus, A. nidulans and A. amstelodami. Therefore, these six isolated Aspergillus species were ...

  11. An attempt to optimize potassium sorbate use to preserve low pH (4.5-5.5) intermediate moisture bakery products by modelling Eurotium spp., Aspergillus spp. and Penicillium corylophilum growth.

    Science.gov (United States)

    Guynot, M Elena; Marín, Sonia; Sanchis, Vicente; Ramos, Antonio J

    2005-05-25

    Mould growth was modelled on fermented bakery product analogues (FBPA) of two different pH (4.5 and 5.5), different water activity (a(w)) levels (0.80-0.90) and potassium sorbate concentrations (0-0.3%) by using seven moulds commonly causing spoilage of bakery products (Eurotium spp., Aspergillus spp. and Penicillium corylophilum). For the description of fungal growth (growth rates) as a function of a(w), potassium sorbate concentration and pH, 10-terms polynomial models were developed. Modelling enables prediction of spoilage during storage as a function of the factors affecting fungal growth. At pH 4.5 the concentration of potassium sorbate could be reduced to some extent only at low levels of a(w), whereas at pH 5.5 fungal growth was observed even by adding 0.3% of potassium sorbate. However, this preservative could be a valuable alternative as antifungal in such bakery product, of slightly acidic pH, if a long shelf life has not to be achieved.

  12. Aspergillus tracheobronchitis in a mild immunocompromised host.

    Science.gov (United States)

    Cho, Byung Ha; Oh, Youngmin; Kang, Eun Seok; Hong, Yong Joo; Jeong, Hye Won; Lee, Ok-Jun; Chang, You-Jin; Choe, Kang Hyeon; Lee, Ki Man; An, Jin-Young

    2014-11-01

    Aspergillus tracheobronchitis is a form of invasive pulmonary aspergillosis in which the Aspergillus infection is limited predominantly to the tracheobronchial tree. It occurs primarily in severely immunocompromised patients such as lung transplant recipients. Here, we report a case of Aspergillus tracheobronchitis in a 42-year-old man with diabetes mellitus, who presented with intractable cough, lack of expectoration of sputum, and chest discomfort. The patient did not respond to conventional treatment with antibiotics and antitussive agents, and he underwent bronchoscopy that showed multiple, discrete, gelatinous whitish plaques mainly involving the trachea and the left bronchus. On the basis of the bronchoscopic and microbiologic findings, we made the diagnosis of Aspergillus tracheobronchitis and initiated antifungal therapy. He showed gradual improvement in his symptoms and continued taking oral itraconazole for 6 months. Physicians should consider Aspergillus tracheobronchitis as a probable diagnosis in immunocompromised patients presenting with atypical respiratory symptoms and should try to establish a prompt diagnosis.

  13. Mutant mice: experimental organisms as materialised models in biomedicine.

    Science.gov (United States)

    Huber, Lara; Keuck, Lara K

    2013-09-01

    Animal models have received particular attention as key examples of material models. In this paper, we argue that the specificities of establishing animal models-acknowledging their status as living beings and as epistemological tools-necessitate a more complex account of animal models as materialised models. This becomes particularly evident in animal-based models of diseases that only occur in humans: in these cases, the representational relation between animal model and human patient needs to be generated and validated. The first part of this paper presents an account of how disease-specific animal models are established by drawing on the example of transgenic mice models for Alzheimer's disease. We will introduce an account of validation that involves a three-fold process including (1) from human being to experimental organism; (2) from experimental organism to animal model; and (3) from animal model to human patient. This process draws upon clinical relevance as much as scientific practices and results in disease-specific, yet incomplete, animal models. The second part of this paper argues that the incompleteness of models can be described in terms of multi-level abstractions. We qualify this notion by pointing to different experimental techniques and targets of modelling, which give rise to a plurality of models for a specific disease. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Spatial arrangement of organic compounds on a model mineral surface: implications for soil organic matter stabilization.

    Science.gov (United States)

    Petridis, Loukas; Ambaye, Haile; Jagadamma, Sindhu; Kilbey, S Michael; Lokitz, Bradley S; Lauter, Valeria; Mayes, Melanie A

    2014-01-01

    The complexity of the mineral-organic carbon interface may influence the extent of stabilization of organic carbon compounds in soils, which is important for global climate futures. The nanoscale structure of a model interface was examined here by depositing films of organic carbon compounds of contrasting chemical character, hydrophilic glucose and amphiphilic stearic acid, onto a soil mineral analogue (Al2O3). Neutron reflectometry, a technique which provides depth-sensitive insight into the organization of the thin films, indicates that glucose molecules reside in a layer between Al2O3 and stearic acid, a result that was verified by water contact angle measurements. Molecular dynamics simulations reveal the thermodynamic driving force behind glucose partitioning on the mineral interface: The entropic penalty of confining the less mobile glucose on the mineral surface is lower than for stearic acid. The fundamental information obtained here helps rationalize how complex arrangements of organic carbon on soil mineral surfaces may arise.

  15. Heterologous expression of Gaeumannomyces graminis lipoxygenase in Aspergillus nidulans

    NARCIS (Netherlands)

    Heshof, R.; Schayck, van J.P.; Tamayo Ramos, J.A.; Graaff, de L.H.

    2014-01-01

    Aspergillus sp. contain ppo genes coding for Ppo enzymes that produce oxylipins from polyunsaturated fatty acids. These oxylipins function as signal molecules in sporulation and influence the asexual to sexual ratio of Aspergillus sp. Fungi like Aspergillus nidulans and Aspergillus niger contain

  16. A Framework for Formal Modeling and Analysis of Organizations

    NARCIS (Netherlands)

    Jonker, C.M.; Sharpanskykh, O.; Treur, J.; P., Yolum

    2007-01-01

    A new, formal, role-based, framework for modeling and analyzing both real world and artificial organizations is introduced. It exploits static and dynamic properties of the organizational model and includes the (frequently ignored) environment. The transition is described from a generic framework of

  17. Healing models for organizations: description, measurement, and outcomes.

    Science.gov (United States)

    Malloch, K

    2000-01-01

    Healthcare leaders are continually searching for ways to improve their ability to provide optimal healthcare services, be financially viable, and retain quality caregivers, often feeling like such goals are impossible to achieve in today's intensely competitive environment. Many healthcare leaders intuitively recognize the need for more humanistic models and the probable connection with positive patient outcomes and financial success but are hesitant to make significant changes in their organizations because of the lack of model descriptions or documented recognition of the clinical and financial advantages of humanistic models. This article describes a study that was developed in response to the increasing work in humanistic or healing environment models and the need for validation of the advantages of such models. The healthy organization model, a framework for healthcare organizations that incorporates humanistic healing values within the traditional structure, is presented as a result of the study. This model addresses the importance of optimal clinical services, financial performance, and staff satisfaction. The five research-based organizational components that form the framework are described, and key indicators of organizational effectiveness over a five-year period are presented. The resulting empirical data are strongly supportive of the healing model and reflect positive outcomes for the organization.

  18. A self-organized criticality model for plasma transport

    International Nuclear Information System (INIS)

    Carreras, B.A.; Newman, D.; Lynch, V.E.

    1996-01-01

    Many models of natural phenomena manifest the basic hypothesis of self-organized criticality (SOC). The SOC concept brings together the self-similarity on space and time scales that is common to many of these phenomena. The application of the SOC modelling concept to the plasma dynamics near marginal stability opens new possibilities of understanding issues such as Bohm scaling, profile consistency, broad band fluctuation spectra with universal characteristics and fast time scales. A model realization of self-organized criticality for plasma transport in a magnetic confinement device is presented. The model is based on subcritical resistive pressure-gradient-driven turbulence. Three-dimensional nonlinear calculations based on this model show the existence of transport under subcritical conditions. This model that includes fluctuation dynamics leads to results very similar to the running sandpile paradigm

  19. An Ising model for metal-organic frameworks

    Science.gov (United States)

    Höft, Nicolas; Horbach, Jürgen; Martín-Mayor, Victor; Seoane, Beatriz

    2017-08-01

    We present a three-dimensional Ising model where lines of equal spins are frozen such that they form an ordered framework structure. The frame spins impose an external field on the rest of the spins (active spins). We demonstrate that this "porous Ising model" can be seen as a minimal model for condensation transitions of gas molecules in metal-organic frameworks. Using Monte Carlo simulation techniques, we compare the phase behavior of a porous Ising model with that of a particle-based model for the condensation of methane (CH4) in the isoreticular metal-organic framework IRMOF-16. For both models, we find a line of first-order phase transitions that end in a critical point. We show that the critical behavior in both cases belongs to the 3D Ising universality class, in contrast to other phase transitions in confinement such as capillary condensation.

  20. Regional Persistent Organic Pollutants' Environmental Impact Assessment and Control Model

    Directory of Open Access Journals (Sweden)

    Jurgis Staniskis

    2008-10-01

    Full Text Available The sources of formation, environmental distribution and fate of persistent organic pollutants (POPs are increasingly seen as topics to be addressed and solved at the global scale. Therefore, there are already two international agreements concerning persistent organic pollutants: the Protocol of 1998 to the 1979 Convention on the Long-Range Transboundary Air Pollution on Persistent Organic Pollutants (Aarhus Protocol; and the Stockholm Convention on Persistent Organic Pollutants. For the assessment of environmental pollution of POPs, for the risk assessment, for the evaluation of new pollutants as potential candidates to be included in the POPs list of the Stokholmo or/and Aarhus Protocol, a set of different models are developed or under development. Multimedia models help describe and understand environmental processes leading to global contamination through POPs and actual risk to the environment and human health. However, there is a lack of the tools based on a systematic and integrated approach to POPs management difficulties in the region.

  1. Modelization of tritium transfer into the organic compartments of algae

    International Nuclear Information System (INIS)

    Bonotto, S.; Gerber, G.B.; Arapis, G.; Kirchmann, R.

    1982-01-01

    Uptake of tritium oxide and its conversion into organic tritium was studied in four different types of algae with widely varying size and growth characteristics (Acetabularia acetabulum, Boergesenia forbesii, two strains of Chlamydomonas and Dunaliella bioculata). Water in the cell and the vacuales equilibrates rapidly with external tritium water. Tritium is actively incorporated into organically bound form as the organisms grow. During the stationary phase, incorporation of tritium is slow. There exists a discrimination against the incorporation of tritium into organically bound form. A model has been elaborated taking in account these different factors. It appears that transfer of organic tritium by algae growing near the sites of release would be significant only for actively growing algae. Algae growing slowly may, however, be useful as cumulative indicators of discontinuous tritium release. (author)

  2. MODELLING CONSUMERS' DEMAND FOR ORGANIC FOOD PRODUCTS: THE SWEDISH EXPERIENCE

    Directory of Open Access Journals (Sweden)

    Manuchehr Irandoust

    2016-07-01

    Full Text Available This paper attempts to examine a few factors characterizing consumer preferences and behavior towards organic food products in the south of Sweden using a proportional odds model which captures the natural ordering of dependent variables and any inherent nonlinearities. The findings show that consumer's choice for organic food depends on perceived benefits of organic food (environment, health, and quality and consumer's perception and attitudes towards labelling system, message framing, and local origin. In addition, high willingness to pay and income level will increase the probability to buy organic food, while the cultural differences and socio-demographic characteristics have no effect on consumer behaviour and attitudes towards organic food products. Policy implications are offered.

  3. Modeling cadmium in the feed chain and cattle organs

    OpenAIRE

    Fels-Klerx, van der, H.J.; Romkens, P.F.A.M.; Franz, E.; Raamsdonk, van, L.W.D.

    2011-01-01

    The objectives of this study were to estimate cadmium contamination levels in different scenarios related to soil characteristics and assumptions regarding cadmium accumulation in the animal tissues, using quantitative supply chain modeling. The model takes into account soil cadmium levels, soil pH, soil-to-plant transfer, animal consumption patterns, and transfer into animal organs (liver and kidneys). The model was applied to cattle up to the age of six years which were fed roughage (maize ...

  4. Lotka-Volterra competition models for sessile organisms.

    Science.gov (United States)

    Spencer, Matthew; Tanner, Jason E

    2008-04-01

    Markov models are widely used to describe the dynamics of communities of sessile organisms, because they are easily fitted to field data and provide a rich set of analytical tools. In typical ecological applications, at any point in time, each point in space is in one of a finite set of states (e.g., species, empty space). The models aim to describe the probabilities of transitions between states. In most Markov models for communities, these transition probabilities are assumed to be independent of state abundances. This assumption is often suspected to be false and is rarely justified explicitly. Here, we start with simple assumptions about the interactions among sessile organisms and derive a model in which transition probabilities depend on the abundance of destination states. This model is formulated in continuous time and is equivalent to a Lotka-Volterra competition model. We fit this model and a variety of alternatives in which transition probabilities do not depend on state abundances to a long-term coral reef data set. The Lotka-Volterra model describes the data much better than all models we consider other than a saturated model (a model with a separate parameter for each transition at each time interval, which by definition fits the data perfectly). Our approach provides a basis for further development of stochastic models of sessile communities, and many of the methods we use are relevant to other types of community. We discuss possible extensions to spatially explicit models.

  5. Modeling Temperature Dependent Singlet Exciton Dynamics in Multilayered Organic Nanofibers

    DEFF Research Database (Denmark)

    de Sousa, Leonardo Evaristo; de Oliveira Neto, Pedro Henrique; Kjelstrup-Hansen, Jakob

    2018-01-01

    Organic nanofibers have shown potential for application in optoelectronic devices because of the tunability of their optical properties. These properties are influenced by the electronic structure of the molecules that compose the nanofibers, but also by the behavior of the excitons generated...... dynamics in multilayered organic nanofibers. By simulating absorption and emission spectra, the possible Förster transitions are identified. Then, a Kinetic Monte Carlo (KMC) model is employed in combination with a genetic algorithm to theoretically reproduce time resolved photoluminescence measurements...

  6. Lysine aminopeptidase of Aspergillus niger

    OpenAIRE

    Basten, D.E.J.W.; Visser, J.; Schaap, P.J.

    2001-01-01

    Conserved regions within the M1 family of metallo-aminopeptidases have been used to clone a zinc aminopeptidase from the industrially used fungus Aspergillus niger. The derived amino acid sequence of ApsA is highly similar to two yeast zinc aminopeptidases, LAPI and AAPI (53.3 and 50.9␘verall similarity, respectively), two members of the M1 family of metallo-aminopeptidases. The encoding gene was successfully overexpressed in A. niger and the overexpressed product was purified and characteriz...

  7. Aspergillus Osteomyelitis of the Skull.

    Science.gov (United States)

    Nicholson, Simon; King, Richard; Chumas, Paul; Russell, John; Liddington, Mark

    2016-07-01

    Osteomyelitis of the craniofacial skeleton is rare, with fungal pathogens least commonly implicated. The authors present 2 patients of osteomyelitis of the skull caused by Aspergillus spp. and discuss the diagnosis, clinicopathological course, and management strategies.Late recurrence seen in this type of infection warrants long-term follow-up and a high index of suspicion for the clinical signs associated with recurrence.Such patients would benefit from their surgical debridement being planned and managed via a specialist craniofacial unit, so as to utilize the most aesthetically sensitive approach and the experience of specialists from several surgical disciplines.

  8. Electrochemical model of the polyaniline based organic memristive device

    International Nuclear Information System (INIS)

    Demin, V. A.; Erokhin, V. V.; Kashkarov, P. K.; Kovalchuk, M. V.

    2014-01-01

    The electrochemical organic memristive device with polyaniline active layer is a stand-alone device designed and realized for reproduction of some synapse properties in the innovative electronic circuits, including the neuromorphic networks capable for learning. In this work, a new theoretical model of the polyaniline memristive is presented. The developed model of organic memristive functioning was based on the detailed consideration of possible electrochemical processes occuring in the active zone of this device. Results of the calculation have demonstrated not only the qualitative explanation of the characteristics observed in the experiment but also the quantitative similarities of the resultant current values. It is shown how the memristive could behave at zero potential difference relative to the reference electrode. This improved model can establish a basis for the design and prediction of properties of more complicated circuits and systems (including stochastic ones) based on the organic memristive devices

  9. A model-independent view of the mature organization

    Energy Technology Data Exchange (ETDEWEB)

    Hanna, M.; Langston, D.

    1996-12-31

    Over the last 10 years, industry has been dealing with the issues of process and organizational maturity. This focus on process is driven by the success that manufacturing organizations have had implementing the management principles of W. Edwards Deming and Joseph M. Juran. The organizational-maturity focus is driven by organizations striving to be ISO 9000 compliant or to achieve a specific level on one of the maturity models. Unfortunately, each of the models takes a specific view into what is a very broad arena. That is to say, each model addresses only a specific subset of the characteristics of maturity. This paper attempts to extend beyond these specific views to answer the general question, What is a mature organization and its relationship to Quantitative management and statistical process control?

  10. Analysis of secreted proteins from Aspergillus flavus.

    Science.gov (United States)

    Medina, Martha L; Haynes, Paul A; Breci, Linda; Francisco, Wilson A

    2005-08-01

    MS/MS techniques in proteomics make possible the identification of proteins from organisms with little or no genome sequence information available. Peptide sequences are obtained from tandem mass spectra by matching peptide mass and fragmentation information to protein sequence information from related organisms, including unannotated genome sequence data. This peptide identification data can then be grouped and reconstructed into protein data. In this study, we have used this approach to study protein secretion by Aspergillus flavus, a filamentous fungus for which very little genome sequence information is available. A. flavus is capable of degrading the flavonoid rutin (quercetin 3-O-glycoside), as the only source of carbon via an extracellular enzyme system. In this continuing study, a proteomic analysis was used to identify secreted proteins from A. flavus when grown on rutin. The growth media glucose and potato dextrose were used to identify differentially expressed secreted proteins. The secreted proteins were analyzed by 1- and 2-DE and MS/MS. A total of 51 unique A. flavus secreted proteins were identified from the three growth conditions. Ten proteins were unique to rutin-, five to glucose- and one to potato dextrose-grown A. flavus. Sixteen secreted proteins were common to all three media. Fourteen identifications were of hypothetical proteins or proteins of unknown functions. To our knowledge, this is the first extensive proteomic study conducted to identify the secreted proteins from a filamentous fungus.

  11. Molecular analysis of the replication program in unicellular model organisms.

    Science.gov (United States)

    Raghuraman, M K; Brewer, Bonita J

    2010-01-01

    Eukaryotes have long been reported to show temporal programs of replication, different portions of the genome being replicated at different times in S phase, with the added possibility of developmentally regulated changes in this pattern depending on species and cell type. Unicellular model organisms, primarily the budding yeast Saccharomyces cerevisiae, have been central to our current understanding of the mechanisms underlying the regulation of replication origins and the temporal program of replication in particular. But what exactly is a temporal program of replication, and how might it arise? In this article, we explore this question, drawing again on the wealth of experimental information in unicellular model organisms.

  12. Secondary metabolite profiles and antifungal drug susceptibility of Aspergillus fumigatus and closely related species, Aspergillus lentulus, Aspergillus udagawae, and Aspergillus viridinutans.

    Science.gov (United States)

    Tamiya, Hiroyuki; Ochiai, Eri; Kikuchi, Kazuyo; Yahiro, Maki; Toyotome, Takahito; Watanabe, Akira; Yaguchi, Takashi; Kamei, Katsuhiko

    2015-05-01

    The incidence of Aspergillus infection has been increasing in the past few years. Also, new Aspergillus fumigatus-related species, namely Aspergillus lentulus, Aspergillus udagawae, and Aspergillus viridinutans, were shown to infect humans. These fungi exhibit marked morphological similarities to A. fumigatus, albeit with different clinical courses and antifungal drug susceptibilities. The present study used liquid chromatography/time-of-flight mass spectrometry to identify the secondary metabolites secreted as virulence factors by these Aspergillus species and compared their antifungal susceptibility. The metabolite profiles varied widely among A. fumigatus, A. lentulus, A. udagawae, and A. viridinutans, producing 27, 13, 8, and 11 substances, respectively. Among the mycotoxins, fumifungin, fumiquinazoline A/B and D, fumitremorgin B, gliotoxin, sphingofungins, pseurotins, and verruculogen were only found in A. fumigatus, whereas auranthine was only found in A. lentulus. The amount of gliotoxin, one of the most abundant mycotoxins in A. fumigatus, was negligible in these related species. In addition, they had decreased susceptibility to antifungal agents such as itraconazole and voriconazole, even though metabolites that were shared in the isolates showing higher minimum inhibitory concentrations than epidemiological cutoff values were not detected. These strikingly different secondary metabolite profiles may lead to the development of more discriminative identification protocols for such closely related Aspergillus species as well as improved treatment outcomes. Copyright © 2015 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  13. Genetic diversity of Aspergillus species isolated from onychomycosis and Aspergillus hongkongensis sp. nov., with implications to antifungal susceptibility testing.

    Science.gov (United States)

    Tsang, Chi-Ching; Hui, Teresa W S; Lee, Kim-Chung; Chen, Jonathan H K; Ngan, Antonio H Y; Tam, Emily W T; Chan, Jasper F W; Wu, Andrea L; Cheung, Mei; Tse, Brian P H; Wu, Alan K L; Lai, Christopher K C; Tsang, Dominic N C; Que, Tak-Lun; Lam, Ching-Wan; Yuen, Kwok-Yung; Lau, Susanna K P; Woo, Patrick C Y

    2016-02-01

    Thirteen Aspergillus isolates recovered from nails of 13 patients (fingernails, n=2; toenails, n=11) with onychomycosis were characterized. Twelve strains were identified by multilocus sequencing as Aspergillus spp. (Aspergillus sydowii [n=4], Aspergillus welwitschiae [n=3], Aspergillus terreus [n=2], Aspergillus flavus [n=1], Aspergillus tubingensis [n=1], and Aspergillus unguis [n=1]). Isolates of A. terreus, A. flavus, and A. unguis were also identifiable by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The 13th isolate (HKU49(T)) possessed unique morphological characteristics different from other Aspergillus spp. Molecular characterization also unambiguously showed that HKU49(T) was distinct from other Aspergillus spp. We propose the novel species Aspergillus hongkongensis to describe this previously unknown fungus. Antifungal susceptibility testing showed most Aspergillus isolates had low MICs against itraconazole and voriconazole, but all Aspergillus isolates had high MICs against fluconazole. A diverse spectrum of Aspergillus species is associated with onychomycosis. Itraconazole and voriconazole are probably better drug options for Aspergillus onychomycosis. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Self-organized Criticality Model for Ocean Internal Waves

    International Nuclear Information System (INIS)

    Wang Gang; Hou Yijun; Lin Min; Qiao Fangli

    2009-01-01

    In this paper, we present a simple spring-block model for ocean internal waves based on the self-organized criticality (SOC). The oscillations of the water blocks in the model display power-law behavior with an exponent of -2 in the frequency domain, which is similar to the current and sea water temperature spectra in the actual ocean and the universal Garrett and Munk deep ocean internal wave model [Geophysical Fluid Dynamics 2 (1972) 225; J. Geophys. Res. 80 (1975) 291]. The influence of the ratio of the driving force to the spring coefficient to SOC behaviors in the model is also discussed. (general)

  15. Device model investigation of bilayer organic light emitting diodes

    International Nuclear Information System (INIS)

    Crone, B. K.; Davids, P. S.; Campbell, I. H.; Smith, D. L.

    2000-01-01

    Organic materials that have desirable luminescence properties, such as a favorable emission spectrum and high luminescence efficiency, are not necessarily suitable for single layer organic light-emitting diodes (LEDs) because the material may have unequal carrier mobilities or contact limited injection properties. As a result, single layer LEDs made from such organic materials are inefficient. In this article, we present device model calculations of single layer and bilayer organic LED characteristics that demonstrate the improvements in device performance that can occur in bilayer devices. We first consider an organic material where the mobilities of the electrons and holes are significantly different. The role of the bilayer structure in this case is to move the recombination away from the electrode that injects the low mobility carrier. We then consider an organic material with equal electron and hole mobilities but where it is not possible to make a good contact for one carrier type, say electrons. The role of a bilayer structure in this case is to prevent the holes from traversing the device without recombining. In both cases, single layer device limitations can be overcome by employing a two organic layer structure. The results are discussed using the calculated spatial variation of the carrier densities, electric field, and recombination rate density in the structures. (c) 2000 American Institute of Physics

  16. Green Algae as Model Organisms for Biological Fluid Dynamics

    Science.gov (United States)

    Goldstein, Raymond E.

    2015-01-01

    In the past decade, the volvocine green algae, spanning from the unicellular Chlamydomonas to multicellular Volvox, have emerged as model organisms for a number of problems in biological fluid dynamics. These include flagellar propulsion, nutrient uptake by swimming organisms, hydrodynamic interactions mediated by walls, collective dynamics and transport within suspensions of microswimmers, the mechanism of phototaxis, and the stochastic dynamics of flagellar synchronization. Green algae are well suited to the study of such problems because of their range of sizes (from 10 μm to several millimeters), their geometric regularity, the ease with which they can be cultured, and the availability of many mutants that allow for connections between molecular details and organism-level behavior. This review summarizes these recent developments and highlights promising future directions in the study of biological fluid dynamics, especially in the context of evolutionary biology, that can take advantage of these remarkable organisms.

  17. Aspergillus uvarum sp. nov., an uniseriate black Aspergillus species isolated from grapes in Europe

    DEFF Research Database (Denmark)

    Perrone, Giancarlo; Varga, János; Susca, Antonia

    2008-01-01

    uvarum sp. nov. isolates produced secalonic acid, common to other Aspergillus japonicus-related taxa, and geodin, erdin and dihydrogeodin, which are not produced by any other black aspergilli. None of the isolates were found to produce ochratoxin A. The novel species is most closely related to two......A novel species, Aspergillus uvarum sp. nov., is described within Aspergillus section Nigri. This species can be distinguished from other black aspergilli based on internal transcribed spacers (ITS), beta-tubulin and calmodulin gene sequences, by AFLP analysis and by extrolite profiles. Aspergillus...

  18. There Is No Simple Model of the Plasma Membrane Organization

    Science.gov (United States)

    Bernardino de la Serna, Jorge; Schütz, Gerhard J.; Eggeling, Christian; Cebecauer, Marek

    2016-01-01

    Ever since technologies enabled the characterization of eukaryotic plasma membranes, heterogeneities in the distributions of its constituents were observed. Over the years this led to the proposal of various models describing the plasma membrane organization such as lipid shells, picket-and-fences, lipid rafts, or protein islands, as addressed in numerous publications and reviews. Instead of emphasizing on one model we in this review give a brief overview over current models and highlight how current experimental work in one or the other way do not support the existence of a single overarching model. Instead, we highlight the vast variety of membrane properties and components, their influences and impacts. We believe that highlighting such controversial discoveries will stimulate unbiased research on plasma membrane organization and functionality, leading to a better understanding of this essential cellular structure. PMID:27747212

  19. An Ontology for Modeling Complex Inter-relational Organizations

    Science.gov (United States)

    Wautelet, Yves; Neysen, Nicolas; Kolp, Manuel

    This paper presents an ontology for organizational modeling through multiple complementary aspects. The primary goal of the ontology is to dispose of an adequate set of related concepts for studying complex organizations involved in a lot of relationships at the same time. In this paper, we define complex organizations as networked organizations involved in a market eco-system that are playing several roles simultaneously. In such a context, traditional approaches focus on the macro analytic level of transactions; this is supplemented here with a micro analytic study of the actors' rationale. At first, the paper overviews enterprise ontologies literature to position our proposal and exposes its contributions and limitations. The ontology is then brought to an advanced level of formalization: a meta-model in the form of a UML class diagram allows to overview the ontology concepts and their relationships which are formally defined. Finally, the paper presents the case study on which the ontology has been validated.

  20. Zebrabase: An intuitive tracking solution for aquatic model organisms

    OpenAIRE

    Oltova, Jana; Bartunek, Petr; Machonova, Olga; Svoboda, Ondrej; Skuta, Ctibor; Jindrich, Jindrich

    2018-01-01

    Small fish species, like zebrafish or medaka, are constantly gaining popularity in basic research and disease modeling as a useful alternative to rodent model organisms. However, the tracking options for fish within a facility are rather limited. Here, we present an aquatic species tracking database, Zebrabase, developed in our zebrafish research and breeding facility that represents a practical and scalable solution and an intuitive platform for scientists, fish managers and caretakers, in b...

  1. A model of virtual organization for corporate visibility and ...

    African Journals Online (AJOL)

    This paper considers the existing numerous research in business, Information and Communication Technology (ICT), examines a theoretical framework for value creation in a virtual world. Following a proposed model, a new strategic paradigm is created for corporate value; and virtual organization (VO) apply the use of ...

  2. Modeling of the transient mobility in disordered organic semiconductors

    NARCIS (Netherlands)

    Germs, W.C.; Van der Holst, J.M.M.; Van Mensfoort, S.L.M.; Bobbert, P.A.; Coehoorn, R.

    2011-01-01

    In non-steady-state experiments, the electrical response of devicesbased on disordered organic semiconductors often shows a large transient contribution due to relaxation of the out-of-equilibrium charge-carrier distribution. We have developed a model describing this process, based only on the

  3. An Integrated Model for Effective Knowledge Management in Chinese Organizations

    Science.gov (United States)

    An, Xiaomi; Deng, Hepu; Wang, Yiwen; Chao, Lemen

    2013-01-01

    Purpose: The purpose of this paper is to provide organizations in the Chinese cultural context with a conceptual model for an integrated adoption of existing knowledge management (KM) methods and to improve the effectiveness of their KM activities. Design/methodology/approaches: A comparative analysis is conducted between China and the western…

  4. Waste Reduction Model (WARM) Resources for Small Businesses and Organizations

    Science.gov (United States)

    This page provides a brief overview of how EPA’s Waste Reduction Model (WARM) can be used by small businesses and organizations. The page includes a brief summary of uses of WARM for the audience and links to other resources.

  5. SOMPROF: A vertically explicit soil organic matter model

    NARCIS (Netherlands)

    Braakhekke, M.C.; Beer, M.; Hoosbeek, M.R.; Kruijt, B.; Kabat, P.

    2011-01-01

    Most current soil organic matter (SOM) models represent the soil as a bulk without specification of the vertical distribution of SOM in the soil profile. However, the vertical SOM profile may be of great importance for soil carbon cycling, both on short (hours to years) time scale, due to

  6. Modeling growth of specific spoilage organisms in tilapia ...

    African Journals Online (AJOL)

    Tilapia is an important aquatic fish, but severe spoilage of tilapia is most likely related to the global aquaculture. The spoilage is mostly caused by specific spoilage organisms (SSO). Therefore, it is very important to use microbial models to predict the growth of SSO in tilapia. This study firstly verified Pseudomonas and Vibrio ...

  7. There Is No Simple Model of the Plasma Membrane Organization

    Czech Academy of Sciences Publication Activity Database

    de la serna, J. B.; Schütz, G.; Eggeling, Ch.; Cebecauer, Marek

    2016-01-01

    Roč. 4, SEP 2016 (2016), 106 ISSN 2296-634X R&D Projects: GA ČR GA15-06989S Institutional support: RVO:61388955 Keywords : plasma membrane * membrane organization models * heterogeneous distribution Subject RIV: CF - Physical ; Theoretical Chemistry

  8. The Cell Factory Aspergillus Enters the Big Data Era: Opportunities and Challenges for Optimising Product Formation.

    Science.gov (United States)

    Meyer, Vera; Fiedler, Markus; Nitsche, Benjamin; King, Rudibert

    2015-01-01

    Living with limits. Getting more from less. Producing commodities and high-value products from renewable resources including waste. What is the driving force and quintessence of bioeconomy outlines the lifestyle and product portfolio of Aspergillus, a saprophytic genus, to which some of the top-performing microbial cell factories belong: Aspergillus niger, Aspergillus oryzae and Aspergillus terreus. What makes them so interesting for exploitation in biotechnology and how can they help us to address key challenges of the twenty-first century? How can these strains become trimmed for better growth on second-generation feedstocks and how can we enlarge their product portfolio by genetic and metabolic engineering to get more from less? On the other hand, what makes it so challenging to deduce biological meaning from the wealth of Aspergillus -omics data? And which hurdles hinder us to model and engineer industrial strains for higher productivity and better rheological performance under industrial cultivation conditions? In this review, we will address these issues by highlighting most recent findings from the Aspergillus research with a focus on fungal growth, physiology, morphology and product formation. Indeed, the last years brought us many surprising insights into model and industrial strains. They clearly told us that similar is not the same: there are different ways to make a hypha, there are more protein secretion routes than anticipated and there are different molecular and physical mechanisms which control polar growth and the development of hyphal networks. We will discuss new conceptual frameworks derived from these insights and the future scientific advances necessary to create value from Aspergillus Big Data.

  9. Lamination of organic solar cells and organic light emitting devices: Models and experiments

    International Nuclear Information System (INIS)

    Oyewole, O. K.; Yu, D.; Du, J.; Asare, J.; Fashina, A.; Anye, V. C.; Zebaze Kana, M. G.; Soboyejo, W. O.

    2015-01-01

    In this paper, a combined experimental, computational, and analytical approach is used to provide new insights into the lamination of organic solar cells and light emitting devices at macro- and micro-scales. First, the effects of applied lamination force (on contact between the laminated layers) are studied. The crack driving forces associated with the interfacial cracks (at the bi-material interfaces) are estimated along with the critical interfacial crack driving forces associated with the separation of thin films, after layer transfer. The conditions for successful lamination are predicted using a combination of experiments and computational models. Guidelines are developed for the lamination of low-cost organic electronic structures

  10. Growth Identification of Aspergillus flavus and Aspergillus parasiticus by Visible/Near-Infrared Hyperspectral Imaging

    Directory of Open Access Journals (Sweden)

    Xuan Chu

    2018-03-01

    Full Text Available Visible/near-infrared (Vis/NIR hyperspectral imaging (400–1000 nm was applied to identify the growth process of Aspergillus flavus and Aspergillus parasiticus. The hyperspectral images of the two fungi that were growing on rose bengal medium were recorded daily for 6 days. A band ratio using two bands at 446 nm and 460 nm separated A. flavus and A. parasiticus on day 1 from other days. Image at band of 520 nm classified A. parasiticus on day 6. Principle component analysis (PCA was performed on the cleaned hyperspectral images. The score plot of the second to sixth principal components (PC2 to PC6 gave a rough clustering of fungi in the same incubation time. However, in the plot, A. flavus on day 3 and day 4 and A. parasiticus on day 2 and day 3 overlapped. The average spectra of each fungus in each growth day were extracted, then PCA and support vector machine (SVM classifier were applied to the full spectral range. SVM models built by PC2 to PC6 could identify fungal growth days with accuracies of 92.59% and 100% for A. flavus and A. parasiticus individually. In order to simplify the prediction models, competitive adaptive reweighted sampling (CARS was employed to choose optimal wavelengths. As a result, nine (402, 442, 487, 502, 524, 553, 646, 671, 760 nm and seven (461, 538, 542, 742, 753, 756, 919 nm wavelengths were selected for A. flavus and A. parasiticus, respectively. New optimal wavelengths SVM models were built, and the identification accuracies were 83.33% and 98.15% for A. flavus and A. parasiticus, respectively. Finally, the visualized prediction images for A. flavus and A. parasiticus in different growth days were made by applying the optimal wavelength’s SVM models on every pixel of the hyperspectral image.

  11. Activity and stability of feruloyl esterase A from Aspergillus niger in ionic liquid systems

    DEFF Research Database (Denmark)

    Zeuner, Birgitte; Riisager, Anders; Meyer, Anne S.

    in solvents that favour synthesis over hydrolysis, i.e. systems with low water content such as organic solvents or ionic liquids (ILs). The esterification of sinapic acid with glycerol catalysed by FAE A from Aspergillus niger (AnFaeA) in a series of ILs containing 15% (v/v) buffer showed that An...

  12. First case of breakthrough pneumonia due to Aspergillus nomius in a patient with acute myeloid leukemia.

    Science.gov (United States)

    Caira, Morena; Posteraro, Brunella; Sanguinetti, Maurizio; de Carolis, Elena; Leone, Giuseppe; Pagano, Livio

    2012-10-01

    We report the first known case of a breakthrough pulmonary infection caused by Aspergillus nomius in an acute myeloid leukemia patient receiving caspofungin therapy. The isolate was identified using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) and sequencing-based methods. The organism was found to be fully susceptible, in vitro, to echinocandin antifungal agents.

  13. Genome sequencing and analysis of the versatile cell factory Aspergillus niger CBS 513.88

    DEFF Research Database (Denmark)

    Pel, Herman J.; de Winde, Johannes H.; Archer, David B.

    2007-01-01

    The filamentous fungus Aspergillus niger is widely exploited by the fermentation industry for the production of enzymes and organic acids, particularly citric acid. We sequenced the 33.9-megabase genome of A. niger CBS 513.88, the ancestor of currently used enzyme production strains. A high level...... clusters for fumonisin and ochratoxin A synthesis....

  14. Genome sequencing and analysis of the versatile cell factory Aspergillus niger CBS 513.88

    NARCIS (Netherlands)

    Pel, Herman J.; de Winde, Johannes H.; Archer, David B.; Dyer, Paul S.; Hofmann, Gerald; Schaap, Peter J.; Turner, Geoffrey; Albang, Richard; Albermann, Kaj; Andersen, Mikael R.; Bendtsen, Jannick D.; Benen, Jacques A. E.; van den Berg, Marco; Breestraat, Stefaan; Caddick, Mark X.; Contreras, Roland; Cornell, Michael; Coutinho, Pedro M.; Danchin, Etienne G. J.; Debets, Alfons J. M.; Dekker, Peter; van Dijck, Piet W. M.; van Dijk, Alard; Dijkhuizen, Lubbert; Driessen, Arnold J. M.; d'Enfert, Christophe; Geysens, Steven; Groot, Gert S. P.; de Groot, Piet W. J.; Guillemette, Thomas; Henrissat, Bernard; Herweijer, Marga; van den Hombergh, Johannes P. T. W.; van den Hondel, Cees A. M. J. J.; van der Heijden, Rene T. J. M.; van der Kaaij, Rachel M.; Klis, Frans M.; Kools, Harrie J.; Kubicek, Christian P.; van Kuyk, Patricia A.; Lauber, Juergen; Lu, Xin; van der Maarel, Marc J. E. C.; Meulenberg, Rogier; Menke, Hildegard; Mortimer, Martin A.; Nielsen, Jens; Oliver, Stephen G.; Olsthoorn, Maurien; Pal, Karoly; van Peij, Noel N. M. E.; Ram, Arthur F. J.; Rinas, Ursula; Roubos, Johannes A.; Sagt, Cees M. J.; Schmoll, Monika; Sun, Jibin; Ussery, David; Varga, Janos; Vervecken, Wouter; de Vondervoort, Peter J. J. van; Wedler, Holger; Wosten, Han A. B.; Zeng, An-Ping; van Ooyen, Albert J. J.; Visser, Jaap; Stam, Hein; Enfert, Christophe d’; Lauber, Jürgen; Goosen, Coenie; de Vries, Ronald P.

    The filamentous fungus Aspergillus niger is widely exploited by the fermentation industry for the production of enzymes and organic acids, particularly citric acid. We sequenced the 33.9-megabase genome of A. niger CBS 513.88, the ancestor of currently used enzyme production strains. A high level of

  15. Monoclonal Antibodies to Hyphal Exoantigens Derived from the Opportunistic Pathogen Aspergillus terreus

    Science.gov (United States)

    Aspergillus terreus has been difficult to identify in cases of aspergillosis, and clinical identification has been restricted to the broad identification of aspergillosis lesions in affected organs or the detection of fungal carbohydrates. As a result, there is a clinical need to...

  16. Effects of Aspergillus niger (K8) on nutritive value of rice straw ...

    African Journals Online (AJOL)

    The objective of this study was to evaluate the use of solid state fermentation for the improvement of the quality of rice straw as animal feed. Rice straw was fermented using Aspergillus niger (K8) with and without additional nitrogen source (urea). Cellulose, hemicelluloses, organic matter (OM), dry matter (DM), acid ...

  17. Internal Carotid Artery Blister-Like Aneurysm Caused by Aspergillus – Case Report

    International Nuclear Information System (INIS)

    Ogawa, Masaki; Sakurai, Keita; Kawaguchi, Takatsune; Naiki-Ito, Aya; Nakagawa, Motoo; Okita, Kenji; Matsukawa, Noriyuki; Shibamoto, Yuta

    2015-01-01

    Blister-like aneurysm of the supraclinoid internal carotid artery (ICA) is a well-documented cause of subarachnoid hemorrhage. Generally, this type of aneurysm is associated with various conditions such as hypertension, arteriosclerosis, and ICA dissection. Although Aspergillus is the most common organism causing intracranial fungal aneurysmal formation, there is no report of a blister-like aneurysm caused by Aspergillus infection. An 83-year-old man received corticosteroid pulse therapy followed by oral steroid therapy for an inflammatory pseudotumor of the clivus. Two months later, the patient was transported to an emergency department due to the diffuse subarachnoid hemorrhage, classified as Fisher group 4. Subsequent 3D computed tomography angiogram revealed a blister-like aneurysm at the superior wall of the left ICA. Six days later, the patient died of subarachnoid hemorrhage caused by the left ICA aneurysm rerupture. Autopsy revealed proliferation of Aspergillus hyphae in the wall of the aneurysm. Notably, that change was present more densely in the inner membrane than in the outer one. Thus, it was considered that Aspergillus hyphae caused infectious aneurysm formation in the left ICA via hematogenous seeding rather than direct invasion. The blister-like aneurysm is a rare but important cause of subarachnoid hemorrhage. This case report documents another cause of blister-like aneurysms, that is an infectious aneurysm associated with Aspergillus infection

  18. Rhizomucor miehei triglyceride lipase is processed and secreted from transformed Aspergillus oryzae.

    Science.gov (United States)

    Huge-Jensen, B; Andreasen, F; Christensen, T; Christensen, M; Thim, L; Boel, E

    1989-09-01

    The cDNA encoding the precursor of the Rhizomucor miehei triglyceride lipase was inserted in an Aspergillus oryzae expression vector. In this vector the expression of the lipase cDNA is under control of the Aspergillus oryzae alpha-amylase gene promoter and the Aspergillus niger glucoamylase gene terminator. The recombinant plasmid was introduced into Aspergillus oryzae, and transformed colonies were selected and screened for lipase expression. Lipase-positive transformants were grown in a small fermentor, and recombinant triglyceride lipase was purified from the culture broth. The purified enzymatically active recombinant lipase (rRML) secreted from A. oryzae was shown to have the same characteristics with respect to mobility on reducing SDS-gels and amino acid composition as the native enzyme. N-terminal amino acid sequencing indicated that approximately 70% of the secreted rRML had the same N-terminal sequence as the native Rhizomucor miehei enzyme, whereas 30% of the secreted rRML was one amino acid residue shorter in the N-terminal. The recombinant lipase precursor, which has a 70 amino acid propeptide, is thus processed in and secreted from Aspergillus oryzae. We have hereby demonstrated the utility of this organism as a host for the production of recombinant triglyceride lipases.

  19. Sustainable Organic Farming For Environmental Health A Social Development Model

    Directory of Open Access Journals (Sweden)

    Ijun Rijwan Susanto

    2015-05-01

    Full Text Available ABSTRACT In this study the researcher attempted 1 to understand the basic features of organic farming in The Paguyuban Pasundans Cianjur 2 to describe and understand how the stakeholders were are able to internalize the challenges of organic farming on their lived experiences in the community 3 to describe and understand how the stakeholders were are able to internalize and applied the values of benefits of organic farming in support of environmental health on their lived experiences in the community 4 The purpose was to describe and understand how the stakeholders who are able to articulate their ideas regarding the model of sustainable organic farming 5 The Policy Recommendation for Organic Farming. The researcher employed triangulation thorough finding that provides breadth and depth to an investigation offering researchers a more accurate picture of the phenomenon. In the implementation of triangulation researchers conducted several interviews to get saturation. After completion of the interview results are written compiled and shown to the participants to check every statement by every participant. In addition researchers also checked the relevant documents and direct observation in the field The participants of this study were the stakeholders namely 1 The leader of Paguyuban Pasundans Organic Farmer Cianjur PPOFC 2 Members of Paguyuban Pasundans Organic FarmersCianjur 3 Leader of NGO 4 Government officials of agriculture 5 Business of organic food 6 and Consumer of organic food. Generally the findings of the study revealed the following 1 PPOFC began to see the reality as the impact of modern agriculture showed in fertility problems due to contaminated soil by residues of agricultural chemicals such as chemical fertilizers and chemical pesticides. So he wants to restore the soil fertility through environmentally friendly of farming practices 2 the challenges of organic farming on their lived experiences in the community farmers did not

  20. On the influence of the exposure model on organ doses

    International Nuclear Information System (INIS)

    Drexler, G.; Eckerl, H.

    1988-01-01

    Based on the design characteristics of the MIRD-V phantom, two sex-specific adult phantoms, ADAM and EVA were introduced especially for the calculation of organ doses resulting from external irradiation. Although the body characteristics of all the phantoms are in good agreement with those of the reference man and woman, they have some disadvantages related to the location and shape of organs and the form of the whole body. To overcome these disadvantages related to the location and shape of organs and form of the whole body. To overcome these disadvantages related to the location and shape of organs and the form of the whole body. To overcome these disadvantages and to obtain more realistic phantoms, a technique based on computer tomographic data (voxel-phantom) was developed. This technique allows any physical phantom or real body to be converted into computer files. The improvements are of special importance with regard to the skeleton, because a better modeling of the bone surfaces and separation of hard bone and bone marrow can be achieved. For photon irradiation, the sensitivity of the model on organ doses or the effective dose equivalent is important for operational radiation protection

  1. Modeling of secondary organic aerosol yields from laboratory chamber data

    Directory of Open Access Journals (Sweden)

    M. N. Chan

    2009-08-01

    Full Text Available Laboratory chamber data serve as the basis for constraining models of secondary organic aerosol (SOA formation. Current models fall into three categories: empirical two-product (Odum, product-specific, and volatility basis set. The product-specific and volatility basis set models are applied here to represent laboratory data on the ozonolysis of α-pinene under dry, dark, and low-NOx conditions in the presence of ammonium sulfate seed aerosol. Using five major identified products, the model is fit to the chamber data. From the optimal fitting, SOA oxygen-to-carbon (O/C and hydrogen-to-carbon (H/C ratios are modeled. The discrepancy between measured H/C ratios and those based on the oxidation products used in the model fitting suggests the potential importance of particle-phase reactions. Data fitting is also carried out using the volatility basis set, wherein oxidation products are parsed into volatility bins. The product-specific model is most likely hindered by lack of explicit inclusion of particle-phase accretion compounds. While prospects for identification of the majority of SOA products for major volatile organic compounds (VOCs classes remain promising, for the near future empirical product or volatility basis set models remain the approaches of choice.

  2. Secretome data from Trichoderma reesei and Aspergillus niger cultivated in submerged and sequential fermentation methods

    Directory of Open Access Journals (Sweden)

    Camila Florencio

    2016-09-01

    Full Text Available The cultivation procedure and the fungal strain applied for enzyme production may influence levels and profile of the proteins produced. The proteomic analysis data presented here provide critical information to compare proteins secreted by Trichoderma reesei and Aspergillus niger when cultivated through submerged and sequential fermentation processes, using steam-explosion sugarcane bagasse as inducer for enzyme production. The proteins were organized according to the families described in CAZy database as cellulases, hemicellulases, proteases/peptidases, cell-wall-protein, lipases, others (catalase, esterase, etc., glycoside hydrolases families, predicted and hypothetical proteins. Further detailed analysis of this data is provided in “Secretome analysis of Trichoderma reesei and Aspergillus niger cultivated by submerged and sequential fermentation process: enzyme production for sugarcane bagasse hydrolysis” C. Florencio, F.M. Cunha, A.C Badino, C.S. Farinas, E. Ximenes, M.R. Ladisch (2016 [1]. Keywords: Tricoderma reesei, Aspergillus Niger, Enzyme Production, Secretome

  3. New species in Aspergillus section Terrei

    DEFF Research Database (Denmark)

    Samson, R. A.; Peterson, S. W.; Frisvad, Jens Christian

    2011-01-01

    . clade including the type isolate of A. niveus (CBS 115.27) constitutes a lineage closely related to A. carneus. Fennellia nivea, the hypothesized teleomorph is not related to this clade. Aspergillus allahabadii, A. niveus var. indicus, and two species originally placed in section Versicolores, A......Section Terrei of Aspergillus was studied using a polyphasic approach including sequence analysis of parts of the beta-tubulin and calmodulin genes and the ITS region, macro- and micromorphological analyses and examination of extrolite profiles to describe three new species in this section. Based....... floccosus, A. terreus var. africanus, A. terreus var. aureus, while Aspergillus hortai is recognised at species level. Aspergillus terreus NRRL 4017 is described as the new species A. pseudoterreus. Also included in section Terrei are some species formerly placed in sections Flavipedes and Versicolores. A...

  4. Metabolites from marine fungus Aspergillus sp.

    Digital Repository Service at National Institute of Oceanography (India)

    Wahidullah, S.; Rajmanickam, R.; DeSouza, L.

    Chemical examination of a methanolic extract of the marine fungus, Aspergillus sp., isolated from marine grass environment, yielded a steroid, ergosterol peroxide (1), and a mixture of known glyceride esters (2,3) of unsaturated fatty acids...

  5. Genomic Diversity in the Genus of Aspergillus

    DEFF Research Database (Denmark)

    Rasmussen, Jane Lind Nybo

    , sections and genus of Aspergillus. The work uncovers a large genomic diversity across all studied groups of species. The genomic diversity was especially evident on the section level, where the proteins shared by all species only represents ⇠55% of the proteome. This number decreases even further, to 38......, sections Nigri, Usti and Cavericolus, clade Tubingensis, and species A. niger. It lastly uses these results to predict genetic traits that take part in fungal speciation. Within a few years the Aspergillus whole-genus sequencing project will have published all currently-accepted Aspergillus genomes......Aspergillus is a highly important genus of saprotrophic filamentous fungi. It is a very diverse genus that is inextricably intertwined with human a↵airs on a daily basis, holding species relevant to plant and human pathology, enzyme and bulk chemistry production, food and beverage biotechnology...

  6. Accounting for microbial habitats in modeling soil organic matter dynamics

    Science.gov (United States)

    Chenu, Claire; Garnier, Patricia; Nunan, Naoise; Pot, Valérie; Raynaud, Xavier; Vieublé, Laure; Otten, Wilfred; Falconer, Ruth; Monga, Olivier

    2017-04-01

    The extreme heterogeneity of soils constituents, architecture and inhabitants at the microscopic scale is increasingly recognized. Microbial communities exist and are active in a complex 3-D physical framework of mineral and organic particles defining pores of various sizes, more or less inter-connected. This results in a frequent spatial disconnection between soil carbon, energy sources and the decomposer organisms and a variety of microhabitats that are more or less suitable for microbial growth and activity. However, current biogeochemical models account for C dynamics at the macroscale (cm, m) and consider time- and spatially averaged relationships between microbial activity and soil characteristics. Different modelling approaches have intended to account for this microscale heterogeneity, based either on considering aggregates as surrogates for microbial habitats, or pores. Innovative modelling approaches are based on an explicit representation of soil structure at the fine scale, i.e. at µm to mm scales: pore architecture and their saturation with water, localization of organic resources and of microorganisms. Three recent models are presented here, that describe the heterotrophic activity of either bacteria or fungi and are based upon different strategies to represent the complex soil pore system (Mosaic, LBios and µFun). These models allow to hierarchize factors of microbial activity in soil's heterogeneous architecture. Present limits of these approaches and challenges are presented, regarding the extensive information required on soils at the microscale and to up-scale microbial functioning from the pore to the core scale.

  7. Post-genomic insights into the plant polysaccharide degradation potential of Aspergillus nidulans and comparison to Aspergillus niger and Aspergillus oryzae

    NARCIS (Netherlands)

    Coutinho, Pedro M; Andersen, Mikael R; Kolenova, Katarina; vanKuyk, Patricia A; Benoit, Isabelle; Gruben, Birgit S; Trejo-Aguilar, Blanca; Visser, Hans; van Solingen, Piet; Pakula, Tiina; Seiboth, Bernard; Battaglia, Evy; Aguilar-Osorio, Guillermo; de Jong, Jan F; Ohm, Robin A; Aguilar, Mariana; Henrissat, Bernard; Nielsen, Jens; Stålbrand, Henrik; de Vries, Ronald P

    The plant polysaccharide degradative potential of Aspergillus nidulans was analysed in detail and compared to that of Aspergillus niger and Aspergillus oryzae using a combination of bioinformatics, physiology and transcriptomics. Manual verification indicated that 28.4% of the A. nidulans ORFs

  8. [Biomechanical modeling of pelvic organ mobility: towards personalized medicine].

    Science.gov (United States)

    Cosson, Michel; Rubod, Chrystèle; Vallet, Alexandra; Witz, Jean-François; Brieu, Mathias

    2011-11-01

    Female pelvic mobility is crucial for urinary, bowel and sexual function and for vaginal delivery. This mobility is ensured by a complex organ suspension system composed of ligaments, fascia and muscles. Impaired pelvic mobility affects one in three women of all ages and can be incapacitating. Surgical management has a high failure rate, largely owing to poor knowledge of the organ support system, including the barely discernible ligamentous system. We propose a 3D digital model of the pelvic cavity based on MRI images and quantitative tools, designed to locate the pelvic ligaments. We thus obtain a coherent anatomical and functional model which can be used to analyze pelvic pathophysiology. This work represents a first step towards creating a tool for localizing and characterizing the source of pelvic imbalance. We examine possible future applications of this model, in terms of personalized therapy and prevention.

  9. The Aspergillus niger RmsA protein

    Science.gov (United States)

    Minkwitz, Susann; Schütze, Tabea; van den Hondel, Cees A.M.J.J; Ram, Arthur F.J

    2010-01-01

    Many cells and organisms go through polarized growth phases during their life. Cell polarization is achieved by local accumulation of signaling molecules which guide the cytoskeleton and vesicular trafficking to specific parts of the cell and thus ensure polarity establishment and maintenance. Polarization of signaling molecules is also fundamental for the lifestyle of filamentous fungi such as Aspergillus niger and essential for their morphogenesis, development and survival under environmental stress conditions. Considerable advances in our understanding on the protagonists and processes mediating polarized growth in filamentous fungi have been made over the past years. However, how the interplay of different signaling pathways is coordinated has yet to be determined. We found that the A. niger RmsA protein is central for the polarization of actin at the hyphal tip but also of vital importance for the metabolism, viability and stress resistance of A. niger. This suggests that RmsA could occupy an important position in the global network of pathways that balance growth, morphogenesis and survival of A. niger. PMID:20585521

  10. Modeling Secondary Organic Aerosol Formation From Emissions of Combustion Sources

    Science.gov (United States)

    Jathar, Shantanu Hemant

    Atmospheric aerosols exert a large influence on the Earth's climate and cause adverse public health effects, reduced visibility and material degradation. Secondary organic aerosol (SOA), defined as the aerosol mass arising from the oxidation products of gas-phase organic species, accounts for a significant fraction of the submicron atmospheric aerosol mass. Yet, there are large uncertainties surrounding the sources, atmospheric evolution and properties of SOA. This thesis combines laboratory experiments, extensive data analysis and global modeling to investigate the contribution of semi-volatile and intermediate volatility organic compounds (SVOC and IVOC) from combustion sources to SOA formation. The goals are to quantify the contribution of these emissions to ambient PM and to evaluate and improve models to simulate its formation. To create a database for model development and evaluation, a series of smog chamber experiments were conducted on evaporated fuel, which served as surrogates for real-world combustion emissions. Diesel formed the most SOA followed by conventional jet fuel / jet fuel derived from natural gas, gasoline and jet fuel derived from coal. The variability in SOA formation from actual combustion emissions can be partially explained by the composition of the fuel. Several models were developed and tested along with existing models using SOA data from smog chamber experiments conducted using evaporated fuel (this work, gasoline, fischertropschs, jet fuel, diesels) and published data on dilute combustion emissions (aircraft, on- and off-road gasoline, on- and off-road diesel, wood burning, biomass burning). For all of the SOA data, existing models under-predicted SOA formation if SVOC/IVOC were not included. For the evaporated fuel experiments, when SVOC/IVOC were included predictions using the existing SOA model were brought to within a factor of two of measurements with minor adjustments to model parameterizations. Further, a volatility

  11. Predicting long-term organic carbon dynamics in organically amended soils using the CQESTR model

    Energy Technology Data Exchange (ETDEWEB)

    Plaza, Cesar; Polo, Alfredo [Consejo Superior de Investigaciones Cientificas, Madrid (Spain). Inst. de Ciencias Agrarias; Gollany, Hero T. [Columbia Plateau Conservation Research Center, Pendleton, OR (United States). USDA-ARS; Baldoni, Guido; Ciavatta, Claudio [Bologna Univ. (Italy). Dept. of Agroenvironmental Sciences and Technologies

    2012-04-15

    Purpose: The CQESTR model is a process-based C model recently developed to simulate soil organic matter (SOM) dynamics and uses readily available or easily measurable input parameters. The current version of CQESTR (v. 2.0) has been validated successfully with a number of datasets from agricultural sites in North America but still needs to be tested in other geographic areas and soil types under diverse organic management systems. Materials and methods: We evaluated the predictive performance of CQESTR to simulate long-term (34 years) soil organic C (SOC) changes in a SOM-depleted European soil either unamended or amended with solid manure, liquid manure, or crop residue. Results and discussion: Measured SOC levels declined over the study period in the unamended soil, remained constant in the soil amended with crop residues, and tended to increase in the soils amended with manure, especially with solid manure. Linear regression analysis of measured SOC contents and CQESTR predictions resulted in a correlation coefficient of 0.626 (P < 0.001) and a slope and an intercept not significantly different from 1 and 0, respectively (95% confidence level). The mean squared deviation and root mean square error were relatively small. Simulated values fell within the 95% confidence interval of the measured SOC, and predicted errors were mainly associated with data scattering. Conclusions: The CQESTR model was shown to predict, with a reasonable degree of accuracy, the organic C dynamics in the soils examined. The CQESTR performance, however, could be improved by adding an additional parameter to differentiate between pre-decomposed organic amendments with varying degrees of stability. (orig.)

  12. Organized versus self-organized criticality in the abelian sandpile model

    OpenAIRE

    Fey-den Boer, AC Anne; Redig, FHJ Frank

    2005-01-01

    We define stabilizability of an infinite volume height configuration and of a probability measure on height configurations. We show that for high enough densities, a probability measure cannot be stabilized. We also show that in some sense the thermodynamic limit of the uniform measures on the recurrent configurations of the abelian sandpile model (ASM) is a maximal element of the set of stabilizable measures. In that sense the self-organized critical behavior of the ASM can be understood in ...

  13. IT Business Value Model for Information Intensive Organizations

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Gastaud Maçada

    2012-01-01

    Full Text Available Many studies have highlighted the capacity Information Technology (IT has for generating value for organizations. Investments in IT made by organizations have increased each year. Therefore, the purpose of the present study is to analyze the IT Business Value for Information Intensive Organizations (IIO - e.g. banks, insurance companies and securities brokers. The research method consisted of a survey that used and combined the models from Weill and Broadbent (1998 and Gregor, Martin, Fernandez, Stern and Vitale (2006. Data was gathered using an adapted instrument containing 5 dimensions (Strategic, Informational, Transactional, Transformational and Infra-structure with 27 items. The instrument was refined by employing statistical techniques such as Exploratory and Confirmatory Factorial Analysis through Structural Equations (first and second order Model Measurement. The final model is composed of four factors related to IT Business Value: Strategic, Informational, Transactional and Transformational, arranged in 15 items. The dimension Infra-structure was excluded during the model refinement process because it was discovered during interviews that managers were unable to perceive it as a distinct dimension of IT Business Value.

  14. Scalability of Sustainable Business Models in Hybrid Organizations

    Directory of Open Access Journals (Sweden)

    Adam Jabłoński

    2016-02-01

    Full Text Available The dynamics of change in modern business create new mechanisms for company management to determine their pursuit and the achievement of their high performance. This performance maintained over a long period of time becomes a source of ensuring business continuity by companies. An ontological being enabling the adoption of such assumptions is such a business model that has the ability to generate results in every possible market situation and, moreover, it has the features of permanent adaptability. A feature that describes the adaptability of the business model is its scalability. Being a factor ensuring more work and more efficient work with an increasing number of components, scalability can be applied to the concept of business models as the company’s ability to maintain similar or higher performance through it. Ensuring the company’s performance in the long term helps to build the so-called sustainable business model that often balances the objectives of stakeholders and shareholders, and that is created by the implemented principles of value-based management and corporate social responsibility. This perception of business paves the way for building hybrid organizations that integrate business activities with pro-social ones. The combination of an approach typical of hybrid organizations in designing and implementing sustainable business models pursuant to the scalability criterion seems interesting from the cognitive point of view. Today, hybrid organizations are great spaces for building effective and efficient mechanisms for dialogue between business and society. This requires the appropriate business model. The purpose of the paper is to present the conceptualization and operationalization of scalability of sustainable business models that determine the performance of a hybrid organization in the network environment. The paper presents the original concept of applying scalability in sustainable business models with detailed

  15. A molecular analysis of L-arabinan degradation in Aspergillus niger and Aspergillus nidulans

    NARCIS (Netherlands)

    Flipphi, M.J.A.

    1995-01-01

    This thesis describes a molecular study of the genetics ofL-arabinan degradation in Aspergillus niger and Aspergillus nidulans. These saprophytic hyphal fungi produce an extracellular hydrolytic enzyme system to

  16. Variability in Galactomannan detection by platelia Aspergillus EIA™ according to the Aspergillus species

    Directory of Open Access Journals (Sweden)

    Melissa Orzechowski Xavier

    2013-06-01

    Full Text Available Here we investigate the extent to which different Aspergillus species release galactomannan (GM in vitro. Marked variability was observed in GM reactivity between and within Aspergillus species, with A. terreus strains showing the highest GM indexes. The in vivo significance of these findings remains to be determined.

  17. A taxonomy of nursing care organization models in hospitals.

    Science.gov (United States)

    Dubois, Carl-Ardy; D'Amour, Danielle; Tchouaket, Eric; Rivard, Michèle; Clarke, Sean; Blais, Régis

    2012-08-28

    Over the last decades, converging forces in hospital care, including cost-containment policies, rising healthcare demands and nursing shortages, have driven the search for new operational models of nursing care delivery that maximize the use of available nursing resources while ensuring safe, high-quality care. Little is known, however, about the distinctive features of these emergent nursing care models. This article contributes to filling this gap by presenting a theoretically and empirically grounded taxonomy of nursing care organization models in the context of acute care units in Quebec and comparing their distinctive features. This study was based on a survey of 22 medical units in 11 acute care facilities in Quebec. Data collection methods included questionnaire, interviews, focus groups and administrative data census. The analytical procedures consisted of first generating unit profiles based on qualitative and quantitative data collected at the unit level, then applying hierarchical cluster analysis to the units' profile data. The study identified four models of nursing care organization: two professional models that draw mainly on registered nurses as professionals to deliver nursing services and reflect stronger support to nurses' professional practice, and two functional models that draw more significantly on licensed practical nurses (LPNs) and assistive staff (orderlies) to deliver nursing services and are characterized by registered nurses' perceptions that the practice environment is less supportive of their professional work. This study showed that medical units in acute care hospitals exhibit diverse staff mixes, patterns of skill use, work environment design, and support for innovation. The four models reflect not only distinct approaches to dealing with the numerous constraints in the nursing care environment, but also different degrees of approximations to an "ideal" nursing professional practice model described by some leaders in the

  18. A taxonomy of nursing care organization models in hospitals

    Science.gov (United States)

    2012-01-01

    Background Over the last decades, converging forces in hospital care, including cost-containment policies, rising healthcare demands and nursing shortages, have driven the search for new operational models of nursing care delivery that maximize the use of available nursing resources while ensuring safe, high-quality care. Little is known, however, about the distinctive features of these emergent nursing care models. This article contributes to filling this gap by presenting a theoretically and empirically grounded taxonomy of nursing care organization models in the context of acute care units in Quebec and comparing their distinctive features. Methods This study was based on a survey of 22 medical units in 11 acute care facilities in Quebec. Data collection methods included questionnaire, interviews, focus groups and administrative data census. The analytical procedures consisted of first generating unit profiles based on qualitative and quantitative data collected at the unit level, then applying hierarchical cluster analysis to the units’ profile data. Results The study identified four models of nursing care organization: two professional models that draw mainly on registered nurses as professionals to deliver nursing services and reflect stronger support to nurses’ professional practice, and two functional models that draw more significantly on licensed practical nurses (LPNs) and assistive staff (orderlies) to deliver nursing services and are characterized by registered nurses’ perceptions that the practice environment is less supportive of their professional work. Conclusions This study showed that medical units in acute care hospitals exhibit diverse staff mixes, patterns of skill use, work environment design, and support for innovation. The four models reflect not only distinct approaches to dealing with the numerous constraints in the nursing care environment, but also different degrees of approximations to an “ideal” nursing professional practice

  19. Aspergillus tubingensis and Aspergillus niger as the dominant black Aspergillus, use of simple PCR-RFLP for preliminary differentiation.

    Science.gov (United States)

    Mirhendi, H; Zarei, F; Motamedi, M; Nouripour-Sisakht, S

    2016-03-01

    This work aimed to identify the species distribution of common clinical and environmental isolates of black Aspergilli based on simple restriction fragment length polymorphism (RFLP) analysis of the β-tubulin gene. A total of 149 clinical and environmental strains of black Aspergilli were collected and subjected to preliminary morphological examination. Total genomic DNAs were extracted, and PCR was performed to amplify part of the β-tubulin gene. At first, 52 randomly selected samples were species-delineated by sequence analysis. In order to distinguish the most common species, PCR amplicons of 117 black Aspergillus strains were identified by simple PCR-RFLP analysis using the enzyme TasI. Among 52 sequenced isolates, 28 were Aspergillus tubingensis, 21 Aspergillus niger, and the three remaining isolates included Aspergillus uvarum, Aspergillus awamori, and Aspergillus acidus. All 100 environmental and 17 BAL samples subjected to TasI-RFLP analysis of the β-tubulin gene, fell into two groups, consisting of about 59% (n=69) A. tubingensis and 41% (n=48) A. niger. Therefore, the method successfully and rapidly distinguished A. tubingensis and A. niger as the most common species among the clinical and environmental isolates. Although tardy, the Ehrlich test was also able to differentiate A. tubingensis and A. niger according to the yellow color reaction specific to A. niger. A. tubingensis and A. niger are the most common black Aspergillus in both clinical and environmental isolates in Iran. PCR-RFLP using TasI digestion of β-tubulin DNA enables rapid screening for these common species. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  20. Molecular analysis of the replication program in unicellular model organisms

    OpenAIRE

    Raghuraman, M. K.; Brewer, Bonita J.

    2010-01-01

    Eukaryotes have long been reported to show temporal programs of replication, different portions of the genome being replicated at different times in S phase, with the added possibility of developmentally regulated changes in this pattern depending on species and cell type. Unicellular model organisms, primarily the budding yeast Saccharomyces cerevisiae, have been central to our current understanding of the mechanisms underlying the regulation of replication origins and the temporal program o...

  1. Understanding rare disease pathogenesis: a grand challenge for model organisms.

    Science.gov (United States)

    Hieter, Philip; Boycott, Kym M

    2014-10-01

    In this commentary, Philip Hieter and Kym Boycott discuss the importance of model organisms for understanding pathogenesis of rare human genetic diseases, and highlight the work of Brooks et al., "Dysfunction of 60S ribosomal protein L10 (RPL10) disrupts neurodevelopment and causes X-linked microcephaly in humans," published in this issue of GENETICS. Copyright © 2014 by the Genetics Society of America.

  2. Quasi-dynamic model for an organic Rankine cycle

    International Nuclear Information System (INIS)

    Bamgbopa, Musbaudeen O.; Uzgoren, Eray

    2013-01-01

    Highlights: • Study presents a simplified transient modeling approach for an ORC under variable heat input. • The ORC model is presented as a synthesis of its models of its sub-components. • The model is compared to benchmark numerical simulations and experimental data at different stages. - Abstract: When considering solar based thermal energy input to an organic Rankine cycle (ORC), intermittent nature of the heat input does not only adversely affect the power output but also it may prevent ORC to operate under steady state conditions. In order to identify reliability and efficiency of such systems, this paper presents a simplified transient modeling approach for an ORC operating under variable heat input. The approach considers that response of the system to heat input variations is mainly dictated by the evaporator. Consequently, overall system is assembled using dynamic models for the heat exchangers (evaporator and condenser) and static models of the pump and the expander. In addition, pressure drop within heat exchangers is neglected. The model is compared to benchmark numerical and experimental data showing that the underlying assumptions are reasonable for cases where thermal input varies in time. Furthermore, the model is studied on another configuration and mass flow rates of both the working fluid and hot water and hot water’s inlet temperature to the ORC unit are shown to have direct influence on the system’s response

  3. Sordaria macrospora, a model organism to study fungal cellular development.

    Science.gov (United States)

    Engh, Ines; Nowrousian, Minou; Kück, Ulrich

    2010-12-01

    During the development of multicellular eukaryotes, the processes of cellular growth and organogenesis are tightly coordinated. Since the 1940s, filamentous fungi have served as genetic model organisms to decipher basic mechanisms underlying eukaryotic cell differentiation. Here, we focus on Sordaria macrospora, a homothallic ascomycete and important model organism for developmental biology. During its sexual life cycle, S. macrospora forms three-dimensional fruiting bodies, a complex process involving the formation of different cell types. S. macrospora can be used for genetic, biochemical and cellular experimental approaches since diverse tools, including fluorescence microscopy, a marker recycling system and gene libraries, are available. Moreover, the genome of S. macrospora has been sequenced and allows functional genomics analyses. Over the past years, our group has generated and analysed a number of developmental mutants which has greatly enhanced our fundamental understanding about fungal morphogenesis. In addition, our recent research activities have established a link between developmental proteins and conserved signalling cascades, ultimately leading to a regulatory network controlling differentiation processes in a eukaryotic model organism. This review summarizes the results of our recent findings, thus advancing current knowledge of the general principles and paradigms underpinning eukaryotic cell differentiation and development. Copyright © 2010 Elsevier GmbH. All rights reserved.

  4. Aging, neurogenesis, and caloric restriction in different model organisms.

    Science.gov (United States)

    Arslan-Ergul, Ayca; Ozdemir, A Tugrul; Adams, Michelle M

    2013-08-01

    Brain aging is a multifactorial process that is occurring across multiple cognitive domains. A significant complaint that occurs in the elderly is a decrement in learning and memory ability. Both rodents and zebrafish exhibit a similar problem with memory during aging. The neurobiological changes that underlie this cognitive decline are complex and undoubtedly influenced by many factors. Alterations in the birth of new neurons and neuron turnover may contribute to age-related cognitive problems. Caloric restriction is the only non-genetic intervention that reliably increases life span and healthspan across multiple organisms although the molecular mechanisms are not well-understood. Recently the zebrafish has become a popular model organism for understanding the neurobiological consequences but to date very little work has been performed. Similarly, few studies have examined the effects of dietary restriction in zebrafish. Here we review the literature related to memory decline, neurogenesis, and caloric restriction across model organisms and suggest that zebrafish has the potential to be an important animal model for understanding the complex interactions between age, neurobiological changes in the brain, and dietary regimens or their mimetics as interventions.

  5. Turbulence and Self-Organization Modeling Astrophysical Objects

    CERN Document Server

    Marov, Mikhail Ya

    2013-01-01

    This book focuses on the development of continuum models of natural turbulent media. It provides a theoretical approach to the solutions of different problems related to the formation, structure and evolution of astrophysical and geophysical objects. A stochastic modeling approach is used in the mathematical treatment of these problems, which reflects self-organization processes in open dissipative systems. The authors also consider examples of ordering for various objects in space throughout their evolutionary processes. This volume is aimed at graduate students and researchers in the fields of mechanics, astrophysics, geophysics, planetary and space science.

  6. Conceptual hierarchical modeling to describe wetland plant community organization

    Science.gov (United States)

    Little, A.M.; Guntenspergen, G.R.; Allen, T.F.H.

    2010-01-01

    Using multivariate analysis, we created a hierarchical modeling process that describes how differently-scaled environmental factors interact to affect wetland-scale plant community organization in a system of small, isolated wetlands on Mount Desert Island, Maine. We followed the procedure: 1) delineate wetland groups using cluster analysis, 2) identify differently scaled environmental gradients using non-metric multidimensional scaling, 3) order gradient hierarchical levels according to spatiotem-poral scale of fluctuation, and 4) assemble hierarchical model using group relationships with ordination axes and post-hoc tests of environmental differences. Using this process, we determined 1) large wetland size and poor surface water chemistry led to the development of shrub fen wetland vegetation, 2) Sphagnum and water chemistry differences affected fen vs. marsh / sedge meadows status within small wetlands, and 3) small-scale hydrologic differences explained transitions between forested vs. non-forested and marsh vs. sedge meadow vegetation. This hierarchical modeling process can help explain how upper level contextual processes constrain biotic community response to lower-level environmental changes. It creates models with more nuanced spatiotemporal complexity than classification and regression tree procedures. Using this process, wetland scientists will be able to generate more generalizable theories of plant community organization, and useful management models. ?? Society of Wetland Scientists 2009.

  7. Isolation, characterization and transcriptome analysis of a novel Antarctic Aspergillus sydowii strain MS-19 as a potential lignocellulosic enzyme source.

    Science.gov (United States)

    Cong, Bailin; Wang, Nengfei; Liu, Shenghao; Liu, Feng; Yin, Xiaofei; Shen, Jihong

    2017-05-30

    With the growing demand for fossil fuels and the severe energy crisis, lignocellulose is widely regarded as a promising cost-effective renewable resource for ethanol production, and the use of lignocellulose residues as raw material is remarkable. Polar organisms have important value in scientific research and development for their novelty, uniqueness and diversity. In this study, a fungus Aspergillus sydowii MS-19, with the potential for lignocellulose degradation was screened out and isolated from an Antarctic region. The growth profile of Aspergillus sydowii MS-19 was measured, revealing that Aspergillus sydowii MS-19 could utilize lignin as a sole carbon source. Its ability to synthesize low-temperature lignin peroxidase (Lip) and manganese peroxidase (Mnp) enzymes was verified, and the properties of these enzymes were also investigated. High-throughput sequencing was employed to identify and characterize the transcriptome of Aspergillus sydowii MS-19. Carbohydrate-Active Enzymes (CAZyme)-annotated genes in Aspergillus sydowii MS-19 were compared with those in the brown-rot fungus representative species, Postia placenta and Penicillium decumbens. There were 701CAZymes annotated in Aspergillus sydowii MS-19, including 17 cellulases and 19 feruloyl esterases related to lignocellulose-degradation. Remarkably, one sequence annotated as laccase was obtained, which can degrade lignin. Three peroxidase sequences sharing a similar structure with typical lignin peroxidase and manganese peroxidase were also found and annotated as haem-binding peroxidase, glutathione peroxidase and catalase-peroxidase. In this study, the fungus Aspergillus sydowii MS-19 was isolated and shown to synthesize low-temperature lignin-degrading enzymes: lignin peroxidase (Lip) and manganese peroxidase (Mnp). These findings provide useful information to improve our understanding of low-temperature lignocellulosic enzyme production by polar microorganisms and to facilitate research and

  8. Silkworm: A Promising Model Organism in Life Science.

    Science.gov (United States)

    Meng, Xu; Zhu, Feifei; Chen, Keping

    2017-09-01

    As an important economic insect, silkworm Bombyx mori (L.) (Lepidoptera: Bombycidae) has numerous advantages in life science, such as low breeding cost, large progeny size, short generation time, and clear genetic background. Additionally, there are rich genetic resources associated with silkworms. The completion of the silkworm genome has further accelerated it to be a modern model organism in life science. Genomic studies showed that some silkworm genes are highly homologous to certain genes related to human hereditary disease and, therefore, are a candidate model for studying human disease. In this article, we provided a review of silkworm as an important model in various research areas, including human disease, screening of antimicrobial agents, environmental safety monitoring, and antitumor studies. In addition, the application potentiality of silkworm model in life sciences was discussed. © The Author 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  9. A nonribosomal peptide synthetase (Pes1) confers protection against oxidative stress in Aspergillus fumigatus.

    Science.gov (United States)

    Reeves, Emer P; Reiber, Kathrin; Neville, Claire; Scheibner, Olaf; Kavanagh, Kevin; Doyle, Sean

    2006-07-01

    Aspergillus fumigatus is an important human fungal pathogen. The Aspergillus fumigatus genome contains 14 nonribosomal peptide synthetase genes, potentially responsible for generating metabolites that contribute to organismal virulence. Differential expression of the nonribosomal peptide synthetase gene, pes1, in four strains of Aspergillus fumigatus was observed. The pattern of pes1 expression differed from that of a putative siderophore synthetase gene, sidD, and so is unlikely to be involved in iron acquisition. The Pes1 protein (expected molecular mass 698 kDa) was partially purified and identified by immunoreactivity, peptide mass fingerprinting (36% sequence coverage) and MALDI LIFT-TOF/TOF MS (four internal peptides sequenced). A pes1 disruption mutant (delta pes1) of Aspergillus fumigatus strain 293.1 was generated and confirmed by Southern and western analysis, in addition to RT-PCR. The delta pes1 mutant also showed significantly reduced virulence in the Galleria mellonella model system (P < 0.001) and increased sensitivity to oxidative stress (P = 0.002) in culture and during neutrophil-mediated phagocytosis. In addition, the mutant exhibited altered conidial surface morphology and hydrophilicity, compared to Aspergillus fumigatus 293.1. It is concluded that pes1 contributes to improved fungal tolerance against oxidative stress, mediated by the conidial phenotype, during the infection process.

  10. 21 CFR 866.3040 - Aspergillus spp. serological reagents.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3040 Aspergillus... consist of antigens and antisera used in various serological tests to identify antibodies to Aspergillus...

  11. An Instructional Development Model for Global Organizations: The GOaL Model.

    Science.gov (United States)

    Hara, Noriko; Schwen, Thomas M.

    1999-01-01

    Presents an instructional development model, GOaL (Global Organization Localization), for use by global organizations. Topics include gaps in language, culture, and needs; decentralized processes; collaborative efforts; predetermined content; multiple perspectives; needs negotiation; learning within context; just-in-time training; and bilingual…

  12. Performance of Aspergillus PCR in cerebrospinal fluid for the diagnosis of cerebral aspergillosis.

    Science.gov (United States)

    Imbert, S; Brossas, J-Y; Palous, M; Joly, I; Meyer, I; Fekkar, A

    2017-11-01

    Cerebral aspergillosis is a rare but often fatal form of invasive aspergillosis that remains difficult to diagnose. The literature has shown the value of Aspergillus PCR in blood-derived samples for the diagnosis of invasive aspergillosis but provides far less information for cerebrospinal fluid (CSF) in cerebral aspergillosis. Here, we evaluated the usefulness of an Aspergillus PCR assay performed on CSF for the diagnosis of cerebral aspergillosis. This retrospective study involved 72 patients with suspected cerebral aspergillosis for a total of 88 CSF samples in whom CSF Aspergillus PCR was performed. Seventeen patients had proven/probable invasive aspergillosis according to the European Organization for Research and Treatment of Cancer/Mycoses Study Group criteria, including 12 cases of proven/probable cerebral aspergillosis. Aspergillus PCR in CSF was positive in nine of the twelve patients with cerebral aspergillosis, i.e. 75% sensitivity. In contrast, CSF culture was positive for Aspergillus in only two patients. In the non-cerebral aspergillosis group (60 patients), PCR was positive in one patient, i.e. 98.3% specificity. In this particular population of high-risk patients with suspicion of cerebral aspergillosis, the disease incidence was 16.7%. Therefore, the positive and negative predictive values of PCR were 90% and 95.2%, respectively. The results of this study indicate that Aspergillus PCR in CSF is an interesting tool that may eliminate the need for cerebral biopsy in patients with suspected cerebral aspergillosis. Copyright © 2017 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  13. Dryout modeling in support of the organic tank safety project

    International Nuclear Information System (INIS)

    Simmons, C.S.

    1998-08-01

    This work was performed for the Organic Tank Safety Project to evaluate the moisture condition of the waste surface organic-nitrate bearing tanks that are classified as being conditionally safe because sufficient water is present. This report describes the predictive modeling procedure used to predict the moisture content of waste in the future, after it has been subjected to dryout caused by water vapor loss through passive ventilation. This report describes a simplified procedure for modeling the drying out of tank waste. Dryout occurs as moisture evaporates from the waste into the headspace and then exits the tank through ventilation. The water vapor concentration within the waste of the headspace is determined by the vapor-liquid equilibrium, which depends on the waste's moisture content and temperature. This equilibrium has been measured experimentally for a variety of waste samples and is described by a curve called the water vapor partial pressure isotherm. This curve describes the lowering of the partial pressure of water vapor in equilibrium with the waste relative to pure water due to the waste's chemical composition and hygroscopic nature. Saltcake and sludge are described by two distinct calculations that emphasize the particular physical behavior or each. A simple, steady-state model is devised for each type to obtain the approximate drying behavior. The report shows the application of the model to Tanks AX-102, C-104, and U-105

  14. Biosorption of uranium with Aspergillus niger

    International Nuclear Information System (INIS)

    Yakubu, N.A.; Dudeney, A.W.L.

    1986-01-01

    This paper considers interactions of uranium with the microfilamentous fungus Aspergillus niger grown as pellets 4 mm in diameter for column application. Adsorption and desorption isotherms, a range of physical measurements, and a derived mechanistic model, indicated that a simple ion exchange process predominates in which uranyl cations reversibly replace protons on the amino acid groups of proteins and glycoproteins within the cell wall structure. Under the conditions employed uranium adsorbed onto A. niger (CMI 296409) some fourteen times more efficiently at pH 4 than onto the ion exchange resin IRA-400, and was readily desorbed at pH 1. The fungus had inferior selectivity and wet volume/dry weight ratio. Uranium was adsorbed semi-continuously by heat-killed A. niger pellets fluidised in a compartmentalised column. When operated with an intermittent countercurrent flow of the biomass, uranium concentrations of 100 g/m 3 and 5 g/m 3 at pH 4 could be reduced to less than 10 g/m 3 and 1 g/m 3 , respectively. (author)

  15. Proteome map of Aspergillus nidulans during osmoadaptation.

    Science.gov (United States)

    Kim, Yonghyun; Nandakumar, M P; Marten, Mark R

    2007-09-01

    The model filamentous fungus Aspergillus nidulans, when grown in a moderate level of osmolyte (+0.6M KCl), was previously found to have a significantly reduced cell wall elasticity (Biotech Prog, 21:292, 2005). In this study, comparative proteomic analysis via two-dimensional gel electrophoresis (2de) and matrix-assisted laser desorption ionization/time-of-flight (MALDI-TOF) mass spectrometry was used to assess molecular level events associated with this phenomenon. Thirty of 90 differentially expressed proteins were identified. Sequence homology and conserved domains were used to assign probable function to twenty-one proteins currently annotated as "hypothetical." In osmoadapted cells, there was an increased expression of glyceraldehyde-3-phosphate dehydrogenase and aldehyde dehydrogenase, as well as a decreased expression of enolase, suggesting an increased glycerol biosynthesis and decreased use of the TCA cycle. There also was an increased expression of heat shock proteins and Shp1-like protein degradation protein, implicating increased protein turnover. Five novel osmoadaptation proteins of unknown functions were also identified.

  16. Mesoscopic kinetic Monte Carlo modeling of organic photovoltaic device characteristics

    Science.gov (United States)

    Kimber, Robin G. E.; Wright, Edward N.; O'Kane, Simon E. J.; Walker, Alison B.; Blakesley, James C.

    2012-12-01

    Measured mobility and current-voltage characteristics of single layer and photovoltaic (PV) devices composed of poly{9,9-dioctylfluorene-co-bis[N,N'-(4-butylphenyl)]bis(N,N'-phenyl-1,4-phenylene)diamine} (PFB) and poly(9,9-dioctylfluorene-co-benzothiadiazole) (F8BT) have been reproduced by a mesoscopic model employing the kinetic Monte Carlo (KMC) approach. Our aim is to show how to avoid the uncertainties common in electrical transport models arising from the need to fit a large number of parameters when little information is available, for example, a single current-voltage curve. Here, simulation parameters are derived from a series of measurements using a self-consistent “building-blocks” approach, starting from data on the simplest systems. We found that site energies show disorder and that correlations in the site energies and a distribution of deep traps must be included in order to reproduce measured charge mobility-field curves at low charge densities in bulk PFB and F8BT. The parameter set from the mobility-field curves reproduces the unipolar current in single layers of PFB and F8BT and allows us to deduce charge injection barriers. Finally, by combining these disorder descriptions and injection barriers with an optical model, the external quantum efficiency and current densities of blend and bilayer organic PV devices can be successfully reproduced across a voltage range encompassing reverse and forward bias, with the recombination rate the only parameter to be fitted, found to be 1×107 s-1. These findings demonstrate an approach that removes some of the arbitrariness present in transport models of organic devices, which validates the KMC as an accurate description of organic optoelectronic systems, and provides information on the microscopic origins of the device behavior.

  17. MIANN models in medicinal, physical and organic chemistry.

    Science.gov (United States)

    González-Díaz, Humberto; Arrasate, Sonia; Sotomayor, Nuria; Lete, Esther; Munteanu, Cristian R; Pazos, Alejandro; Besada-Porto, Lina; Ruso, Juan M

    2013-01-01

    Reducing costs in terms of time, animal sacrifice, and material resources with computational methods has become a promising goal in Medicinal, Biological, Physical and Organic Chemistry. There are many computational techniques that can be used in this sense. In any case, almost all these methods focus on few fundamental aspects including: type (1) methods to quantify the molecular structure, type (2) methods to link the structure with the biological activity, and others. In particular, MARCH-INSIDE (MI), acronym for Markov Chain Invariants for Networks Simulation and Design, is a well-known method for QSAR analysis useful in step (1). In addition, the bio-inspired Artificial-Intelligence (AI) algorithms called Artificial Neural Networks (ANNs) are among the most powerful type (2) methods. We can combine MI with ANNs in order to seek QSAR models, a strategy which is called herein MIANN (MI & ANN models). One of the first applications of the MIANN strategy was in the development of new QSAR models for drug discovery. MIANN strategy has been expanded to the QSAR study of proteins, protein-drug interactions, and protein-protein interaction networks. In this paper, we review for the first time many interesting aspects of the MIANN strategy including theoretical basis, implementation in web servers, and examples of applications in Medicinal and Biological chemistry. We also report new applications of the MIANN strategy in Medicinal chemistry and the first examples in Physical and Organic Chemistry, as well. In so doing, we developed new MIANN models for several self-assembly physicochemical properties of surfactants and large reaction networks in organic synthesis. In some of the new examples we also present experimental results which were not published up to date.

  18. [Aspergillus fumigatus endocarditis in a patient with a biventricular pacemaker].

    Science.gov (United States)

    Cuesta, José M; Fariñas, María C; Rodilla, Irene G; Salesa, Ricardo; de Berrazueta, José R

    2005-05-01

    Aspergillus fumigatus endocarditis is one of the rarest and severest complications in cardiological patients. We describe a patient with an intracardial pacemaker who was diagnosed as having Aspergillus fumigatus endocarditis. Postmortem examination showed a large, Aspergillus-infected thrombus encased in the right ventricle, pulmonary trunk and main pulmonary branches.

  19. Genome-scale analysis of the high-efficient protein secretion system of Aspergillus oryzae

    DEFF Research Database (Denmark)

    Liu, Lifang; Feizi, Amir; Osterlund, Tobias

    2014-01-01

    related fungal species such as Aspergillus nidulans and Aspergillus niger. To evaluate the defined component list, we performed transcriptome analysis on three a-amylase over-producing strains with varying levels of secretion capacities. Specifically, secretory components involved in the ER......Background: The koji mold, Aspergillus oryzae is widely used for the production of industrial enzymes due to its particularly high protein secretion capacity and ability to perform post-translational modifications. However, systemic analysis of its secretion system is lacking, generally due...... to the poorly annotated proteome. Results: Here we defined a functional protein secretory component list of A. oryzae using a previously reported secretory model of S. cerevisiae as scaffold. Additional secretory components were obtained by blast search with the functional components reported in other closely...

  20. OBJECT ORIENTED MODELLING, A MODELLING METHOD OF AN ECONOMIC ORGANIZATION ACTIVITY

    Directory of Open Access Journals (Sweden)

    TĂNĂSESCU ANA

    2014-05-01

    Full Text Available Now, most economic organizations use different information systems types in order to facilitate their activity. There are different methodologies, methods and techniques that can be used to design information systems. In this paper, I propose to present the advantages of using the object oriented modelling at the information system design of an economic organization. Thus, I have modelled the activity of a photo studio, using Visual Paradigm for UML as a modelling tool. For this purpose, I have identified the use cases for the analyzed system and I have presented the use case diagram. I have, also, realized the system static and dynamic modelling, through the most known UML diagrams.

  1. Healthy human T-Cell Responses to Aspergillus fumigatus antigens.

    Directory of Open Access Journals (Sweden)

    Neelkamal Chaudhary

    2010-02-01

    Full Text Available Aspergillus fumigatus is associated with both invasive and allergic pulmonary diseases, in different hosts. The organism is inhaled as a spore, which, if not cleared from the airway, germinates into hyphal morphotypes that are responsible for tissue invasion and resultant inflammation. Hyphae secrete multiple products that function as antigens, evoking both a protective (T(H1-T(H17 and destructive allergic (T(H2 immunity. How Aspergillus allergens (Asp f proteins participate in the development of allergic sensitization is unknown.To determine whether Asp f proteins are strictly associated with T(H2 responses, or represent soluble hyphal products recognized by healthy hosts, human T cell responses to crude and recombinant products were characterized by ELISPOT. While responses (number of spots producing IFN-gamma, IL-4 or IL-17 to crude hyphal antigen preparations were weak, responses to recombinant Asp f proteins were higher. Recombinant allergens stimulated cells to produce IFN-gamma more so than IL-4 or IL-17. Volunteers exhibited a diverse CD4+ and CD8+ T cell antigen recognition profile, with prominent CD4 T(H1-responses to Asp f3 (a putative peroxismal membrane protein, Asp f9/16 (cell wall glucanase, Asp f11 (cyclophilin type peptidyl-prolyl isomerase and Asp f22 (enolase. Strong IFN-gamma responses were reproduced in most subjects tested over 6 month intervals.Products secreted after conidial germination into hyphae are differentially recognized by protective T cells in healthy, non-atopic individuals. Defining the specificity of the human T cell repertoire, and identifying factors that govern early responses may allow for development of novel diagnostics and therapeutics for both invasive and allergic Aspergillus diseases.

  2. The infrared spectral transmittance of Aspergillus niger spore aggregated particle swarm

    Science.gov (United States)

    Zhao, Xinying; Hu, Yihua; Gu, Youlin; Li, Le

    2015-10-01

    Microorganism aggregated particle swarm, which is quite an important composition of complex media environment, can be developed as a new kind of infrared functional materials. Current researches mainly focus on the optical properties of single microorganism particle. As for the swarm, especially the microorganism aggregated particle swarm, a more accurate simulation model should be proposed to calculate its extinction effect. At the same time, certain parameters deserve to be discussed, which helps to better develop the microorganism aggregated particle swarm as a new kind of infrared functional materials. In this paper, take Aspergillus Niger spore as an example. On the one hand, a new calculation model is established. Firstly, the cluster-cluster aggregation (CCA) model is used to simulate the structure of Aspergillus Niger spore aggregated particle. Secondly, the single scattering extinction parameters for Aspergillus Niger spore aggregated particle are calculated by using the discrete dipole approximation (DDA) method. Thirdly, the transmittance of Aspergillus Niger spore aggregated particle swarm is simulated by using Monte Carlo method. On the other hand, based on the model proposed above, what influences can wavelength causes has been studied, including the spectral distribution of scattering intensity of Aspergillus Niger spore aggregated particle and the infrared spectral transmittance of the aggregated particle swarm within the range of 8-14μm incident infrared wavelengths. Numerical results indicate that the scattering intensity of Aspergillus Niger spore aggregated particle reduces with the increase of incident wavelengths at each scattering angle. Scattering energy mainly concentrates on the scattering angle between 0-40°, forward scattering has an obvious effect. In addition, the infrared transmittance of Aspergillus Niger spore aggregated particle swarm goes up with the increase of incident wavelengths. However, some turning points of the trend are

  3. Biodegradation kinetics of thin-stillage treatment by Aspergillus awamori and characterization of recovered chitosan.

    Science.gov (United States)

    Ray, S Ghosh; Ghangrekar, M M

    2016-02-01

    An attempt has been made to provide solution for distillery wastewater using fungal pretreatment followed by an anaerobic process to achieve higher organic matter removal, which is a challenge at present with currently adopted technologies. Submerged growth kinetics of distillery wastewater supernatant by Aspergillus awamori was also evaluated. The proposed kinetic models using a logistic equation for fungal growth and the Leudeking-Piret equation for product formation were validated experimentally, and substrate consumption equation was derived using estimated kinetic coefficients. Up to 59.6 % chemical oxygen demand (COD) and 70 % total organic carbon (TOC) removals were observed in 96 h of fungal incubation. Maximum specific growth rate of fungi, coefficient of biomass yield on substrate and growth-associated product formation coefficient were estimated to be 0.07 ± 0.01 h(-1), 0.614 kg biomass/kg utilized COD and 0.215 kg CO2/kg utilized TOC, respectively. The chitosan recovery of 0.072-0.078 kg/kg of dry mycelium was obtained using dilute sulphuric acid extraction, showing high purity and characteristic chitosan properties according to FTIR and XRD analyses. After anaerobic treatment of the fungal pretreated effluent with COD concentration of 7.920 ± 0.120 kg COD/m(3) (organic loading rate of 3.28 kg COD/m(3) day), overall COD reduction of 91.07 % was achieved from distillery wastewater.

  4. Organization And Financing Models Of Health Service In Selected Countries

    Directory of Open Access Journals (Sweden)

    Branimir Marković

    2009-07-01

    Full Text Available The introductory part of the work gives a short theoretical presentation regarding possible financing models of health services in the world. In the applicative part of the work we shall present the basic practical models of financing health services in the countries that are the leaders of classic methods of health services financing, e. g. the USA, Great Britain, Germany and Croatia. Working out the applicative part of the work we gave the greatest significance to analysis of some macroeconomic indicators in health services (tendency of total health consumption in relation to GDP, average consumption per insured person etc., to structure analysis of health insurance and just to the scheme of health service organization and financing. We presume that each model of health service financing contains certain limitations that can cause problem (weak organization, increase of expenses etc.. This is the reason why we, in the applicative part of the work, paid a special attention to analysis of financial difficulties in the health sector and pointed to the needs and possibilities of solving them through possible reform measures. The end part of the work aims to point out to advantages and disadvantages of individual financing sources through the comparison method (budgetary – taxes or social health insurance – contributions.

  5. A neural model of figure-ground organization.

    Science.gov (United States)

    Craft, Edward; Schütze, Hartmut; Niebur, Ernst; von der Heydt, Rüdiger

    2007-06-01

    Psychophysical studies suggest that figure-ground organization is a largely autonomous process that guides--and thus precedes--allocation of attention and object recognition. The discovery of border-ownership representation in single neurons of early visual cortex has confirmed this view. Recent theoretical studies have demonstrated that border-ownership assignment can be modeled as a process of self-organization by lateral interactions within V2 cortex. However, the mechanism proposed relies on propagation of signals through horizontal fibers, which would result in increasing delays of the border-ownership signal with increasing size of the visual stimulus, in contradiction with experimental findings. It also remains unclear how the resulting border-ownership representation would interact with attention mechanisms to guide further processing. Here we present a model of border-ownership coding based on dedicated neural circuits for contour grouping that produce border-ownership assignment and also provide handles for mechanisms of selective attention. The results are consistent with neurophysiological and psychophysical findings. The model makes predictions about the hypothetical grouping circuits and the role of feedback between cortical areas.

  6. Lumazine Peptides from the Marine-Derived Fungus Aspergillus terreus

    Directory of Open Access Journals (Sweden)

    Minjung You

    2015-03-01

    Full Text Available Terrelumamides A (1 and B (2, two new lumazine-containing peptides, were isolated from the culture broth of the marine-derived fungus Aspergillus terreus. From the results of combined spectroscopic and chemical analyses, the structures of these compounds were determined to be linear assemblies of 1-methyllumazine-6-carboxylic acid, an amino acid residue and anthranilic acid methyl ester connected by peptide bonds. These new compounds exhibited pharmacological activity by improving insulin sensitivity, which was evaluated in an adipogenesis model using human bone marrow mesenchymal stem cells. In addition, the compounds exhibited fluorescence changes upon binding to DNA, demonstrating their potential applications to DNA sequence recognition.

  7. Molecular simulation of a model of dissolved organic matter.

    Science.gov (United States)

    Sutton, Rebecca; Sposito, Garrison; Diallo, Mamadou S; Schulten, Hans-Rolf

    2005-08-01

    A series of atomistic simulations was performed to assess the ability of the Schulten dissolved organic matter (DOM) molecule, a well-established model humic molecule, to reproduce the physical and chemical behavior of natural humic substances. The unhydrated DOM molecule had a bulk density value appropriate to humic matter, but its Hildebrand solubility parameter was lower than the range of current experimental estimates. Under hydrated conditions, the DOM molecule went through conformational adjustments that resulted in disruption of intramolecular hydrogen bonds (H-bonds), although few water molecules penetrated the organic interior. The radius of gyration of the hydrated DOM molecule was similar to those measured for aquatic humic substances. To simulate humic materials under aqueous conditions with varying pH levels, carboxyl groups were deprotonated, and hydrated Na+ or Ca2+ were added to balance the resulting negative charge. Because of intrusion of the cation hydrates, the model metal-humic structures were more porous, had greater solvent-accessible surface areas, and formed more H-bonds with water than the protonated, hydrated DOM molecule. Relative to Na+, Ca2+ was both more strongly bound to carboxylate groups and more fully hydrated. This difference was attributed to the higher charge of the divalent cation. The Ca-DOM hydrate, however, featured fewer H-bonds than the Na-DOM hydrate, perhaps because of the reduced orientational freedom of organic moieties and water molecules imposed by Ca2+. The present work is, to our knowledge, the first rigorous computational exploration regarding the behavior of a model humic molecule under a range of physical conditions typical of soil and water systems.

  8. Modeling nanostructure-enhanced light trapping in organic solar cells

    DEFF Research Database (Denmark)

    Adam, Jost

    A promising approach for improving the power conversion efficiencies of organic solar cells (OSCs) is by incorporating nanostructures in their thin film architecture to improve the light absorption in the device’s active polymer layers. Here, we present a modelling framework for the prediction...... of optical and plasmonic field enhancement by nanostructures in (or close to) the active layers and electrodes in OSCs. We incorporate finite-difference time-domain (FDTD) calculations alongside semi- analytical approaches, as the rigorous coupled-wave analysis (RCWA) and mode-coupling theory. Our simulation...

  9. Aspergillus luchuensis, an industrially important black Aspergillus in East Asia.

    Directory of Open Access Journals (Sweden)

    Seung-Beom Hong

    Full Text Available Aspergilli known as black- and white-koji molds which are used for awamori, shochu, makgeolli and other food and beverage fermentations, are reported in the literature as A. luchuensis, A. awamori, A. kawachii, or A. acidus. In order to elucidate the taxonomic position of these species, available ex-type cultures were compared based on morphology and molecular characters. A. luchuensis, A. kawachii and A. acidus showed the same banding patterns in RAPD, and the three species had the same rDNA-ITS, β-tubulin and calmodulin sequences and these differed from those of the closely related A. niger and A. tubingensis. Morphologically, the three species are not significantly different from each other or from A. niger and A. tubingensis. It is concluded that A. luchuensis, A. kawachii and A. acidus are the same species, and A. luchuensis is selected as the correct name based on priority. Strains of A. awamori which are stored in National Research Institute of Brewing in Japan, represent A. niger (n = 14 and A. luchuensis (n = 6. The neotype of A. awamori (CBS 557.65 =  NRRL 4948 does not originate from awamori fermentation and it is shown to be identical with the unknown taxon Aspergillus welwitschiae. Extrolite analysis of strains of A. luchuensis showed that they do not produce mycotoxins and therefore can be considered safe for food and beverage fermentations. A. luchuensis is also frequently isolated from meju and nuruk in Korea and Puerh tea in China and the species is probably common in the fermentation environment of East Asia. A re-description of A. luchuensis is provided because the incomplete data in the original literature.

  10. Aspergillus triggers phenazine production in Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Jensen, Britt Guillaume; Jelsbak, Lars; Søndergaard, Ib

    in the contact area of A. niger, A. flavus, A. oryzae, but not A. fumigatus. In addition, other metabolites with UV chromophores similar to the phenazines were only found in the contact zone between Aspergillus and Pseudomonas. No change in secondary metabolite profiles were seen for the Aspergilli, when......Objectives: Pseudomonas aeruginosa is an opportunistic human pathogen, commonly infecting cystic fibrosis (CF) patients. Aspergilli, especially Aspergillus fumigatus, are also frequently isolated from CF patients. Our aim was to examine the possible interaction between P. aeruginosa and different...... Aspergillus species. Methods: A suspension of fungal spores was streaked onto WATM agar plates. After 24 hours incubation at 37 °C, a P. aeruginosa overnight culture was streaked out perpendicular to the fungal streak. The plates were incubated at 37 °C for five days, examined and plugs were extracted...

  11. Antithrombin III in animal models of sepsis and organ failure.

    Science.gov (United States)

    Dickneite, G

    1998-01-01

    Antithrombin III (AT III) is the physiological inhibitor of thrombin and other serine proteases of the clotting cascade. In the development of sepsis, septic shock and organ failure, the plasma levels of AT III decrease considerably, suggesting the concept of a substitution therapy with the inhibitor. A decrease of AT III plasma levels might also be associated with other pathological disorders like trauma, burns, pancreatitis or preclampsia. Activation of coagulation and consumption of AT III is the consequence of a generalized inflammation called SIRS (systemic inflammatory response syndrome). The clotting cascade is also frequently activated after organ transplantation, especially if organs are grafted between different species (xenotransplantation). During the past years AT III has been investigated in numerous corresponding disease models in different animal species which will be reviewed here. The bulk of evidence suggests, that AT III substitution reduces morbidity and mortality in the diseased animals. While gaining more experience with AT III, the concept of substitution therapy to maximal baseline plasma levels (100%) appears to become insufficient. Evidence from clinical and preclinical studies now suggests to adjust the AT III plasma levels to about 200%, i.e., doubling the normal value. During the last few years several authors proposed that AT III might not only be an anti-thrombotic agent, but to have in addition an anti-inflammatory effect.

  12. A Multiagent Modeling Environment for Simulating Work Practice in Organizations

    Science.gov (United States)

    Sierhuis, Maarten; Clancey, William J.; vanHoof, Ron

    2004-01-01

    In this paper we position Brahms as a tool for simulating organizational processes. Brahms is a modeling and simulation environment for analyzing human work practice, and for using such models to develop intelligent software agents to support the work practice in organizations. Brahms is the result of more than ten years of research at the Institute for Research on Learning (IRL), NYNEX Science & Technology (the former R&D institute of the Baby Bell telephone company in New York, now Verizon), and for the last six years at NASA Ames Research Center, in the Work Systems Design and Evaluation group, part of the Computational Sciences Division (Code IC). Brahms has been used on more than ten modeling and simulation research projects, and recently has been used as a distributed multiagent development environment for developing work practice support tools for human in-situ science exploration on planetary surfaces, in particular a human mission to Mars. Brahms was originally conceived of as a business process modeling and simulation tool that incorporates the social systems of work, by illuminating how formal process flow descriptions relate to people s actual located activities in the workplace. Our research started in the early nineties as a reaction to experiences with work process modeling and simulation . Although an effective tool for convincing management of the potential cost-savings of the newly designed work processes, the modeling and simulation environment was only able to describe work as a normative workflow. However, the social systems, uncovered in work practices studied by the design team played a significant role in how work actually got done-actual lived work. Multi- tasking, informal assistance and circumstantial work interactions could not easily be represented in a tool with a strict workflow modeling paradigm. In response, we began to develop a tool that would have the benefits of work process modeling and simulation, but be distinctively able to

  13. Modeling the role of microplastics in Bioaccumulation of organic chemicals to marine aquatic organisms. Critical Review

    NARCIS (Netherlands)

    Koelmans, A.A.

    2015-01-01

    It has been shown that ingestion of microplastics may increase bioaccumulation of organic chemicals by aquatic organisms. This paper critically reviews the literature on the effects of plastic ingestion on the bioaccumulation of organic chemicals, emphasizing quantitative approaches and mechanistic

  14. Generic Modelling of Faecal Indicator Organism Concentrations in the UK

    Directory of Open Access Journals (Sweden)

    Carl M. Stapleton

    2011-06-01

    Full Text Available To meet European Water Framework Directive requirements, data are needed on faecal indicator organism (FIO concentrations in rivers to enable the more heavily polluted to be targeted for remedial action. Due to the paucity of FIO data for the UK, especially under high-flow hydrograph event conditions, there is an urgent need by the policy community for generic models that can accurately predict FIO concentrations, thus informing integrated catchment management programmes. This paper reports the development of regression models to predict base- and high-flow faecal coliform (FC and enterococci (EN concentrations for 153 monitoring points across 14 UK catchments, using land cover, population (human and livestock density and other variables that may affect FIO source strength, transport and die-off. Statistically significant models were developed for both FC and EN, with greater explained variance achieved in the high-flow models. Both land cover and, in particular, population variables are significant predictors of FIO concentrations, with r2 maxima for EN of 0.571 and 0.624, respectively. It is argued that the resulting models can be applied, with confidence, to other UK catchments, both to predict FIO concentrations in unmonitored watercourses and evaluate the likely impact of different land use/stocking level and human population change scenarios.

  15. LSOT: A Lightweight Self-Organized Trust Model in VANETs

    Directory of Open Access Journals (Sweden)

    Zhiquan Liu

    2016-01-01

    Full Text Available With the advances in automobile industry and wireless communication technology, Vehicular Ad hoc Networks (VANETs have attracted the attention of a large number of researchers. Trust management plays an important role in VANETs. However, it is still at the preliminary stage and the existing trust models cannot entirely conform to the characteristics of VANETs. This work proposes a novel Lightweight Self-Organized Trust (LSOT model which contains trust certificate-based and recommendation-based trust evaluations. Both the supernodes and trusted third parties are not needed in our model. In addition, we comprehensively consider three factor weights to ease the collusion attack in trust certificate-based trust evaluation, and we utilize the testing interaction method to build and maintain the trust network and propose a maximum local trust (MLT algorithm to identify trustworthy recommenders in recommendation-based trust evaluation. Furthermore, a fully distributed VANET scenario is deployed based on the famous Advogato dataset and a series of simulations and analysis are conducted. The results illustrate that our LSOT model significantly outperforms the excellent experience-based trust (EBT and Lightweight Cross-domain Trust (LCT models in terms of evaluation performance and robustness against the collusion attack.

  16. [Survival Strategies of Aspergillus in the Human Body].

    Science.gov (United States)

    Tashiro, Masato; Izumikawa, Koichi

    2017-01-01

     The human body is a hostile environment for Aspergillus species, which originally live outside the human body. There are lots of elimination mechanisms against Aspergillus inhaled into the human body, such as high body temperature, soluble lung components, mucociliary clearance mechanism, or responses of phagocytes. Aspergillus fumigatus, which is the primary causative agent of human infections among the human pathogenic species of Aspergillus, defend itself from the hostile human body environment by various mechanisms, such as thermotolerance, mycotoxin production, and characteristic morphological features. Here we review mechanisms of defense in Aspergillus against elimination from the human body.

  17. Self-Organized Criticality Theory Model of Thermal Sandpile

    International Nuclear Information System (INIS)

    Peng Xiao-Dong; Qu Hong-Peng; Xu Jian-Qiang; Han Zui-Jiao

    2015-01-01

    A self-organized criticality model of a thermal sandpile is formulated for the first time to simulate the dynamic process with interaction between avalanche events on the fast time scale and diffusive transports on the slow time scale. The main characteristics of the model are that both particle and energy avalanches of sand grains are considered simultaneously. Properties of intermittent transport and improved confinement are analyzed in detail. The results imply that the intermittent phenomenon such as blobs in the low confinement mode as well as edge localized modes in the high confinement mode observed in tokamak experiments are not only determined by the edge plasma physics, but also affected by the core plasma dynamics. (paper)

  18. Dynamical quenching and annealing in self-organization multiagent models

    Science.gov (United States)

    Burgos, E.; Ceva, Horacio; Perazzo, R. P.

    2001-07-01

    We study the dynamics of a generalized minority game (GMG) and of the bar attendance model (BAM) in which a number of agents self-organize to match an attendance that is fixed externally as a control parameter. We compare the usual dynamics used for the minority game with one for the BAM that makes a better use of the available information. We study the asymptotic states reached in both frameworks. We show that states that can be assimilated to either thermodynamic equilibrium or quenched configurations can appear in both models, but with different settings. We discuss the relevance of the parameter G that measures the value of the prize for winning in units of the fine for losing. We also provide an annealing protocol by which the quenched configurations of the GMG can progressively be modified to reach an asymptotic equilibrium state that coincides with the one obtained with the BAM.

  19. Modeling financial markets by self-organized criticality

    Science.gov (United States)

    Biondo, Alessio Emanuele; Pluchino, Alessandro; Rapisarda, Andrea

    2015-10-01

    We present a financial market model, characterized by self-organized criticality, that is able to generate endogenously a realistic price dynamics and to reproduce well-known stylized facts. We consider a community of heterogeneous traders, composed by chartists and fundamentalists, and focus on the role of informative pressure on market participants, showing how the spreading of information, based on a realistic imitative behavior, drives contagion and causes market fragility. In this model imitation is not intended as a change in the agent's group of origin, but is referred only to the price formation process. We introduce in the community also a variable number of random traders in order to study their possible beneficial role in stabilizing the market, as found in other studies. Finally, we also suggest some counterintuitive policy strategies able to dampen fluctuations by means of a partial reduction of information.

  20. Models of charge pair generation in organic solar cells.

    Science.gov (United States)

    Few, Sheridan; Frost, Jarvist M; Nelson, Jenny

    2015-01-28

    Efficient charge pair generation is observed in many organic photovoltaic (OPV) heterojunctions, despite nominal electron-hole binding energies which greatly exceed the average thermal energy. Empirically, the efficiency of this process appears to be related to the choice of donor and acceptor materials, the resulting sequence of excited state energy levels and the structure of the interface. In order to establish a suitable physical model for the process, a range of different theoretical studies have addressed the nature and energies of the interfacial states, the energetic profile close to the heterojunction and the dynamics of excited state transitions. In this paper, we review recent developments underpinning the theory of charge pair generation and phenomena, focussing on electronic structure calculations, electrostatic models and approaches to excited state dynamics. We discuss the remaining challenges in achieving a predictive approach to charge generation efficiency.

  1. Effects of Aspergillus niger treated Shea butter cake based diets on ...

    African Journals Online (AJOL)

    Effects of feed intake, weight gain and digestibility when growing Red Sokoto goats consuming Aspergillus niger treated and untreated shea-butter cake (SBC) were determined. Twenty five Red Sokoto goats in a completely randomized design model with 56 d periods consumed diet A (control, without SBC), B (15% ...

  2. Polyol accumulation by Aspergillus oryzae at low water activity in solid-state fermentation

    NARCIS (Netherlands)

    Ruijter, G.J.G.; Visser, J.; Rinzema, A.

    2004-01-01

    Polyol accumulation and metabolism were examined in Aspergillus oryzae cultured on whole wheat grains or on wheat dough as a model for solid-state culture. In solid-state fermentation (SSF), water activity (a(w)) is typically low resulting in osmotic stress. In addition to a high level of mannitol,

  3. Partitioning of Nanoparticles into Organic Phases and Model Cells

    Energy Technology Data Exchange (ETDEWEB)

    Posner, J.D.; Westerhoff, P.; Hou, W-C.

    2011-08-25

    There is a recognized need to understand and predict the fate, transport and bioavailability of engineered nanoparticles (ENPs) in aquatic and soil ecosystems. Recent research focuses on either collection of empirical data (e.g., removal of a specific NP through water or soil matrices under variable experimental conditions) or precise NP characterization (e.g. size, degree of aggregation, morphology, zeta potential, purity, surface chemistry, and stability). However, it is almost impossible to transition from these precise measurements to models suitable to assess the NP behavior in the environment with complex and heterogeneous matrices. For decades, the USEPA has developed and applies basic partitioning parameters (e.g., octanol-water partition coefficients) and models (e.g., EPI Suite, ECOSAR) to predict the environmental fate, bioavailability, and toxicity of organic pollutants (e.g., pesticides, hydrocarbons, etc.). In this project we have investigated the hypothesis that NP partition coefficients between water and organic phases (octanol or lipid bilayer) is highly dependent on their physiochemical properties, aggregation, and presence of natural constituents in aquatic environments (salts, natural organic matter), which may impact their partitioning into biological matrices (bioaccumulation) and human exposure (bioavailability) as well as the eventual usage in modeling the fate and bioavailability of ENPs. In this report, we use the terminology "partitioning" to operationally define the fraction of ENPs distributed among different phases. The mechanisms leading to this partitioning probably involve both chemical force interactions (hydrophobic association, hydrogen bonding, ligand exchange, etc.) and physical forces that bring the ENPs in close contact with the phase interfaces (diffusion, electrostatic interactions, mixing turbulence, etc.). Our work focuses on partitioning, but also provides insight into the relative behavior of ENPs as either "more like

  4. Aspergillus Niger Genomics: Past, Present and into the Future

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Scott E.

    2006-09-01

    Aspergillus niger is a filamentous ascomycete fungus that is ubiquitous in the environment and has been implicated in opportunistic infections of humans. In addition to its role as an opportunistic human pathogen, A. niger is economically important as a fermentation organism used for the production of citric acid. Industrial citric acid production by A. niger represents one of the most efficient, highest yield bioprocesses in use currently by industry. The genome size of A. niger is estimated to be between 35.5 and 38.5 megabases (Mb) divided among eight chromosomes/linkage groups that vary in size from 3.5 - 6.6 Mb. Currently, there are three independent A. niger genome projects, an indication of the economic importance of this organism. The rich amount of data resulting from these multiple A. niger genome sequences will be used for basic and applied research programs applicable to fermentation process development, morphology and pathogenicity.

  5. The hamster flank organ model: Is it relevant to man

    International Nuclear Information System (INIS)

    Franz, T.J.; Lehman, P.A.; Pochi, P.; Odland, G.F.; Olerud, J.

    1989-01-01

    The critical role that androgens play in the etiology of acne has led to a search for topically active antiandrogens and the frequent use of the flank organ of the golden Syrian hamster as an animal model. 17-alpha-propyltestosterone (17-PT) has been identified as having potent antiandrogenic activity in the hamster model, and this report describes its clinical evaluation. Two double-blind placebo controlled studies comparing 4% 17-PT in 80% alcohol versus vehicle alone were conducted. One study examined 17-PT sebosuppressive activity in 20 subjects. The second study examined its efficacy in 44 subjects having mild to moderate acne. A third study measured in vitro percutaneous absorption of 17-PT through hamster flank and monkey skin, and human face skin in-vivo, using radioactive drug. 17-PT was found to be ineffective in reducing either the sebum excretion rate or the number of inflammatory acne lesions. Failure of 17-PT to show clinical activity was not a result of poor percutaneous absorption. Total absorption in man was 7.7% of the dose and only 1.0% in the hamster. The sebaceous gland of hamster flank organ is apparently more sensitive to antiandrogens than the human sebaceous gland

  6. Modeling temperature dependent singlet exciton dynamics in multilayered organic nanofibers

    Science.gov (United States)

    de Sousa, Leonardo Evaristo; de Oliveira Neto, Pedro Henrique; Kjelstrup-Hansen, Jakob; da Silva Filho, Demétrio Antônio

    2018-05-01

    Organic nanofibers have shown potential for application in optoelectronic devices because of the tunability of their optical properties. These properties are influenced by the electronic structure of the molecules that compose the nanofibers and also by the behavior of the excitons generated in the material. Exciton diffusion by means of Förster resonance energy transfer is responsible, for instance, for the change with temperature of colors in the light emitted by systems composed of different types of nanofibers. To study in detail this mechanism, we model temperature dependent singlet exciton dynamics in multilayered organic nanofibers. By simulating absorption and emission spectra, the possible Förster transitions are identified. Then, a kinetic Monte Carlo model is employed in combination with a genetic algorithm to theoretically reproduce time-resolved photoluminescence measurements for several temperatures. This procedure allows for the obtainment of different information regarding exciton diffusion in such a system, including temperature effects on the Förster transfer efficiency and the activation energy of the Förster mechanism. The method is general and may be employed for different systems where exciton diffusion plays a role.

  7. Towards a paradigm shift in the modeling of soil organic carbon decomposition for earth system models

    Science.gov (United States)

    He, Yujie

    Soils are the largest terrestrial carbon pools and contain approximately 2200 Pg of carbon. Thus, the dynamics of soil carbon plays an important role in the global carbon cycle and climate system. Earth System Models are used to project future interactions between terrestrial ecosystem carbon dynamics and climate. However, these models often predict a wide range of soil carbon responses and their formulations have lagged behind recent soil science advances, omitting key biogeochemical mechanisms. In contrast, recent mechanistically-based biogeochemical models that explicitly account for microbial biomass pools and enzyme kinetics that catalyze soil carbon decomposition produce notably different results and provide a closer match to recent observations. However, a systematic evaluation of the advantages and disadvantages of the microbial models and how they differ from empirical, first-order formulations in soil decomposition models for soil organic carbon is still needed. This dissertation consists of a series of model sensitivity and uncertainty analyses and identifies dominant decomposition processes in determining soil organic carbon dynamics. Poorly constrained processes or parameters that require more experimental data integration are also identified. This dissertation also demonstrates the critical role of microbial life-history traits (e.g. microbial dormancy) in the modeling of microbial activity in soil organic matter decomposition models. Finally, this study surveys and synthesizes a number of recently published microbial models and provides suggestions for future microbial model developments.

  8. Density and molecular epidemiology of Aspergillus in air and relationship to outbreaks of Aspergillus infection

    NARCIS (Netherlands)

    A.C.A.P. Leenders (Alexander); A.F. van Belkum (Alex); M.D. Behrendt (Myra); A. Luijendijk (Ad); H.A. Verbrugh (Henri)

    1999-01-01

    textabstractAfter five patients were diagnosed with nosocomial invasive aspergillosis caused by Aspergillus fumigatus and A. flavus, a 14-month surveillance program for pathogenic and nonpathogenic fungal conidia in the air within and outside the University Hospital in

  9. Identification and toxigenic potential of the industrially important fungi, Aspergillus oryzae and Aspergillus sojae

    DEFF Research Database (Denmark)

    Jørgensen, Thomas R

    2007-01-01

    Mold strains belonging to the species Aspergillus oryzae and Aspergillus sojae are highly valued as koji molds in the traditional preparation of fermented foods, such as miso, sake, and shoyu, and as protein production hosts in modern industrial processes. A. oryzae and A. sojae are relatives...... of the wild molds Aspergillus flavus and Aspergillus parasiticus. All four species are classified to the A. flavus group. Strains of the A. flavus group are characterized by a high degree of morphological similarity. Koji mold species are generally perceived of as being nontoxigenic, whereas wild molds...... are associated with the carcinogenic aflatoxins. Thus, reliable identification of individual strains is very important for application purposes. This review considers the pheno- and genotypic markers used in the classification of A. flavus group strains and specifically in the identification of A. oryzae and A...

  10. Modeling organic aerosols during MILAGRO: importance of biogenic secondary organic aerosols

    Directory of Open Access Journals (Sweden)

    A. Hodzic

    2009-09-01

    Full Text Available The meso-scale chemistry-transport model CHIMERE is used to assess our understanding of major sources and formation processes leading to a fairly large amount of organic aerosols – OA, including primary OA (POA and secondary OA (SOA – observed in Mexico City during the MILAGRO field project (March 2006. Chemical analyses of submicron aerosols from aerosol mass spectrometers (AMS indicate that organic particles found in the Mexico City basin contain a large fraction of oxygenated organic species (OOA which have strong correspondence with SOA, and that their production actively continues downwind of the city. The SOA formation is modeled here by the one-step oxidation of anthropogenic (i.e. aromatics, alkanes, biogenic (i.e. monoterpenes and isoprene, and biomass-burning SOA precursors and their partitioning into both organic and aqueous phases. Conservative assumptions are made for uncertain parameters to maximize the amount of SOA produced by the model. The near-surface model evaluation shows that predicted OA correlates reasonably well with measurements during the campaign, however it remains a factor of 2 lower than the measured total OA. Fairly good agreement is found between predicted and observed POA within the city suggesting that anthropogenic and biomass burning emissions are reasonably captured. Consistent with previous studies in Mexico City, large discrepancies are encountered for SOA, with a factor of 2–10 model underestimate. When only anthropogenic SOA precursors were considered, the model was able to reproduce within a factor of two the sharp increase in OOA concentrations during the late morning at both urban and near-urban locations but the discrepancy increases rapidly later in the day, consistent with previous results, and is especially obvious when the column-integrated SOA mass is considered instead of the surface concentration. The increase in the missing SOA mass in the afternoon coincides with the sharp drop in POA

  11. Aspergillus pragensis sp nov discovered during molecular reidentification of clinical isolates belonging to Aspergillus section Candidi

    Czech Academy of Sciences Publication Activity Database

    Hubka, Vít; Lysková, P.; Frisvad, J.C.; Peterson, S.W.; Skořepová, M.; Kolařík, Miroslav

    2014-01-01

    Roč. 52, č. 6 (2014), s. 565-576 ISSN 1369-3786 R&D Projects: GA MŠk(CZ) EE2.3.20.0055; GA MŠk(CZ) EE2.3.30.0003 Institutional support: RVO:61388971 Keywords : Aspergillus candidus * Aspergillus tritici * antifungal susceptibility testing Subject RIV: EE - Microbiology, Virology Impact factor: 2.335, year: 2014

  12. Aspergillus saccharolyticus sp. nov., a new black Aspergillus species isolated in Denmark

    DEFF Research Database (Denmark)

    Sørensen, Annette; Lübeck, Peter S.; Lübeck, Mette

    2011-01-01

    A novel species, Aspergillus saccharolyticus sp. nov., belonging to the Aspergillus section Nigri group is described. This species was isolated in Denmark from treated hardwood. Its taxonomic status was determined using a polyphasic taxonomic approach including phenotypic (morphology and extrolite...... profiles) and molecular (β-tubulin, internal transcribed spacer and calmodulin gene sequences, and universally primed PCR fingerprinting) analysis. Phenotypic and molecular data enabled this novel species to be clearly distinguished from other black aspergilli. A. saccharolyticus is a uniseriate...

  13. Trichocomaceae: biodiversity of Aspergillus spp and Penicillium spp residing in libraries.

    Science.gov (United States)

    Leite, Diniz Pereira; Yamamoto, Ana Caroline Akeme; Amadio, Janaína Vasconcellos Ribeiro de Souza; Martins, Evelin Rodrigues; do Santos, Fábio Alexandre Leal; Simões, Sara de Almeida Alves; Hahn, Rosane Christine

    2012-10-19

    Atmospheric air is the most common vehicle for the dispersion of fungi. Fungi belonging to the genera Aspergillus and Penicillium are cosmopolitan and are classified in the family Trichocomaceae. Species of the genera are commonly found in soil, decaying organic materials, animal feed, stored grains, and other materials. This study aimed to determine the taxonomic diversity of airborne fungi of the genera Aspergillus and Penicillium residing in the dust of library environments to contribute to current knowledge of these characteristic genera. Three libraries in the city of Cuiaba, State of Mato Grosso, Brazil, were selected as the study areas. A total of 168 samples were collected at randomized sites within each library in areas containing journals, archives, in study rooms, and in collection storage areas in two different periods, the dry season (n = 42)  and the rainy season (n = 42). Samples were collected by exposing Petri dishes containing Sabouraud agar with chloramphenicol to the environmental air. Additional samples were collected with sterile swabs which were rubbed over the surface of randomly chosen books on the shelves; the swabs were subsequently incubated in the laboratory. The genus Aspergillus was highlighted as one of the principal airborne fungi present in indoor environments. Aspergillus spp was identified in 1,277 (89.6%) samples and Penicillium spp in 148 (10.4%). The dry period exhibited a greater number of isolates of the two taxons.

  14. Study of effect ultraviolet radiation on Aspergillus Flavus and Aspergillus Parasiticus

    International Nuclear Information System (INIS)

    Ghafourian, H.; Kafaei, F.; Raouf, J.B.

    2000-01-01

    In this article the results of ultraviolet radiation effects on Aspergillus Flavus and Aspergillus parasiticus to reach the quality control standards are presented. The purpose was to test the effect of ultraviolet radiation in 254 nanometer wavelength for fungi decontamination with respect to the exposure time of radiation and the distance between samples and radiation source. The ultraviolet radiation effects on plates containing Aspergillus Flavus and Aspergillus Parasiticus fungi were studied in the exposure time duration of 30, to 360 seconds of a fixed distance, and also for variable distances from 10 to 40 cm at a given exposure time. It is shown that in the exposure time of more than 360 second the ultraviolet radiation exposure highly decreases the number of Aspergillus Flavus and Aspergillus Parasiticus fungi colonies. By reducing the distance, the number of colonies decreases and it is minimized at a 10 cm distance in the time exposure of 360 second. The above results show that the ultraviolet radiation is an effective method for food decontamination and can be used in industry

  15. Taxonomic Characterization and Secondary Metabolite Profiling of Aspergillus Section Aspergillus Contaminating Feeds and Feedstuffs

    Science.gov (United States)

    Greco, Mariana; Kemppainen, Minna; Pose, Graciela; Pardo, Alejandro

    2015-01-01

    Xerophilic fungal species of the genus Aspergillus are economically highly relevant due to their ability to grow on low water activity substrates causing spoilage of stored goods and animal feeds. These fungi can synthesize a variety of secondary metabolites, many of which show animal toxicity, creating a health risk for food production animals and to humans as final consumers, respectively. Animal feeds used for rabbit, chinchilla and rainbow trout production in Argentina were analysed for the presence of xerophilic Aspergillus section Aspergillus species. High isolation frequencies (>60%) were detected in all the studied rabbit and chinchilla feeds, while the rainbow trout feeds showed lower fungal charge (25%). These section Aspergillus contaminations comprised predominantly five taxa. Twenty isolates were subjected to taxonomic characterization using both ascospore SEM micromorphology and two independent DNA loci sequencing. The secondary metabolite profiles of the isolates were determined qualitatively by HPLC-MS. All the isolates produced neoechinulin A, 17 isolates were positive for cladosporin and echinulin, and 18 were positive for neoechinulin B. Physcion and preechinulin were detected in a minor proportion of the isolates. This is the first report describing the detailed species composition and the secondary metabolite profiles of Aspergillus section Aspergillus contaminating animal feeds. PMID:26364643

  16. Taxonomic Characterization and Secondary Metabolite Profiling of Aspergillus Section Aspergillus Contaminating Feeds and Feedstuffs

    Directory of Open Access Journals (Sweden)

    Mariana Greco

    2015-09-01

    Full Text Available Xerophilic fungal species of the genus Aspergillus are economically highly relevant due to their ability to grow on low water activity substrates causing spoilage of stored goods and animal feeds. These fungi can synthesize a variety of secondary metabolites, many of which show animal toxicity, creating a health risk for food production animals and to humans as final consumers, respectively. Animal feeds used for rabbit, chinchilla and rainbow trout production in Argentina were analysed for the presence of xerophilic Aspergillus section Aspergillus species. High isolation frequencies (>60% were detected in all the studied rabbit and chinchilla feeds, while the rainbow trout feeds showed lower fungal charge (25%. These section Aspergillus contaminations comprised predominantly five taxa. Twenty isolates were subjected to taxonomic characterization using both ascospore SEM micromorphology and two independent DNA loci sequencing. The secondary metabolite profiles of the isolates were determined qualitatively by HPLC-MS. All the isolates produced neoechinulin A, 17 isolates were positive for cladosporin and echinulin, and 18 were positive for neoechinulin B. Physcion and preechinulin were detected in a minor proportion of the isolates. This is the first report describing the detailed species composition and the secondary metabolite profiles of Aspergillus section Aspergillus contaminating animal feeds.

  17. Taxonomic Characterization and Secondary Metabolite Profiling of Aspergillus Section Aspergillus Contaminating Feeds and Feedstuffs.

    Science.gov (United States)

    Greco, Mariana; Kemppainen, Minna; Pose, Graciela; Pardo, Alejandro

    2015-09-02

    Xerophilic fungal species of the genus Aspergillus are economically highly relevant due to their ability to grow on low water activity substrates causing spoilage of stored goods and animal feeds. These fungi can synthesize a variety of secondary metabolites, many of which show animal toxicity, creating a health risk for food production animals and to humans as final consumers, respectively. Animal feeds used for rabbit, chinchilla and rainbow trout production in Argentina were analysed for the presence of xerophilic Aspergillus section Aspergillus species. High isolation frequencies (>60%) were detected in all the studied rabbit and chinchilla feeds, while the rainbow trout feeds showed lower fungal charge (25%). These section Aspergillus contaminations comprised predominantly five taxa. Twenty isolates were subjected to taxonomic characterization using both ascospore SEM micromorphology and two independent DNA loci sequencing. The secondary metabolite profiles of the isolates were determined qualitatively by HPLC-MS. All the isolates produced neoechinulin A, 17 isolates were positive for cladosporin and echinulin, and 18 were positive for neoechinulin B. Physcion and preechinulin were detected in a minor proportion of the isolates. This is the first report describing the detailed species composition and the secondary metabolite profiles of Aspergillus section Aspergillus contaminating animal feeds.

  18. Nephrology around Europe: organization models and management strategies: Spain.

    Science.gov (United States)

    de Francisco, Angel L M; Piñera, Celestino

    2011-01-01

    The main aim of this report is to present a picture of the current organization of nephrology in Spain. The Spanish health system offers almost universal coverage, a wide variety of services and a high-quality network of hospitals and primary care centers. Spain has a specialized health care training system that is highly developed, highly regulated, with the capacity to provide high-quality training in 54 different specialties. Nephrology is basically a hospital-based specialty. There are no private dialysis patients in Spain. Hemodialysis centers are 40% public, 15% private and 45% run by companies. The National Health System covers 95% of the population, and there is no cost to patients for treatment of renal disease (dialysis and transplant). We observed a clear decrease of nephrology in residents' election rankings, with position 29 out of 47 specialties in 2007. Some of the reasons for this are the complexity of the subject, no clear information at the university, reduction of professional posts and a very good public service with minimal private practice. In Spain, a model of organization for transplantation was adopted based on a decentralized transplant coordinating network. For cadaveric donors, it compares favorably with rates in other Western countries. Living donor transplantation is very low in Spain--just 10% of total renal transplantation activity. New programs due to financial constraints need to include reduced dialysis costs, greater cost-effectiveness of prescriptions, better handling of ethical issues related to the need for using a clinical score of chronic kidney disease patients to make decisions about conservative or renal replacement therapy and an action plan for improvement of organ donation and transplantation. Recovery of skills (acute kidney injury, biopsies, vascular access, etc.), research and advances in autonomous activities (imaging, surgical and medical vascular training, etc.) are some of the future educational paths needed in

  19. Modeling evolutionary dynamics of epigenetic mutations in hierarchically organized tumors.

    Directory of Open Access Journals (Sweden)

    Andrea Sottoriva

    2011-05-01

    Full Text Available The cancer stem cell (CSC concept is a highly debated topic in cancer research. While experimental evidence in favor of the cancer stem cell theory is apparently abundant, the results are often criticized as being difficult to interpret. An important reason for this is that most experimental data that support this model rely on transplantation studies. In this study we use a novel cellular Potts model to elucidate the dynamics of established malignancies that are driven by a small subset of CSCs. Our results demonstrate that epigenetic mutations that occur during mitosis display highly altered dynamics in CSC-driven malignancies compared to a classical, non-hierarchical model of growth. In particular, the heterogeneity observed in CSC-driven tumors is considerably higher. We speculate that this feature could be used in combination with epigenetic (methylation sequencing studies of human malignancies to prove or refute the CSC hypothesis in established tumors without the need for transplantation. Moreover our tumor growth simulations indicate that CSC-driven tumors display evolutionary features that can be considered beneficial during tumor progression. Besides an increased heterogeneity they also exhibit properties that allow the escape of clones from local fitness peaks. This leads to more aggressive phenotypes in the long run and makes the neoplasm more adaptable to stringent selective forces such as cancer treatment. Indeed when therapy is applied the clone landscape of the regrown tumor is more aggressive with respect to the primary tumor, whereas the classical model demonstrated similar patterns before and after therapy. Understanding these often counter-intuitive fundamental properties of (non-hierarchically organized malignancies is a crucial step in validating the CSC concept as well as providing insight into the therapeutical consequences of this model.

  20. A geometrical model for DNA organization in bacteria.

    Directory of Open Access Journals (Sweden)

    Mathias Buenemann

    Full Text Available Recent experimental studies have revealed that bacteria, such as C. crescentus, show a remarkable spatial ordering of their chromosome. A strong linear correlation has been found between the position of genes on the chromosomal map and their spatial position in the cellular volume. We show that this correlation can be explained by a purely geometrical model. Namely, self-avoidance of DNA, specific positioning of one or few DNA loci (such as origin or terminus together with the action of DNA compaction proteins (that organize the chromosome into topological domains are sufficient to get a linear arrangement of the chromosome along the cell axis. We develop a Monte-Carlo method that allows us to test our model numerically and to analyze the dependence of the spatial ordering on various physiologically relevant parameters. We show that the proposed geometrical ordering mechanism is robust and universal (i.e. does not depend on specific bacterial details. The geometrical mechanism should work in all bacteria that have compacted chromosomes with spatially fixed regions. We use our model to make specific and experimentally testable predictions about the spatial arrangement of the chromosome in mutants of C. crescentus and the growth-stage dependent ordering in E. coli.

  1. Modeling cooperating micro-organisms in antibiotic environment.

    Science.gov (United States)

    Book, Gilad; Ingham, Colin; Ariel, Gil

    2017-01-01

    Recent experiments with the bacteria Paenibacillus vortex reveal a remarkable strategy enabling it to cope with antibiotics by cooperating with a different bacterium-Escherichia coli. While P. vortex is a highly effective swarmer, it is sensitive to the antibiotic ampicillin. On the other hand, E. coli can degrade ampicillin but is non-motile when grown on high agar percentages. The two bacterial species form a shared colony in which E. coli is transported by P. vortex and E. coli detoxifies the ampicillin. The paper presents a simplified model, consisting of coupled reaction-diffusion equations, describing the development of ring patterns in the shared colony. Our results demonstrate some of the possible cooperative movement strategies bacteria utilize in order to survive harsh conditions. In addition, we explore the behavior of mixed colonies under new conditions such as antibiotic gradients, synchronization between colonies and possible dynamics of a 3-species system including P. vortex, E. coli and a carbon producing algae that provides nutrients under illuminated, nutrient poor conditions. The derived model was able to simulate an asymmetric relationship between two or three micro-organisms where cooperation is required for survival. Computationally, in order to avoid numerical artifacts due to symmetries within the discretizing grid, the model was solved using a second order Vectorizable Random Lattices method, which is developed as a finite volume scheme on a random grid.

  2. Modeling cooperating micro-organisms in antibiotic environment.

    Directory of Open Access Journals (Sweden)

    Gilad Book

    Full Text Available Recent experiments with the bacteria Paenibacillus vortex reveal a remarkable strategy enabling it to cope with antibiotics by cooperating with a different bacterium-Escherichia coli. While P. vortex is a highly effective swarmer, it is sensitive to the antibiotic ampicillin. On the other hand, E. coli can degrade ampicillin but is non-motile when grown on high agar percentages. The two bacterial species form a shared colony in which E. coli is transported by P. vortex and E. coli detoxifies the ampicillin. The paper presents a simplified model, consisting of coupled reaction-diffusion equations, describing the development of ring patterns in the shared colony. Our results demonstrate some of the possible cooperative movement strategies bacteria utilize in order to survive harsh conditions. In addition, we explore the behavior of mixed colonies under new conditions such as antibiotic gradients, synchronization between colonies and possible dynamics of a 3-species system including P. vortex, E. coli and a carbon producing algae that provides nutrients under illuminated, nutrient poor conditions. The derived model was able to simulate an asymmetric relationship between two or three micro-organisms where cooperation is required for survival. Computationally, in order to avoid numerical artifacts due to symmetries within the discretizing grid, the model was solved using a second order Vectorizable Random Lattices method, which is developed as a finite volume scheme on a random grid.

  3. Spectrophotometry and organic matter on Iapetus. 1: Composition models

    Science.gov (United States)

    Wilson, Peter D.; Sagan, Carl

    1995-01-01

    Iapetus shows a greater hemispheric albedo asymmetry than any other body in the solar system. Hapke scattering theory and optical constants measured in the laboratory are used to identify possible compositions for the dark material on the leading hemisphere of Iapetus. The materials considered are poly-HCN, kerogen, Murchison organic residue, Titan tholin, ice tholin, and water ice. Three-component mixtures of these materials are modeled in intraparticle mixture of 25% poly-HCN, 10% Murchison residue, and 65% water ice is found to best fit the spectrum, albedo, and phase behavior of the dark material. The Murchison residue and/or water ice can be replaced by kerogen and ice tholin, respectively, and still produce very good fits. Areal and particle mixtures of poly-HCN, Titan tholin, and either ice tholin or Murchison residue are also possible models. Poly-HCN is a necessary component in almost all good models. The presence of poly-HCN can be further tested by high-resolution observations near 4.5 micrometers.

  4. Self-Organized Criticality in an Anisotropic Earthquake Model

    Science.gov (United States)

    Li, Bin-Quan; Wang, Sheng-Jun

    2018-03-01

    We have made an extensive numerical study of a modified model proposed by Olami, Feder, and Christensen to describe earthquake behavior. Two situations were considered in this paper. One situation is that the energy of the unstable site is redistributed to its nearest neighbors randomly not averagely and keeps itself to zero. The other situation is that the energy of the unstable site is redistributed to its nearest neighbors randomly and keeps some energy for itself instead of reset to zero. Different boundary conditions were considered as well. By analyzing the distribution of earthquake sizes, we found that self-organized criticality can be excited only in the conservative case or the approximate conservative case in the above situations. Some evidence indicated that the critical exponent of both above situations and the original OFC model tend to the same result in the conservative case. The only difference is that the avalanche size in the original model is bigger. This result may be closer to the real world, after all, every crust plate size is different. Supported by National Natural Science Foundation of China under Grant Nos. 11675096 and 11305098, the Fundamental Research Funds for the Central Universities under Grant No. GK201702001, FPALAB-SNNU under Grant No. 16QNGG007, and Interdisciplinary Incubation Project of SNU under Grant No. 5

  5. In Vivo RNAi-Based Screens: Studies in Model Organisms

    Directory of Open Access Journals (Sweden)

    Miki Yamamoto-Hino

    2013-11-01

    Full Text Available RNA interference (RNAi is a technique widely used for gene silencing in organisms and cultured cells, and depends on sequence homology between double-stranded RNA (dsRNA and target mRNA molecules. Numerous cell-based genome-wide screens have successfully identified novel genes involved in various biological processes, including signal transduction, cell viability/death, and cell morphology. However, cell-based screens cannot address cellular processes such as development, behavior, and immunity. Drosophila and Caenorhabditis elegans are two model organisms whose whole bodies and individual body parts have been subjected to RNAi-based genome-wide screening. Moreover, Drosophila RNAi allows the manipulation of gene function in a spatiotemporal manner when it is implemented using the Gal4/UAS system. Using this inducible RNAi technique, various large-scale screens have been performed in Drosophila, demonstrating that the method is straightforward and valuable. However, accumulated results reveal that the results of RNAi-based screens have relatively high levels of error, such as false positives and negatives. Here, we review in vivo RNAi screens in Drosophila and the methods that could be used to remove ambiguity from screening results.

  6. Chronic necrotising pneumonia caused by Aspergillus niger.

    Science.gov (United States)

    Wiggins, J; Clark, T J; Corrin, B

    1989-01-01

    A woman with asthma developed chronic necrotising semi-invasive pneumonia due to mixed Aspergillus niger and Candida albicans infection; though not severely immunosuppressed, she may have been predisposed by long term oral corticosteroid and recurrent oral antibiotic treatment. The diagnosis should be considered in patients with chronic airflow limitation who develop cavitating pneumonia. Images PMID:2763249

  7. Thermostable crude endoglucanase produced by Aspergillus ...

    African Journals Online (AJOL)

    Cellulases are used in many industries worldwide and there is an ever increasing need to isolate, produce or develop thermostable cellulases. Manipulation of fermentation techniques in order to obtain desirable product(s) can be one line of action. In this study Aspergillus fumigatus was grown on chopped wheat straw in a ...

  8. Aspergillus bertholletius sp. nov. from Brazil Nuts

    DEFF Research Database (Denmark)

    Taniwaki, Marta H.; Pitt, John I.; Iamanaka, Beatriz T.

    2012-01-01

    During a study on the mycobiota of brazil nuts (Bertholletia excelsa) in Brazil, a new Aspergillus species, A. bertholletius, was found, and is described here. A polyphasic approach was applied using morphological characters, extrolite data as well as partial beta-tubulin, calmodulin and ITS sequ...

  9. Genome sequence of Aspergillus luchuensis NBRC 4314

    Science.gov (United States)

    Yamada, Osamu; Machida, Masayuki; Hosoyama, Akira; Goto, Masatoshi; Takahashi, Toru; Futagami, Taiki; Yamagata, Youhei; Takeuchi, Michio; Kobayashi, Tetsuo; Koike, Hideaki; Abe, Keietsu; Asai, Kiyoshi; Arita, Masanori; Fujita, Nobuyuki; Fukuda, Kazuro; Higa, Ken-ichi; Horikawa, Hiroshi; Ishikawa, Takeaki; Jinno, Koji; Kato, Yumiko; Kirimura, Kohtaro; Mizutani, Osamu; Nakasone, Kaoru; Sano, Motoaki; Shiraishi, Yohei; Tsukahara, Masatoshi; Gomi, Katsuya

    2016-01-01

    Awamori is a traditional distilled beverage made from steamed Thai-Indica rice in Okinawa, Japan. For brewing the liquor, two microbes, local kuro (black) koji mold Aspergillus luchuensis and awamori yeast Saccharomyces cerevisiae are involved. In contrast, that yeasts are used for ethanol fermentation throughout the world, a characteristic of Japanese fermentation industries is the use of Aspergillus molds as a source of enzymes for the maceration and saccharification of raw materials. Here we report the draft genome of a kuro (black) koji mold, A. luchuensis NBRC 4314 (RIB 2604). The total length of nonredundant sequences was nearly 34.7 Mb, comprising approximately 2,300 contigs with 16 telomere-like sequences. In total, 11,691 genes were predicted to encode proteins. Most of the housekeeping genes, such as transcription factors and N-and O-glycosylation system, were conserved with respect to Aspergillus niger and Aspergillus oryzae. An alternative oxidase and acid-stable α-amylase regarding citric acid production and fermentation at a low pH as well as a unique glutamic peptidase were also found in the genome. Furthermore, key biosynthetic gene clusters of ochratoxin A and fumonisin B were absent when compared with A. niger genome, showing the safety of A. luchuensis for food and beverage production. This genome information will facilitate not only comparative genomics with industrial kuro-koji molds, but also molecular breeding of the molds in improvements of awamori fermentation. PMID:27651094

  10. Characterisation of Aspergillus niger prolyl aminopeptidase

    NARCIS (Netherlands)

    Basten, E.J.W.; Moers, A.P.H.A.; Ooyen, van A.J.J.; Schaap, P.J.

    2005-01-01

    We have cloned a gene (papA) that encodes a prolyl aminopeptidase from Aspergillus niger. Homologous genes are present in the genomes of the Eurotiales A. nidulans, A. fumigatus and Talaromyces emersonii, but the gene is not present in the genome of the yeast Saccharomyces cerevisiae. Cell extracts

  11. Biotransformation of Stypotriol triacetate by Aspergillus niger

    Science.gov (United States)

    Areche, Carlos; Vaca, Inmaculada; Labbe, Pamela; Soto-Delgado, Jorge; Astudillo, Luis; Silva, Mario; Rovirosa, Juana; San-Martin, Aurelio

    2011-07-01

    Biological transformation of the meroditerpenoid, stypotriol triacetate ( 1) by the fungi Aspergillus niger, Cunninghamella elegans, Gibberella fujikuroi and Mucor plumbeus was studied. The incubation of 1 with A. niger yielded the new compound 6',14-diacetoxy-stypol-4,5-dione ( 2) whose structure was established by 1H, 13C and 2D NMR and supported by DFT/GIAO.

  12. Overexpression, purification and characterization of the Aspergillus ...

    African Journals Online (AJOL)

    Cellulases are industrially important hydrolytic enzymes applicable in the bioconversion of cellulosic biomass to simple sugars. In this work, an endoglucanase from Aspergillus niger ATCC 10574, EglA, was expressed in the methylotrophic yeast Pichia pastoris and the properties of the recombinant protein were ...

  13. Polyphasic taxonomy of Aspergillus section Cervini

    DEFF Research Database (Denmark)

    Chen, A.J.; Varga, J.; Frisvad, Jens Christian

    2016-01-01

    Species belonging to Aspergillus section Cervini are characterised by radiate or short columnar, fawn coloured, uniseriate conidial heads. The morphology of the taxa in this section is very similar and isolates assigned to these species are frequently misidentified. In this study, a polyphasic...

  14. Avirulent mutants of Macrophomina phaseolina and Aspergillus ...

    Indian Academy of Sciences (India)

    A human pathogen, Aspergillus fumigatus was also able to infect germinating seeds of P. mungo in the presence of 5 g/ml concentration of phaseolinone. Phaseolinone seemed to facilitate infection by A. fumigatus, which is not normally phytopathogenic, by reducing the immunity of germinating seedlings in a nonspecific ...

  15. Comparative Studies on Pectinases obtained from Aspergillus ...

    African Journals Online (AJOL)

    Prof. Ogunji

    Abstract. Pectinase was produced from Aspergillus species (A. fumigatus, and A. niger) in a submerged fermentation system after 4 and 5 days of fermentation, respectively using pectin extracted from different agro-wastes (mango, orange and pineapple peels) as the carbon sources. The pectin was extracted from mango, ...

  16. Biosynthesis of silver nanoparticles synthesized by Aspergillus

    Indian Academy of Sciences (India)

    In the present study, biosynthesis of silver nanoparticles and its antioxidant, antimicrobial and cytotoxic activities were investigated. Silver nanoparticles were extracellularly synthesized using Aspergillus flavus and the formation of nanoparticles was observed after 72 h of incubation. The results recorded from colour ...

  17. Phylogeny and subgeneric taxonomy of Aspergillus

    DEFF Research Database (Denmark)

    Peterson, S.W.; Varga, Janos; Frisvad, Jens Christian

    2008-01-01

    The phylogeny of the genus Aspergillus and its teleomorphs is discussed based on multilocus sequence data. DNA sequence analysis was used to formulate a nucleotide sequence framework of the genus and to analyze character changes in relationship to the phylogeny hypothesized from the DNA sequence...

  18. Azolla--a model organism for plant genomic studies.

    Science.gov (United States)

    Qiu, Yin-Long; Yu, Jun

    2003-02-01

    The aquatic ferns of the genus Azolla are nitrogen-fixing plants that have great potentials in agricultural production and environmental conservation. Azolla in many aspects is qualified to serve as a model organism for genomic studies because of its importance in agriculture, its unique position in plant evolution, its symbiotic relationship with the N2-fixing cyanobacterium, Anabaena azollae, and its moderate-sized genome. The goals of this genome project are not only to understand the biology of the Azolla genome to promote its applications in biological research and agriculture practice but also to gain critical insights about evolution of plant genomes. Together with the strategic and technical improvement as well as cost reduction of DNA sequencing, the deciphering of their genetic code is imminent.

  19. Giant plasma membrane vesicles: models for understanding membrane organization.

    Science.gov (United States)

    Levental, Kandice R; Levental, Ilya

    2015-01-01

    The organization of eukaryotic membranes into functional domains continues to fascinate and puzzle cell biologists and biophysicists. The lipid raft hypothesis proposes that collective lipid interactions compartmentalize the membrane into coexisting liquid domains that are central to membrane physiology. This hypothesis has proven controversial because such structures cannot be directly visualized in live cells by light microscopy. The recent observations of liquid-liquid phase separation in biological membranes are an important validation of the raft hypothesis and enable application of the experimental toolbox of membrane physics to a biologically complex phase-separated membrane. This review addresses the role of giant plasma membrane vesicles (GPMVs) in refining the raft hypothesis and expands on the application of GPMVs as an experimental model to answer some of key outstanding problems in membrane biology. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Corporate Social Responsibility And Islamic Business Organizations: A Proposed Model

    Directory of Open Access Journals (Sweden)

    Rusnah Muhamad

    2008-01-01

    Full Text Available The issue of corporate social responsibility (CSR has been of growing concern among business communities in recent years. Various corporate leaders maintain that business is considered to contribute fully to the society if it is effi cient, profi table and socially responsible. Islam is considered as addin (a way of life, thus, providing comprehensive guidelines in every aspects of the believers’ life. It is the aim of this paper to propose an Islamic model of corporate social responsibility based on human relationships with the God (hablun min’Allah; with other fellow human being (hablun min’an-nas and with the environment.Keywords : Corporate Social Responsibility, Islamic Business Organization

  1. A NEW ORGANIZATIONAL FORM: STARFISH ORGANIZATION IN BUSINESS MODEL PERSPECTIVE

    OpenAIRE

    Aygul Turan; Aysegul Ozbebek Tunc

    2013-01-01

    As we moved into new economy, decentralization is a very powerful strategy day by day. A large number of traditional organizations are decentralized- some of them decentralize a part of the organization, some of them decentralize whole of the organizations- because of being a winner of the competition. As a decentralized organization, starfish organization is a new concept of the organizational science literature. In this framework, we focus on the starfish organization’s structure. The aim o...

  2. Free chlorine and monochloramine inactivation kinetics of Aspergillus and Penicillium in drinking water.

    Science.gov (United States)

    Ma, Xiao; Bibby, Kyle

    2017-09-01

    Fungi are near-ubiquitous in potable water distribution systems, but the disinfection kinetics of commonly identified fungi are poorly studied. In the present study, laboratory scale experiments were conducted to evaluate the inactivation kinetics of Aspergillus fumigatus, Aspergillus versicolor, and Penicillium purpurogenum by free chlorine and monochloramine. The observed inactivation data were then fit to a delayed Chick-Watson model. Based on the model parameter estimation, the Ct values (integrated product of disinfectant concentration C and contact time t over defined time intervals) for 99.9% inactivation of the tested fungal strains ranged from 48.99 mg min/L to 194.7 mg min/L for free chlorine and from 90.33 mg min/L to 531.3 mg min/L for monochloramine. Fungal isolates from a drinking water system (Aspergillus versicolor and Penicillium purpurogenum) were more disinfection resistant than Aspergillus fumigatus type and clinical isolates. The required 99.9% inactivation Ct values for the tested fungal strains are higher than E. coli, a commonly monitored indicator bacteria, and within a similar range for bacteria commonly identified within water distribution systems, such as Mycobacterium spp. and Legionella spp. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Aspergillus niger contains the cryptic phylogenetic species A. awamori.

    Science.gov (United States)

    Perrone, Giancarlo; Stea, Gaetano; Epifani, Filomena; Varga, János; Frisvad, Jens C; Samson, Robert A

    2011-11-01

    Aspergillus section Nigri is an important group of species for food and medical mycology, and biotechnology. The Aspergillus niger 'aggregate' represents its most complicated taxonomic subgroup containing eight morphologically indistinguishable taxa: A. niger, Aspergillus tubingensis, Aspergillus acidus, Aspergillus brasiliensis, Aspergillus costaricaensis, Aspergillus lacticoffeatus, Aspergillus piperis, and Aspergillus vadensis. Aspergillus awamori, first described by Nakazawa, has been compared taxonomically with other black aspergilli and recently it has been treated as a synonym of A. niger. Phylogenetic analyses of sequences generated from portions of three genes coding for the proteins β-tubulin (benA), calmodulin (CaM), and the translation elongation factor-1 alpha (TEF-1α) of a population of A. niger strains isolated from grapes in Europe revealed the presence of a cryptic phylogenetic species within this population, A. awamori. Morphological, physiological, ecological and chemical data overlap occurred between A. niger and the cryptic A. awamori, however the splitting of these two species was also supported by AFLP analysis of the full genome. Isolates in both phylospecies can produce the mycotoxins ochratoxin A and fumonisin B₂, and they also share the production of pyranonigrin A, tensidol B, funalenone, malformins, and naphtho-γ-pyrones. In addition, sequence analysis of four putative A. awamori strains from Japan, used in the koji industrial fermentation, revealed that none of these strains belong to the A. awamori phylospecies. Copyright © 2011 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  4. Rhino-oculo-cerebral aspergillus and mucor co-infections in an immunocompromised patient with type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Kalidas Rit

    2014-01-01

    Full Text Available Mucormycosis are pathogenic moulds of the mucorales species usually occurring in immunocompromised patients or in patients with uncontrolled diabetes mellitus. Aspergillosis is the clinical condition caused by Aspergillus species and may cause an invasive disease with high case fatality rate, especially in immunosuppressed patients. A 46-year-old male patient with Type 2 diabetes mellitus with underlying malignancy presented with proptosis of left eye. Combined infections of Mucor and Aspergillus were diagnosed by means of computed tomography (CT scan and biopsy. Treatment with Amphotericin B and Voriconazole was started, the patient died within 3 months, from multi-organ failure.

  5. Stimulating action of continuous γ-irradiation with low dose-rates on the growth and development of Aspergillus niger

    International Nuclear Information System (INIS)

    Kuzin, A.M.; Nikitina, A.N.; Yurov, S.S.; Primak, V.N.

    1976-01-01

    Continuous γ-irradiation (1.6 - 4.1 rad/hr) of Aspergillus niger cultured in a mineral medium has been shown to stimulate markedly the growth of the culture and the production of organic acids. Optimum conditions for the stimulating effect have been found

  6. The weak acid preservative sorbic acid inhibits conidial germination and mycelial growth of Aspergillus niger through intracellular acidification

    NARCIS (Netherlands)

    Plumridge, A.; Hesse, S.J.A.; Watson, A.J.; Lowe, K.C.; Stratford, M.; Archer, D.B.

    2004-01-01

    The growth of the filamentous fungus Aspergillus niger, a common food spoilage organism, is inhibited by the weak acid preservative sorbic acid (trans-trans-2,4-hexadienoic acid). Conidia inoculated at 105/ml of medium showed a sorbic acid MIC of 4.5 mM at pH 4.0, whereas the MIC for the amount of

  7. The Shewanella algae strain YM8 produces volatiles with strong inhibition activity against Aspergillus pathogens and aflatoxins

    Directory of Open Access Journals (Sweden)

    Andong eGong

    2015-10-01

    Full Text Available Aflatoxigenic Aspergillus fungi and associated aflatoxins are ubiquitous in the production and storage of food/feed commodities. Controlling these pests is a challenge. In this study, the Shewanella algae strain YM8 was found to produce volatiles that have strong antifungal activity against Aspergillus pathogens. Gas chromatography-mass spectrometry profiling revealed 15 volatile organic compounds (VOCs emitted from YM8, of which dimethyl trisulfide was the most abundant. We obtained authentic reference standards for six of the VOCs; these all significantly reduced mycelial growth and conidial germination in Aspergillus; dimethyl trisulfide and 2,4-bis(1,1-dimethylethyl-phenol showed the strongest inhibitory activity. YM8 completely inhibited Aspergillus growth and aflatoxin biosynthesis in maize and peanut samples stored at different water activity levels, and scanning electron microscopy revealed severely damaged conidia and a complete lack of mycelium development and conidiogenesis. YM8 also completely inhibited the growth of eight other agronomically important species of phytopathogenic fungi: A. parasiticus, A. niger, Alternaria alternate, Botrytis cinerea, Fusarium graminearum, Fusarium oxysporum, Monilinia fructicola, and Sclerotinia sclerotiorum. This study demonstrates the susceptibility of Aspergillus and other fungi to VOCs from marine bacteria and indicates a new strategy for effectively controlling these pathogens and the associated mycotoxin production in the field and during storage.

  8. Modeling Organic Contaminant Desorption from Municipal Solid Waste Components

    Science.gov (United States)

    Knappe, D. R.; Wu, B.; Barlaz, M. A.

    2002-12-01

    Approximately 25% of the sites on the National Priority List (NPL) of Superfund are municipal landfills that accepted hazardous waste. Unlined landfills typically result in groundwater contamination, and priority pollutants such as alkylbenzenes are often present. To select cost-effective risk management alternatives, better information on factors controlling the fate of hydrophobic organic contaminants (HOCs) in landfills is required. The objectives of this study were (1) to investigate the effects of HOC aging time, anaerobic sorbent decomposition, and leachate composition on HOC desorption rates, and (2) to simulate HOC desorption rates from polymers and biopolymer composites with suitable diffusion models. Experiments were conducted with individual components of municipal solid waste (MSW) including polyvinyl chloride (PVC), high-density polyethylene (HDPE), newsprint, office paper, and model food and yard waste (rabbit food). Each of the biopolymer composites (office paper, newsprint, rabbit food) was tested in both fresh and anaerobically decomposed form. To determine the effects of aging on alkylbenzene desorption rates, batch desorption tests were performed after sorbents were exposed to toluene for 30 and 250 days in flame-sealed ampules. Desorption tests showed that alkylbenzene desorption rates varied greatly among MSW components (PVC slowest, fresh rabbit food and newsprint fastest). Furthermore, desorption rates decreased as aging time increased. A single-parameter polymer diffusion model successfully described PVC and HDPE desorption data, but it failed to simulate desorption rate data for biopolymer composites. For biopolymer composites, a three-parameter biphasic polymer diffusion model was employed, which successfully simulated both the initial rapid and the subsequent slow desorption of toluene. Toluene desorption rates from MSW mixtures were predicted for typical MSW compositions in the years 1960 and 1997. For the older MSW mixture, which had a

  9. 21 CFR 173.120 - Carbohydrase and cellulase derived from Aspergillus niger.

    Science.gov (United States)

    2010-04-01

    ... cellulase derived from Aspergillus niger. Carbohydrase and cellulase enzyme preparation derived from Aspergillus niger may be safely used in food in accordance with the following prescribed conditions: (a) Aspergillus niger is classified as follows: Class, Deuteromycetes; order, Moniliales; family, Moniliaceae...

  10. Two novel species of Aspergillus section Nigri from Thai coffee beans

    DEFF Research Database (Denmark)

    Noonim, Paramee; Mahakarnchanakul, Warapa; Varga, Janos

    2008-01-01

    Two novel species of Aspergillus section Nigri from Thai coffee beans are described as Aspergillus aculeatinus sp. nov. and Aspergillus sclerotiicarbonarius sp. nov. Their taxonomic status was determined using a polyphasic taxonomic approach with phenotypic (morphology and extrolite profiles...

  11. Two novel species of Aspergillus section Nigri from Thai coffee beans.

    NARCIS (Netherlands)

    Noonim, P.; Mahakarnchanakul, W.; Varga, J.; Frisvad, J.C.; Samson, R.A.

    2008-01-01

    Two novel species of Aspergillus section Nigri from Thai coffee beans are described as Aspergillus aculeatinus sp. nov. and Aspergillus sclerotiicarbonarius sp. nov. Their taxonomic status was determined using a polyphasic taxonomic approach with phenotypic (morphology and extrolite profiles) and

  12. Development of a statistical shape model of multi-organ and its performance evaluation

    International Nuclear Information System (INIS)

    Nakada, Misaki; Shimizu, Akinobu; Kobatake, Hidefumi; Nawano, Shigeru

    2010-01-01

    Existing statistical shape modeling methods for an organ can not take into account the correlation between neighboring organs. This study focuses on a level set distribution model and proposes two modeling methods for multiple organs that can take into account the correlation between neighboring organs. The first method combines level set functions of multiple organs into a vector. Subsequently it analyses the distribution of the vectors of a training dataset by a principal component analysis and builds a multiple statistical shape model. Second method constructs a statistical shape model for each organ independently and assembles component scores of different organs in a training dataset so as to generate a vector. It analyses the distribution of the vectors of to build a statistical shape model of multiple organs. This paper shows results of applying the proposed methods trained by 15 abdominal CT volumes to unknown 8 CT volumes. (author)

  13. Toward systems metabolic engineering of Aspergillus and Pichia species for the production of chemicals and biofuels

    DEFF Research Database (Denmark)

    Caspeta, Luis; Nielsen, Jens

    2013-01-01

    trends in systems biology of Aspergillus and Pichia species, highlighting the relevance of these developments for systems metabolic engineering of these organisms for the production of hydrolytic enzymes, biofuels and chemicals from biomass. Metabolic engineering is moving from traditional methods...... for the production of hydrolytic enzymes, biofuels and chemicals from biomass. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim....

  14. Spatial differentiation of gene expression in Aspergillus niger colony grown for sugar beet pulp utilization

    OpenAIRE

    Benoit, Isabelle; Zhou, Miaomiao; Duarte, Alexandra Vivas; Downes, Damien J.; Todd, Richard B.; Kloezen, Wendy; Post, Harm; Heck, Albert J. R.; Altelaar, A. F. Maarten; de Vries, Ronald P.

    2015-01-01

    Degradation of plant biomass to fermentable sugars is of critical importance for the use of plant materials for biofuels. Filamentous fungi are ubiquitous organisms and major plant biomass degraders. Single colonies of some fungal species can colonize massive areas as large as five soccer stadia. During growth, the mycelium encounters heterogeneous carbon sources. Here we assessed whether substrate heterogeneity is a major determinant of spatial gene expression in colonies of Aspergillus nige...

  15. Karnatakafuran A and B: Two novel dibenzofurans isolated from the fungus Aspergillus karnatakaensis

    DEFF Research Database (Denmark)

    Manniche, S.; Sprogøe, K.; Dalsgaard, Petur

    2004-01-01

    Karnatakafurans A (1) and B (2), two novel dibenzofurans, have been isolated from the Specie Novum Aspergillus karnatakaensis Frisvad. The compounds were the major secondary metabolites and were isolated through UV-guided fractionation. of the organic extract. The structures were elucidated by sp...... by spectroscopic methods including MS and NMR. The compounds were tested for antimicrobial and antimalarial activity and proved to be moderately active against Plasmodium falciparum....

  16. Tannase production by Aspergillus aculeatus DBF9 through solid-state fermentation.

    Science.gov (United States)

    Banerjee, D; Mondal, K C; Pati, B R

    2007-06-01

    Tannase an industrially important enzyme was produced by Aspergillus aculeatus DBF9 through a solid-state fermentation (SSF). The organism produced good amount of enzyme and gallic acid in wheat bran among the solid substrate used in SSF. Maximum enzyme and gallic acid production occurred in 5% tannic acid after 72 h. Eighty percent initial substrate moisture and 30 degrees C temperature was found suitable for tannase production.

  17. Differential impact of some Aspergillus species on Meloidogyne javanica biocontrol by Pseudomonas fluorescens strain CHA0.

    Science.gov (United States)

    Siddiqui, I A; Shaukat, S S; Khan, A

    2004-01-01

    The aim was to determine the influence of some Aspergillus species on the production of nematicidal agent(s) in vitro and biocontrol of Meloidogyne javanica in tomato by Pseudomonas fluorescens strains CHA0 and CHA0/pME3424. Six species of Aspergillus, isolated from the rhizosphere of certain crops, produced a variety of secondary metabolites in vitro. Culture filtrate (CF) obtained from Ps. fluorescens strain CHA0 and its2,4-diacetylphloroglucinol overproducing mutant CHA0/pME3424 grown in King's B liquid medium caused significant mortality of M. javanica juveniles in vitro. Bacterial growth medium amended with CF of A. niger enhanced nematicidal and beta-galactosidase activities of fluorescent pseudomonads while A. quadrilineatus repressed such activities. Methanol or ethyl acetate extracts of the CF of A. niger markedly optimized bacterial efficacy to cause nematode deaths while hexane extract of the fungus had no influence on the nematicidal activity of the bacterial strains. A. niger applied alone or in conjunction with the bacterial inoculants inhibited root-knot nematode galling in tomato. On the other hand, A. quadrilineatus used alone or together with CHA0 did not inhibit nematode galling but when used in combination with strain CHA0/pME3424 did reduce galling intensity. Aspergillus niger enhances the production of nematicidal compounds by Ps. fluorescensin vitro and improves biocontrol potential of the bacterial inoculants in tomato while A. quadrilineatus reduces bacterial performance to suppress root-knot nematodes. Rhizosphere harbours a variety of micro-organisms including bacteria, fungi and viruses. Aspergillus species are ubiquitous in most agricultural soils and generally produce a variety of secondary metabolites. Such metabolites synthesized by Aspergillus species may influence the production of nematicidal agents and subsequent biocontrol performance of the bacterial inoculants against plant-parasitic nematodes. This fact needs to be taken into

  18. Elimination kinetic model for organic chemicals in earthworms.

    NARCIS (Netherlands)

    Dimitrova, N.; Dimitrov, S.; Georgieva, D.; van Gestel, C.A.M.; Hankard, P.; Spurgeon, D.J.; Li, H.; Mekenyan, O.

    2010-01-01

    Mechanistic understanding of bioaccumulation in different organisms and environments should take into account the influence of organism and chemical depending factors on the uptake and elimination kinetics of chemicals. Lipophilicity, metabolism, sorption (bioavailability) and biodegradation of

  19. Citric acid production from whey by fermentation using Aspergillus spp.

    Directory of Open Access Journals (Sweden)

    Óscar Julián Sánchez Toro

    2004-01-01

    Full Text Available Whey has become the main dairy-industry waste product, despite continuous efforts aimed at finding a way to use it. The aim of this research was to investigate citric acid production by submerged fermentation using Aspergillus genus fungi, using whey as substrate to take economical advantage of it and to reduce the environmental impact caused by discharging this by-product into nearby streams. The following three strains were used: A. carbonarius NRRL 368, A. carbonarius NRRL 67 and A. niger NRRL 3. The best adaptation medium for inoculum propagation was selected. Proposed experimental design for evaluating citric acid biosynthesis from whey modified through different treatments showed that the two A. carbonarius strains did not present significant differences in acid production whereas A. niger NRRL 3 reached higher concentration when evaporated, deproteinised and p-galactosidase lactose-hydrolysed whey was used. However, A. carbonarius gave higher average citric acid titres than those found for A. niger. This suggests the need for carrying out further research on it as a potential producing strain. Cell growth, substrate consumption and acid production kinetics in a 3-L stirred-tank bioreactor with aeration were developed in the case of A. niger; kinetics were simulated through non-structured mathematical models. Key words: Aspergilluscarbonarius, Aspergillus niger, bioreactor, simulation, p-galactosidase.

  20. Aspergillus vaccines: Hardly worth studying or worthy of hard study?

    Science.gov (United States)

    Levitz, Stuart M

    2017-01-01

    Vaccines rank among the greatest advances in the history of public health. Yet, despite the need, there are no licensed vaccines to protect humans against fungal diseases, including aspergillosis. In this focused review, some of the major scientific and logistical challenges to developing vaccines to protect at-risk individuals against aspergillosis are discussed. Approaches that have shown promise in animal models include vaccines that protect against multiple fungal genera and those that are specifically directed to Aspergillus Advances in proteomics and glycomics have facilitated identification of candidate antigens for use in subunit vaccines. Novel adjuvants and delivery systems are becoming available that can skew vaccine responses toward those associated with protection. Immunotherapy consisting of adoptive transfer of Aspergillus-specific T cells to allogeneic hematopoietic transplant recipients has advanced to human testing but is technically difficult and of unproven benefit. While progress has been impressive, much work still needs to be done if vaccines against aspergillosis are to become a reality. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. KICS: A Model of Motivational Leadership in Organizations

    Directory of Open Access Journals (Sweden)

    John N. N. Ugoani

    2015-09-01

    Full Text Available This pure research gave birth to a Model of Motivational Leadership – KICS: which embraces knowledge, intelligence, collaboration and synergy. It is a synergistic  proposition based on the theory of emotional intelligence as the index of competencies needed for effective leadership. It opened with a general discussion on traditional models of leadership, then the roles of knowledge, intelligence, collaboration and synergy as they relate to motivational leadership. Issues of emotional intelligence clusters and synthesis of the model’s elements were discussed, emphasizing how KICS-based motivational leadership skills can be developed and sustained. Motivational leadership entails exciting people’s imaginations and inspiring them to move in a desired direction. It takes more than simple power to motivate and lead in organizations. Realizing that unity and cohesiveness are built from personal bonds, the best leaders ensure to deepen their rapport with employees and colleagues which enhances organizational performance. This pure research argues that the synergy of related emotional intelligence competencies can lead to motivational leadership behaviour. Knowledge is critical to leadership because there are different types of leadership and different situations require different kinds of knowledge, and the person possessing the knowledge demanded by a certain situation in most cases, tends to become the best leader. A knowledgeable person is one who is trained to consider his actions to undertake them deliberately, in a disciplined manner. Added to this ability is the intelligence to endure in a chosen course in the face of distraction, confusion and difficulty, all combined in producing a motivational leader. Knowledge tends to be procedural in nature and to operate outside of focal awareness. It also reflects the structure of the situation more closely than it does in the structure of formal disciplinary knowledge. The survey research design

  2. Use of Aspergillus niger for bioconversion of apple distillery waste

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, J.; Cimerman, A.; Perdih, A.

    1983-01-01

    The bioconversion of waste material remaining after apple brandy distillation was investigated. Different cellulolytic fungi were tested for their ability to convert the waste organic substances into microbial biomass. An Aspergillus niger strain was chosen as the most convenient microorganism. By growing this mold on the apple slop the following results were obtained: filtration time was shortened by 30 times, reduction of the chemical oxygen demand in the liquid phase in the range of 50-80% depending on the substrate dilution and a dry filter cake enriched with fungal biomass to about 12 g/l containing up to 22% raw proteins and certain amounts of cellulolytic enzymes in the filtrate. The influence of the initial pH, the salt addition and the dilution of the substrate were studied as well. 12 references.

  3. In-silico analysis of Aspergillus niger beta-glucosidases

    Science.gov (United States)

    Yeo S., L.; Shazilah, K.; Suhaila, S.; Abu Bakar F., D.; Murad A. M., A.

    2014-09-01

    Genomic data mining was carried out and revealed a total of seventeen β-glucosidases in filamentous fungi Aspergillus niger. Two of them belonged to glycoside hydrolase family 1 (GH1) while the rest belonged to genes in family 3 (GH3). These proteins were then named according to the nomenclature as proposed by the International Union of Biochemistry (IUB), starting from the lowest pI and glycoside hydrolase family. Their properties were predicted using various bionformatic tools showing the presence of domains for signal peptide and active sites. Interestingly, one particular domain, PA14 (protective antigen) was present in four of the enzymes, predicted to be involved in carbohydrate binding. A phylogenetic tree grouped the two glycoside hydrolase families with GH1 and GH3 related organisms. This study showed that the various domains present in these β-glucosidases are postulated to be crucial for the survival of this fungus, as supported by other analysis.

  4. Production and qualification of transglucosidase from Aspergillus niger

    Energy Technology Data Exchange (ETDEWEB)

    Benson, C.P.; Kelly, C.T.; Fogarty, W.M.

    1982-08-01

    The production of transglucosidase by Aspergillus niger was examined in batch culture with thin-layer chromatography (t.l.c.). Corn steep liquor was used as the nitrogen source and the activities obtained with four different carbon sources were examiend both qualitatively and quantitatively. Prompted by the non-quantitative nature of the t.l.c. assay technique, a quantiative transglucosidase assay procedure was developed subsequently. This was based on the hydrolysis of alpha-methyl-D-glucoside which was shown to be unaffected not only by amyloglucosidase of A. niger but also by that from a number of other organisms. The glucose released was measured by the glucose oxidase-peroxidase reagent, thus providing a rapid and reliable quantitative assay procedure for determining transglucosidase in the presence of amyloglucosidase. (Refs. 30).

  5. First Report of an Atypical New Aspergillus parasiticus Isolates with Nucleotides Insertion in aflR Gene Identical to Aspergillus sojae

    Science.gov (United States)

    Aflatoxins are toxic and carcinogenic secondary metabolites produced primarily by the filamentous fungi Aspergillus favus and Aspergillus parasitic and cause toxin contamination in food chain worldwide. Aspergillus oryzae and Aspergillus sojae are highly valued as koji molds in the traditional prep...

  6. Evaluation of approaches focused on modelling of organic carbon stocks using the RothC model

    Science.gov (United States)

    Koco, Štefan; Skalský, Rastislav; Makovníková, Jarmila; Tarasovičová, Zuzana; Barančíková, Gabriela

    2014-05-01

    The aim of current efforts in the European area is the protection of soil organic matter, which is included in all relevant documents related to the protection of soil. The use of modelling of organic carbon stocks for anticipated climate change, respectively for land management can significantly help in short and long-term forecasting of the state of soil organic matter. RothC model can be applied in the time period of several years to centuries and has been tested in long-term experiments within a large range of soil types and climatic conditions in Europe. For the initialization of the RothC model, knowledge about the carbon pool sizes is essential. Pool size characterization can be obtained from equilibrium model runs, but this approach is time consuming and tedious, especially for larger scale simulations. Due to this complexity we search for new possibilities how to simplify and accelerate this process. The paper presents a comparison of two approaches for SOC stocks modelling in the same area. The modelling has been carried out on the basis of unique input of land use, management and soil data for each simulation unit separately. We modeled 1617 simulation units of 1x1 km grid on the territory of agroclimatic region Žitný ostrov in the southwest of Slovakia. The first approach represents the creation of groups of simulation units based on the evaluation of results for simulation unit with similar input values. The groups were created after the testing and validation of modelling results for individual simulation units with results of modelling the average values of inputs for the whole group. Tests of equilibrium model for interval in the range 5 t.ha-1 from initial SOC stock showed minimal differences in results comparing with result for average value of whole interval. Management inputs data from plant residues and farmyard manure for modelling of carbon turnover were also the same for more simulation units. Combining these groups (intervals of initial

  7. Interaction of Wild Strains of Aspergilla with Aspergillus parasiticus ATCC15517 and Aflatoxin Production †

    Science.gov (United States)

    Martins, H. Marina; Almeida, Inês; Marques, Marta; Bernardo, Fernando

    2008-01-01

    Aflatoxins are secondary metabolites produced by some competent mould strains of Aspergillus flavus, A. parasiticus and A. nomius. These compounds have been extensively studied with regards to their toxicity for animals and humans; they are able to induce liver cancer and may cause a wide range of adverse effects in living organisms. Aflatoxins are found as natural contaminants of food and feed; the main line of the strategy to control them is based on the prevention of the mould growth in raw vegetable or during its storage and monitoring of each crop batch. Mould growth is conditioned by many ecological factors, including biotic ones. Hazard characterization models for aflatoxins in crops must take into consideration biotic interactions between moulds and their potential effects on growth development. The aim of this work is to study the effect of the biotic interaction of 14 different wild strains of Aspergilla (different species), with a competent strain (Aspergillus parasiticus ATCC 15517) using an in vitro production model. The laboratory model used was a natural matrix (humidified cracked corn), on which each wild strain challenged the aflatoxin production of a producer strain. Cultures were incubated at 28°C for 12 days and sampled at the 8th and 12th. Aflatoxin detection and quantification was performed by HPLC using a procedure with a MRPL = 1 μg/kg. Results of those interactive cultures revealed both synergic and antagonistic effects on aflatoxin biosynthesis. Productivity increases were particularly evident on the 8th day of incubation with wild strains of A. flavipes (+ 70.4 %), A. versicolor (+ 54.9 %) and A. flavus 3 (+ 62.6 %). Antagonistic effects were found with A. niger (− 69.5%), A. fumigatus (− 47.6 %) and A. terreus (− 47.6 %) on the 12th day. The increased effects were more evident on the 8th of incubation and the decreases were more patent on the 12th day. Results show that the development of Aspergilla strains concomitantly with

  8. Aspergillus species as emerging causative agents of onychomycosis.

    Science.gov (United States)

    Nouripour-Sisakht, S; Mirhendi, H; Shidfar, M R; Ahmadi, B; Rezaei-Matehkolaei, A; Geramishoar, M; Zarei, F; Jalalizand, N

    2015-06-01

    Onychomycosis is a common nail infection caused by dermatophytes, non-dermatophyte molds (NDM), and yeasts. Aspergillus species are emerging as increasing causes of toenail onychomycosis. The purpose of this study was species delineation of Aspergillus spp. isolated from patients with onychomycosis. During a period of one year (2012-2013), nail samples were collected from patients clinically suspected of onychomycosis and subjected to microscopic examination and culture. Species identification was performed based on macro- and micro-morphology of colonies. For precise species identification, PCR-amplification and sequencing of the beta-tubulin gene followed by BLAST queries were performed where required. A total of 463/2,292 (20.2%) tested nails were diagnosed with onychomycosis. Among the positive specimens, 154 cases (33.2%) were identified as saprophytic NDM onychomycosis, 135 (29.2%) of which were attributable to Aspergillus. Aspergillus species isolated from the infected nails included Aspergillus flavus (77.3%, n=119), Aspergillus niger (n=4), Aspergillus tubingensis (n=4), Aspergillus terreus (n=3), Aspergillus sydowii (n=2), Aspergillus spp. (n=2), and Aspergillus candidus (n=1). Among the patients diagnosed with onychomycosis due to Aspergillus (average patient age, 47.4 years), 40 had fingernail and 95 toenail involvement. The large toenails were most commonly affected. This study identified a markedly high occurrence of A. flavus, and this fungus appears to be an emerging cause of saprophytic onychomycosis in Iran. The study moreover highlights the necessity of differentiating between dermatophytic and non-dermatophytic nail infections for informed decisions on appropriate therapy. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  9. Aflatoxigenic Aspergillus flavus and Aspergillus parasiticus strains in Hungarian maize fields.

    Science.gov (United States)

    Sebők, Flóra; Dobolyi, Csaba; Zágoni, Dóra; Risa, Anita; Krifaton, Csilla; Hartman, Mátyás; Cserháti, Mátyás; Szoboszlay, Sándor; Kriszt, Balázs

    2016-12-01

    Due to the climate change, aflatoxigenic Aspergillus species and strains have appeared in several European countries, contaminating different agricultural commodities with aflatoxin. Our aim was to screen the presence of aflatoxigenic fungi in maize fields throughout the seven geographic regions of Hungary. Fungi belonging to Aspergillus section Flavi were isolated in the ratio of 26.9% and 42.3% from soil and maize samples in 2013, and these ratios decreased to 16.1% and 34.7% in 2014. Based on morphological characteristics and the sequence analysis of the partial calmodulin gene, all isolates proved to be Aspergillus flavus, except four strains, which were identified as Aspergillus parasiticus. About half of the A. flavus strains and all the A. parasiticus strains were able to synthesize aflatoxins. Aflatoxigenic Aspergillus strains were isolated from all the seven regions of Hungary. A. parasiticus strains were found in the soil of the regions Southern Great Plain and Southern Transdanubia and in a maize sample of the region Western Transdanubia. In spite of the fact that aflatoxins have rarely been detected in feeds and foods in Hungary, aflatoxigenic A. flavus and A. parasiticus strains are present in the maize culture throughout Hungary posing a potential threat to food safety.

  10. The prisoner as model organism: malaria research at Stateville Penitentiary

    Science.gov (United States)

    Comfort, Nathaniel

    2009-01-01

    In a military-sponsored research project begun during the Second World War, inmates of the Stateville Penitentiary in Illinois were infected with malaria and treated with experimental drugs that sometimes had vicious side effects. They were made into reservoirs for the disease and they provided a food supply for the mosquito cultures. They acted as secretaries and technicians, recording data on one another, administering malarious mosquito bites and experimental drugs to one another, and helping decide who was admitted to the project and who became eligible for early parole as a result of his participation. Thus, the prisoners were not simply research subjects; they were deeply constitutive of the research project. Because a prisoner’s time on the project was counted as part of his sentence, and because serving on the project could shorten one’s sentence, the project must be seen as simultaneously serving the functions of research and punishment. Michel Foucault wrote about such ‘mixed mechanisms’ in his Discipline and punish. His shining example of such a ‘transparent’ and subtle style of punishment was the panopticon, Jeremy Bentham’s architectural invention of prison cellblocks arrayed around a central guard tower. Stateville prison was designed on Bentham’s model; Foucault featured it in his own discussion. This paper, then, explores the power relations in this highly idiosyncratic experimental system, in which the various roles of model organism, reagent, and technician are all occupied by sentient beings who move among them fluidly. This, I argue, created an environment in the Stateville hospital wing more panoptic than that in the cellblocks. Research and punishment were completely interpenetrating, and mutually reinforcing. PMID:19720327

  11. Towards Increased Relevance: Context-Adapted Models of the Learning Organization

    Science.gov (United States)

    Örtenblad, Anders

    2015-01-01

    Purpose: The purposes of this paper are to take a closer look at the relevance of the idea of the learning organization for organizations in different generalized organizational contexts; to open up for the existence of multiple, context-adapted models of the learning organization; and to suggest a number of such models.…

  12. On agent cooperation : the relevance of cognitive plausibility for multiagent simulation models of organizations

    NARCIS (Netherlands)

    van den Broek, J.

    2001-01-01

    Human organizations and computational multiagent systems both are social systems because they are both made up of a large number of interacting parts. Since human organizations are arrangements of distributed real intelligence, any DAI model is in some sense a model of an organization. This

  13. On agent cooperation : The relevance of cognitive plausibility for multiagent simulation models of organizations

    NARCIS (Netherlands)

    Broek, J. van den

    2001-01-01

    Human organizations and computational multiagent systems both are social systems because they are both made up of a large number of interacting parts. Since human organizations are arrangements of distributed real intelligence, any DAI model is in some sense a model of an organization. This

  14. Modelling and Optimization of Organization of Workplaces in a Foundry

    Directory of Open Access Journals (Sweden)

    Kukla S.

    2016-09-01

    Full Text Available The paper presents a practical example of improvement of foundry production systems in terms of post-finishing of nodular iron castings produced in the conditions of bulk production for automotive industry. The attention was paid to high labour-intensive efforts, which are difficult to be subjected to mechanization and automation. The times of actions related to grinding processing of castings in three grinding positions connected with a belt conveyor were estimated with the use of a time study method. A bottleneck as well as limiting factors were specified in a system. A number of improvements were proposed, aimed at improving work organization on the castings post-finishing line. An analysis of work ergonomics at the workplace was made in order to eliminate unnecessary and onerous for the employee actions. A model of production system using the Arena software, on which a simulation experiment was conducted, was drawn up in order to visualize the analysed phenomena. The effects of the project were shown on graphs comparing times, costs, work ergonomics and overall efficiency of production equipment indicator.

  15. Drug repurposing for aging research using model organisms.

    Science.gov (United States)

    Ziehm, Matthias; Kaur, Satwant; Ivanov, Dobril K; Ballester, Pedro J; Marcus, David; Partridge, Linda; Thornton, Janet M

    2017-10-01

    Many increasingly prevalent diseases share a common risk factor: age. However, little is known about pharmaceutical interventions against aging, despite many genes and pathways shown to be important in the aging process and numerous studies demonstrating that genetic interventions can lead to a healthier aging phenotype. An important challenge is to assess the potential to repurpose existing drugs for initial testing on model organisms, where such experiments are possible. To this end, we present a new approach to rank drug-like compounds with known mammalian targets according to their likelihood to modulate aging in the invertebrates Caenorhabditis elegans and Drosophila. Our approach combines information on genetic effects on aging, orthology relationships and sequence conservation, 3D protein structures, drug binding and bioavailability. Overall, we rank 743 different drug-like compounds for their likelihood to modulate aging. We provide various lines of evidence for the successful enrichment of our ranking for compounds modulating aging, despite sparse public data suitable for validation. The top ranked compounds are thus prime candidates for in vivo testing of their effects on lifespan in C. elegans or Drosophila. As such, these compounds are promising as research tools and ultimately a step towards identifying drugs for a healthier human aging. © 2017 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  16. Aspergillus thyroiditis in a renal transplant recipient mimicking subacute thyroiditis.

    Science.gov (United States)

    Solak, Y; Atalay, H; Nar, A; Ozbek, O; Turkmen, K; Erekul, S; Turk, S

    2011-04-01

    Fungal pathogens are increasingly encountered after renal transplantation. Aspergillus causes significant morbidity and mortality in transplant patients. Fungal thyroiditis is a rare occurrence owing to unique features of the thyroid gland. Most cases are caused by Aspergillus species and have been described in immunocompromised patients. Presentation may be identical with that of subacute thyroiditis, in which hyperthyroidism features and painful thyroid are the prominent findings. Diagnosis can be ascertained by fine-needle aspiration of thyroid showing branching hyphae of Aspergillus. We describe a renal transplant patient who developed Aspergillus thyroiditis as part of a disseminated infection successfully treated with voriconazole. © 2010 John Wiley & Sons A/S.

  17. Analytical and computational approaches to define the Aspergillus niger secretome

    Energy Technology Data Exchange (ETDEWEB)

    Tsang, Adrian; Butler, Gregory D.; Powlowski, Justin; Panisko, Ellen A.; Baker, Scott E.

    2009-03-01

    We used computational and mass spectrometric approaches to characterize the Aspergillus niger secretome. The 11,200 gene models predicted in the genome of A. niger strain ATCC 1015 were the data source for the analysis. Depending on the computational methods used, 691 to 881 proteins were predicted to be secreted proteins. We cultured A. niger in six different media and analyzed the extracellular proteins produced using mass spectrometry. A total of 222 proteins were identified, with 39 proteins expressed under all six conditions and 74 proteins expressed under only one condition. The secreted proteins identified by mass spectrometry were used to guide the correction of about 20 gene models. Additional analysis focused on extracellular enzymes of interest for biomass processing. Of the 63 glycoside hydrolases predicted to be capable of hydrolyzing cellulose, hemicellulose or pectin, 94% of the exo-acting enzymes and only 18% of the endo-acting enzymes were experimentally detected.

  18. Small-angle scattering study of Aspergillus awamori glycoprotein glucoamylase

    International Nuclear Information System (INIS)

    Schmidt, A. E.; Shvetsov, A. V.; Kuklin, A. I.; Lebedev, D. V.; Surzhik, M. A.; Sergeev, V. R.; Isaev-Ivanov, V. V.

    2016-01-01

    Glucoamylase from fungus Aspergillus awamori is glycoside hydrolase that catalyzes the hydrolysis of α-1,4- and α-1,6-glucosidic bonds in glucose polymers and oligomers. This glycoprotein consists of a catalytic domain and a starch-binding domain connected by an O-glycosylated polypeptide chain. The conformation of the linker, the relative arrangement of the domains, and the structure of the full-length enzyme are unknown. The structure of the recombinant glucoamylase GA1 was studied by molecular modelling and small-angle neutron scattering (SANS) methods. The experimental SANS data provide evidence that glucoamylase exists as a monomer in solution and contains a glycoside component, which makes a substantial contribution to the scattering. The model of full-length glucoamylase, which was calculated without taking into account the effect of glycosylation, is consistent with the experimental data and has a radius of gyration of 33.4 ± 0.6 Å

  19. Small-angle scattering study of Aspergillus awamori glycoprotein glucoamylase

    Science.gov (United States)

    Schmidt, A. E.; Shvetsov, A. V.; Kuklin, A. I.; Lebedev, D. V.; Surzhik, M. A.; Sergeev, V. R.; Isaev-Ivanov, V. V.

    2016-01-01

    Glucoamylase from fungus Aspergillus awamori is glycoside hydrolase that catalyzes the hydrolysis of α-1,4- and α-1,6-glucosidic bonds in glucose polymers and oligomers. This glycoprotein consists of a catalytic domain and a starch-binding domain connected by an O-glycosylated polypeptide chain. The conformation of the linker, the relative arrangement of the domains, and the structure of the full-length enzyme are unknown. The structure of the recombinant glucoamylase GA1 was studied by molecular modelling and small-angle neutron scattering (SANS) methods. The experimental SANS data provide evidence that glucoamylase exists as a monomer in solution and contains a glycoside component, which makes a substantial contribution to the scattering. The model of full-length glucoamylase, which was calculated without taking into account the effect of glycosylation, is consistent with the experimental data and has a radius of gyration of 33.4 ± 0.6 Å.

  20. Small-angle scattering study of Aspergillus awamori glycoprotein glucoamylase

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, A. E., E-mail: schmidt@omrb.pnpi.spb.ru; Shvetsov, A. V. [National Research Center “Kurchatov Institute”, Konstantinov Petersburg Nuclear Physics Institute (Russian Federation); Kuklin, A. I. [Joint Institute for Nuclear Research (Russian Federation); Lebedev, D. V.; Surzhik, M. A.; Sergeev, V. R.; Isaev-Ivanov, V. V. [National Research Center “Kurchatov Institute”, Konstantinov Petersburg Nuclear Physics Institute (Russian Federation)

    2016-01-15

    Glucoamylase from fungus Aspergillus awamori is glycoside hydrolase that catalyzes the hydrolysis of α-1,4- and α-1,6-glucosidic bonds in glucose polymers and oligomers. This glycoprotein consists of a catalytic domain and a starch-binding domain connected by an O-glycosylated polypeptide chain. The conformation of the linker, the relative arrangement of the domains, and the structure of the full-length enzyme are unknown. The structure of the recombinant glucoamylase GA1 was studied by molecular modelling and small-angle neutron scattering (SANS) methods. The experimental SANS data provide evidence that glucoamylase exists as a monomer in solution and contains a glycoside component, which makes a substantial contribution to the scattering. The model of full-length glucoamylase, which was calculated without taking into account the effect of glycosylation, is consistent with the experimental data and has a radius of gyration of 33.4 ± 0.6 Å.

  1. Aspergillus bertholletius sp. nov. from Brazil Nuts

    Science.gov (United States)

    Taniwaki, Marta H.; Pitt, John I.; Iamanaka, Beatriz T.; Sartori, Daniele; Copetti, Marina V.; Balajee, Arun; Fungaro, Maria Helena P.; Frisvad, Jens C.

    2012-01-01

    During a study on the mycobiota of brazil nuts (Bertholletia excelsa) in Brazil, a new Aspergillus species, A. bertholletius, was found, and is described here. A polyphasic approach was applied using morphological characters, extrolite data as well as partial β-tubulin, calmodulin and ITS sequences to characterize this taxon. A. bertholletius is represented by nineteen isolates from samples of brazil nuts at various stages of production and soil close to Bertholletia excelsa trees. The following extrolites were produced by this species: aflavinin, cyclopiazonic acid, kojic acid, tenuazonic acid and ustilaginoidin C. Phylogenetic analysis using partial β-tubulin and camodulin gene sequences showed that A. bertholletius represents a new phylogenetic clade in Aspergillus section Flavi. The type strain of A. bertholletius is CCT 7615 ( = ITAL 270/06 = IBT 29228). PMID:22952594

  2. Aspergillus bertholletius sp. nov. from Brazil nuts.

    Directory of Open Access Journals (Sweden)

    Marta H Taniwaki

    Full Text Available During a study on the mycobiota of brazil nuts (Bertholletia excelsa in Brazil, a new Aspergillus species, A. bertholletius, was found, and is described here. A polyphasic approach was applied using morphological characters, extrolite data as well as partial β-tubulin, calmodulin and ITS sequences to characterize this taxon. A. bertholletius is represented by nineteen isolates from samples of brazil nuts at various stages of production and soil close to Bertholletia excelsa trees. The following extrolites were produced by this species: aflavinin, cyclopiazonic acid, kojic acid, tenuazonic acid and ustilaginoidin C. Phylogenetic analysis using partial β-tubulin and camodulin gene sequences showed that A. bertholletius represents a new phylogenetic clade in Aspergillus section Flavi. The type strain of A. bertholletius is CCT 7615 ( = ITAL 270/06 = IBT 29228.

  3. New taxa in Aspergillus section Usti

    DEFF Research Database (Denmark)

    Samson, R. A.; Varga, J.; Meijer, M.

    2011-01-01

    identical ITS sequences with A. insuetus CBS 119.27, but is clearly distinct from that species based on beta-tubulin and calmodulin sequence data. This species is unable to grow at 37 degrees C, similarly to A. keveii and A. insuetus. Aspergillus carlsbadensis sp. nov. was isolated from the Carlsbad Caverns...... National Park in New Mexico. This taxon is related to, but distinct from a dade including A. calidoustus, A. pseudodeflectus, A. insuetus and A. keveii on all trees. This species is also unable to grow at 37 degrees C, and acid production was not observed on CREA. Aspergillus californicus sp. nov....... Isolates from stored maize, South Africa, as a culture contaminant of Bipolaris sorokiniana from indoor air in Finland proved to be related to, but different from A. ustus and A. puniceus. The taxon is proposed as the new species A. pseudoustus. Although supported only by low bootstrap values, F monodii...

  4. Organics.

    Science.gov (United States)

    Chian, Edward S. K.; DeWalle, Foppe B.

    1978-01-01

    Presents water analysis literature for 1978. This review is concerned with organics, and it covers: (1) detergents and surfactants; (2) aliphatic and aromatic hydrocarbons; (3) pesticides and chlorinated hydrocarbons; and (4) naturally occurring organics. A list of 208 references is also presented. (HM)

  5. Organizers.

    Science.gov (United States)

    Callison, Daniel

    2000-01-01

    Focuses on "organizers," tools or techniques that provide identification and classification along with possible relationships or connections among ideas, concepts, and issues. Discusses David Ausubel's research and ideas concerning advance organizers; the implications of Ausubel's theory to curriculum and teaching; "webbing," a…

  6. Modeling the current and future role of particulate organic nitrates in the southeastern United States

    Science.gov (United States)

    Organic nitrates are an important aerosol constituent in locations where biogenic hydrocarbon emissions mix with anthropogenic NOx sources. While regional and global chemical transport models may include a representation of organic aerosol from monoterpene reactions with nitrate ...

  7. Aspergillus waksmanii sp. nov. and Aspergillus marvanovae sp. nov., two closely related species in section Fumigati

    DEFF Research Database (Denmark)

    Hubka, Vit; Peterson, Stephen W.; Frisvad, Jens Christian

    2013-01-01

    Two new and phylogenetically closely related species in Aspergillus section Fumigati are described and illustrated. Homothallic Aspergillus waksmanii sp. nov. was isolated from New Jersey soil (USA) and is represented by the ex-type isolate NRRL 179T (=CCF 4266T=Thom 4138.HS2T=IBT 31900T......). Aspergillus marvanovae sp. nov. was isolated from water with high boracic acid anions content in Dukovany nuclear power station (Czech Republic). The sexual stage of this species is unknown, but the MAT1-1 locus was successfully amplified suggesting that the species is probably heterothallic and teleomorphic...... but is represented by only the ex-type isolate CCM 8003T (=CCF 4037T=NRRL 62486T=IBT 31279T=IFM 60873T). Both species can be distinguished from all previously described species in section Fumigati based on morphology, maximum growth temperature, sequence data from five unlinked loci and unique secondary metabolites...

  8. Biosolubilization of poorly soluble rock phosphates by Aspergillus tubingensis and Aspergillus niger

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, M.S.; Kumar, S.; Babita, K. [Thapar Institute of Engineering and Technology, Patiala (India). School of Biotechnology; Reddy, M.S. [Auburn University, AL (United States). Department of Entomology and Plant Pathology

    2002-09-01

    Three isolates of Aspergillus tubingensis and two isolates of Aspergillus niger isolated from rhizospheric soils were tested on solubilization of different rock phosphates. All the isolates of Aspergillus were capable of solubilizing all the natural rock phosphates. A. tubingensis (AT1) showed maximum percent solubilization in all the rock phosphates tested in this study when compared to other isolates. This isolate also showed highest phosphorus (P) solubilization when grown in the presence of 2% of rock phosphate. A. tubingensis (AT1) seems to be more efficient in solubilization of rock phosphates compared to other isolates reported elsewhere. This is the first report of rock phosphate solubilization by A. tubingensis and might provide an efficient large scale biosolubilization of rock phosphates intended for P fertilizer. (author)

  9. A Rare Cause of Headache: Aspergillus Sinusitis

    Directory of Open Access Journals (Sweden)

    Şehnaz Arıcı

    2015-09-01

    Full Text Available Fungal sinusitis are mostly seen in immunosuppressive individuals and somtimes which can be mortal. Most frequently species of Aspergillus were isolated from, clinical forms of mycotic sinonasal disease.Surgical debridement,sinus ventilation and medical therapy in treatment of fungal sinusitis, are recommended. In this article, a case of healthy immune patient with fungal sinusitis who peresent with headache was repoted.

  10. Enzyme hydrolysis of waste cellulose. [Aspergillus awamori

    Energy Technology Data Exchange (ETDEWEB)

    Mustranta, A; Nybergh, P; Hatakka, A

    1976-01-01

    Hydrolysis of brewers' spent grain and of wastes from the furfural process was investigated with culture filtrates from Trichoderma viride and Aspergillus awamori. The furfural process is evidently a good pretreatment for cellulose, and no further pretreatment is needed. Syrups containing 5% reducing sugars and 3-4% glucose were obtained from furfural process wastes and hydrolyzates containing 1.5% reducing sugars and 0.7% glucose were obtained from brewers' spent grains.

  11. DESIGNING A DATA GOVERNANCE MODEL BASED ON SOFT SYSTEM METHODOLOGY (SSM) IN ORGANIZATION

    OpenAIRE

    Hanung Nindito Prasetyo; Kridanto surendro

    2015-01-01

    Today, many emerging various models of data governance like DAMA, DGI and the latest is a model from IBM. Model DAMA International is a data governance model designed by industry associations. The model requires the fulfillment of the entire artifact in a matrix that has been determined that too many components that must be built in data governance in an organization. While the data governance model is built from the data DGI consulting organization which requires the development of data gove...

  12. Mature and emerging organic markets: Modelling consumer attitude and behaviour with Partial Least Square Approach

    OpenAIRE

    von Meyer-Höfer, Marie; von der Wense, Vera; Padilla Bravo, Carlos; Spiller, Achim

    2013-01-01

    Although the organic food sector has been the subject of research for around 20 years, little is known about consumer behaviour when comparing developed and emerging organic food markets using causal research models. Thus, by developing a behavioural model based on the Theory of Planned Behaviour (TPB), the aim of this research article is to investigate the main determinants of organic food consumption in a mature (Germany) and an emerging (Chile) organic market. Subjects aged 18 or above wer...

  13. Triazole resistance surveillance in Aspergillus fumigatus.

    Science.gov (United States)

    Resendiz Sharpe, Agustin; Lagrou, Katrien; Meis, Jacques F; Chowdhary, Anuradha; Lockhart, Shawn R; Verweij, Paul E

    2018-04-01

    Triazole resistance is an increasing concern in the opportunistic mold Aspergillus fumigatus. Resistance can develop through exposure to azole compounds during azole therapy or in the environment. Resistance mutations are commonly found in the Cyp51A-gene, although other known and unknown resistance mechanisms may be present. Surveillance studies show triazole resistance in six continents, although the presence of resistance remains unknown in many countries. In most countries, resistance mutations associated with the environment dominate, but it remains unclear if these resistance traits predominately migrate or arise locally. Patients with triazole-resistant aspergillus disease may fail to antifungal therapy, but only a limited number of cohort studies have been performed that show conflicting results. Treatment failure might be due to diagnostic delay or due to the limited number of alternative treatment options. The ISHAM/ECMM Aspergillus Resistance Surveillance working group was set up to facilitate surveillance studies and stimulate international collaborations. Important aims are to determine the resistance epidemiology in countries where this information is currently lacking, to gain more insight in the clinical implications of triazole resistance through a registry and to unify nomenclature through consensus definitions.

  14. Aspergillus serology: Have we arrived yet?

    Science.gov (United States)

    Richardson, Malcolm D; Page, Iain D

    2017-01-01

    Aspergillosis presents in various clinical forms, among them chronic pulmonary aspergillosis, which is a spectrum of disease entities including aspergilloma, chronic cavitary pulmonary aspergillosis, and chronic fibrosing pulmonary aspergillosis. Aspergillus also contributes to fungal allergy and sensitization. Analysis of the immune response to Aspergillus and its antigens is an integral part of the diagnosis of these diseases. Over the past half century, the techniques used to determine antibody titers have evolved from testing for precipitating and agglutinating antibodies by agar gel double diffusion and immunolectrophoresis to enzyme-linked immunosorbent assays using recombinant proteins as capture antigens. A resurgence of interest in the detection of immunoglobulins, primarily Aspergillus-specific IgG, has hinted at the possibility of distinguishing between colonization and invasion in immunocompromised patients with invasive aspergillosis. Even though there appears to be a greater degree of discrimination between the clinical forms of aspergillosis there is still a long way to travel. This review presents illustrative examples of where new diagnostic platforms and technologies have been applied to this intriguing spectrum of diseases. © The Authors 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. COMPARATIVE ANALYSIS OF THE ORGANIZATIONAL MODELS IN ORGANIC FARMING

    Directory of Open Access Journals (Sweden)

    Alexandra MUSCĂNESCU

    2013-10-01

    Full Text Available As regards to organic farming, organic farms have a lot of shortcomings in ensuring smooth organization of production due to climatic factors or crop sensitivity and action of pests and diseases, but especially to the high cost of inputs, reduced subsidies and difficulties in obtaining fair prices on the market. Understanding how the organizational structure of the business can compete to ensure efficiency at farm level is an important means to resolve these deficiencies. In this context, this paper aims to identify the characteristics of the organization of organic crop farms starting from an interview-based analysis of two large crop specialised farms in Tulcea and Calaraşi Counties. The information obtained through this method of investigation has been translated into a SWOT analysis and represented the basis for comparison with information gathered from other interviews from two organic farms in Scotland. The main conclusions we reached highlight two types of organization systems, one without integration and another with supply chain integration, very similar to the Scottish ones, but also showing a very obvious difference in the mentality of the farm owners; Romanians focusing on meeting the conditions for certification and maintenance of crops in organic, and the Scots at finding new markets.

  16. Modelling the subgenual organ of the honeybee, Apis mellifera

    DEFF Research Database (Denmark)

    Storm, Jesper; Kilpinen, Ole

    1998-01-01

    In a recent study on the honeybee (Apis mellifera), the subgenual organ was observed moving inside the leg during sinusoidal vibrations of the leg (Kilpinen and Storm 1997). The subgenual organ of the honeybee is suspended in a haemolymph channel in the tibia of each leg. When the leg accelerates...

  17. Antibiotic Extraction as a Recent Biocontrol Method for Aspergillus Niger andAspergillus Flavus Fungi in Ancient Egyptian mural paintings

    Science.gov (United States)

    Hemdan, R. Elmitwalli; Fatma, Helmi M.; Rizk, Mohammed A.; Hagrassy, Abeer F.

    Biodeterioration of mural paintings by Aspergillus niger and Aspergillus flavus Fungi has been proved in different mural paintings in Egypt nowadays. Several researches have studied the effect of fungi on mural paintings, the mechanism of interaction and methods of control. But none of these researches gives us the solution without causing a side effect. In this paper, for the first time, a recent treatment by antibiotic "6 penthyl α pyrone phenol" was applied as a successful technique for elimination of Aspergillus niger and Aspergillus flavus. On the other hand, it is favorable for cleaning Surfaces of Murals executed by tembera technique from the fungi metabolism which caused a black pigments on surfaces.

  18. Heterologous expression, purification and characterization of nitrilase from Aspergillus niger K10

    Directory of Open Access Journals (Sweden)

    Felsberg Jürgen

    2011-01-01

    Full Text Available Abstract Background Nitrilases attract increasing attention due to their utility in the mild hydrolysis of nitriles. According to activity and gene screening, filamentous fungi are a rich source of nitrilases distinct in evolution from their widely examined bacterial counterparts. However, fungal nitrilases have been less explored than the bacterial ones. Nitrilases are typically heterogeneous in their quaternary structures, forming short spirals and extended filaments, these features making their structural studies difficult. Results A nitrilase gene was amplified by PCR from the cDNA library of Aspergillus niger K10. The PCR product was ligated into expression vectors pET-30(+ and pRSET B to construct plasmids pOK101 and pOK102, respectively. The recombinant nitrilase (Nit-ANigRec expressed in Escherichia coli BL21-Gold(DE3(pOK101/pTf16 was purified with an about 2-fold increase in specific activity and 35% yield. The apparent subunit size was 42.7 kDa, which is approx. 4 kDa higher than that of the enzyme isolated from the native organism (Nit-ANigWT, indicating post-translational cleavage in the enzyme's native environment. Mass spectrometry analysis showed that a C-terminal peptide (Val327 - Asn356 was present in Nit-ANigRec but missing in Nit-ANigWT and Asp298-Val313 peptide was shortened to Asp298-Arg310 in Nit-ANigWT. The latter enzyme was thus truncated by 46 amino acids. Enzymes Nit-ANigRec and Nit-ANigWT differed in substrate specificity, acid/amide ratio, reaction optima and stability. Refolded recombinant enzyme stored for one month at 4°C was fractionated by gel filtration, and fractions were examined by electron microscopy. The late fractions were further analyzed by analytical centrifugation and dynamic light scattering, and shown to consist of a rather homogeneous protein species composed of 12-16 subunits. This hypothesis was consistent with electron microscopy and our modelling of the multimeric nitrilase, which supports an

  19. Intra and extracellular nuclease production by Aspergillus niger and Aspergillus nidulans

    Directory of Open Access Journals (Sweden)

    Ferreira Adlane V. B.

    1998-01-01

    Full Text Available Intra and extracellular nuclease production by strains of Aspergillus niger and Aspergillus nidulans was estimated using a modified DNAse test agar and cell-free extract assays. Differences in the production of nucleases by A. niger and A. nidulans were observed. These observations suggest that the DNAse test agar can be helpful for a quick screening for some types of nucleases in filamentous fungi. The assays using cell-free extracts can also be useful for initial characterization of other types of nucleases.

  20. Identification of thermostable β-xylosidase activities produced by Aspergillus brasiliensis and Aspergillus niger

    DEFF Research Database (Denmark)

    Pedersen, Mads; Lauritzen, Henrik Klitgaard; Frisvad, Jens Christian

    2007-01-01

    Twenty Aspergillus strains were evaluated for production of extracellular cellulolytic and xylanolytic activities. Aspergillus brasiliensis, A. niger and A. japonicus produced the highest xylanase activities with the A. brasiliensis and A. niger strains producing thermostable beta......-xylosidases. The beta-xylosidase activities of the A. brasiliensis and A. niger strains had similar temperature and pH optima at 75 degrees C and pH 5 and retained 62% and 99%, respectively, of these activities over 1 h at 60 degrees C. At 75 degrees C, these values were 38 and 44%, respectively. Whereas A. niger...

  1. High-yields heterologous production of the novel Aspergillus fumigatus elastase inhibitor AFUEI in Aspergillus oryzae.

    Science.gov (United States)

    Yamashita, Nobuo; Komori, Yumiko; Okumura, Yoshiyuki; Uchiya, Kei-Ichi; Matsui, Takeshi; Nishimura, Akira; Ogawa, Kenji; Nikai, Toshiaki

    2011-08-01

    AFUEI, an elastase inhibitor produced by Aspergillus fumigatus strongly inhibits the elastolytic activity of A. fumigatus etc. To purify AFUEI, we constructed a strain that overproduces AFUEI by introducing the gene encoding AFUEI (Genbank accession no. AB546725) under control of the amyB promoter into the heterologous host Aspergillus oryzae. A. oryzae TF-4 displayed strong elastase inhibitory activity and produced considerably more AFUEI than that of A. fumigatus. Furthermore, AFUEI could be purified using culture broth and single ultrafiltration (UF) treatment, allowing for the effective production of AFUEI for use in clinical trials. Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  2. Current developments in soil organic matter modeling and the expansion of model applications: a review

    International Nuclear Information System (INIS)

    Campbell, Eleanor E; Paustian, Keith

    2015-01-01

    Soil organic matter (SOM) is an important natural resource. It is fundamental to soil and ecosystem functions across a wide range of scales, from site-specific soil fertility and water holding capacity to global biogeochemical cycling. It is also a highly complex material that is sensitive to direct and indirect human impacts. In SOM research, simulation models play an important role by providing a mathematical framework to integrate, examine, and test the understanding of SOM dynamics. Simulation models of SOM are also increasingly used in more ‘applied’ settings to evaluate human impacts on ecosystem function, and to manage SOM for greenhouse gas mitigation, improved soil health, and sustainable use as a natural resource. Within this context, there is a need to maintain a robust connection between scientific developments in SOM modeling approaches and SOM model applications. This need forms the basis of this review. In this review we first provide an overview of SOM modeling, focusing on SOM theory, data-model integration, and model development as evidenced by a quantitative review of SOM literature. Second, we present the landscape of SOM model applications, focusing on examples in climate change policy. We conclude by discussing five areas of recent developments in SOM modeling including: (1) microbial roles in SOM stabilization; (2) modeling SOM saturation kinetics; (3) temperature controls on decomposition; (4) SOM dynamics in deep soil layers; and (5) SOM representation in earth system models. Our aim is to comprehensively connect SOM model development to its applications, revealing knowledge gaps in need of focused interdisciplinary attention and exposing pitfalls that, if avoided, can lead to best use of SOM models to support policy initiatives and sustainable land management solutions. (topical review)

  3. The phosphoproteome of Aspergillus nidulans reveals functional association with cellular processes involved in morphology and secretion.

    Science.gov (United States)

    Ramsubramaniam, Nikhil; Harris, Steven D; Marten, Mark R

    2014-11-01

    We describe the first phosphoproteome of the model filamentous fungus Aspergillus nidulans. Phosphopeptides were enriched using titanium dioxide, separated using a convenient ultra-long reverse phase gradient, and identified using a "high-high" strategy (high mass accuracy on the parent and fragment ions) with higher-energy collisional dissociation. Using this approach 1801 phosphosites, from 1637 unique phosphopeptides, were identified. Functional classification revealed phosphoproteins were overrepresented under GO categories related to fungal morphogenesis: "sites of polar growth," "vesicle mediated transport," and "cytoskeleton organization." In these same GO categories, kinase-substrate analysis of phosphoproteins revealed the majority were target substrates of CDK and CK2 kinase families, indicating these kinase families play a prominent role in fungal morphogenesis. Kinase-substrate analysis also identified 57 substrates for kinases known to regulate secretion of hydrolytic enzymes (e.g. PkaA, SchA, and An-Snf1). Altogether this data will serve as a benchmark that can be used to elucidate regulatory networks functionally associated with fungal morphogenesis and secretion. All MS data have been deposited in the ProteomeXchange with identifier PXD000715 (http://proteomecentral.proteomexchange.org/dataset/PXD000715). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. A review of modelling the interaction between natural organic matter and metal cations

    International Nuclear Information System (INIS)

    Falck, W.E.

    1989-01-01

    This report reviews techniques available to model the interaction between natural organic matter (mainly fulvic and humic acids) and metal cations and protons. A comprehensive overview over the properties of natural organic matter is given and experimental techniques are presented briefly. Two major concepts of modelling have been identified: discrete ligand models and continuous distribution model. Different modelling approaches like Discrete Ligand Models (s.s.), Random-Structure Model, Affinity Spectra, Statistical Distribution Models, Continuous Stability Function Models and surface sorption models and their advantages/disadvantages are discussed. (author)

  5. Participatory plant breeding and organic agriculture: A synergistic model for organic variety development in the United States

    Directory of Open Access Journals (Sweden)

    Adrienne C. Shelton

    2016-12-01

    Full Text Available Abstract Organic farmers require improved varieties that have been adapted to their unique soils, nutrient inputs, management practices, and pest pressures. One way to develop adapted varieties is to situate breeding programs in the environment of intended use, such as directly on organic farms, and in collaboration with organic farmers. This model is a form of participatory plant breeding, and was originally created in order to meet the needs of under-served, small-scale farmers in developing countries. A robust body of literature supports the quantitative genetic selection theory of participatory plant breeding, and helps to explain its increasing prevalence among organic breeding projects in the United States. The history of the organic farming movement in the United States highlights the cultural relevance of engaging organic farmers in the breeding process, complementing the biological rationale for participatory plant breeding. In addition, limited private investment in organic plant breeding encourages the involvement of plant breeders at public institutions. This paper synthesizes the biological, cultural, and economic justifications for utilizing participatory plant breeding as an appropriate methodology for organic cultivar development.

  6. Stage-structured matrix models for organisms with non-geometric development times

    Science.gov (United States)

    Andrew Birt; Richard M. Feldman; David M. Cairns; Robert N. Coulson; Maria Tchakerian; Weimin Xi; James M. Guldin

    2009-01-01

    Matrix models have been used to model population growth of organisms for many decades. They are popular because of both their conceptual simplicity and their computational efficiency. For some types of organisms they are relatively accurate in predicting population growth; however, for others the matrix approach does not adequately model...

  7. 76 FR 34712 - Medicare Program; Pioneer Accountable Care Organization Model; Extension of the Submission...

    Science.gov (United States)

    2011-06-14

    ... stakeholders to develop initiatives to test innovative payment and service delivery models to reduce program...] Medicare Program; Pioneer Accountable Care Organization Model; Extension of the Submission Deadlines for... of the Pioneer Accountable Care Organization Model letters of intent to June 30, 2011 and the...

  8. Organizations

    DEFF Research Database (Denmark)

    Hatch, Mary Jo

    and considers many more. Mary Jo Hatch introduces the concept of organizations by presenting definitions and ideas drawn from the a variety of subject areas including the physical sciences, economics, sociology, psychology, anthropology, literature, and the visual and performing arts. Drawing on examples from......Most of us recognize that organizations are everywhere. You meet them on every street corner in the form of families and shops, study in them, work for them, buy from them, pay taxes to them. But have you given much thought to where they came from, what they are today, and what they might become...... prehistory and everyday life, from the animal kingdom as well as from business, government, and other formal organizations, Hatch provides a lively and thought provoking introduction to the process of organization....

  9. Characterization of Specific Immune Responses to Different Aspergillus Antigens during the Course of Invasive Aspergillosis in Hematologic Patients

    Science.gov (United States)

    Beauvais, Anne; Beau, Remi; Candoni, Anna; Maertens, Johan; Rossi, Giulio; Morselli, Monica; Zanetti, Eleonora; Quadrelli, Chiara; Codeluppi, Mauro; Guaraldi, Giovanni; Pagano, Livio; Caira, Morena; Giovane, Cinzia Del; Maccaferri, Monica; Stefani, Alessandro; Morandi, Uliano; Tazzioli, Giovanni; Girardis, Massimo; Delia, Mario; Specchia, Giorgina; Longo, Giuseppe; Marasca, Roberto; Narni, Franco; Merli, Francesco; Imovilli, Annalisa; Apolone, Giovanni; Carvalho, Agostinho; Comoli, Patrizia; Romani, Luigina; Latgè, Jean Paul; Luppi, Mario

    2013-01-01

    Several studies in mouse model of invasive aspergillosis (IA) and in healthy donors have shown that different Aspergillus antigens may stimulate different adaptive immune responses. However, the occurrence of Aspergillus-specific T cells have not yet been reported in patients with the disease. In patients with IA, we have investigated during the infection: a) whether and how specific T-cell responses to different Aspergillus antigens occur and develop; b) which antigens elicit the highest frequencies of protective immune responses and, c) whether such protective T cells could be expanded ex-vivo. Forty hematologic patients have been studied, including 22 patients with IA and 18 controls. Specific T cells producing IL-10, IFN-γ, IL-4 and IL-17A have been characterized through enzyme linked immunospot and cytokine secretion assays on 88 peripheral blood (PB) samples, by using the following recombinant antigens: GEL1p, CRF1p, PEP1p, SOD1p, α1–3glucan, β1–3glucan, galactomannan. Specific T cells were expanded through short term culture. Aspergillus-specific T cells producing non-protective interleukin-10 (IL-10) and protective interferon-gamma (IFN-γ) have been detected to all the antigens only in IA patients. Lower numbers of specific T cells producing IL-4 and IL-17A have also been shown. Protective T cells targeted predominantly Aspergillus cell wall antigens, tended to increase during the IA course and to be associated with a better clinical outcome. Aspergillus-specific T cells could be successfully generated from the PB of 8 out of 8 patients with IA and included cytotoxic subsets able to lyse Aspergillus hyphae. Aspergillus specific T-cell responses contribute to the clearance of the pathogen in immunosuppressed patients with IA and Aspergillus cell wall antigens are those mainly targeted by protective immune responses. Cytotoxic specific T cells can be expanded from immunosuppressed patients even during the infection by using the above mentioned

  10. PROCESS DOCUMENTATION: A MODEL FOR KNOWLEDGE MANAGEMENT IN ORGANIZATIONS.

    Science.gov (United States)

    Haddadpoor, Asefeh; Taheri, Behjat; Nasri, Mehran; Heydari, Kamal; Bahrami, Gholamreza

    2015-10-01

    Continuous and interconnected processes are a chain of activities that turn the inputs of an organization to its outputs and help achieve partial and overall goals of the organization. These activates are carried out by two types of knowledge in the organization called explicit and implicit knowledge. Among these, implicit knowledge is the knowledge that controls a major part of the activities of an organization, controls these activities internally and will not be transferred to the process owners unless they are present during the organization's work. Therefore the goal of this study is identification of implicit knowledge and its integration with explicit knowledge in order to improve human resources management, physical resource management, information resource management, training of new employees and other activities of Isfahan University of Medical Science. The project for documentation of activities in department of health of Isfahan University of Medical Science was carried out in several stages. First the main processes and related sub processes were identified and categorized with the help of planning expert. The categorization was carried out from smaller processes to larger ones. In this stage the experts of each process wrote down all their daily activities and organized them into general categories based on logical and physical relations between different activities. Then each activity was assigned a specific code. The computer software was designed after understanding the different parts of the processes, including main and sup processes, and categorization, which will be explained in the following sections. The findings of this study showed that documentation of activities can help expose implicit knowledge because all of inputs and outputs of a process along with the length, location, tools and different stages of the process, exchanged information, storage location of the information and information flow can be identified using proper

  11. Organic chemistry in the atmosphere. [laboratory modeling of Titan atmosphere

    Science.gov (United States)

    Sagan, C.

    1974-01-01

    The existence of an at least moderately complex organic chemistry on Titan is stipulated based on clear evidence of methane, and at least presumptive evidence of hydrogen in its atmosphere. The ratio of methane to hydrogen is the highest of any atmosphere in the solar system. Irradiation of hydrogen/methane mixtures produces aromatic and aliphatic hydrocarbons. A very reasonable hypothesis assumes that the red cloud cover of Titan is made of organic chemicals. Two-carbon hydrocarbons experimentally produced from irradiated mixtures of methane, ammonia, water, and hydrogen bear out the possible organic chemistry of the Titanian environment.

  12. Tracking the long-distance dispersal of marine organisms: sensitivity to ocean model resolution

    OpenAIRE

    Putman, Nathan F.; He, Ruoying

    2013-01-01

    Ocean circulation models are widely used to simulate organism transport in the open sea, where challenges of directly tracking organisms across vast spatial and temporal scales are daunting. Many recent studies tout the use of ‘high-resolution’ models, which are forced with atmospheric data on the scale of several hours and integrated with a time step of several minutes or seconds. However, in many cases, the model's outputs that are used to simulate organism movement have been averaged to co...

  13. A phase model of intergenerational learning in organizations

    NARCIS (Netherlands)

    Gerpott, F.H.; Lehmann-Willenbrock, N.; Voelpel, S.C.

    Demographic changes challenge organizations to qualify employees across all career stages and to ensure the transfer of company-specific knowledge between experienced and young workers. Human resource development programs for employees from different generations may help address these challenges.

  14. Public attitudes to financial incentive models for organs

    DEFF Research Database (Denmark)

    Hoeyer, Klaus; Schicktanz, Silke; Deleuran, Ida

    2013-01-01

    Waiting lists for organs have stimulated interest in the use of financial incentives for organ donation (FIs), but the literature does not contain an adequate overview of studies of public attitudes toward this mode of procurement. We conducted a literature review of international peer......-reviewed research published between 2002 and 2012 on how members of the public position themselves toward FIs. We identified and analyzed 23 studies using MEDLINE, PsycINFO, Sociological Abstracts and cross-reference search. The search included whole organs, donation, quantitative and empirical qualitative social...... scientific studies on, public attitudes (excluding professionals and medical students). The review reveals a broad divergence of public opinions on financial incentives. However, quantitative studies showed a low overall level of acceptance of payment for organs in living donation (LD); only a slightly...

  15. Modelling and mapping the topsoil organic carbon content for Tanzania

    Science.gov (United States)

    Kempen, Bas; Kaaya, Abel; Ngonyani Mhaiki, Consolatha; Kiluvia, Shani; Ruiperez-Gonzalez, Maria; Batjes, Niels; Dalsgaard, Soren

    2014-05-01

    Soil organic carbon (SOC), held in soil organic matter, is a key indicator of soil health and plays an important role in the global carbon cycle. The soil can act as a net source or sink of carbon depending on land use and management. Deforestation and forest degradation lead to the release of vast amounts of carbon from the soil in the form of greenhouse gasses, especially in tropical countries. Tanzania has a high deforestation rate: it is estimated that the country loses 1.1% of its total forested area annually. During 2010-2013 Tanzania has been a pilot country under the UN-REDD programme. This programme has supported Tanzania in its initial efforts towards reducing greenhouse gas emission from forest degradation and deforestation and towards preserving soil carbon stocks. Formulation and implementation of the national REDD strategy requires detailed information on the five carbon pools among these the SOC pool. The spatial distribution of SOC contents and stocks was not available for Tanzania. The initial aim of this research, was therefore to develop high-resolution maps of the SOC content for the country. The mapping exercise was carried out in a collaborative effort with four Tanzanian institutes and data from the Africa Soil Information Service initiative (AfSIS). The mapping exercise was provided with over 3200 field observations on SOC from four sources; this is the most comprehensive soil dataset collected in Tanzania so far. The main source of soil samples was the National Forest Monitoring and Assessment (NAFORMA). The carbon maps were generated by means of digital soil mapping using regression-kriging. Maps at 250 m spatial resolution were developed for four depth layers: 0-10 cm, 10-20 cm, 20-30 cm, and 0-30 cm. A total of 37 environmental GIS data layers were prepared for use as covariates in the regression model. These included vegetation indices, terrain parameters, surface temperature, spectral reflectances, a land cover map and a small

  16. A sustainable business model for public service organizations?

    OpenAIRE

    S.P. Osborne; Z. Radnor; I. Vidal; T. Kinder

    2014-01-01

    The current global economic recession presents significant challenges to public service organizations (PSOs) that deliver public services to local communities – irrespective of whether these organizations are situated in the public, private, or third sectors. Governments around the world have responded to this recession by a range of strategies intended to reduce public spending and generate growth. This is not the place to debate such strategies – this task has been undertaken...

  17. Modelling the fate of persistent organic pollutants in Europe: parameterisation of a gridded distribution model

    International Nuclear Information System (INIS)

    Prevedouros, Konstantinos; MacLeod, Matthew; Jones, Kevin C.; Sweetman, Andrew J.

    2004-01-01

    A regionally segmented multimedia fate model for the European continent is described together with an illustrative steady-state case study examining the fate of γ-HCH (lindane) based on 1998 emission data. The study builds on the regionally segmented BETR North America model structure and describes the regional segmentation and parameterisation for Europe. The European continent is described by a 5 deg. x 5 deg. grid, leading to 50 regions together with four perimetric boxes representing regions buffering the European environment. Each zone comprises seven compartments including; upper and lower atmosphere, soil, vegetation, fresh water and sediment and coastal water. Inter-regions flows of air and water are described, exploiting information originating from GIS databases and other georeferenced data. The model is primarily designed to describe the fate of Persistent Organic Pollutants (POPs) within the European environment by examining chemical partitioning and degradation in each region, and inter-region transport either under steady-state conditions or fully dynamically. A test case scenario is presented which examines the fate of estimated spatially resolved atmospheric emissions of lindane throughout Europe within the lower atmosphere and surface soil compartments. In accordance with the predominant wind direction in Europe, the model predicts high concentrations close to the major sources as well as towards Central and Northeast regions. Elevated soil concentrations in Scandinavian soils provide further evidence of the potential of increased scavenging by forests and subsequent accumulation by organic-rich terrestrial surfaces. Initial model predictions have revealed a factor of 5-10 underestimation of lindane concentrations in the atmosphere. This is explained by an underestimation of source strength and/or an underestimation of European background levels. The model presented can further be used to predict deposition fluxes and chemical inventories, and it

  18. Modeling the Structure and Effectiveness of Intelligence Organizations: Dynamic Information Flow Simulation

    National Research Council Canada - National Science Library

    Behrman, Robert; Carley, Kathleen

    2003-01-01

    This paper describes the Dynamic Information Flow Simulation (DIFS), an abstract model for analyzing the structure and function of intelligence support organizations and the activities of entities within...

  19. Reconstruction of the central carbon metabolism of Aspergillus niger

    DEFF Research Database (Denmark)

    David, Helga; Åkesson, Mats Fredrik; Nielsen, Jens

    2003-01-01

    The topology of central carbon metabolism of Aspergillus niger was identified and the metabolic network reconstructed, by integrating genomic, biochemical and physiological information available for this microorganism and other related fungi. The reconstructed network may serve as a valuable...... of metabolic fluxes using metabolite balancing. This framework was employed to perform an in silico characterisation of the phenotypic behaviour of A. niger grown on different carbon sources. The effects on growth of single reaction deletions were assessed and essential biochemical reactions were identified...... for different carbon sources. Furthermore, application of the stoichiometric model for assessing the metabolic capabilities of A. niger to produce metabolites was evaluated by using succinate production as a case study....

  20. Glycan analysis of recombinant Aspergillus niger endo-polygalacturonase A.

    Science.gov (United States)

    Woosley, Bryan D; Kim, Young Hwan; Kumar Kolli, V S; Wells, Lance; King, Dan; Poe, Ryan; Orlando, Ron; Bergmann, Carl

    2006-10-16

    The enzyme endo-polygalacturonase A, or PGA, is produced by the fungus, Aspergillus niger, and appears to play a critical role during invasion of plant cell walls. The enzyme has been homologously overexpressed in order to provide sufficient quantities of purified enzyme for structural and biological studies. We have characterized this enzyme in terms of its post-translational modifications (PTMs) and found it to be both N- and O-glycosylated. Additionally, we have characterized the glycosyl moieties using MALDI-TOF and LC-ESI mass spectrometry. The characterization of all PTMs on PGA, along with molecular modeling, allows us to reveal potential roles played by the glycans in modulating the interaction of the enzyme with other macromolecules.

  1. Post-genomic insights into the plant polysaccharide degradation potential of Aspergillus nidulans and comparison to Aspergillus niger and Aspergillus oryzae

    DEFF Research Database (Denmark)

    Coutinho, Pedro M.; Andersen, Mikael Rørdam; Kolenova, Katarina

    2009-01-01

    The plant polysaccharide degradative potential of Aspergillus nidulans was analysed in detail and compared to that of Aspergillus niger and Aspergillus oryzae using a combination of bioinformatics, physiology and transcriptomics. Manual verification indicated that 28.4% of the A. nidulans ORFs...... between the Aspergilli in the presence Of putative regulatory sequences in the promoters of the ORFs Of this Study and correlation of the presence Of putative XlnR binding sites to induction by xylose was detected for A. niger. These data demonstrate differences at genome content, Substrate specificity...

  2. Unique antimicrobial spectrum of ophiobolin K produced by Aspergillus ustus.

    Science.gov (United States)

    Sohsomboon, Natthapat; Kanzaki, Hiroshi; Nitoda, Teruhiko

    2018-03-01

    A co-cultivation study of two fungal strains showed that Aspergillus ustus could inhibit Aspergillus repens growth. The bioactive compound responsible for the observed activity was purified and identified as a sesterterpene, ophiobolin K. Ophiobolin K exhibited marked inhibition against both fungi and bacteria, especially A. repens, A. glaucus and gram-positive bacteria including Bacillus subtilis, Staphylococcus aureus, and Micrococcus luteus.

  3. Fatal coinfection with Legionella pneumophila serogroup 8 and Aspergillus fumigatus.

    Science.gov (United States)

    Guillouzouic, Aurélie; Bemer, Pascale; Gay-Andrieu, Françoise; Bretonnière, Cédric; Lepelletier, Didier; Mahé, Pierre-Joachim; Villers, Daniel; Jarraud, Sophie; Reynaud, Alain; Corvec, Stéphane

    2008-02-01

    Legionella pneumophila is an important cause of community-acquired and nosocomial pneumonia. We report on a patient who simultaneously developed L. pneumophila serogroup 8 pneumonia and Aspergillus fumigatus lung abscesses. Despite appropriate treatments, Aspergillus disease progressed with metastasis. Coinfections caused by L. pneumophila and A. fumigatus remain exceptional. In apparently immunocompetent patients, corticosteroid therapy is a key risk factor for aspergillosis.

  4. Allergens/Antigens, toxins and polyketides of important Aspergillus species.

    Science.gov (United States)

    Bhetariya, Preetida J; Madan, Taruna; Basir, Seemi Farhat; Varma, Anupam; Usha, Sarma P

    2011-04-01

    The medical, agricultural and biotechnological importance of the primitive eukaryotic microorganisms, the Fungi was recognized way back in 1920. Among various groups of fungi, the Aspergillus species are studied in great detail using advances in genomics and proteomics to unravel biological and molecular mechanisms in these fungi. Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger, Aspergillus parasiticus, Aspergillus nidulans and Aspergillus terreus are some of the important species relevant to human, agricultural and biotechnological applications. The potential of Aspergillus species to produce highly diversified complex biomolecules such as multifunctional proteins (allergens, antigens, enzymes) and polyketides is fascinating and demands greater insight into the understanding of these fungal species for application to human health. Recently a regulator gene for secondary metabolites, LaeA has been identified. Gene mining based on LaeA has facilitated new metabolites with antimicrobial activity such as emericellamides and antitumor activity such as terrequinone A from A. nidulans. Immunoproteomic approach was reported for identification of few novel allergens for A. fumigatus. In this context, the review is focused on recent developments in allergens, antigens, structural and functional diversity of the polyketide synthases that produce polyketides of pharmaceutical and biological importance. Possible antifungal drug targets for development of effective antifungal drugs and new strategies for development of molecular diagnostics are considered.

  5. New and revisited species in Aspergillus section Nigri

    DEFF Research Database (Denmark)

    Varga, J.; Frisvad, Jens Christian; Kocsube, S.

    2011-01-01

    based on either beta-tubulin or calmodulin sequence data. Aspergillus eucalypticola produced pyranonigrin A, funalenone, aurasperone B and other naphtho-gamma-pyrones. Aspergillus neoniger is also a biseriate species isolated from desert sand in Namibia, and mangrove water in Venezuela, which produces...

  6. Aspergillus fumigatus conidial melanin modulates host cytokine response

    NARCIS (Netherlands)

    L.Y.A. Chai (Louis); M.G. Netea (Mihai); J. Sugui (Janyce); A.G. Vonk (Alieke); W.W.J. van de Sande (Wendy); A. Warris (Adilia); K.J. Kwon-Chung (Kyung); B. Jan Kullberg (Bart)

    2010-01-01

    textabstractMelanin biopigments have been linked to fungal virulence. Aspergillus fumigatus conidia are melanised and are weakly immunogenic. We show that melanin pigments on the surface of resting Aspergillus fumigatus conidia may serve to mask pathogen-associated molecular patterns (PAMPs)-induced

  7. Aspergillus fumigatus conidial melanin modulates host cytokine response.

    NARCIS (Netherlands)

    Chai, L.; Netea, M.G.; Sugui, J.; Vonk, A.G.; Sande, W.W. van de; Warris, A.; Kwon-Chung, K.J.; Kullberg, B.J.

    2010-01-01

    Melanin biopigments have been linked to fungal virulence. Aspergillus fumigatus conidia are melanised and are weakly immunogenic. We show that melanin pigments on the surface of resting Aspergillus fumigatus conidia may serve to mask pathogen-associated molecular patterns (PAMPs)-induced cytokine

  8. Aspergillus Monitoring Project in a Large Educational Hospital ...

    African Journals Online (AJOL)

    Also molecular method, PCR-RFLP using single restriction enzyme as a rapid and available method was performed to investigate environmental sources of Aspergillus infections. Results: Total of 110 clinical fungal isolates included Candida and Aspergillus species and some other opportunistic fungi. Among the clinical

  9. Production of aspartic peptidases by Aspergillus spp. using tuna ...

    African Journals Online (AJOL)

    The production of extracellular aspartic peptidase by the fungi Aspergillus niger and Aspergillus awamori was carried out in a shake flask and in stirred tank submerged fermentations using tuna cooked wastewater, an industrial effluent, as nitrogen source for culture medium. In stirred tank fermentation, biomass production ...

  10. Specific detection of Aspergillus fumigatus in sputum sample of ...

    African Journals Online (AJOL)

    We developed a two-step PCR assay that specifically amplifies a region of the 18S rRNA gene that is highly conserved in Aspergillus fumigatus. This assay allows direct and rapid detection of down to 10 fg of Aspergillus fumigatus DNA corresponding to 1 to 5 colony forming unit (CFU) per ml of sputum sample of pulmonary ...

  11. The Inhibition of aflatoxin production from Aspergillus parasiticus ...

    African Journals Online (AJOL)

    The inhibition of Aflatoxin production from Aspergillus parasiticus strain NRRL 2999 was investigated using ethanol extracts of Aframommon danielli flower at concentrations of 250ìg/g, 500ìg/g, 750ìg/g and 1000ìg/g with whole wheat bread as a substrate. Aspergillus parasiticus grew abundantly on whole wheat bread; ...

  12. Phylogeny, identification and nomenclature of the genus Aspergillus

    Science.gov (United States)

    Samson, R.A.; Visagie, C.M.; Houbraken, J.; Hong, S.-B.; Hubka, V.; Klaassen, C.H.W.; Perrone, G.; Seifert, K.A.; Susca, A.; Tanney, J.B.; Varga, J.; Kocsubé, S.; Szigeti, G.; Yaguchi, T.; Frisvad, J.C.

    2014-01-01

    Aspergillus comprises a diverse group of species based on morphological, physiological and phylogenetic characters, which significantly impact biotechnology, food production, indoor environments and human health. Aspergillus was traditionally associated with nine teleomorph genera, but phylogenetic data suggest that together with genera such as Polypaecilum, Phialosimplex, Dichotomomyces and Cristaspora, Aspergillus forms a monophyletic clade closely related to Penicillium. Changes in the International Code of Nomenclature for algae, fungi and plants resulted in the move to one name per species, meaning that a decision had to be made whether to keep Aspergillus as one big genus or to split it into several smaller genera. The International Commission of Penicillium and Aspergillus decided to keep Aspergillus instead of using smaller genera. In this paper, we present the arguments for this decision. We introduce new combinations for accepted species presently lacking an Aspergillus name and provide an updated accepted species list for the genus, now containing 339 species. To add to the scientific value of the list, we include information about living ex-type culture collection numbers and GenBank accession numbers for available representative ITS, calmodulin, β-tubulin and RPB2 sequences. In addition, we recommend a standard working technique for Aspergillus and propose calmodulin as a secondary identification marker. PMID:25492982

  13. screening and improvement of local isolates of aspergillus niger

    African Journals Online (AJOL)

    DR. AMINU

    ABSTRACT. The study involved the screening of fourteen isolates of Aspergillus niger for citric acid production from glucose. The study was aimed at screening and improving local strains of Aspergillus niger with potential for citric acid production. All the isolates screened produced varying amounts of citric acid, the highest ...

  14. Exact Molecular Typing of Aspergillus fumigatus. Methods and Applications.

    NARCIS (Netherlands)

    Valk-van Haren, J.A. de

    2008-01-01

    Aspergillus species are widely distributed fungi that release large amounts of airborne conidia that are dispersed in the environment. Aspergillus fumigatus is the species most frequently isolated from human infections. In this thesis a novel assay for fingerprinting A. fumigatus is described and

  15. Induced accumulation of Au, Ag and Cu in Brassica napus grown in a mine tailings with the inoculation of Aspergillus niger and the application of two chemical compounds.

    Science.gov (United States)

    González-Valdez, Eduardo; Alarcón, Alejandro; Ferrera-Cerrato, Ronald; Vega-Carrillo, Héctor René; Maldonado-Vega, María; Salas-Luévano, Miguel Ángel; Argumedo-Delira, Rosalba

    2018-06-15

    This study evaluated the ability of Brassica napus for extracting gold (Au), silver (Ag) and copper (Cu) from a mine tailings, with the inoculation of two Aspergillus niger strains, and the application of ammonium thiocyanate (NH 4 SCN) or ammonium thiosulfate [(NH 4 ) 2 S 2 O 3 ]. After seven weeks of growth inoculated or non-inoculated plants were applied with 1 or 2 g kg -1 of either NH 4 SCN or (NH 4 ) 2 S 2 O 3 , respectively. Eight days after the application of the chemical compounds, plants were harvested for determining the total dry biomass, and the content of Au, Ag, and Cu in plant organs. Application of (NH 4 ) 2 S 2 O 3 or NH 4 SCN resulted in enhanced Au-accumulation in stems (447% and 507%, respectively), while either (NH 4 ) 2 S 2 O 3 +Aspergillus, or NH 4 SCN increased the Au-accumulation in roots (198.5% and 404%, respectively) when compared to the control. Treatments with (NH 4 ) 2 S 2 O 3 or (NH 4 ) 2 S 2 O 3 +Aspergillus significantly increased (P ≤ 0.001) the accumulation of Ag in leaves (677% and 1376%, respectively), while NH 4 SCN + Aspergillus, and (NH 4 ) 2 S 2 O 3 enhanced the accumulation in stems (7153% and 6717.5%). The Ag-accumulation in roots was stimulated by NH 4 SCN+ Aspergillus, and (NH 4 ) 2 S 2 O 3 + Aspergillus (132.5% and 178%, respectively), when compared to the control. The combination of NH 4 SCN+Aspergillus significantly enhanced the Cu-accumulation in leaves (228%); whereas NH 4 SCN+ Aspergillus, or (NH 4 ) 2 S 2 O 3 + Aspergillus resulted in greater accumulation of Cu in stems (1233.5% and 1580%, respectively) than the control. Results suggest that either NH 4 SCN or (NH 4 ) 2 S 2 O 3 (with or without Aspergillus) improved the accumulation of Au and Ag by B. napus. Accumulation of Au and Ag in plant organs overpassed the hyperaccumulation criterion (> 1 mg kg -1 of plant biomass); whereas Cu-accumulation in stems and roots also overpassed such criterion (> 1000 mg kg -1 ) by applying

  16. Aspergillus niger Secretes Citrate to Increase Iron Bioavailability

    Science.gov (United States)

    Odoni, Dorett I.; van Gaal, Merlijn P.; Schonewille, Tom; Tamayo-Ramos, Juan A.; Martins dos Santos, Vitor A. P.; Suarez-Diez, Maria; Schaap, Peter J.

    2017-01-01

    Aspergillus niger has an innate ability to secrete various organic acids, including citrate. The conditions required for A. niger citrate overproduction are well described, but the physiological reasons underlying extracellular citrate accumulation are not yet fully understood. One of the less understood culture conditions is the requirement of growth-limiting iron concentrations. While this has been attributed to iron-dependent citrate metabolizing enzymes, this straightforward relationship does not always hold true. Here, we show that an increase in citrate secretion under iron limited conditions is a physiological response consistent with a role of citrate as A. niger iron siderophore. We found that A. niger citrate secretion increases with decreasing amounts of iron added to the culture medium and, in contrast to previous findings, this response is independent of the nitrogen source. Differential transcriptomics analyses of the two A. niger mutants NW305 (gluconate non-producer) and NW186 (gluconate and oxalate non-producer) revealed up-regulation of the citrate biosynthesis gene citA under iron limited conditions compared to iron replete conditions. In addition, we show that A. niger can utilize Fe(III) citrate as iron source. Finally, we discuss our findings in the general context of the pH-dependency of A. niger organic acid production, offering an explanation, besides competition, for why A. niger organic acid production is a sequential process influenced by the external pH of the culture medium. PMID:28824560

  17. Lead immobilization by geological fluorapatite and fungus Aspergillus niger.

    Science.gov (United States)

    Li, Zhen; Wang, Fuwei; Bai, Tongshuo; Tao, Jinjin; Guo, Jieyun; Yang, Mengying; Wang, Shimei; Hu, Shuijin

    2016-12-15

    Phosphate solubilizing fungi have high ability to secrete organic acids. In this study, fungus Aspergillus niger and geological fluorapatite were applied in lead remediation in aqueous solution. Formation and morphology of the lead minerals, e.g., pyromorphite and lead oxalate, were investigated by SEM, XRD, and ATR-IR. The total quantity of organic acids reached the maximum at the sixth day, which improved the concentration of soluble P up to ∼370mg/L from ∼0.4mg/L. The organic acids, especially the oxalic acid, enhance the solubility of fluorapatite significantly. The stable fluoropyromorphite [Pb 5 (PO 4 ) 3 F] is precipitated with the elevated solubility of fluorapatite in the acidic environment. Furthermore, A. niger grows normally with the presence of lead cations. It is shown that >99% lead cations can be removed from the solution. However, immobilization caused by the precipitation of lead oxalate cannot be ignored if the fungus A. niger was cultured in the Pb solution. This study elucidates the mechanisms of lead immobilization by FAp and A. niger, and sheds its perspective in lead remediation, especially for high Pb concentration solution. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Phylogeny, identification and nomenclature of the genus Aspergillus

    DEFF Research Database (Denmark)

    Samson, R.A.; Visagie, C.M.; Houbraken, J.

    2014-01-01

    , meaning that a decision had to be made whether to keep Aspergillus as one big genus or to split it into several smaller genera. The International Commission of Penicillium and Aspergillus decided to keep Aspergillus instead of using smaller genera. In this paper, we present the arguments for this decision...... data suggest that together with genera such as Polypaecilum, Phialosimplex, Dichotomomyces and Cristaspora, Aspergillus forms a monophyletic clade closely related to Penicillium. Changes in the International Code of Nomenclature for algae, fungi and plants resulted in the move to one name per species....... We introduce new combinations for accepted species presently lacking an Aspergillus name and provide an updated accepted species list for the genus, now containing 339 species. To add to the scientific value of the list, we include information about living ex-type culture collection numbers and Gen...

  19. Arabinase induction and carbon catabolite repression in Aspergillus niger and Aspergillus nidulans

    NARCIS (Netherlands)

    Veen, van der P.

    1995-01-01

    The first aim of this thesis was to get a better understanding of the properties and the induction features of arabinan degrading enzymes and enzymes involved in the intracellular L-arabinose catabolic pathway in Aspergillus niger. The second aim was to understand the

  20. Aspergillus brasiliensis sp. nov., a biseriate black Aspergillus species with world-wide distribution

    DEFF Research Database (Denmark)

    Varga, János; Kocsubé, Sándor; Tóth, Beáta

    2007-01-01

    to produce ochratoxin A, kotanins, funalenone or pyranonigrins. The novel species was most closely related to A. niger, and was isolated from soil from Brazil, Australia, USA and The Netherlands, and from grape berries from Portugal. The type strain of Aspergillus brasiliensis sp. nov. is CBS 101740(T) (=IM...

  1. Aspergillus pragensis sp nov discovered during molecular reidentification of clinical isolates belonging to Aspergillus section Candidi

    DEFF Research Database (Denmark)

    Lyskova, Pavlina; Hubka, Vit; Kolarik, Miroslav

    2014-01-01

    The identity of nine clinical isolates recovered from Czech patients and presumptively identified as Aspergillus sp. section Candidi based on colony morphology was revised using sequences of beta-tubulin, calmodulin gene sequence, and internal transcribed spacer rDNA. Six isolates were from suspe...

  2. Application of several activity coefficient models to water-organic-electrolyte aerosols of atmospheric interest

    Directory of Open Access Journals (Sweden)

    T. Raatikainen

    2005-01-01

    Full Text Available In this work, existing and modified activity coefficient models are examined in order to assess their capabilities to describe the properties of aqueous solution droplets relevant in the atmosphere. Five different water-organic-electrolyte activity coefficient models were first selected from the literature. Only one of these models included organics and electrolytes which are common in atmospheric aerosol particles. In the other models, organic species were solvents such as alcohols, and important atmospheric ions like NH4+ could be missing. The predictions of these models were compared to experimental activity and solubility data in aqueous single electrolyte solutions with 31 different electrolytes. Based on the deviations from experimental data and on the capabilities of the models, four predictive models were selected for fitting of new parameters for binary and ternary solutions of common atmospheric electrolytes and organics. New electrolytes (H+, NH4+, Na+, Cl-, NO3- and SO42- and organics (dicarboxylic and some hydroxy acids were added and some modifications were made to the models if it was found useful. All new and most of the existing parameters were fitted to experimental single electrolyte data as well as data for aqueous organics and aqueous organic-electrolyte solutions. Unfortunately, there are very few data available for organic activities in binary solutions and for organic and electrolyte activities in aqueous organic-electrolyte solutions. This reduces model capabilities in predicting solubilities. After the parameters were fitted, deviations from measurement data were calculated for all fitted models, and for different data types. These deviations and the calculated property values were compared with those from other non-electrolyte and organic-electrolyte models found in the literature. Finally, hygroscopic growth factors were calculated for four 100 nm organic-electrolyte particles and these predictions were compared to

  3. Table of 3D organ model IDs and organ names (PART-OF Tree) - BodyParts3D | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available List Contact us BodyParts3D Table of 3D organ model IDs and organ names (PART-OF Tree) Data detail Data name Table of 3D org...an model IDs and organ names (PART-OF Tree) DOI 10.18908/lsdba.nbdc00837-002 Description of ...data contents List of downloadable 3D organ models in a tab-delimited text file format, describing the correspondence between 3D org...an model IDs and organ names available in PART-OF Tree. D...atabase Site Policy | Contact Us Table of 3D organ model IDs and organ names (PART-OF Tree) - BodyParts3D | LSDB Archive ...

  4. Multi-scale modeling of spin transport in organic semiconductors

    Science.gov (United States)

    Hemmatiyan, Shayan; Souza, Amaury; Kordt, Pascal; McNellis, Erik; Andrienko, Denis; Sinova, Jairo

    In this work, we present our theoretical framework to simulate simultaneously spin and charge transport in amorphous organic semiconductors. By combining several techniques e.g. molecular dynamics, density functional theory and kinetic Monte Carlo, we are be able to study spin transport in the presence of anisotropy, thermal effects, magnetic and electric field effects in a realistic morphologies of amorphous organic systems. We apply our multi-scale approach to investigate the spin transport in amorphous Alq3 (Tris(8-hydroxyquinolinato)aluminum) and address the underlying spin relaxation mechanism in this system as a function of temperature, bias voltage, magnetic field and sample thickness.

  5. Constitutive expression of fluorescent protein by Aspergillus var. niger and Aspergillus carbonarius to monitor fungal colonization in maize plants

    Science.gov (United States)

    Aspergillus niger and A. carbonarius are two species in the Aspergillus section Nigri (black-spored aspergilli) frequently associated with peanut (Arachis hypogea), maize (Zea mays), and other plants as pathogens. These infections are symptomless and as such are major concerns since some black aspe...

  6. Human T-cell responses to Aspergillus fumigatus : In healthy individuals and patients with Aspergillus-related disease

    NARCIS (Netherlands)

    Jolink, H.

    2017-01-01

    The T-cell mediated immune response to Aspergillus fumigatus was studied in healthy individuals and in several patient groups. In peripheral blood of healthy individuals low frequencies of Aspergillus-specific CD4+ T-cells with a Thelper 1 profile were present. In patients with invasive

  7. Expression of Aspergillus hemoglobin domain activities in Aspergillus oryzae grown on solid substrates improves growth rate and enzyme production

    NARCIS (Netherlands)

    Biesebeke, te R.; Boussier, A.; Biezen van, N.; Braaksma, M.; Hondel, van den C.A.M.J.J.; Vos, de W.M.; Punt, P.J.

    2006-01-01

    DNA fragments coding for hemoglobin domains (HBD) were isolated from Aspergillus oryzae and Aspergillus niger. The HBD activities were expressed in A. oryzae by introduction of HBD gene fragments under the control of the promoter of the constitutively expressed gpdA gene. In the transformants,

  8. Similarity-based search of model organism, disease and drug effect phenotypes

    KAUST Repository

    Hoehndorf, Robert; Gruenberger, Michael; Gkoutos, Georgios V; Schofield, Paul N

    2015-01-01

    Background: Semantic similarity measures over phenotype ontologies have been demonstrated to provide a powerful approach for the analysis of model organism phenotypes, the discovery of animal models of human disease, novel pathways, gene functions

  9. Discrimination of Aspergillus lentulus from Aspergillus fumigatus by Raman spectroscopy and MALDI-TOF MS.

    Science.gov (United States)

    Verwer, P E B; van Leeuwen, W B; Girard, V; Monnin, V; van Belkum, A; Staab, J F; Verbrugh, H A; Bakker-Woudenberg, I A J M; van de Sande, W W J

    2014-02-01

    In 2005, a new sibling species of Aspergillus fumigatus was discovered: Aspergillus lentulus. Both species can cause invasive fungal disease in immune-compromised patients. The species are morphologically very similar. Current techniques for identification are PCR-based or morphology-based. These techniques are labour-intense and not sufficiently discriminatory. Since A. lentulus is less susceptible to several antifungal agents, it is important to correctly identify the causative infectious agent in order to optimize antifungal therapy. In this study we determined whether Raman spectroscopy and/or MALDI-TOF MS were able to differentiate between A. lentulus and A. fumigatus. For 16 isolates of A. lentulus and 16 isolates of A. fumigatus, Raman spectra and peptide profiles were obtained using the Spectracell and MALDI-TOF MS (VITEK MS RUO, bioMérieux) respectively. In order to obtain reliable Raman spectra for A. fumigatus and A. lentulus, the culture medium needed to be adjusted to obtain colourless conidia. Only Raman spectra obtained from colourless conidia were reproducible and correctly identified 25 out of 32 (78 %) of the Aspergillus strains. For VITEK MS RUO, no medium adjustments were necessary. Pigmented conidia resulted in reproducible peptide profiles as well in this case. VITEK MS RUO correctly identified 100 % of the Aspergillus isolates, within a timeframe of approximately 54 h including culture. Of the two techniques studied here, VITEK MS RUO was superior to Raman spectroscopy in the discrimination of A. lentulus from A. fumigatus. VITEK MS RUO seems to be a successful technique in the daily identification of Aspergillus spp. within a limited timeframe.

  10. Models of Purposive Human Organization: A Comparative Study

    Science.gov (United States)

    1984-02-01

    develop techniques for organizational diagnosis with the D-M model, to be followed by intervention by S-T methodology. 2. Introduction 2.1. Background In...relational and object data for Dinnat-Murphree model construction. 2. Develop techniques for organizational diagnosis with the Dinnat-Murphree model

  11. The Learning Organization: A Model for Educational Change.

    Science.gov (United States)

    Brown, Rexford

    1997-01-01

    Analyzes public school bureaucracy and ways to reform institutions into learning communities that value shared knowledge and learning experiences. Describes how a bureaucratic organizational structure impairs learning. Proposes the "learning organization" in which adults learn alongside students, planning is decentralized, families are…

  12. Mitochondrial damage and ageing using skin as a model organ.

    Science.gov (United States)

    Hudson, Laura; Bowman, Amy; Rashdan, Eyman; Birch-Machin, Mark A

    2016-11-01

    Ageing describes the progressive functional decline of an organism over time, leading to an increase in susceptibility to age-related diseases and eventually to death, and it is a phenomenon observed across a wide range of organisms. Despite a vast repertoire of ageing studies performed over the past century, the exact causes of ageing remain unknown. For over 50 years it has been speculated that mitochondria play a key role in the ageing process, due mainly to correlative data showing an increase in mitochondrial dysfunction, mitochondrial DNA (mtDNA) damage, and reactive oxygen species (ROS) with age. However, the exact role of the mitochondria in the ageing process remains unknown. The skin is often used to study human ageing, due to its easy accessibility, and the observation that the ageing process is able to be accelerated in this organ via environmental insults, such as ultra violet radiation (UVR). This provides a useful tool to investigate the mechanisms regulating ageing and, in particular, the role of the mitochondria. Observations from dermatological and photoageing studies can provide useful insights into chronological ageing of the skin and other organs such as the brain and liver. Moreover, a wide range of diseases are associated with ageing; therefore, understanding the cause of the ageing process as well as regulatory mechanisms involved could provide potentially advantageous therapeutic targets for the prevention or treatment of such diseases. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  13. Lifetimes of organic photovoltaics: photooxidative degradation of a model compound

    DEFF Research Database (Denmark)

    Norrman, K.; Alstrup, J.; Jørgensen, M.

    2006-01-01

    A poly phenylene vinylene (PPV-type) oligomer used in organic photovoltaics was designed to facilitate the interpretation of mass spectral data. A film of the oligomer was subjected to various degrees of illumination (1000 W m(-2), AM1.5) in air resulting in photooxidation of the material...

  14. Modelling conventional and organic farming : a literature review

    NARCIS (Netherlands)

    Acs, S.; Berentsen, P.B.M.; Huirne, R.B.M.

    2005-01-01

    Literature shows a significant development of organic farming in Europe but with considerable differences between countries. These depend on general agricultural policy (the set of regulations and laws), specific policy incentives, and also on differences in consumer behaviour. This paper reviews

  15. Mechanistic modelling of the vertical soil organic matter profile

    NARCIS (Netherlands)

    Braakhekke, M.C.

    2014-01-01

    Soil organic matter (SOM) constitutes a large global pool of carbon that may play a considerable role for future climate. The vertical distribution of SOM in the profile may be important due to depth-dependence of physical, chemical, and biological conditions, and links to physical processes

  16. Modeling organic aerosol concentrations and properties during winter 2014 in the northwestern Mediterranean region

    OpenAIRE

    Chrit, Mounir; Sartelet, Karine; Sciare, Jean; Majdi, Marwa; Nicolas, José; Petit, Jean-Eudes; Dulac, François

    2018-01-01

    Organic aerosols are measured at a remote site (Ersa) on Corsica Cape in the northwestern Mediterranean basin during the Chemistry-Aerosol Mediterranean Experiment (CharMEx) winter campaign of 2014, when high organic concentrations from anthropogenic origin are observed. This work aims at representing the observed organic aerosol concentrations and properties (oxidation state) using the air-quality model Polyphemus with a surrogate approach for secondary organic aerosol (SOA) formation. Becau...

  17. Modelling the Impact of Organization Structure and Whistle Blowers on Intra-Organizational Corruption Contagion

    OpenAIRE

    Nekovee, Maziar; Pinto, Jonathan

    2017-01-01

    We complement the rich conceptual work on organizational corruption by quantitatively modelling the spread of corruption within organizations. We systematically vary four organizational culture-related parameters, i.e., organization structure, location of bad apple, employees propensity to become corrupted (corruption probability), and number of whistle-blowers. Our simulation studies find that in organizations with flatter structures, corruption permeates the organization at a lower threshol...

  18. Plausible carrier transport model in organic-inorganic hybrid perovskite resistive memory devices

    Science.gov (United States)

    Park, Nayoung; Kwon, Yongwoo; Choi, Jaeho; Jang, Ho Won; Cha, Pil-Ryung

    2018-04-01

    We demonstrate thermally assisted hopping (TAH) as an appropriate carrier transport model for CH3NH3PbI3 resistive memories. Organic semiconductors, including organic-inorganic hybrid perovskites, have been previously speculated to follow the space-charge-limited conduction (SCLC) model. However, the SCLC model cannot reproduce the temperature dependence of experimental current-voltage curves. Instead, the TAH model with temperature-dependent trap densities and a constant trap level are demonstrated to well reproduce the experimental results.

  19. Model to the evolution of the organic matter in the pampa's soil. Relation with cultivation systems

    International Nuclear Information System (INIS)

    Andriulo, Adrian; Mary, Bruno; Guerif, Jerome; Balesdent, Jerome

    1996-08-01

    The objective of the work is to present a model to describe the evolution of the organic matter in soils of the Argentine's pampa. This model can be utilised to evaluate the evolution of the soil's fertility in the agricultural production at this moment. Three kinds of assay were done. The determination of organic carbon made possible to prove the Henin-Dupuis model and a derived model

  20. Comparative genomics reveals high biological diversity and specific adaptations in the industrially and medically important fungal genus Aspergillus

    DEFF Research Database (Denmark)

    de Vries, Ronald P.; Riley, Robert; Wiebenga, Ad

    2017-01-01

    Background:  The fungal genus Aspergillus is of critical importance to humankind. Species include those with industrial applications, important pathogens of humans, animals and crops, a source of potent carcinogenic contaminants of food, and an important genetic model. The genome sequences of eig...

  1. 68Ga-triacetylfusarinine C and 68Ga-ferrioxamine E for Aspergillus infection imaging: uptake specificity in various microorganisms

    NARCIS (Netherlands)

    Petrik, M.; Haas, H. de; Laverman, P.; Schrettl, M.; Franssen, G.M.; Blatzer, M.; Decristoforo, C.

    2014-01-01

    (68)Ga-triacetylfusarinine C ((68)Ga-TAFC) and (68)Ga-ferrioxamine E ((68)Ga-FOXE) showed excellent targeting properties in Aspergillus fumigatus rat infection model. Here, we report on the comparison of specificity towards different microorganisms and human lung cancer cells (H1299).The in vitro

  2. Formation of Sclerotia and Production of Indoloterpenes by Aspergillus niger and Other Species in Section Nigri

    Science.gov (United States)

    Frisvad, Jens C.; Petersen, Lene M.; Lyhne, E. Kirstine; Larsen, Thomas O.

    2014-01-01

    Several species in Aspergillus section Nigri have been reported to produce sclerotia on well-known growth media, such as Czapek yeast autolysate (CYA) agar, with sclerotia considered to be an important prerequisite for sexual development. However Aspergillus niger sensu stricto has not been reported to produce sclerotia, and is thought to be a purely asexual organism. Here we report, for the first time, the production of sclerotia by certain strains of Aspergillus niger when grown on CYA agar with raisins, or on other fruits or on rice. Up to 11 apolar indoloterpenes of the aflavinine type were detected by liquid chromatography and diode array and mass spectrometric detection where sclerotia were formed, including 10,23-dihydro-24,25-dehydroaflavinine. Sclerotium induction can thus be a way of inducing the production of new secondary metabolites from previously silent gene clusters. Cultivation of other species of the black aspergilli showed that raisins induced sclerotium formation by A. brasiliensis, A. floridensis A. ibericus, A. luchuensis, A. neoniger, A. trinidadensis and A. saccharolyticus for the first time. PMID:24736731

  3. Formation of sclerotia and production of indoloterpenes by Aspergillus niger and other species in section Nigri.

    Directory of Open Access Journals (Sweden)

    Jens C Frisvad

    Full Text Available Several species in Aspergillus section Nigri have been reported to produce sclerotia on well-known growth media, such as Czapek yeast autolysate (CYA agar, with sclerotia considered to be an important prerequisite for sexual development. However Aspergillus niger sensu stricto has not been reported to produce sclerotia, and is thought to be a purely asexual organism. Here we report, for the first time, the production of sclerotia by certain strains of Aspergillus niger when grown on CYA agar with raisins, or on other fruits or on rice. Up to 11 apolar indoloterpenes of the aflavinine type were detected by liquid chromatography and diode array and mass spectrometric detection where sclerotia were formed, including 10,23-dihydro-24,25-dehydroaflavinine. Sclerotium induction can thus be a way of inducing the production of new secondary metabolites from previously silent gene clusters. Cultivation of other species of the black aspergilli showed that raisins induced sclerotium formation by A. brasiliensis, A. floridensis A. ibericus, A. luchuensis, A. neoniger, A. trinidadensis and A. saccharolyticus for the first time.

  4. From Learning Object to Learning Cell: A Resource Organization Model for Ubiquitous Learning

    Science.gov (United States)

    Yu, Shengquan; Yang, Xianmin; Cheng, Gang; Wang, Minjuan

    2015-01-01

    This paper presents a new model for organizing learning resources: Learning Cell. This model is open, evolving, cohesive, social, and context-aware. By introducing a time dimension into the organization of learning resources, Learning Cell supports the dynamic evolution of learning resources while they are being used. In addition, by introducing a…

  5. Peningkatan Keterampilan Pengambilan Keputusan Dan Penguasaan Konsep IPA Melalui Model Pembelajaran Advance Organizer Di Sekolah Dasar

    OpenAIRE

    Badarudin

    2017-01-01

    Peningkatan Keterampilan Pengambilan Keputusan dan Penguasaan Konsep IPA melalui Model Pembelajaran Advance Organizer di Sekolah Dasar. Penelitian ini bertujuan untuk mengetahui perbedaan peningkatan keterampilan pengambilan keputusan dan pemahaman konsep IPA siswa sebagai dampak dari implementasi model Advance Organizer. Penelitian ini menggunakan metode kuasi eksperimen dengan desain Non equivalent (Pre-Test and Post- Test) Control Groups Design. Subyek penelitian adalah siswa kelas V pada ...

  6. Retting of Flax by Aspergillus niger

    Science.gov (United States)

    De França, F. P.; Rosemberg, J. A.; De Jesus, A. M.

    1969-01-01

    In this study, retting was carried out by Aspergillus niger. The pH, galacturonic acid (GA), and total reducing sugar were determined; the end point was identified by the classic empirical processes and by the maximal GA content of the retting water. The process gave clear and resistent fibers, and the retting time was similar to that of current industrial processes with bacterial enzymes. Control of total acidity was not required, since the pH remained close to neutrality throughout the entire process. PMID:16349835

  7. A reductive aminase from Aspergillus oryzae

    OpenAIRE

    Grogan, Gideon James; Aleku, Godwin; France, Scott; Man, Henry Wing-Hong; Mangas-Sanchez, Juan; Sharma, Mahima; Montgomery, Sarah L; Leipold, Friedemann; Hussain, Shahed; Turner, Nicholas

    2017-01-01

    Reductive amination is one of the most important methods for the synthesis of chiral amines. Here we report the discovery of an NADP(H)-dependent reductive aminase from Aspergillus oryzae (AspRedAm, Uniprot code Q2TW47) which can catalyse the reductive coupling of a broad set of carbonyl compounds with a variety of primary and secondary amines with up to >98% conversion and with up to >98% enantiomeric excess. In cases where both carbonyl and amine show high reactivity, it is possible to empl...

  8. Modeling the Current and Future Roles of Particulate Organic Nitrates in the Southeastern United States.

    Science.gov (United States)

    Pye, Havala O T; Luecken, Deborah J; Xu, Lu; Boyd, Christopher M; Ng, Nga L; Baker, Kirk R; Ayres, Benjamin R; Bash, Jesse O; Baumann, Karsten; Carter, William P L; Edgerton, Eric; Fry, Juliane L; Hutzell, William T; Schwede, Donna B; Shepson, Paul B

    2015-12-15

    Organic nitrates are an important aerosol constituent in locations where biogenic hydrocarbon emissions mix with anthropogenic NOx sources. While regional and global chemical transport models may include a representation of organic aerosol from monoterpene reactions with nitrate radicals (the primary source of particle-phase organic nitrates in the Southeast United States), secondary organic aerosol (SOA) models can underestimate yields. Furthermore, SOA parametrizations do not explicitly take into account organic nitrate compounds produced in the gas phase. In this work, we developed a coupled gas and aerosol system to describe the formation and subsequent aerosol-phase partitioning of organic nitrates from isoprene and monoterpenes with a focus on the Southeast United States. The concentrations of organic aerosol and gas-phase organic nitrates were improved when particulate organic nitrates were assumed to undergo rapid (τ = 3 h) pseudohydrolysis resulting in nitric acid and nonvolatile secondary organic aerosol. In addition, up to 60% of less oxidized-oxygenated organic aerosol (LO-OOA) could be accounted for via organic nitrate mediated chemistry during the Southern Oxidants and Aerosol Study (SOAS). A 25% reduction in nitrogen oxide (NO + NO2) emissions was predicted to cause a 9% reduction in organic aerosol for June 2013 SOAS conditions at Centreville, Alabama.

  9. Democracy versus dictatorship in self-organized models of financial markets

    Science.gov (United States)

    D'Hulst, R.; Rodgers, G. J.

    2000-06-01

    Models to mimic the transmission of information in financial markets are introduced. As an attempt to generate the demand process, we distinguish between dictatorship associations, where groups of agents rely on one of them to make decision, and democratic associations, where each agent takes part in the group decision. In the dictatorship model, agents segregate into two distinct populations, while the democratic model is driven towards a critical state where groups of agents of all sizes exist. Hence, both models display a level of organization, but only the democratic model is self-organized. We show that the dictatorship model generates less-volatile markets than the democratic model.

  10. Neotropical electric fishes (Gymnotiformes as model organisms for bioassays

    Directory of Open Access Journals (Sweden)

    Milena Ferreira

    2015-04-01

    Full Text Available Electric fishes (Gymnotiformes inhabit Central and South America and form a relatively large group with more than 200 species. Besides a taxonomic challenge due to their still unresolved systematic, wide distribution and the variety of habitats they occupy, these fishes have been intensively studied due to their peculiar use of bioelectricity for electrolocation and communication. Conventional analysis of cells, tissues and organs have been complemented with the studies on the electric organ discharges of these fishes. This review compiles the results of 13 bioassays developed during the last 50 years, which used the quickness, low costs and functionality of the bioelectric data collection of Gymnotiformes to evaluate the effects of environmental contaminants and neuroactive drugs.

  11. Organisms modeling: The question of radial basis function networks

    Directory of Open Access Journals (Sweden)

    Muzy Alexandre

    2014-01-01

    Full Text Available There exists usually a gap between bio-inspired computational techniques and what biologists can do with these techniques in their current researches. Although biology is the root of system-theory and artifical neural networks, computer scientists are tempted to build their own systems independently of biological issues. This publication is a first-step re-evalution of an usual machine learning technique (radial basis funtion(RBF networks in the context of systems and biological reactive organisms.

  12. A double moral hazard model of organization design

    OpenAIRE

    Berkovitch, Elazar; Israel, Ronen; Spiegel, Yossi

    2007-01-01

    We develop a theory of organization design in which the firm's structure is chosen to mitigate moral hazard problems in the selection and the implementation of projects. For a given set of projects, the 'divisional structure' which gives each agent the full responsibility over a subset of projects is in general more efficient than the functional structure under which projects are implemented by teams of agents, each of whom specializes in one task. However, the ex post efficiency of the divis...

  13. Models for governing relationships in healthcare organizations: Some empirical evidence.

    Science.gov (United States)

    Romiti, Anna; Del Vecchio, Mario; Grazzini, Maddalena

    2018-01-01

    Recently, most European countries have undergone integration processes through mergers and strategic alliances between healthcare organizations. The present paper examined three cases within the Italian National Health Service in order to determine how different organizations, within differing institutional contexts, govern an healthcare integration process. Furthermore, we explored the possibility that the governance mode, usually seen as alternatives (i.e., merger or alliance), could be considered as a separate step in the development of a more suitable integration process. Multiple case studies were used to compare different integration approaches. Specifically, three cases were considered, of which two were characterized by collaborative processes and the other by a merger. Semi-structured interviews were conducted with managers involved in the processes. Each case presents different governing modes, structures, and mechanisms for achieving integration. The role played by the institutional context also led to different results with unique advantages and disadvantages. Three main conclusions are discussed: (a) Alliances and mergers can be interpreted as different steps in a path leading to a better integration; (b) The alignment between institutional/political time horizon and the time needed for the organizations to achieve an integration process lead to a better integration; (c) Trust plays an important role in integration process operating at different levels that of institutional and organizational level and that built between people.

  14. Particle size distribution of airborne Aspergillus fumigatus spores emitted from compost using membrane filtration

    Science.gov (United States)

    Deacon, L. J.; Pankhurst, L. J.; Drew, G. H.; Hayes, E. T.; Jackson, S.; Longhurst, P. J.; Longhurst, J. W. S.; Liu, J.; Pollard, S. J. T.; Tyrrel, S. F.

    Information on the particle size distribution of bioaerosols emitted from open air composting operations is valuable in evaluating potential health impacts and is a requirement for improved dispersion simulation modelling. The membrane filter method was used to study the particle size distribution of Aspergillus fumigatus spores in air 50 m downwind of a green waste compost screening operation at a commercial facility. The highest concentrations (approximately 8 × 10 4 CFU m -3) of culturable spores were found on filters with pore diameters in the range 1-2 μm which suggests that the majority of spores are emitted as single cells. The findings were compared to published data collected using an Andersen sampler. Results were significantly correlated ( p < 0.01) indicating that the two methods are directly comparable across all particles sizes for Aspergillus spores.

  15. Dynamic root uptake model for neutral lipophilic organics

    DEFF Research Database (Denmark)

    Trapp, Stefan

    2002-01-01

    and output to stem with the transpiration stream plus first-order metabolism and dilution by exponential growth. For chemicals with low or intermediate lipophilicity (log Kow , 2), there was no relevant difference between dynamic model and equilibrium approach. For lipophilic compounds, the dynamic model...

  16. Modeling cadmium in the feed chain and cattle organs

    NARCIS (Netherlands)

    Fels-Klerx, van der H.J.; Romkens, P.F.A.M.; Franz, E.; Raamsdonk, van L.W.D.

    2011-01-01

    The objectives of this study were to estimate cadmium contamination levels in different scenarios related to soil characteristics and assumptions regarding cadmium accumulation in the animal tissues, using quantitative supply chain modeling. The model takes into account soil cadmium levels, soil pH,

  17. Computational Modeling of Cultural Dimensions in Adversary Organizations

    Science.gov (United States)

    2010-01-01

    theatre of operations. 50 51 Chapter 5 Adversary Modeling Applications 5.1 Modeling Uncertainty in Adversary Behavior: Attacks in...Underestimate the Strength of Coalition Power 1 1 (= True) 1 1 1 -- Coalition Deploys Forces to Indonesia 1 1 2 1 2 -- Thai can Conduct Unilateral NEO 1 1

  18. Gβ-like CpcB plays a crucial role for growth and development of Aspergillus nidulans and Aspergillus fumigatus.

    Directory of Open Access Journals (Sweden)

    Qing Kong

    Full Text Available Growth, development, virulence and secondary metabolism in fungi are governed by heterotrimeric G proteins (G proteins. A Gβ-like protein called Gib2 has been shown to function as an atypical Gβ in Gpa1-cAMP signaling in Cryptococcus neoformans. We found that the previously reported CpcB (cross pathway control B protein is the ortholog of Gib2 in Aspergillus nidulans and Aspergillus fumigatus. In this report, we further characterize the roles of CpcB in governing growth, development and toxigenesis in the two aspergilli. The deletion of cpcB results in severely impaired cellular growth, delayed spore germination, and defective asexual sporulation (conidiation in both aspergilli. Moreover, CpcB is necessary for proper expression of the key developmental activator brlA during initiation and progression of conidiation in A. nidulans and A. fumigatus. Somewhat in accordance with the previous study, the absence of cpcB results in the formation of fewer, but not micro-, cleistothecia in A. nidulans in the presence of wild type veA, an essential activator of sexual development. However, the cpcB deletion mutant cleistothecia contain no ascospores, validating that CpcB is required for progression and completion of sexual fruiting including ascosporogenesis. Furthermore, unlike the canonical GβSfaD, CpcB is not needed for the biosynthesis of the mycotoxin sterigmatocystin (ST as the cpcB null mutant produced reduced amount of ST with unaltered STC gene expression. However, in A. fumigatus, the deletion of cpcB results in the blockage of gliotoxin (GT production. Further genetic analyses in A. nidulans indicate that CpcB may play a central role in vegetative growth, which might be independent of FadA- and GanB-mediated signaling. A speculative model summarizing the roles of CpcB in conjunction with SfaD in A. nidulans is presented.

  19. Intraspecies Volatile Interactions Affect Growth Rates and Exometabolomes in Aspergillus oryzae KCCM 60345.

    Science.gov (United States)

    Singh, Digar; Lee, Choong Hwan

    2018-02-28

    Volatile organic compounds (VOCs) are increasingly been recognized as the chemical mediators of mold interactions, shaping their community dynamics, growth, and metabolism. Herein, we selectively examined the time-correlated (0 D-11 D, where D = incubation days) effects of intraspecies VOC-mediated interactions (VMI) on Aspergillus oryzae KCCM 60345 (S1), following co-cultivation with partner strain A. oryzae KACC 44967 (S2), in a specially designed twin plate assembly. The comparative evaluation of S1 VMI (S1 subjected to VMI with S2) and its control (S1 Con ) showed a notable disparity in their radial growth (S1 VMI S1 Con ) at 3-5 D, amylase activity (S1 VMI S1 Con ) at 3 D. Furthermore, we observed a distinct clustering pattern for gas chromatography-time of flight-mass spectrometry datasets from 5 D extracts of S1 VMI and S1 Con in principle component analysis (PC1: 30.85%; PC2: 10.31%) and partial least squares discriminant analysis (PLS-DA) (PLS1: 30.77; PLS2: 10.15%). Overall, 43 significantly discriminant metabolites were determined for engendering the metabolic variance based on the PLS-DA model (VIP > 0.7, p S1 Con ) at 5 D, organic acids (S1 VMI > S1 Con ) at 5 D, and kojic acid (S1 VMI < S1 Con ) at 5-7 D were observed. Examining the headspace VOCs shared between S1 and S2 in the twin plate for 5 D incubated samples, we observed the relatively higher abundance of C-8 VOCs (1-octen-3-ol, (5Z)-octa-1,5-dien-3-ol, 3-octanone, 1-octen-3-ol acetate) having known semiochemical functions. The present study potentially illuminates the effects of VMI on commercially important A. oryzae's growth and biochemical phenotypes with subtle details of altered metabolomes.

  20. Ames Culture Chamber System: Enabling Model Organism Research Aboard the international Space Station

    Science.gov (United States)

    Steele, Marianne

    2014-01-01

    Understanding the genetic, physiological, and behavioral effects of spaceflight on living organisms and elucidating the molecular mechanisms that underlie these effects are high priorities for NASA. Certain organisms, known as model organisms, are widely studied to help researchers better understand how all biological systems function. Small model organisms such as nem-atodes, slime mold, bacteria, green algae, yeast, and moss can be used to study the effects of micro- and reduced gravity at both the cellular and systems level over multiple generations. Many model organisms have sequenced genomes and published data sets on their transcriptomes and proteomes that enable scientific investigations of the molecular mechanisms underlying the adaptations of these organisms to space flight.

  1. Chronological aging in conidia of pathogenic Aspergillus: Comparison between species.

    Science.gov (United States)

    Oliveira, Manuela; Pereira, Clara; Bessa, Cláudia; Araujo, Ricardo; Saraiva, Lucília

    2015-11-01

    Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus and Aspergillus niger are common airborne fungi, and the most frequent causative agents of human fungal infections. However, the resistance and lifetime persistence of these fungi in the atmosphere, and the mechanism of aging of Aspergillus conidia are unknown.With this work, we intended to study the processes underlying conidial aging of these four relevant and pathogenic Aspergillus species. Chronological aging was therefore evaluated in A. fumigatus, A. flavus, A. terreus and A. niger conidia exposed to environmental and human body temperatures. The results showed that the aging process in Aspergillus conidia involves apoptosis,with metacaspase activation, DNA fragmentation, and reactive oxygen species production, associated with secondary necrosis. Distinct results were observed for the selected pathogenic species. At environmental conditions, A. niger was the species with the highest resistance to aging, indicating a higher adaption to environmental conditions, whereas A. flavus followed by A. terreus were the most sensitive species. At higher temperatures (37 °C), A. fumigatus presented the longest lifespan, in accordance with its good adaptation to the human body temperature. Altogether,with this work new insights regarding conidia aging are provided, which may be useful when designing treatments for aspergillosis.

  2. Uranium uptake by the filamentous fungal biomass, Aspergillus fumigatus and mechanism of biosorption

    International Nuclear Information System (INIS)

    Bhainsa, Kuber C.; D'Souza, S.F.

    2010-01-01

    Uptake of uranium by Aspergillus fumigatus was investigated in a batch study. Previously, we had reported good uranium uptake capacity, i.e., 423 mg U/g by this fungal biomass. The objective of the present study was to investigate the uranium uptake and mechanism of biosorption by Aspergillus fumigatus. The metal uptake was rapid and 80% of metal ion could be removed within 4 minutes of contact time. Kinetic modeling indicated that the uptake of uranium followed Lagergren's pseudo-second order reaction indicating the process to be mediated through chemisorption mechanism. Further studies on isotherm modeling were carried out using D-R isotherm to confirm the same. The energy of biosorption obtained from D-R isotherm was found to be 14.4 kJ/mol. This energy corresponds to the energy of chemisorption (ion-exchange) which varies between 8-16 kJ/mol. All these results suggest that uranium uptake by Aspergillus fumigatus is mediated through chemisorptions mechanism. (author)

  3. Modeling the surface tension of complex, reactive organic-inorganic mixtures

    Science.gov (United States)

    Schwier, A. N.; Viglione, G. A.; Li, Z.; McNeill, V. Faye

    2013-11-01

    Atmospheric aerosols can contain thousands of organic compounds which impact aerosol surface tension, affecting aerosol properties such as heterogeneous reactivity, ice nucleation, and cloud droplet formation. We present new experimental data for the surface tension of complex, reactive organic-inorganic aqueous mixtures mimicking tropospheric aerosols. Each solution contained 2-6 organic compounds, including methylglyoxal, glyoxal, formaldehyde, acetaldehyde, oxalic acid, succinic acid, leucine, alanine, glycine, and serine, with and without ammonium sulfate. We test two semi-empirical surface tension models and find that most reactive, complex, aqueous organic mixtures which do not contain salt are well described by a weighted Szyszkowski-Langmuir (S-L) model which was first presented by Henning et al. (2005). Two approaches for modeling the effects of salt were tested: (1) the Tuckermann approach (an extension of the Henning model with an additional explicit salt term), and (2) a new implicit method proposed here which employs experimental surface tension data obtained for each organic species in the presence of salt used with the Henning model. We recommend the use of method (2) for surface tension modeling of aerosol systems because the Henning model (using data obtained from organic-inorganic systems) and Tuckermann approach provide similar modeling results and goodness-of-fit (χ2) values, yet the Henning model is a simpler and more physical approach to modeling the effects of salt, requiring less empirically determined parameters.

  4. Modeling equilibrium adsorption of organic micropollutants onto activated carbon

    KAUST Repository

    De Ridder, David J.; Villacorte, Loreen O.; Verliefde, Arne R. D.; Verberk, Jasper Q J C; Heijman, Bas G J; Amy, Gary L.; Van Dijk, Johannis C.

    2010-01-01

    to these properties occur in parallel, and their respective dominance depends on the solute properties as well as carbon characteristics. In this paper, a model based on multivariate linear regression is described that was developed to predict equilibrium carbon

  5. Fruit tree model for uptake of organic compounds from soil

    DEFF Research Database (Denmark)

    Trapp, Stefan; Rasmussen, D.; Samsoe-Petersen, L.

    2003-01-01

    -state, and an example calculation is given. The Fruit Tree Model is compared to the empirical equation of Travis and Arms (T&A), and to results from fruits, collected in contaminated areas. For polar compounds, both T&A and the Fruit Tree Model predict bioconcentration factors fruit to soil (BCF, wet weight based......) of > 1. No empirical data are available to support this prediction. For very lipophilic compounds (log K-OW > 5), T&A overestimates the uptake. The conclusion from the Fruit Tree Model is that the transfer of lipophilic compounds into fruits is not relevant. This was also found by an empirical study...... with PCDD/F. According to the Fruit Tree Model, polar chemicals are transferred efficiently into fruits, but empirical data to verify these predictions are lacking....

  6. Integrated corporate structure life cycle management modeling and organization

    OpenAIRE

    Naumenko, M.; Morozova, L.

    2011-01-01

    Integrated business structure presented as complementary pool of its participants skills. The methodical approach to integrated business structure life cycle modeling proposed. Recommendations of enterprises life cycles stages correlate are submitted.

  7. A QUADTREE ORGANIZATION CONSTRUCTION AND SCHEDULING METHOD FOR URBAN 3D MODEL BASED ON WEIGHT

    OpenAIRE

    C. Yao; G. Peng; Y. Song; M. Duan

    2017-01-01

    The increasement of Urban 3D model precision and data quantity puts forward higher requirements for real-time rendering of digital city model. Improving the organization, management and scheduling of 3D model data in 3D digital city can improve the rendering effect and efficiency. This paper takes the complexity of urban models into account, proposes a Quadtree construction and scheduling rendering method for Urban 3D model based on weight. Divide Urban 3D model into different rendering weigh...

  8. Integrating centralized and decentralized organization structures: an education and development model.

    Science.gov (United States)

    Sheriff, R; Banks, A

    2001-01-01

    Organization change efforts have led to critically examining the structure of education and development departments within hospitals. This qualitative study evaluated an education and development model in an academic health sciences center. The model combines centralization and decentralization. The study results can be used by staff development educators and administrators when organization structure is questioned. This particular model maximizes the benefits and minimizes the limitations of centralized and decentralized structures.

  9. Modeling of iodine radiation chemistry in the presence of organic compounds

    International Nuclear Information System (INIS)

    Taghipour, Fariborz; Evans, Greg J.

    2002-01-01

    A kinetic-based model was developed that simulates the radiation chemistry of iodine in the presence of organic compounds. The model's mechanistic description of iodine chemistry and generic semi-mechanistic reactions for various classes of organics, provided a reasonable representation of experimental results. The majority of the model and experimental results of iodine volatilization rates were in agreement within an order of magnitude

  10. Chemometric Analysis of the Volatile Compounds Generated by Aspergillus carbonarius Strains Isolated from Grapes and Dried Vine Fruits

    Directory of Open Access Journals (Sweden)

    Zhan Cheng

    2018-02-01

    Full Text Available Ochratoxin A (OTA contamination in grape production is an important problem worldwide. Microbial volatile organic compounds (MVOCs have been demonstrated as useful tools to identify different toxigenic strains. In this study, Aspergillus carbonarius strains were classified into two groups, moderate toxigenic strains (MT and high toxigenic strains (HT, according to OTA-forming ability. The MVOCs were analyzed by GC-MS and the data processing was based on untargeted profiling using XCMS Online software. Orthogonal projection to latent structures discriminant analysis (OPLS-DA was performed using extract ion chromatogram GC-MS datasets. For contrast, quantitative analysis was also performed. Results demonstrated that the performance of the OPLS-DA model of untargeted profiling was better than the quantitative method. Potential markers were successfully discovered by variable importance on projection (VIP and t-test. (E-2-octen-1-ol, octanal, 1-octen-3-one, styrene, limonene, methyl-2-phenylacetate and 3 unknown compounds were selected as potential markers for the MT group. Cuparene, (Z-thujopsene, methyl octanoate and 1 unknown compound were identified as potential markers for the HT groups. Finally, the selected markers were used to construct a supported vector machine classification (SVM-C model to check classification ability. The models showed good performance with the accuracy of cross-validation and test prediction of 87.93% and 92.00%, respectively.

  11. [Utility of Aspergillus-LFD: first experience in Chile].

    Science.gov (United States)

    Alvarez, Eduardo

    2015-02-01

    The diagnosis of invasive aspergillosis remains a challenge. Detection of galactomannan in serum and bronchoalveolar lavage is a useful tool; however due to methodological and economic reasons, the test frequencies of galactomannan assays vary from daily to weekly, which constitute a risk to the patient. In this study, we aimed to evaluate and correlate the performance of the new kit Aspergillus-LFD with the GM-EIA. Aspergillus-LFD kit represents a fast, economical and simple test; showed a good performance and excellent correlation with GM-EIA kit. Given the above, the Aspergillus-LFD is emerging as an alternative to consider in the early diagnosis of invasive aspergillosis.

  12. Aspergillus in the lung: diverse and coincident forms

    International Nuclear Information System (INIS)

    Buckingham, Susan J.; Hansell, David M.

    2003-01-01

    Pulmonary disease caused by the fungus Aspergillus has traditionally been regarded as belonging to one of the following, apparently distinct, entities: saprophytic aspergilloma; allergic bronchopulmonary aspergillosis (ABPA); and invasive aspergillosis (IPA); which may be further categorised as angioinvasive, acute or chronic airway invasive [1]. It is not always obvious that there is overlap between these entities, and that in any given patient more than one Aspergillus-related pathological process can co-exist [2]. The aim of this article is to review the clinical and imaging features of the main categories of Aspergillus-related pulmonary disease and, in particular, to highlight the overlap between them. (orig.)

  13. PENGARUH RHIZOPUS ORYZAE DAN ASPERGILLUS ORYZAE TERHADAP KUALITAS KECAP

    Directory of Open Access Journals (Sweden)

    Dewi Sabita Slamet

    2012-11-01

    Full Text Available Telah diteliti pengganti fermentasi mikroorganisme Aspergillus oryzae Rhyzopus oryzae dan campuran Aspergillus dan Rhyzopus oryzae, dengan perendaman dalam larutan garam 20% dalam waktu yang berbeda terhadap kualitas kecap.Lamanya perendaman dalam larutan garam 20% yang berbeda menghasilkan kadar protein kecap yang berbeda. Aspergillus oryzae lebih baik dalam menghasilkan enzima protease dari pada Rhyzopus oryzae.Uji organoleptik menunjukkan perbedaan tidak bermakna dalam hal rasa maupun aroma antar kecap yang dibuat dengan strain jamur yang berlainan serta waktu perendaman yang berbeda. Untuk membuat kecap, sebaiknya dilakukan perendaman dalam larutan garam 20% selama 14 hari.

  14. Modeling the acid-base chemistry of organic solutes in Adirondack, New York, lakes

    Science.gov (United States)

    Driscoll, Charles T.; Lehtinen, Michael D.; Sullivan, Timothy J.

    1994-02-01

    Data from the large and diverse Adirondack Lake Survey were used to calibrate four simple organic acid analog models in an effort to quantify the influence of naturally occurring organic acids on lake water pH and acid-neutralizing capacity (ANC). The organic acid analog models were calibrated to observations of pH, dissolved organic carbon (DOC), and organic anion (An-) concentrations from a reduced data set representing 1128 individual lake samples, expressed as 41 observations of mean pH, in intervals of 0.1 pH units from pH 3.9 to 7.0. Of the four organic analog approaches examined, including the Oliver et al. (1983) model, as well as monoprotic, diprotic, and triprotic representations, the triprotic analog model yielded the best fit (r2 = 0.92) to the observed data. Moreover, the triprotic model was qualitatively consistent with observed patterns of change in organic solute charge density as a function of pH. A low calibrated value for the first H+ dissociation constant (pKal = 2.62) and the observation that organic anion concentrations were significant even at very low pH (acidic functional groups. Inclusion of organic acidity in model calculations resulted in good agreement between measured and predicted values of lake water pH and ANC. Assessments to project the response of surface waters to future changes in atmospheric deposition, through the use of acidification models, will need to include representations of organic acids in model structure to make accurate predictions of pH and ANC.

  15. Two models for absorption by coloured dissolved organic matter (CDOM

    Directory of Open Access Journals (Sweden)

    Jill N. Schwarz

    2002-06-01

    Full Text Available The standard exponential model for CDOM absorption has been applied to data from diverse waters. Absorption at 440 nm (ag440 ranged between close to zero and 10 m-1, and the slope of the semilogarithmic absorption spectrum over a minimum range of 400 to 440 nm (s440 ranged between < 0.01 and 0.04 nm-1. No relationship was found between ag440 or s440 and salinity. Except in the southern Baltic, s440 was found to have a broad distribution (0.0165 ± 0.0035, suggesting that it should be introduced as an additional variable in bio-optical models when ag440 is large. An alternative model for CDOM absorption was applied to available high quality UV-visible absorption spectra from the Wisla river (Poland. This model assumes that the CDOM absorption spectrum comprises distinct Gaussian absorption bands in the UV, similar to those of benzene. Five bands were fit to the data. The mean central energy of all bands was higher in early summer (E~7.2, 6.6, 6.4, 6.2 and 5.5 eV or 172, 188, 194, 200 and 226 nm than in winter. The higher energy bands were found to decay in both height and width with increasing salinity, while lower energy bands broadened with increasing salinity. s440 was found to be correlated with shape parameters of the bands centred at 6.4 and 5.5 eV. While the exponential model is convenient for optical modelling and remote sensing applications, these results suggest that the Gaussian model offers a deeper understanding of chemical interactions affecting CDOM molecular structure.

  16. Self-organized critical model for protein folding

    Science.gov (United States)

    Moret, M. A.

    2011-09-01

    The major factor that drives a protein toward collapse and folding is the hydrophobic effect. At the folding process a hydrophobic core is shielded by the solvent-accessible surface area of the protein. We study the fractal behavior of 5526 protein structures present in the Brookhaven Protein Data Bank. Power laws of protein mass, volume and solvent-accessible surface area are measured independently. The present findings indicate that self-organized criticality is an alternative explanation for the protein folding. Also we note that the protein packing is an independent and constant value because the self-similar behavior of the volumes and protein masses have the same fractal dimension. This power law guarantees that a protein is a complex system. From the analyzed data, q-Gaussian distributions seem to fit well this class of systems.

  17. Presenting a comprehensive market oriented model and evaluating its impact on organization performance

    Directory of Open Access Journals (Sweden)

    Mohammad Taqi Amini

    2013-08-01

    Full Text Available Like other innovative strategies, companies have paid more attention to market oriented strategies in recent years. This has been focused by organizations for improved effectiveness and the organization performance accelerated a lot in business competition. In responding to this fact, organizations are trying to formulate many of the issues familiar to large organizations, which have involved with market oriented strategy planning. This paper reviews key elements in market-oriented strategy planning with regard to competitiveness and performance in large organizations and outlines a comprehensive model for strategy planning in profit organizations. These elements include environment, top management, organization structure and market oriented strategy. Professional question of this study has a particularly important role in formulating relations of this model. These elements are well positioned to evaluate the impact of market-oriented strategy planning on organizations and their expected impacts on organization performance. A well-organized questionnaire to help organizations with their planning is proposed in this survey. Based on the proposed questionnaire, data obtained from Tehran food industry experts and analyzed by using SEM method. Results accepted eight hypotheses and rejected one.

  18. Effect of gamma radiation on Aspergillus flavus and Aspergillus ochraceus ultrastructure and mycotoxin production

    International Nuclear Information System (INIS)

    Ribeiro, J.; Cavaglieri, L.; Vital, H.; Cristofolini, A.; Merkis, C.; Astoreca, A.; Orlando, J.; Caru, M.; Dalcero, A.; Rosa, C.A.R.

    2011-01-01

    The aim of this work was to study the effect of gamma radiation (2 kGy) on Aspergillus flavus and Aspergillus ochraceus ultrastructure. Moreover, the influence on aflatoxin B 1 and ochratoxin A production was also observed. Irradiated A. flavus strain showed a dull orangish colony while control strain showed the typical green color. Minor differences were observed on stipes, metulae and conidia size between control and irradiated A. flavus and A. ochraceus strains. Irradiated fungi showed ultrastructural changes on cell wall, plasmalema and cytoplasm levels. The levels of mycotoxins produced by irradiated strains were two times greater than those produced by control strains. Successive transferences of irradiated strains on malt extract agar allowed the fungus to recuperate morphological characteristics. Although minor changes in the fungal morphology were observed, ultrastructural changes at cell wall level and the increase of mycotoxin production ability were observed. Inappropriate storage of irradiated food and feed would allow the development of potentially more toxicogenic fungal propagules.

  19. An Incremental Model for Cloud Adoption: Based on a Study of Regional Organizations

    Directory of Open Access Journals (Sweden)

    Emre Erturk

    2017-11-01

    Full Text Available Many organizations that use cloud computing services intend to increase this commitment. A survey was distributed to organizations in Hawke’s Bay, New Zealand to understand their adoption of cloud solutions, in comparison with global trends and practices. The survey also included questions on the benefits and challenges, and which delivery model(s they have adopted and are planning to adopt. One aim is to contribute to the cloud computing literature and build on the existing adoption models. This study also highlights additional aspects applicable to various organizations (small, medium, large and regional. Finally, recommendations are provided for related future research projects.

  20. A survey of xerophilic Aspergillus from indoor environment, including descriptions of two new section Aspergillus species producing eurotium-like sexual states

    DEFF Research Database (Denmark)

    Visagie, Cobus M.; Yilmaz, Neriman; Renaud, Justin B.

    2017-01-01

    of 1039 strains; 296 strains belong to Aspergillus and represented 37 species. Reference sequences were generated for all species and deposited in GenBank. Aspergillus sect. Aspergillus (formerly called Eurotium) was one of the most predominant groups from house dust with nine species identified...