Amphibian Chytrid Fungus in Madagascar neither Shows Widespread Presence nor Signs of Certain Establishment.

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Kolby, Jonathan E; Skerratt, Lee F

2015-01-01

The global spread of amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) is associated with amphibian mass mortality, population decline, and extinction. Over the past decade, concern has been expressed for the potential introduction of Bd to Madagascar, a global hotspot of amphibian biodiversity. Following years without detection, widespread Bd presence in Madagascar has now been reported (Bletz et al. 2015a), raising international conservation concern. Before reacting to this finding with a significant management response, the accuracy and context of the data warrant cautious review. Re-examination of a 10-year dataset together with results from more recent surveillance (Kolby et al. 2015) does not yet demonstrate widespread Bd presence. Detection of Bd at "positive" locations in Madagascar has been inconsistent for unknown reasons. Whether Bd is established in Madagascar (i.e. populations are self-sustaining) or instead requires continued introduction to persist also remains uncertain. The deployment of emergency conservation rescue initiatives is expected to target areas where the distribution of Bd and the risk of chytridiomycosis endangering amphibians is believed to overlap. Thus, erroneous description of Bd presence would misdirect limited conservation resources. Standardized surveillance and confirmatory surveys are now imperative to reliably characterize the distribution, potential spread, virulence and overall risk of Bd to amphibians in Madagascar.

Amphibian Chytrid Fungus in Madagascar neither Shows Widespread Presence nor Signs of Certain Establishment.

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Jonathan E Kolby

Full Text Available The global spread of amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd is associated with amphibian mass mortality, population decline, and extinction. Over the past decade, concern has been expressed for the potential introduction of Bd to Madagascar, a global hotspot of amphibian biodiversity. Following years without detection, widespread Bd presence in Madagascar has now been reported (Bletz et al. 2015a, raising international conservation concern. Before reacting to this finding with a significant management response, the accuracy and context of the data warrant cautious review. Re-examination of a 10-year dataset together with results from more recent surveillance (Kolby et al. 2015 does not yet demonstrate widespread Bd presence. Detection of Bd at "positive" locations in Madagascar has been inconsistent for unknown reasons. Whether Bd is established in Madagascar (i.e. populations are self-sustaining or instead requires continued introduction to persist also remains uncertain. The deployment of emergency conservation rescue initiatives is expected to target areas where the distribution of Bd and the risk of chytridiomycosis endangering amphibians is believed to overlap. Thus, erroneous description of Bd presence would misdirect limited conservation resources. Standardized surveillance and confirmatory surveys are now imperative to reliably characterize the distribution, potential spread, virulence and overall risk of Bd to amphibians in Madagascar.

Effects of amphibian chytrid fungus on individual survival probability in wild boreal toads

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Pilliod, D.S.; Muths, E.; Scherer, R. D.; Bartelt, P.E.; Corn, P.S.; Hossack, B.R.; Lambert, B.A.; Mccaffery, R.; Gaughan, C.

2010-01-01

Chytridiomycosis is linked to the worldwide decline of amphibians, yet little is known about the demographic effects of the disease. We collected capture-recapture data on three populations of boreal toads (Bufo boreas [Bufo = Anaxyrus]) in the Rocky Mountains (U.S.A.). Two of the populations were infected with chytridiomycosis and one was not. We examined the effect of the presence of amphibian chytrid fungus (Batrachochytrium dendrobatidis [Bd]; the agent of chytridiomycosis) on survival probability and population growth rate. Toads that were infected with Bd had lower average annual survival probability than uninfected individuals at sites where Bd was detected, which suggests chytridiomycosis may reduce survival by 31-42% in wild boreal toads. Toads that were negative for Bd at infected sites had survival probabilities comparable to toads at the uninfected site. Evidence that environmental covariates (particularly cold temperatures during the breeding season) influenced toad survival was weak. The number of individuals in diseased populations declined by 5-7%/year over the 6 years of the study, whereas the uninfected population had comparatively stable population growth. Our data suggest that the presence of Bd in these toad populations is not causing rapid population declines. Rather, chytridiomycosis appears to be functioning as a low-level, chronic disease whereby some infected individuals survive but the overall population effects are still negative. Our results show that some amphibian populations may be coexisting with Bd and highlight the importance of quantitative assessments of survival in diseased animal populations. Journal compilation. ?? 2010 Society for Conservation Biology. No claim to original US government works.

Effects of pesticide exposure and the amphibian chytrid fungus on gray treefrog (Hyla chrysoscelis) metamorphosis.

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Gaietto, Kristina M; Rumschlag, Samantha L; Boone, Michelle D

2014-10-01

Pesticides are detectable in most aquatic habitats and have the potential to alter host-pathogen interactions. The amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), has been associated with amphibian declines around the world. However, Bd-associated declines are more prominent in some areas, despite nearly global distribution of Bd, suggesting other factors contribute to disease outbreaks. In a laboratory study, the authors examined the effects of 6 different isolates of Bd in the presence or absence of a pesticide (the insecticide carbaryl or the fungicide copper sulfate) to recently hatched Cope's gray treefrog (Hyla chrysoscelis) tadpoles reared through metamorphosis. The authors found the presence or absence of pesticides differentially altered the mass at metamorphosis of tadpoles exposed to different Bd isolates, suggesting that isolate could influence metamorphosis but not in ways expected based on origin of the isolate. Pesticide exposure had the strongest impact on metamorphosis of all treatment combinations. Whereas copper sulfate exposure reduced the length of the larval period, carbaryl exposure had apparent positive effects by increasing mass at metamorphosis and lengthening larval period, which adds to evidence that carbaryl can stimulate development in counterintuitive ways. The present study provides limited support to the hypothesis that pesticides can alter the response of tadpoles to isolates of Bd and that the insecticide carbaryl can alter developmental decisions. © 2014 SETAC.

No evidence for effects of infection with the amphibian chytrid fungus on populations of yellow-bellied toads.

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Wagner, Norman; Neubeck, Claus; Guicking, Daniela; Finke, Lennart; Wittich, Martin; Weising, Kurt; Geske, Christian; Veith, Michael

2017-02-08

The parasitic chytrid fungus Batrachochytrium dendrobatidis (Bd) can cause the lethal disease chytridiomycosis in amphibians and therefore may play a role in population declines. The yellow-bellied toad Bombina variegata suffered strong declines throughout western and northwestern parts of its range and is therefore listed as highly endangered for Germany and the federal state of Hesse. Whether chytridiomycosis may play a role in the observed local declines of this strictly protected anuran species has never been tested. We investigated 19 Hessian yellow-bellied toad populations for Bd infection rates, conducted capture-mark-recapture studies in 4 of them over 2 to 3 yr, examined survival histories of recaptured infected individuals, and tested whether multi-locus heterozygosity of individuals as well as expected heterozygosity and different environmental variables of populations affect probabilities of Bd infection. Our results show high prevalence of Bd infection in Hessian yellow-bellied toad populations, but although significant decreases in 2 populations could be observed, no causative link to Bd as the reason for this can be established. Mass mortalities or obvious signs of disease in individuals were not observed. Conversely, we show that growth of Bd-infected populations is possible under favorable habitat conditions and that most infected individuals could be recaptured with improved body indices. Neither genetic diversity nor environmental variables appeared to affect Bd infection probabilities. Hence, genetically diverse amphibian specimens and populations may not automatically be less susceptible for Bd infection.

Unlocking the story in the swab: A new genotyping assay for the amphibian chytrid fungus Batrachochytrium dendrobatidis.

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Byrne, Allison Q; Rothstein, Andrew P; Poorten, Thomas J; Erens, Jesse; Settles, Matthew L; Rosenblum, Erica Bree

2017-11-01

One of the most devastating emerging pathogens of wildlife is the chytrid fungus, Batrachochytrium dendrobatidis (Bd), which affects hundreds of amphibian species around the world. Genomic data from pure Bd cultures have advanced our understanding of Bd phylogenetics, genomic architecture and mechanisms of virulence. However, pure cultures are laborious to obtain and whole-genome sequencing is comparatively expensive, so relatively few isolates have been genetically characterized. Thus, we still know little about the genetic diversity of Bd in natural systems. The most common noninvasive method of sampling Bd from natural populations is to swab amphibian skin. Hundreds of thousands of swabs have been collected from amphibians around the world, but Bd DNA collected via swabs is often low in quality and/or quantity. In this study, we developed a custom Bd genotyping assay using the Fluidigm Access Array platform to amplify 192 carefully selected regions of the Bd genome. We obtained robust sequence data for pure Bd cultures and field-collected skin swabs. This new assay has the power to accurately discriminate among the major Bd clades, recovering the basic tree topology previously revealed using whole-genome data. Additionally, we established a critical value for initial Bd load for swab samples (150 Bd genomic equivalents) above which our assay performs well. By leveraging advances in microfluidic multiplex PCR technology and the globally distributed resource of amphibian swab samples, noninvasive skin swabs can now be used to address critical spatial and temporal questions about Bd and its effects on declining amphibian populations. © 2017 John Wiley & Sons Ltd.

Batrachochytrium salamandrivorans sp. nov. causes lethal chytridiomycosis in amphibians.

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Martel, An; Spitzen-van der Sluijs, Annemarieke; Blooi, Mark; Bert, Wim; Ducatelle, Richard; Fisher, Matthew C; Woeltjes, Antonius; Bosman, Wilbert; Chiers, Koen; Bossuyt, Franky; Pasmans, Frank

2013-09-17

The current biodiversity crisis encompasses a sixth mass extinction event affecting the entire class of amphibians. The infectious disease chytridiomycosis is considered one of the major drivers of global amphibian population decline and extinction and is thought to be caused by a single species of aquatic fungus, Batrachochytrium dendrobatidis. However, several amphibian population declines remain unexplained, among them a steep decrease in fire salamander populations (Salamandra salamandra) that has brought this species to the edge of local extinction. Here we isolated and characterized a unique chytrid fungus, Batrachochytrium salamandrivorans sp. nov., from this salamander population. This chytrid causes erosive skin disease and rapid mortality in experimentally infected fire salamanders and was present in skin lesions of salamanders found dead during the decline event. Together with the closely related B. dendrobatidis, this taxon forms a well-supported chytridiomycete clade, adapted to vertebrate hosts and highly pathogenic to amphibians. However, the lower thermal growth preference of B. salamandrivorans, compared with B. dendrobatidis, and resistance of midwife toads (Alytes obstetricans) to experimental infection with B. salamandrivorans suggest differential niche occupation of the two chytrid fungi.

West Africa - A Safe Haven for Frogs? A Sub-Continental Assessment of the Chytrid Fungus (Batrachochytrium dendrobatidis)

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Penner, Johannes; Adum, Gilbert B.; McElroy, Matthew T.; Doherty-Bone, Thomas; Hirschfeld, Mareike; Sandberger, Laura; Weldon, Ché; Cunningham, Andrew A.; Ohst, Torsten; Wombwell, Emma; Portik, Daniel M.; Reid, Duncan; Hillers, Annika; Ofori-Boateng, Caleb; Oduro, William; Plötner, Jörg; Ohler, Annemarie; Leaché, Adam D.; Rödel, Mark-Oliver

2013-01-01

A putative driver of global amphibian decline is the panzootic chytrid fungus Batrachochytrium dendrobatidis (Bd). While Bd has been documented across continental Africa, its distribution in West Africa remains ambiguous. We tested 793 West African amphibians (one caecilian and 61 anuran species) for the presence of Bd. The samples originated from seven West African countries - Bénin, Burkina Faso, Côte d'Ivoire, Ghana, Guinea, Liberia, Sierra Leone - and were collected from a variety of habitats, ranging from lowland rainforests to montane forests, montane grasslands to humid and dry lowland savannahs. The species investigated comprised various life-history strategies, but we focused particularly on aquatic and riparian species. We used diagnostic PCR to screen 656 specimen swabs and histology to analyse 137 specimen toe tips. All samples tested negative for Bd, including a widespread habitat generalist Hoplobatrachus occipitalis which is intensively traded on the West African food market and thus could be a potential dispersal agent for Bd. Continental fine-grained (30 arc seconds) environmental niche models suggest that Bd should have a broad distribution across West Africa that includes most of the regions and habitats that we surveyed. The surprising apparent absence of Bd in West Africa indicates that the Dahomey Gap may have acted as a natural barrier. Herein we highlight the importance of this Bd-free region of the African continent - especially for the long-term conservation of several threatened species depending on fast flowing forest streams (Conraua alleni (“Vulnerable”) and Petropedetes natator (“Near Threatened”)) as well as the “Critically Endangered” viviparous toad endemic to the montane grasslands of Mount Nimba (Nimbaphrynoides occidentalis). PMID:23426141

West Africa - a safe haven for frogs? A sub-continental assessment of the chytrid fungus (Batrachochytrium dendrobatidis.

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Johannes Penner

Full Text Available A putative driver of global amphibian decline is the panzootic chytrid fungus Batrachochytrium dendrobatidis (Bd. While Bd has been documented across continental Africa, its distribution in West Africa remains ambiguous. We tested 793 West African amphibians (one caecilian and 61 anuran species for the presence of Bd. The samples originated from seven West African countries - Bénin, Burkina Faso, Côte d'Ivoire, Ghana, Guinea, Liberia, Sierra Leone - and were collected from a variety of habitats, ranging from lowland rainforests to montane forests, montane grasslands to humid and dry lowland savannahs. The species investigated comprised various life-history strategies, but we focused particularly on aquatic and riparian species. We used diagnostic PCR to screen 656 specimen swabs and histology to analyse 137 specimen toe tips. All samples tested negative for Bd, including a widespread habitat generalist Hoplobatrachus occipitalis which is intensively traded on the West African food market and thus could be a potential dispersal agent for Bd. Continental fine-grained (30 arc seconds environmental niche models suggest that Bd should have a broad distribution across West Africa that includes most of the regions and habitats that we surveyed. The surprising apparent absence of Bd in West Africa indicates that the Dahomey Gap may have acted as a natural barrier. Herein we highlight the importance of this Bd-free region of the African continent - especially for the long-term conservation of several threatened species depending on fast flowing forest streams (Conraua alleni ("Vulnerable" and Petropedetes natator ("Near Threatened" as well as the "Critically Endangered" viviparous toad endemic to the montane grasslands of Mount Nimba (Nimbaphrynoides occidentalis.

Integrating chytrid fungal parasites into plankton ecology: research gaps and needs.

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Frenken, Thijs; Alacid, Elisabet; Berger, Stella A; Bourne, Elizabeth C; Gerphagnon, Mélanie; Grossart, Hans-Peter; Gsell, Alena S; Ibelings, Bas W; Kagami, Maiko; Küpper, Frithjof C; Letcher, Peter M; Loyau, Adeline; Miki, Takeshi; Nejstgaard, Jens C; Rasconi, Serena; Reñé, Albert; Rohrlack, Thomas; Rojas-Jimenez, Keilor; Schmeller, Dirk S; Scholz, Bettina; Seto, Kensuke; Sime-Ngando, Télesphore; Sukenik, Assaf; Van de Waal, Dedmer B; Van den Wyngaert, Silke; Van Donk, Ellen; Wolinska, Justyna; Wurzbacher, Christian; Agha, Ramsy

2017-10-01

Chytridiomycota, often referred to as chytrids, can be virulent parasites with the potential to inflict mass mortalities on hosts, causing e.g. changes in phytoplankton size distributions and succession, and the delay or suppression of bloom events. Molecular environmental surveys have revealed an unexpectedly large diversity of chytrids across a wide range of aquatic ecosystems worldwide. As a result, scientific interest towards fungal parasites of phytoplankton has been gaining momentum in the past few years. Yet, we still know little about the ecology of chytrids, their life cycles, phylogeny, host specificity and range. Information on the contribution of chytrids to trophic interactions, as well as co-evolutionary feedbacks of fungal parasitism on host populations is also limited. This paper synthesizes ideas stressing the multifaceted biological relevance of phytoplankton chytridiomycosis, resulting from discussions among an international team of chytrid researchers. It presents our view on the most pressing research needs for promoting the integration of chytrid fungi into aquatic ecology. © 2017 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

First record of the chytrid fungus in Lithobates catesbeianus from Argentina: exotic species and conservation Primer registro del hongo quitridio en Lithobates catesbeianus de Argentina: especies exóticas y conservación

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Romina Ghirardi

2011-12-01

Full Text Available Chytridiomycosis, a disease caused by the chytrid fungus Batrachochytrium dendrobatidis (B.d., is recognized as one of the major factors of amphibian decline. Global trade of amphibians has been identified as one of the causes of B.d. spread, involving hundreds of species world wide. In this work we detected the presence of B.d. through histological examination on 5 out of 9 analyzed specimens of bullfrogs (Lithobates catesbeianus from a farm in Santa Fe City (Argentina, deposited since 1993 in the herpetological collection of the Provincial Museum of Natural Sciences "Florentino Ameghino". Our finding represents the oldest record of B.d. for Argentina and the first case of the chytrid fungus infecting the exotic bullfrog in this country. We emphasize the importance of determining and monitoring the distribution and spread of B.d in Argentina, particularly in areas where feral bullfrog populations have already been identified.La quitridiomicosis, enfermedad emergente producida por el hongo Batrachochytrium dendrobatidis (B.d., es reconocida como uno de los factores causantes de la declinación de anfibios. El comercio mundial de anfibios ha sido señalado como una de las fuentes de dispersión de B.d. En este trabajo se detectó la presencia de B.d. en la especie exótica rana toro (Lithobates catesbeianus mediante cortes histológicos en 5 de 9 ejemplares provenientes de un criadero de la ciudad de Santa Fe (Argentina, depositados y conservados desde 1993 en la Colección Herpetológica del Museo Provincial de Ciencias Naturales "Florentino Ameghino". Este registro representa el hallazgo más antiguo de B.d. en Argentina y el primer caso de este hongo en la rana toro exótica en el país; por lo que enfatizamos la importancia de determinar y monitorear la distribución y dispersión de B.d., particularmente en los sitios donde ya se han detectado poblaciones silvestres de rana toro.

Assessing the Threat of Amphibian Chytrid Fungus in the Albertine Rift: Past, Present and Future

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Seimon, Tracie A.; Ayebare, Samuel; Sekisambu, Robert; Muhindo, Emmanuel; Mitamba, Guillain; Greenbaum, Eli; Menegon, Michele; Pupin, Fabio; McAloose, Denise; Ammazzalorso, Alyssa; Meirte, Danny; Lukwago, Wilbur; Behangana, Mathias; Seimon, Anton; Plumptre, Andrew J.

2015-01-01

Batrachochytrium dendrobatidis (Bd), the cause of chytridiomycosis, is a pathogenic fungus that is found worldwide and is a major contributor to amphibian declines and extinctions. We report results of a comprehensive effort to assess the distribution and threat of Bd in one of the Earth’s most important biodiversity hotspots, the Albertine Rift in central Africa. In herpetological surveys conducted between 2010 and 2014, 1018 skin swabs from 17 amphibian genera in 39 sites across the Albertine Rift were tested for Bd by PCR. Overall, 19.5% of amphibians tested positive from all sites combined. Skin tissue samples from 163 amphibians were examined histologically; of these two had superficial epidermal intracorneal fungal colonization and lesions consistent with the disease chytridiomycosis. One amphibian was found dead during the surveys, and all others encountered appeared healthy. We found no evidence for Bd-induced mortality events, a finding consistent with other studies. To gain a historical perspective about Bd in the Albertine Rift, skin swabs from 232 museum-archived amphibians collected as voucher specimens from 1925–1994 were tested for Bd. Of these, one sample was positive; an Itombwe River frog (Phrynobatrachus asper) collected in 1950 in the Itombwe highlands. This finding represents the earliest record of Bd in the Democratic Republic of Congo. We modeled the distribution of Bd in the Albertine Rift using MaxEnt software, and trained our model for improved predictability. Our model predicts that Bd is currently widespread across the Albertine Rift, with moderate habitat suitability extending into the lowlands. Under climatic modeling scenarios our model predicts that optimal habitat suitability of Bd will decrease causing a major range contraction of the fungus by 2080. Our baseline data and modeling predictions are important for comparative studies, especially if significant changes in amphibian health status or climactic conditions are

Genomic adaptations of the halophilic Dead Sea filamentous fungus Eurotium rubrum.

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Kis-Papo, Tamar; Weig, Alfons R; Riley, Robert; Peršoh, Derek; Salamov, Asaf; Sun, Hui; Lipzen, Anna; Wasser, Solomon P; Rambold, Gerhard; Grigoriev, Igor V; Nevo, Eviatar

2014-05-09

The Dead Sea is one of the most hypersaline habitats on Earth. The fungus Eurotium rubrum (Eurotiomycetes) is among the few species able to survive there. Here we highlight its adaptive strategies, based on genome analysis and transcriptome profiling. The 26.2 Mb genome of E. rubrum shows, for example, gains in gene families related to stress response and losses with regard to transport processes. Transcriptome analyses under different salt growth conditions revealed, among other things differentially expressed genes encoding ion and metabolite transporters. Our findings suggest that long-term adaptation to salinity requires cellular and metabolic responses that differ from short-term osmotic stress signalling. The transcriptional response indicates that halophilic E. rubrum actively counteracts the salinity stress. Many of its genes encode for proteins with a significantly higher proportion of acidic amino acid residues. This trait is characteristic of the halophilic prokaryotes as well, supporting the theory of convergent evolution under extreme hypersaline stress.

Chytrid parasitism facilitates trophic transfer between bloom-forming cyanobacteria and zooplankton (Daphnia).

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Agha, Ramsy; Saebelfeld, Manja; Manthey, Christin; Rohrlack, Thomas; Wolinska, Justyna

2016-10-13

Parasites are rarely included in food web studies, although they can strongly alter trophic interactions. In aquatic ecosystems, poorly grazed cyanobacteria often dominate phytoplankton communities, leading to the decoupling of primary and secondary production. Here, we addressed the interface between predator-prey and host-parasite interactions by conducting a life-table experiment, in which four Daphnia galeata genotypes were maintained on quantitatively comparable diets consisting of healthy cyanobacteria or cyanobacteria infected by a fungal (chytrid) parasite. In four out of five fitness parameters, at least one Daphnia genotype performed better on parasitised cyanobacteria than in the absence of infection. Further treatments consisting of purified chytrid zoospores and heterotrophic bacteria suspensions established the causes of improved fitness. First, Daphnia feed on chytrid zoospores which trophically upgrade cyanobacterial carbon. Second, an increase in heterotrophic bacterial biomass, promoted by cyanobacterial decay, provides an additional food source for Daphnia. In addition, chytrid infection induces fragmentation of cyanobacterial filaments, which could render cyanobacteria more edible. Our results demonstrate that chytrid parasitism can sustain zooplankton under cyanobacterial bloom conditions, and exemplify the potential of parasites to alter interactions between trophic levels.

Nothing a hot bath won't cure: infection rates of amphibian chytrid fungus correlate negatively with water temperature under natural field settings.

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Forrest, Matthew J; Schlaepfer, Martin A

2011-01-01

Dramatic declines and extinctions of amphibian populations throughout the world have been associated with chytridiomycosis, an infectious disease caused by the pathogenic chytrid fungus Batrachochytrium dendrobatidis (Bd). Previous studies indicated that Bd prevalence correlates with cooler temperatures in the field, and laboratory experiments have demonstrated that Bd ceases growth at temperatures above 28°C. Here we investigate how small-scale variations in water temperature correlate with Bd prevalence in the wild. We sampled 221 amphibians, including 201 lowland leopard frogs (Rana [Lithobates] yavapaiensis), from 12 sites in Arizona, USA, and tested them for Bd. Amphibians were encountered in microhabitats that exhibited a wide range of water temperatures (10-50°C), including several geothermal water sources. There was a strong inverse correlation between the water temperature in which lowland leopard frogs were captured and Bd prevalence, even after taking into account the influence of year, season, and host size. In locations where Bd was known to be present, the prevalence of Bd infections dropped from 75-100% in water 30°C. A strong inverse correlation between Bd infection status and water temperature was also observed within sites. Our findings suggest that microhabitats where water temperatures exceed 30°C provide lowland leopard frogs with significant protection from Bd, which could have important implications for disease dynamics, as well as management applications.There must be quite a few things a hot bath won't cure, but I don't know many of them--Sylvia Plath, "The Bell Jar" (1963).

Nothing a hot bath won't cure: infection rates of amphibian chytrid fungus correlate negatively with water temperature under natural field settings.

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Matthew J Forrest

Full Text Available Dramatic declines and extinctions of amphibian populations throughout the world have been associated with chytridiomycosis, an infectious disease caused by the pathogenic chytrid fungus Batrachochytrium dendrobatidis (Bd. Previous studies indicated that Bd prevalence correlates with cooler temperatures in the field, and laboratory experiments have demonstrated that Bd ceases growth at temperatures above 28°C. Here we investigate how small-scale variations in water temperature correlate with Bd prevalence in the wild. We sampled 221 amphibians, including 201 lowland leopard frogs (Rana [Lithobates] yavapaiensis, from 12 sites in Arizona, USA, and tested them for Bd. Amphibians were encountered in microhabitats that exhibited a wide range of water temperatures (10-50°C, including several geothermal water sources. There was a strong inverse correlation between the water temperature in which lowland leopard frogs were captured and Bd prevalence, even after taking into account the influence of year, season, and host size. In locations where Bd was known to be present, the prevalence of Bd infections dropped from 75-100% in water 30°C. A strong inverse correlation between Bd infection status and water temperature was also observed within sites. Our findings suggest that microhabitats where water temperatures exceed 30°C provide lowland leopard frogs with significant protection from Bd, which could have important implications for disease dynamics, as well as management applications.There must be quite a few things a hot bath won't cure, but I don't know many of them--Sylvia Plath, "The Bell Jar" (1963.

Rapid Response to Evaluate the Presence of Amphibian Chytrid Fungus (Batrachochytrium dendrobatidis) and Ranavirus in Wild Amphibian Populations in Madagascar

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Kolby, Jonathan E.; Smith, Kristine M.; Ramirez, Sara D.; Rabemananjara, Falitiana; Pessier, Allan P.; Brunner, Jesse L.; Goldberg, Caren S.; Berger, Lee; Skerratt, Lee F.

2015-01-01

We performed a rapid response investigation to evaluate the presence and distribution of amphibian pathogens in Madagascar following our identification of amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) and ranavirus in commercially exported amphibians. This targeted risk-based field surveillance program was conducted from February to April 2014 encompassing 12 regions and 47 survey sites. We simultaneously collected amphibian and environmental samples to increase survey sensitivity and performed sampling both in wilderness areas and commercial amphibian trade facilities. Bd was not detected in any of 508 amphibian skin swabs or 68 water filter samples, suggesting pathogen prevalence was below 0.8%, with 95% confidence during our visit. Ranavirus was detected in 5 of 97 amphibians, including one adult Mantidactylus cowanii and three unidentified larvae from Ranomafana National Park, and one adult Mantidactylus mocquardi from Ankaratra. Ranavirus was also detected in water samples collected from two commercial amphibian export facilities. We also provide the first report of an amphibian mass-mortality event observed in wild amphibians in Madagascar. Although neither Bd nor ranavirus appeared widespread in Madagascar during this investigation, additional health surveys are required to disentangle potential seasonal variations in pathogen abundance and detectability from actual changes in pathogen distribution and rates of spread. Accordingly, our results should be conservatively interpreted until a comparable survey effort during winter months has been performed. It is imperative that biosecurity practices be immediately adopted to limit the unintentional increased spread of disease through the movement of contaminated equipment or direct disposal of contaminated material from wildlife trade facilities. The presence of potentially introduced strains of ranaviruses suggests that Madagascar's reptile species might also be threatened by disease

Rapid Response to Evaluate the Presence of Amphibian Chytrid Fungus (Batrachochytrium dendrobatidis and Ranavirus in Wild Amphibian Populations in Madagascar.

Directory of Open Access Journals (Sweden)

Jonathan E Kolby

Full Text Available We performed a rapid response investigation to evaluate the presence and distribution of amphibian pathogens in Madagascar following our identification of amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd and ranavirus in commercially exported amphibians. This targeted risk-based field surveillance program was conducted from February to April 2014 encompassing 12 regions and 47 survey sites. We simultaneously collected amphibian and environmental samples to increase survey sensitivity and performed sampling both in wilderness areas and commercial amphibian trade facilities. Bd was not detected in any of 508 amphibian skin swabs or 68 water filter samples, suggesting pathogen prevalence was below 0.8%, with 95% confidence during our visit. Ranavirus was detected in 5 of 97 amphibians, including one adult Mantidactylus cowanii and three unidentified larvae from Ranomafana National Park, and one adult Mantidactylus mocquardi from Ankaratra. Ranavirus was also detected in water samples collected from two commercial amphibian export facilities. We also provide the first report of an amphibian mass-mortality event observed in wild amphibians in Madagascar. Although neither Bd nor ranavirus appeared widespread in Madagascar during this investigation, additional health surveys are required to disentangle potential seasonal variations in pathogen abundance and detectability from actual changes in pathogen distribution and rates of spread. Accordingly, our results should be conservatively interpreted until a comparable survey effort during winter months has been performed. It is imperative that biosecurity practices be immediately adopted to limit the unintentional increased spread of disease through the movement of contaminated equipment or direct disposal of contaminated material from wildlife trade facilities. The presence of potentially introduced strains of ranaviruses suggests that Madagascar's reptile species might also be threatened by

Rapid Response to Evaluate the Presence of Amphibian Chytrid Fungus (Batrachochytrium dendrobatidis) and Ranavirus in Wild Amphibian Populations in Madagascar.

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Kolby, Jonathan E; Smith, Kristine M; Ramirez, Sara D; Rabemananjara, Falitiana; Pessier, Allan P; Brunner, Jesse L; Goldberg, Caren S; Berger, Lee; Skerratt, Lee F

2015-01-01

We performed a rapid response investigation to evaluate the presence and distribution of amphibian pathogens in Madagascar following our identification of amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) and ranavirus in commercially exported amphibians. This targeted risk-based field surveillance program was conducted from February to April 2014 encompassing 12 regions and 47 survey sites. We simultaneously collected amphibian and environmental samples to increase survey sensitivity and performed sampling both in wilderness areas and commercial amphibian trade facilities. Bd was not detected in any of 508 amphibian skin swabs or 68 water filter samples, suggesting pathogen prevalence was below 0.8%, with 95% confidence during our visit. Ranavirus was detected in 5 of 97 amphibians, including one adult Mantidactylus cowanii and three unidentified larvae from Ranomafana National Park, and one adult Mantidactylus mocquardi from Ankaratra. Ranavirus was also detected in water samples collected from two commercial amphibian export facilities. We also provide the first report of an amphibian mass-mortality event observed in wild amphibians in Madagascar. Although neither Bd nor ranavirus appeared widespread in Madagascar during this investigation, additional health surveys are required to disentangle potential seasonal variations in pathogen abundance and detectability from actual changes in pathogen distribution and rates of spread. Accordingly, our results should be conservatively interpreted until a comparable survey effort during winter months has been performed. It is imperative that biosecurity practices be immediately adopted to limit the unintentional increased spread of disease through the movement of contaminated equipment or direct disposal of contaminated material from wildlife trade facilities. The presence of potentially introduced strains of ranaviruses suggests that Madagascar's reptile species might also be threatened by disease

Salamander chytrid fungus (Batrachochytrium salamandrivorans) in the United States—Developing research, monitoring, and management strategies

Science.gov (United States)

Grant, Evan H. Campbell; Muths, Erin L.; Katz, Rachel A.; Canessa, Stefano; Adams, Michael J.; Ballard, Jennifer R.; Berger, Lee; Briggs, Cheryl J.; Coleman, Jeremy; Gray, Matthew J.; Harris, M. Camille; Harris, Reid N.; Hossack, Blake R.; Huyvaert, Kathryn P.; Kolby, Jonathan E.; Lips, Karen R.; Lovich, Robert E.; McCallum, Hamish I.; Mendelson, Joseph R.; Nanjappa, Priya; Olson, Deanna H.; Powers, Jenny G.; Richgels, Katherine L. D.; Russell, Robin E.; Schmidt, Benedikt R.; Spitzen-van der Sluijs, Annemarieke; Watry, Mary Kay; Woodhams, Douglas C.; White, C. LeAnn

2016-01-20

The recently (2013) identified pathogenic chytrid fungus, Batrachochytrium salamandrivorans (Bsal), poses a severe threat to the distribution and abundance of salamanders within the United States and Europe. Development of a response strategy for the potential, and likely, invasion of Bsal into the United States is crucial to protect global salamander biodiversity. A formal working group, led by Amphibian Research and Monitoring Initiative (ARMI) scientists from the U.S. Geological Survey (USGS) Patuxent Wildlife Research Center, Fort Collins Science Center, and Forest and Rangeland Ecosystem Science Center, was held at the USGS Powell Center for Analysis and Synthesis in Fort Collins, Colorado, United States from June 23 to June 25, 2015, to identify crucial Bsal research and monitoring needs that could inform conservation and management strategies for salamanders in the United States. Key findings of the workshop included the following: (1) the introduction of Bsal into the United States is highly probable, if not inevitable, thus requiring development of immediate short-term and long-term intervention strategies to prevent Bsal establishment and biodiversity decline; (2) management actions targeted towards pathogen containment may be ineffective in reducing the long-term spread of Bsal throughout the United States; and (3) early detection of Bsal through surveillance at key amphibian import locations, among high-risk wild populations, and through analysis of archived samples is necessary for developing management responses. Top research priorities during the preinvasion stage included the following: (1) deployment of qualified diagnostic methods for Bsal and establishment of standardized laboratory practices, (2) assessment of susceptibility for amphibian hosts (including anurans), and (3) development and evaluation of short- and long-term pathogen intervention and management strategies. Several outcomes were achieved during the workshop, including development

Low prevalence of chytrid fungus (Batrachochytrium dendrobatidis) in amphibians of U.S

Science.gov (United States)

Blake R. Hossack; Michael J. Adams; Evan H. Campbell Grant; Christopher A. Pearl; James B. Bettaso; William J. Barichivich; Winsor H. Lowe; Kimberly True; Joy L. Ware; Paul Stephen Corn

2010-01-01

Many declines of amphibian populations have been associated with chytridiomycosis, a disease caused by the aquatic fungus Batrachochytrium dendrobatidis (Bd). Despite the relatively high prevalence of chytridiomycosis in stream amphibians globally, most surveys in North America have focused primarily on wetland-associated species, which are frequently infected. To...

Genetic evidence for a high diversity and wide distribution of endemic strains of the pathogenic chytrid fungus Batrachochytrium dendrobatidis in wild Asian amphibians.

Science.gov (United States)

Bataille, Arnaud; Fong, Jonathan J; Cha, Moonsuk; Wogan, Guinevere O U; Baek, Hae Jun; Lee, Hang; Min, Mi-Sook; Waldman, Bruce

2013-08-01

Population declines and extinctions of amphibians have been attributed to the chytrid fungus Batrachochytrium dendrobatidis (Bd), especially one globally emerging recombinant lineage ('Bd-GPL'). We used PCR assays that target the ribosomal internal transcribed spacer region (ITS) of Bd to determine the prevalence and genetic diversity of Bd in South Korea, where Bd is widely distributed but is not known to cause morbidity or mortality in wild populations. We isolated Korean Bd strains from native amphibians with low infection loads and compared them to known worldwide Bd strains using 19 polymorphic SNP and microsatellite loci. Bd prevalence ranged between 12.5 and 48.0%, in 11 of 17 native Korean species, and 24.7% in the introduced bullfrog Lithobates catesbeianus. Based on ITS sequence variation, 47 of the 50 identified Korean haplotypes formed a group closely associated with a native Brazilian Bd lineage, separated from the Bd-GPL lineage. However, multilocus genotyping of three Korean Bd isolates revealed strong divergence from both Bd-GPL and the native Brazilian Bd lineages. Thus, the ITS region resolves genotypes that diverge from Bd-GPL but otherwise generates ambiguous phylogenies. Our results point to the presence of highly diversified endemic strains of Bd across Asian amphibian species. The rarity of Bd-GPL-associated haplotypes suggests that either this lineage was introduced into Korea only recently or Bd-GPL has been outcompeted by native Bd strains. Our results highlight the need to consider possible complex interactions among native Bd lineages, Bd-GPL and their associated amphibian hosts when assessing the spread and impact of Bd-GPL on worldwide amphibian populations. © 2013 John Wiley & Sons Ltd.

Long-term monitoring of tropical alpine habitat change, Andean anurans, and chytrid fungus in the Cordillera Vilcanota, Peru: Results from a decade of study.

Science.gov (United States)

Seimon, Tracie A; Seimon, Anton; Yager, Karina; Reider, Kelsey; Delgado, Amanda; Sowell, Preston; Tupayachi, Alfredo; Konecky, Bronwen; McAloose, Denise; Halloy, Stephan

2017-03-01

The Cordillera Vilcanota in southern Peru is the second largest glacierized range in the tropics and home to one of the largest high-alpine lakes, Sibinacocha (4,860 m). Here, Telmatobius marmoratus (marbled water frog), Rhinella spinulosa (Andean toad), and Pleurodema marmoratum (marbled four-eyed frog) have expanded their range vertically within the past century to inhabit newly formed ponds created by ongoing deglaciation. These anuran populations, geographically among the highest (5,200-5,400 m) recorded globally, are being impacted by the chytrid fungus Batrachochytrium dendrobatidis ( Bd ), and the disease it causes, chytridiomycosis. In this study, we report results from over a decade of monitoring these three anuran species, their habitat, and Bd infection status. Our observations reveal dynamic changes in habitat including ongoing rapid deglaciation (18.4 m/year widening of a corridor between retreating glaciers from 2005 to 2015), new pond formation, changes in vegetation in amphibian habitat, and widespread occurrence of Bd in amphibians in seven sites. Three of these sites have tested positive for Bd over a 9- to 12-year period. In addition, we observed a widespread reduction in T. marmoratus encounters in the Vilcanota in 2008, 2009, and 2012, while encounters increased in 2013 and 2015. Despite the rapid and dynamic changes in habitat under a warming climate, continued presence of Bd in the environment for over a decade, and a reduction in one of three anuran species, we document that these anurans continue to breed and survive in this high Andean environment. High variability in anuran encounters across sites and plasticity in these populations across habitats, sites, and years are all factors that could favor repopulation postdecline. Preserving the connectivity of wetlands in the Cordillera Vilcanota is therefore essential in ensuring that anurans continue to breed and adapt as climate change continues to reshape the environment.

The effects of α-cellulose extraction and blue-stain fungus on retrospective studies of carbon and oxygen isotope variation in live and dead trees.

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English, Nathan B; McDowell, Nate G; Allen, Craig D; Mora, Claudia

2011-10-30

Tree-ring carbon and oxygen isotope ratios from live and recently dead trees may reveal important mechanisms of tree mortality. However, wood decay in dead trees may alter the δ(13)C and δ(18)O values of whole wood obscuring the isotopic signal associated with factors leading up to and including physiological death. We examined whole sapwood and α-cellulose from live and dead specimens of ponderosa pine (Pinus ponderosa), one-seed juniper (Juniperous monosperma), piñon pine (Pinus edulis) and white fir (Abies concolor), including those with fungal growth and beetle frass in the wood, to determine if α-cellulose extraction is necessary for the accurate interpretation of isotopic compositions in the dead trees. We found that the offset between the δ(13)C or δ(18)O values of α-cellulose and whole wood was the same for both live and dead trees across a large range of inter-annual and regional climate differences. The method of α-cellulose extraction, whether Leavitt-Danzer or Standard Brendel modified for small samples, imparts significant differences in the δ(13)C (up to 0.4‰) and δ(18) O (up to 1.2‰) of α-cellulose, as reported by other studies. There was no effect of beetle frass or blue-stain fungus (Ophiostoma) on the δ(13)C and δ(18)O of whole wood or α-cellulose. The relationships between whole wood and α-cellulose δ(13)C for ponderosa, piñon and juniper yielded slopes of ~1, while the relationship between δ(18)O of whole wood and α-cellulose was less clear. We conclude that there are few analytical or sampling obstacles to retrospective studies of isotopic patterns of tree mortality in forests of the western United States. Published in 2011 by John Wiley & Sons, Ltd.

The effects of α-cellulose extraction and blue-stain fungus on retrospective studies of carbon and oxygen isotope variation in live and dead trees†

Science.gov (United States)

English, N.B.; McDowell, N.G.; Allen, Craig D.; Mora, C.

2011-01-01

Tree-ring carbon and oxygen isotope ratios from live and recently dead trees may reveal important mechanisms of tree mortality. However, wood decay in dead trees may alter the δ13C and δ18O values of whole wood obscuring the isotopic signal associated with factors leading up to and including physiological death. We examined whole sapwood and α-cellulose from live and dead specimens of ponderosa pine (Pinus ponderosa), one-seed juniper (Juniperous monosperma), piñon pine (Pinus edulis) and white fir (Abies concolor), including those with fungal growth and beetle frass in the wood, to determine if α-cellulose extraction is necessary for the accurate interpretation of isotopic compositions in the dead trees. We found that the offset between the δ13C or δ18O values of α-cellulose and whole wood was the same for both live and dead trees across a large range of inter-annual and regional climate differences. The method of α-cellulose extraction, whether Leavitt-Danzer or Standard Brendel modified for small samples, imparts significant differences in the δ13C (up to 0.4‰) and δ18O (up to 1.2‰) of α-cellulose, as reported by other studies. There was no effect of beetle frass or blue-stain fungus (Ophiostoma) on the δ13C and δ18O of whole wood or α-cellulose. The relationships between whole wood and α-cellulose δ13C for ponderosa, piñon and juniper yielded slopes of ~1, while the relationship between δ18O of whole wood and α-cellulose was less clear. We conclude that there are few analytical or sampling obstacles to retrospective studies of isotopic patterns of tree mortality in forests of the western United States.

Chytrid fungus acts as a generalist pathogen infecting species-rich amphibian families in Brazilian rainforests.

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Valencia-Aguilar, Anyelet; Ruano-Fajardo, Gustavo; Lambertini, Carolina; da Silva Leite, Domingos; Toledo, Luís Felipe; Mott, Tamí

2015-05-11

The fungus Batrachochytrium dendrobatidis (Bd) is among the main causes of declines in amphibian populations. This fungus is considered a generalist pathogen because it infects several species and spreads rapidly in the wild. To date, Bd has been detected in more than 100 anuran species in Brazil, mostly in the southern portion of the Atlantic forest. Here, we report survey data from some poorly explored regions; these data considerably extend current information on the distribution of Bd in the northern Atlantic forest region. In addition, we tested the hypothesis that Bd is a generalist pathogen in this biome. We also report the first positive record for Bd in an anuran caught in the wild in Amazonia. In total, we screened 90 individuals (from 27 species), of which 39 individuals (from 22 species) were Bd-positive. All samples collected in Bahia (2 individuals), Pernambuco (3 individuals), Pará (1 individual), and Minas Gerais (1 individual) showed positive results for Bd. We found a positive correlation between anuran richness per family and the number of infected species in the Atlantic forest, supporting previous observations that Bd lacks strong host specificity; of 38% of the anuran species in the Atlantic forest that were tested for Bd infection, 25% showed positive results. The results of our study exemplify the pandemic and widespread nature of Bd infection in amphibians.

Genetic diversity and population structure of Raffaelea quercus-mongolicae, a fungus associated with oak mortality in South Korea

Science.gov (United States)

M. -S. Kim; P. A. Hohenlohe; K. -H. Kim; S. -T. Seo; Ned Klopfenstein

2016-01-01

Raffaelea quercus-mongolicae is a fungus associated with oak wilt and deemed to cause extensive oak mortality in South Korea. Since the discovery of this fungus on a dead Mongolian oak (Quercus mongolica) in 2004, the mortality continued to spread southwards in South Korea. Despite continued expansion of the disease and associated significant impacts on forest...

Extra and intracellular synthesis of nickel oxide nanoparticles mediated by dead fungal biomass.

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Marcia Regina Salvadori

Full Text Available The use of dead biomass of the fungus Hypocrea lixii as a biological system is a new, effective and environmentally friendly bioprocess for the production and uptake of nickel oxide nanoparticles (NPs, which has become a promising field in nanobiotechnology. Dead biomass of the fungus was successfully used to convert nickel ions into nickel oxide NPs in aqueous solution. These NPs accumulated intracellularly and extracellularly on the cell wall surface through biosorption. The average size, morphology and location of the NPs were characterized by transmission electron microscopy, high-resolution transmission electron microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. The NPs were mainly spherical and extra and intracellular NPs had an average size of 3.8 nm and 1.25 nm, respectively. X-ray photoelectron spectroscopy analysis confirmed the formation of nickel oxide NPs. Infrared spectroscopy detected the presence of functional amide groups, which are probable involved in particle binding to the biomass. The production of the NPs by dead biomass was analyzed by determining physicochemical parameters and equilibrium concentrations. The present study opens new perspectives for the biosynthesis of nanomaterials, which could become a potential biosorbent for the removal of toxic metals from polluted sites.

Priority effects of early successional insects influence late successional fungi in dead wood.

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Jacobsen, Rannveig Margrete; Birkemoe, Tone; Sverdrup-Thygeson, Anne

2015-11-01

Community assembly is an integral process in all ecosystems, producing patterns of species distributions, biodiversity, and ecosystem functioning. Environmental filters and colonization history govern the assembly process, but their relative importance varies depending on the study system. Dead wood decomposition is a slow process, allowing decomposer communities to develop within a slowly changing substrate for decades. Despite this, there are few long-term studies of priority effects from colonization history in this ecosystem. In this study, we investigate the importance of insects in early succession of dead wood on the fungal community present one decade later. Sixty aspen trees were killed in two study landscapes, each tree producing one aspen high stump and log. Insects were sampled with flight interception traps during the first 4 years after tree death, and fungal fruiting bodies were registered in year twelve. We found positive priority effects of two fungivorous beetles, the sap beetle Glischrochilus quadripunctatus and the round fungus beetle Agathidium nigripenne, on the Artist's bracket (Ganoderma applanatum) and a positive priority effect of wood-boring beetles on the ascomycete Yellow fairy cup (Bisporella citrina). The Aspen bracket (Phellinus tremulae) did not respond to insects in early succession of the dead wood. Our results suggest that early successional insects can have significant, long-lasting effects on the late successional fungal community in dead wood. Also, the effect can be specific, with one fungus species depending on one or a few fungivorous beetle species. This has implications for decomposition and biodiversity in dead wood, as loss of early colonizing beetles may also affect the successional pathways they seem to initiate.

Pseudacris triseriata (western chorus frog) and Rana sylvatica (wood frog) chytridiomycosis

Science.gov (United States)

Rittman, S.E.; Muths, E.; Green, D.E.

2003-01-01

The chytrid fungus Batrachochytrium dendrobatidis is a known pathogen of anuran amphibians, and has been correlated with amphibian die-offs worldwide (Daszak et. al. 1999. Emerging Infectious Diseases 5:735-748). In Colorado, B. dendrobatidis has infected Boreal toads (Bufo boreas) (Muths et. al., in review) and has been identified on museum specimens of northern leopard frogs (Rana pipiens) (Carey et. al. 1999. Develop. Comp. Immunol. 23:459-472). We report the first verified case of chytrid fungus in chorus frogs (Pseudacris triseriata) and wood frogs (Rana sylvatica) in the United States. We collected seven P. triseriata, and two adult and two juvenile R. sylvatica in the Kawuneeche Valley in Rocky Mountain National Park (RMNP) during June 2001. These animals were submitted to the National Wildlife Health Center (NWHC) as part of an amphibian health evaluation in RMNP. Chorus frogs were shipped in one container. Wood frog adults and juveniles were shipped in two separate containers. Histological examinations of all chorus frogs and 3 of 4 wood frogs were positive for chytrid fungus infection. The fourth (adult) wood frog was too decomposed for meaningful histology. Histological findings consisted of multifocally mild to diffusely severe infections of the epidermis of the ventrum and hindlimb digital skin. Chytrid thalli were confined to the thickened epidermis (hyperkeratosis), were spherical to oval, and occasional thalli contained characteristic discharge pores or zoospores (Green and Kagarise Sherman 1999. J. Herpetol 35:92-103; Fellers et al. 2001. Copeia 2001:945-953). We cannot confirm that all specimens carried the fungus at collection, because infection may have spread from one individual to all other individuals in each container during transport. Further sampling of amphibians in Kawuneeche Valley is warranted to determine the rate of infection and mortality in these populations.

Unlikely remedy: fungicide clears infection from pathogenic fungus in larval southern leopard frogs (Lithobates sphenocephalus.

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Shane M Hanlon

Full Text Available Amphibians are often exposed to a wide variety of perturbations. Two of these, pesticides and pathogens, are linked to declines in both amphibian health and population viability. Many studies have examined the separate effects of such perturbations; however, few have examined the effects of simultaneous exposure of both to amphibians. In this study, we exposed larval southern leopard frog tadpoles (Lithobates sphenocephalus to the chytrid fungus Batrachochytrium dendrobatidis and the fungicide thiophanate-methyl (TM at 0.6 mg/L under laboratory conditions. The experiment was continued until all larvae completed metamorphosis or died. Overall, TM facilitated increases in tadpole mass and length. Additionally, individuals exposed to both TM and Bd were heavier and larger, compared to all other treatments. TM also cleared Bd in infected larvae. We conclude that TM affects larval anurans to facilitate growth and development while clearing Bd infection. Our findings highlight the need for more research into multiple perturbations, specifically pesticides and disease, to further promote amphibian heath.

Efficacy of Entomopathogenic Fungus Beauveria Bassiana and Gamma Irradiation Against the Greater Date Moth, Arenipses Sabella

International Nuclear Information System (INIS)

Mikhaiel, A.A.; Abul Fadl, H.A.A.

2011-01-01

The fungus Beauveria bassiana (Bals.) was isolated locally from dead larvae of the greater date moth, Arenipses sabella (Hampson) (Lepidoptera: Pyralidae). The effect of three exposure methods and two environmental factors (temperature and relative humidity) on pathogenicity of the fungus with different concentrations to A. sabella second instar larvae were examined. The study demonstrated that the entomopathogenic fungus was most efficient in the control of second instar larvae at 25 degree C and 100% humidity and the percent of mortality was increased when increasing the concentration of fungus. The mode of exposure of fungus to larvae directly sprayed, larvae exposed to the treated dates or larvae both sprayed and exposed to the treated dates showed 56.66, 26.66 and 75% mortality, respectively, at concentration 1x10 10 spores/ml and three days post-treatment. The F1 larvae resulting from irradiated male pupae with 150 Gy were more susceptible to pathogenic fungus at low concentration ((1x10 8 spores/ml) than non-irradiated ones. The scanning electron microscope was used to delineate the morphological stages of fungus to the germinated conidia and the hyphae penetrating the larva cuticle.

Evidence of disease-related amphibian decline in Colorado

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Muths, Erin; Corn, Paul Stephen; Pessier, Allan P.; Green, D. Earl

2003-01-01

The recent discovery of a pathogenic fungus (Batrachochytrium dendrobatidis) associated with declines of frogs in the American and Australian tropics, suggests that at least the proximate cause, may be known for many previously unexplained amphibian declines. We have monitored boreal toads in Colorado since 1991 at four sites using capturea??recapture of adults and counts of egg masses to examine the dynamics of this metapopulation. Numbers of male toads declined in 1996 and 1999 with annual survival rate averaging 78% from 1991 to 1994, 45% in 1995 and 3% between 1998 and 1999. Numbers of egg masses also declined. An etiological diagnosis of chytridiomycosis consistent with infections by the genus Batrachochytrium was made in six wild adult toads. Characteristic histomorphological features (i.e. intracellular location, shape of thalli, presence of discharge tubes and rhizoids) of chytrid organisms, and host tissue response (acanthosis and hyperkeratosis) were observed in individual toads. These characteristics were indistinguishable from previously reported mortality events associated with chytrid fungus. We also observed epizootiological features consistent with mortality events associated with chytrid fungus: an increase in the ratio of female:male toads captured, an apparent spread of mortalities within the metapopulation and mortalities restricted to post metamorphic animals. Eleven years of population data suggest that this metapopulation of toads is in danger of extinction, pathological and epizootiological evidence indicates that B. dendrobatidis has played a proximate role in this process

Low prevalence of chytrid fungus (Batrachochytrium dendrobatidis) in amphibians of U.S. headwater streams

Science.gov (United States)

Hossack, Blake R.; Adams, Michael J.; Campbell Grant, Evan H.; Pearl, Chistopher A.; Bettaso, James B.; Barichivich, William J.; Lowe, Winsor H.; True, Kimberly; Ware, Joy L.; Corn, Paul Stephen

2010-01-01

Many declines of amphibian populations have been associated with chytridiomycosis, a disease caused by the aquatic fungus Batrachochytrium dendrobatidis (Bd). Despite the relatively high prevalence of chytridiomycosis in stream amphibians globally, most surveys in North America have focused primarily on wetland-associated species, which are frequently infected. To better understand the distribution and prevalence of Bd in headwater amphibian communities, we sampled 452 tailed frogs (Ascaphus truei and Ascaphus montanus) and 304 stream salamanders (seven species in the Dicamptodontidae and Plethodontidae) for Bd in 38, first- to third-order streams in five montane areas across the United States. We tested for presence of Bd by using PCR on skin swabs from salamanders and metamorphosed tailed frogs or the oral disc of frog larvae. We detected Bd on only seven individuals (0.93%) in four streams. Based on our study and results from five other studies that have sampled headwater- or seep-associated amphibians in the United States, Bd has been detected on only 3% of 1,322 individuals from 21 species. These results differ strongly from surveys in Central America and Australia, where Bd is more prevalent on stream-breeding species, as well as results from wetland-associated anurans in the same regions of the United States that we sampled. Differences in the prevalence of Bd between stream- and wetland-associated amphibians in the United States may be related to species-specific variation in susceptibility to chytridiomycosis or habitat differences.

Quantitative Proteomics of an Amphibian Pathogen, Batrachochytrium dendrobatidis, following Exposure to Thyroid Hormone

OpenAIRE

Thekkiniath, Jose; Zabet-Moghaddam, Masoud; Kottapalli, Kameswara Rao; Pasham, Mithun R.; San Francisco, Susan; San Francisco, Michael

2015-01-01

Batrachochytrium dendrobatidis (Bd), a chytrid fungus, has increasingly been implicated as a major factor in the worldwide decline of amphibian populations. The fungus causes chytridiomycosis in susceptible species leading to massive die-offs of adult amphibians. Although Bd infects the keratinized mouthparts of tadpoles and negatively affects foraging behavior, these infections are non-lethal. An important morphogen controlling amphibian metamorphosis is thyroid hormone (T3). Tadpoles may be...

Using the fungus Entomophthora muscae (chon Fresenius to eliminate some larval roles of Musca domestica

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Walaa Yas Lahmood

2017-07-01

Full Text Available Studied effect serial concentrations from spores filtrate of fungus Entomophthora muscae on some larval roles of musca domestica in laboratory. Results were made clear that the insect roles are sensitive to fungus, and treated the food larva of musca domestica and sprinkle it by concentration 2.8×106 , 2.8×107, 2.8×108 (spore/ml has led to get rates of destruction of cumulative faculty certified on the concentration and time its magnitude 16.60 , 47.67, 53.30 % respectively , also recorded some phenotypic distortion infected dead larva represent by contraction and blackening body. The treatment of pupael by sprinkling the previous fungus concentration recorded rate of destruction of accumulative faculty its magnitude 13.33, 26.67, 33.33% respectively, also the rates emergence of adults ranged between 66.67 – 86.67 % in comparison with rates of emergence of adults in control treatment 96.67% The results are made clear that adults treatment by sprinkle with last concentration from fungus spore filtrate recorded rates of distraction its magnitude 46.61, 56.67, 70% respectively after one week from treatment .

Love the dead, fear the dead

DEFF Research Database (Denmark)

Seebach, Sophie Hooge

2017-01-01

The dead are everywhere in the landscape in Acholi, northern Uganda. In the homes, the dead are present through their gravesites, situated next to houses and huts, and as spiritual presences in their family’s daily lives. In the bush, the dead are present as a constant potentiality, in the form...

Ethanol Production from Various Sugars and Cellulosic Biomass by White Rot Fungus Lenzites betulinus.

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Im, Kyung Hoan; Nguyen, Trung Kien; Choi, Jaehyuk; Lee, Tae Soo

2016-03-01

Lenzites betulinus, known as gilled polypore belongs to Basidiomycota was isolated from fruiting body on broadleaf dead trees. It was found that the mycelia of white rot fungus Lenzites betulinus IUM 5468 produced ethanol from various sugars, including glucose, mannose, galactose, and cellobiose with a yield of 0.38, 0.26, 0.07, and 0.26 g of ethanol per gram of sugar consumed, respectively. This fungus relatively exhibited a good ethanol production from xylose at 0.26 g of ethanol per gram of sugar consumed. However, the ethanol conversion rate of arabinose was relatively low (at 0.07 g of ethanol per gram sugar). L. betulinus was capable of producing ethanol directly from rice straw and corn stalks at 0.22 g and 0.16 g of ethanol per gram of substrates, respectively, when this fungus was cultured in a basal medium containing 20 g/L rice straw or corn stalks. These results indicate that L. betulinus can produce ethanol efficiently from glucose, mannose, and cellobiose and produce ethanol very poorly from galactose and arabinose. Therefore, it is suggested that this fungus can ferment ethanol from various sugars and hydrolyze cellulosic materials to sugars and convert them to ethanol simultaneously.

The life of a dead ant -the expression of an adaptive extended phenotype

DEFF Research Database (Denmark)

Andersen, Sandra Breum; Gerritsma, Sylvia; Yusah, Kalsum M.

2009-01-01

to make hosts bite onto vegetation prior to killing them. We show that this represents a fine-tuned fungal adaptation: an extended phenotype. Dead ants were found under leaves, attached by their mandibles, on the northern side of saplings ca. 25 cm above the soil, where temperature and humidity conditions......Specialized parasites are expected to express complex adaptations to their hosts. Manipulation of host behavior is such an adaptation. We studied the fungus Ophiocordyceps unilateralis, a locally specialized parasite of arboreal Camponotus leonardi ants. Ant-infecting Ophiocordyceps are known...

Fungal infection intensity and zoospore output of Atelopus zeteki, a potential acute chytrid supershedder.

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Graziella V Direnzo

Full Text Available Amphibians vary in their response to infection by the amphibian-killing chytrid fungus, Batrachochytrium dendrobatidis (Bd. Highly susceptible species are the first to decline and/or disappear once Bd arrives at a site. These competent hosts likely facilitate Bd proliferation because of ineffective innate and/or acquired immune defenses. We show that Atelopus zeteki, a highly susceptible species that has undergone substantial population declines throughout its range, rapidly and exponentially increases skin Bd infection intensity, achieving intensities that are several orders of magnitude greater than most other species reported. We experimentally infected individuals that were never exposed to Bd (n = 5 or previously exposed to an attenuated Bd strain (JEL427-P39; n = 3. Within seven days post-inoculation, the average Bd infection intensity was 18,213 zoospores (SE: 9,010; range: 0 to 66,928. Both average Bd infection intensity and zoospore output (i.e., the number of zoospores released per minute by an infected individual increased exponentially until time of death (t50 = 7.018, p<0.001, t46 = 3.164, p = 0.001, respectively. Mean Bd infection intensity and zoospore output at death were 4,334,422 zoospores (SE: 1,236,431 and 23.55 zoospores per minute (SE: 22.78, respectively, with as many as 9,584,158 zoospores on a single individual. The daily percent increases in Bd infection intensity and zoospore output were 35.4% (SE: 0.05 and 13.1% (SE: 0.04, respectively. We also found that Bd infection intensity and zoospore output were positively correlated (t43 = 3.926, p<0.001. All animals died between 22 and 33 days post-inoculation (mean: 28.88; SE: 1.58. Prior Bd infection had no effect on survival, Bd infection intensity, or zoospore output. We conclude that A. zeteki, a highly susceptible amphibian species, may be an acute supershedder. Our results can inform epidemiological models to estimate Bd outbreak probability, especially as they relate

Ecology of coarse wood decomposition by the saprotrophic fungus Fomes fomentarius.

Science.gov (United States)

Větrovský, Tomáš; Voříšková, Jana; Snajdr, Jaroslav; Gabriel, Jiří; Baldrian, Petr

2011-07-01

Saprotrophic wood-inhabiting basidiomycetes are the most important decomposers of lignin and cellulose in dead wood and as such they attracted considerable attention. The aims of this work were to quantify the activity and spatial distribution of extracellular enzymes in coarse wood colonised by the white-rot basidiomycete Fomes fomentarius and in adjacent fruitbodies of the fungus and to analyse the diversity of the fungal and bacterial community in a fungus-colonised wood and its potential effect on enzyme production by F. fomentarius. Fungus-colonised wood and fruitbodies were collected in low management intensity forests in the Czech Republic. There were significant differences in enzyme production by F. fomentarius between Betula pendula and Fagus sylvatica wood, the activity of cellulose and xylan-degrading enzymes was significantly higher in beech wood than in birch wood. Spatial analysis of a sample B. pendula log segment proved that F. fomentarius was the single fungal representative found in the log. There was a high level of spatial variability in the amount of fungal biomass detected, but no effects on enzyme activities were observed. Samples from the fruiting body showed high β-glucosidase and chitinase activities compared to wood samples. Significantly higher levels of xylanase and cellobiohydrolase were found in samples located near the fruitbody (proximal), and higher laccase and Mn-peroxidase activities were found in the distal ones. The microbial community in wood was dominated by the fungus (fungal to bacterial DNA ratio of 62-111). Bacterial abundance composition was lower in proximal than distal parts of wood by a factor of 24. These results show a significant level of spatial heterogeneity in coarse wood. One of the explanations may be the successive colonization of wood by the fungus: due to differential enzyme production, the rates of biodegradation of coarse wood are also spatially inhomogeneous.

Biosorption of heavy metals using a dead macro fungus schizophyllum commune fries: evaluation of equilibrium and kinetic models

International Nuclear Information System (INIS)

Javid, A.; Bajwa, R.; Javid, A.

2010-01-01

Biomass of a wood rotting fungus viz., Schizophyllum commune Fries was utilized for the treatment of electroplating wastewater that contained Cu(II), Ni(II), Zn(II) and Cr(VI) ions. Preliminary batch assays were conducted with synthetic pure metal-bearing solutions. Results obtained showed that among various parameters studied, solution pH between a range of 2.0-6.0 induced negligible uptake at pH < 3.5 and exhibited maximum at around 4.5-5.5 for Ni(II), Cu(II) and Zn(II) ions, while for Cr(VI) ion the highest was evidenced at pH 2.0-2.5. The kinetics of all metal ions was fast and biosorption equilibrium was established in 1 hour with appropriateness of pseudo-second-order. A temperature change in the range of 15 - 45 deg. C did not affect the biosorption capacity of the candidate fungus. The biosorption of metal ion increased on elevating initial metal ions concentrations (20-100 mg L/sup -1/) in the medium. The maximum biosorption capacity of fungus biomass was 9.0, 21.27, 4.83, 18.54 mg g/sup -1/ for Ni(II), Cu(II) and Zn(II) and Cr(VI), respectively. The experimental data was best adjusted by Langmuir, Freundlich and modified Langmuir models. Biosorption assays conducted with actual electroplating effluents under pre-optimized conditions revealed efficiency of 72.01, 53.16, 7.08 and 19.87% for Cu(II), Ni(II), Zn(II) and Cr(VI) ions, respectively by candidate biomass. (author)

The effects of the fungus Metarhizium anisopliae var. acridum on different stages of Lutzomyia longipalpis (Diptera: Psychodidae).

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Amóra, Sthenia Santos Albano; Bevilaqua, Claudia Maria Leal; Feijó, Francisco Marlon Carneiro; Pereira, Romeika Hermínia de Macedo Assunção; Alves, Nilza Dutra; Freire, Fúlvio Aurélio de Morais; Kamimura, Michel Toth; de Oliveira, Diana Magalhães; Luna-Alves Lima, Elza Aurea; Rocha, Marcos Fábio Gadelha

2010-03-01

The control of Visceral Leishmaniasis (VL) vector is often based on the application of chemical residual insecticide. However, this strategy has not been effective. The continuing search for an appropriate vector control may include the use of biological control. This study evaluates the effects of the fungus Metarhizium anisopliae var. acridum on Lutzomyia longipalpis. Five concentrations of the fungus were utilized, 1 x 10(4) to 1 x 10(8) conidia/ml, accompanied by controls. The unhatched eggs, larvae and dead adults previously exposed to fungi were sown to reisolate the fungi and analysis of parameters of growth. The fungus was subsequently identified by PCR and DNA sequencing. M. anisopliae var. acridum reduced egg hatching by 40%. The mortality of infected larvae was significant. The longevity of infected adults was lower than that of negative controls. The effects of fungal infection on the hatching of eggs laid by infected females were also significant. With respect to fungal growth parameters post-infection, only vegetative growth was not significantly higher than that of the fungi before infection. The revalidation of the identification of the reisolated fungus was confirmed post-passage only from adult insects. In terms of larvae mortality and the fecundity of infected females, the results were significant, proving that the main vector species of VL is susceptible to infection by this entomopathogenic fungus in the adult stage. Copyright 2009 Elsevier B.V. All rights reserved.

Species-specific chitin-binding module 18 expansion in the amphibian pathogen Batrachochytrium dendrobatidis.

Science.gov (United States)

Abramyan, John; Stajich, Jason E

2012-01-01

Batrachochytrium dendrobatidis is the causative agent of chytridiomycosis, which is considered one of the driving forces behind the worldwide decline in populations of amphibians. As a member of the phylum Chytridiomycota, B. dendrobatidis has diverged significantly to emerge as the only pathogen of adult vertebrates. Such shifts in lifestyle are generally accompanied by various degrees of genomic modifications, yet neither its mode of pathogenicity nor any factors associated with it have ever been identified. Presented here is the identification and characterization of a unique expansion of the carbohydrate-binding module family 18 (CBM18), specific to B. dendrobatidis. CBM (chitin-binding module) expansions have been likened to the evolution of pathogenicity in a variety of fungus species, making this expanded group a prime candidate for the identification of potential pathogenicity factors. Furthermore, the CBM18 expansions are confined to three categories of genes, each having been previously implicated in host-pathogen interactions. These correlations highlight this specific domain expansion as a potential key player in the mode of pathogenicity in this unique fungus. The expansion of CBM18 in B. dendrobatidis is exceptional in its size and diversity compared to other pathogenic species of fungi, making this genomic feature unique in an evolutionary context as well as in pathogenicity. Amphibian populations are declining worldwide at an unprecedented rate. Although various factors are thought to contribute to this phenomenon, chytridiomycosis has been identified as one of the leading causes. This deadly fungal disease is cause by Batrachochytrium dendrobatidis, a chytrid fungus species unique in its pathogenicity and, furthermore, its specificity to amphibians. Despite more than two decades of research, the biology of this fungus species and its deadly interaction with amphibians had been notoriously difficult to unravel. Due to the alarming rate of worldwide

Saprophytic Activity and Sporulation of Cryphonectria parasitica on Dead Chestnut Wood in Forests with Naturally Established Hypovirulence.

Science.gov (United States)

Prospero, S; Conedera, M; Heiniger, U; Rigling, D

2006-12-01

ABSTRACT Sustainable biological control of the chestnut blight fungus Crypho-nectria parasitica with hypovirulence depends on the production and dissemination of hypovirus-infected propagules of the pathogen. We investigated the ability of C. parasitica to sporulate and produce hypo-virus-infected spores on recently dead chestnut wood in coppice stands in southern Switzerland where hypovirulence has been naturally established. The number and type (active, inactive, or none) of cankers was assessed on experimentally cut and stacked stems, firewood stacks, and natural dead wood. Hypovirus-free and hypovirus-infected strains readily survived for more than 1 year in the chestnut blight cankers of the stacked stems. Sporulation of C. parasitica was observed on the surface of preexisting inactive and active cankers, as well as on newly colonized bark areas and was significantly more abundant than on comparable cankers on living stems. On all types of dead wood, we observed more stromata with perithecia than with pycnidia; however, a large proportion of the stromata was not differentiated. All perithecia examined yielded only hypovirus-free ascospores. The incidence of pycnidia that produced hypovirus-infected conidia ranged from 5% on natural dead wood to 41% on the experimental stacks. The mean virus transmission rate into conidia was 69%. Our study demonstrates a considerable saprophytic activity of C. parasitica on recently dead chestnut wood and supports the hypothesis of a role of this saprophytic phase in the epidemiology of hypovirulence.

Evolution of genomic diversity and sex at extreme environments: Fungal life under hypersaline Dead Sea stress

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Kis-Papo, Tamar; Kirzhner, Valery; Wasser, Solomon P.; Nevo, Eviatar

2003-01-01

We have found that genomic diversity is generally positively correlated with abiotic and biotic stress levels (1–3). However, beyond a high-threshold level of stress, the diversity declines to a few adapted genotypes. The Dead Sea is the harshest planetary hypersaline environment (340 g·liter–1 total dissolved salts, ≈10 times sea water). Hence, the Dead Sea is an excellent natural laboratory for testing the “rise and fall” pattern of genetic diversity with stress proposed in this article. Here, we examined genomic diversity of the ascomycete fungus Aspergillus versicolor from saline, nonsaline, and hypersaline Dead Sea environments. We screened the coding and noncoding genomes of A. versicolor isolates by using >600 AFLP (amplified fragment length polymorphism) markers (equal to loci). Genomic diversity was positively correlated with stress, culminating in the Dead Sea surface but dropped drastically in 50- to 280-m-deep seawater. The genomic diversity pattern paralleled the pattern of sexual reproduction of fungal species across the same southward gradient of increasing stress in Israel. This parallel may suggest that diversity and sex are intertwined intimately according to the rise and fall pattern and adaptively selected by natural selection in fungal genome evolution. Future large-scale verification in micromycetes will define further the trajectories of diversity and sex in the rise and fall pattern. PMID:14645702

DIVERSITY AND ECOLOGICAL DETERMINANTS OF DEAD WOOD FUNGI IN TREE NATURAL RESERVES OF BROAD LEAVED FORESTS FROM SUCEAVA COUNTY

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Ciprian BÎRSAN

2014-12-01

Full Text Available Dead wood fungi have a major importance for forests biodiversity as they produce wood degradation in forest habitats. In this paper are presented some aspects related to the diversity of dead wood fungi in tree deciduous forest types from tree natural reserves (Crujana, Dragomirna and Zamostea from Suceava County and the effect of some ecological factors (host tree, diameter and decomposition degree of the dead wood and some microclimatic characteristics of sites on their occurrence and diversity. Investigations carried out in 2013 resulted in the identification of 44 lignicolous fungi species. Analysis of similarities between lingnicolous fungi species from the investigated natural reserves (by hierarchical clustering shows a separation of three fungi groups, depending on the host-trees species. The effect of the tree host species was highlighted also by detrended correspondence analysis, which, in addition presented the existence of an altitudinal gradient and a weaker effect of site conditions (slope and aspect and microclimatic variables (solar radiation on dead wood fungi occurrence. The effect of diameter and decomposition degree of fallen trunks and branches on dead wood fungi species was investigated using the redundancy analysis showing that wood debris with large surfaces are more easily colonized by the fungi species developing large sporocarps compared to small branches with low diameters colonized only by few or a single fungus species.

Parasite fitness traits under environmental variation: disentangling the roles of a chytrid's immediate host and external environment.

Science.gov (United States)

Van den Wyngaert, Silke; Vanholsbeeck, Olivier; Spaak, Piet; Ibelings, Bas W

2014-10-01

Parasite environments are heterogeneous at different levels. The first level of variability is the host itself. The second level represents the external environment for the hosts, to which parasites may be exposed during part of their life cycle. Both levels are expected to affect parasite fitness traits. We disentangle the main and interaction effects of variation in the immediate host environment, here the diatom Asterionella formosa (variables host cell volume and host condition through herbicide pre-exposure) and variation in the external environment (variables host density and acute herbicide exposure) on three fitness traits (infection success, development time and reproductive output) of a chytrid parasite. Herbicide exposure only decreased infection success in a low host density environment. This result reinforces the hypothesis that chytrid zoospores use photosynthesis-dependent chemical cues to locate its host. At high host densities, chemotaxis becomes less relevant due to increasing chance contact rates between host and parasite, thereby following the mass-action principle in epidemiology. Theoretical support for this finding is provided by an agent-based simulation model. The immediate host environment (cell volume) substantially affected parasite reproductive output and also interacted with the external herbicide exposed environment. On the contrary, changes in the immediate host environment through herbicide pre-exposure did not increase infection success, though it had subtle effects on zoospore development time and reproductive output. This study shows that both immediate host and external environment as well as their interaction have significant effects on parasite fitness. Disentangling these effects improves our understanding of the processes underlying parasite spread and disease dynamics.

Who's Counting Dead Wood ?

OpenAIRE

Woodall, C. W.; Verkerk, H.; Rondeux, Jacques; Ståhl, G.

2009-01-01

Dead wood in forests is a critical component of biodiversity, carbon and nutrient cycles, stand structure, and fuel loadings. Until recently, very few countries have conducted systematic inventories of dead wood resources across their forest lands. This may be changing as an increasing number of countries implement dead wood inventories. A recent survey looks at the status and attributes of forest dead wood inventories in over 60 countries. About 13 percent of countries inventory dead wood gl...

Raising the Dead without a Red Sea-Dead Sea project? Hydro-economics and governance

Directory of Open Access Journals (Sweden)

D. E. Rosenberg

2011-04-01

Full Text Available Seven decades of extractions have dramatically reduced Jordan River flows, lowered the Dead Sea level, opened sink holes, and caused other environmental problems. The fix Jordan, Israel, and the Palestinians propose would build an expensive multipurpose conveyance project from the Red Sea to the Dead Sea that would also generate hydropower and desalinate water. This paper compares the Red-Dead project to alternatives that may also raise the Dead Sea level. Hydro-economic model results for the Jordan-Israel-Palestinian inter-tied water systems show two restoration alternatives are more economically viable than the proposed Red-Dead project. Many decentralized new supply, wastewater reuse, conveyance, conservation, and leak reduction projects and programs in each country can together increase economic benefits and reliably deliver up to 900 MCM yr⁻¹ to the Dead Sea. Similarly, a smaller Red-Dead project that only generates hydropower can deliver large flows to the Dead Sea when the sale price of generated electricity is sufficiently high. However, for all restoration options, net benefits fall and water scarcity rises as flows to the Dead Sea increase. This finding suggests (i each country has no individual incentive to return water to the Dead Sea, and (ii outside institutions that seek to raise the Dead must also offer countries direct incentives to deliver water to the Sea besides building the countries new infrastructure.

New locality of Hymenochaete cruenta in the Olbina nature reserve and revisiting of distribution of this fungus in Poland

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Marta Brygida Kujawska

2016-12-01

Full Text Available Hymenochaete cruenta is a saprotrophic fungus, grown mainly on the bark of dead branches and trunks of Abies trees and thus the distribution of this fungus in Poland and other European countries is closely connected with natural range of silver fir. Despite its wide range, H. cruenta is considered as rare in the whole area of its occurrence. In this paper, we present a new locality of H. cruenta, discovered in May and September 2016 in the Olbina nature reserve (southern Wielkopolska Lowland, Kalisz Forest District. Ecological notes and macro- and microscopic feature of basidiocarps of this fungus are presented. Additionally, the current distribution of H. cruenta in Poland comprising 78 localities is provided. The rank of H. cruenta among threatened species categories in different European countries is discussed. It seems that the species is rare and threatened in Poland, and it should be still classified as “vulnerable” on the red list of macrofungi. The significance of H. cruenta for diversity of mycobiota and the necessity of further research on the dynamic of occurrence of H. cruenta inside and outside of the natural range of A. alba is underlined.

Effects of amphibian phylogeny, climate and human impact on the occurrence of the amphibian-killing chytrid fungus.

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Bacigalupe, Leonardo D; Soto-Azat, Claudio; García-Vera, Cristobal; Barría-Oyarzo, Ismael; Rezende, Enrico L

2017-09-01

Chytridiomycosis, due to the fungus Batrachochytrium dendrobatidis (Bd), has been associated with the alarming decline and extinction crisis of amphibians worldwide. Because conservation programs are implemented locally, it is essential to understand how the complex interactions among host species, climate and human activities contribute to Bd occurrence at regional scales. Using weighted phylogenetic regressions and model selection, we investigated geographic patterns of Bd occurrence along a latitudinal gradient of 1500 km within a biodiversity hot spot in Chile (1845 individuals sampled from 253 sites and representing 24 species), and its association with climatic, socio-demographic and economic variables. Analyses show that Bd prevalence decreases with latitude although it has increased by almost 10% between 2008 and 2013, possibly reflecting an ongoing spread of Bd following the introduction of Xenopus laevis. Occurrence of Bd was higher in regions with high gross domestic product (particularly near developed centers) and with a high variability in rainfall regimes, whereas models including other bioclimatic or geographic variables, including temperature, exhibited substantially lower fit and virtually no support based on Akaike weights. In addition, Bd prevalence exhibited a strong phylogenetic signal, with five species having high numbers of infected individuals and higher prevalence than the average of 13.3% across all species. Taken together, our results highlight that Bd in Chile might still be spreading south, facilitated by a subset of species that seem to play an important epidemiological role maintaining this pathogen in the communities, in combination with climatic and human factors affecting the availability and quality of amphibian breeding sites. This information may be employed to design conservation strategies and mitigate the impacts of Bd in the biodiversity hot spot of southern Chile, and similar studies may prove useful to disentangle the

Simulating detectors dead time

International Nuclear Information System (INIS)

Rustom, Ibrahim Farog Ibrahim

2015-06-01

Nuclear detectors are used in all aspects of nuclear measurements. All nuclear detectors are characterized by their dead time i.e. the time needed by a detector to recover from a previous incident. A detector dead time influences measurements taken by a detector and specially when measuring high decay rate (>) where is the detector dead time. Two models are usually used to correct for the dead time effect: the paralayzable and the non-paralayzable models. In the current work we use Monte Carlo simulation techniques to simulate radioactivity and the effect of dead time and the count rate of a detector with a dead time =5x10 - 5s assuming the non-paralayzable model. The simulation indicates that assuming a non -paralayzable model could be used to correct for decay rate measured by a detector. The reliability of the non-paralayzable model to correct the measured decay rate could be gauged using the Monte Carlo simulation. (Author)

Wing pathology of white-nose syndrome in bats suggests life-threatening disruption of physiology.

Science.gov (United States)

Cryan, Paul M; Meteyer, Carol Uphoff; Boyles, Justin G; Blehert, David S

2010-11-11

White-nose syndrome (WNS) is causing unprecedented declines in several species of North American bats. The characteristic lesions of WNS are caused by the fungus Geomyces destructans, which erodes and replaces the living skin of bats while they hibernate. It is unknown how this infection kills the bats. We review here the unique physiological importance of wings to hibernating bats in relation to the damage caused by G. destructans and propose that mortality is caused by catastrophic disruption of wing-dependent physiological functions. Mechanisms of disease associated with G. destructans seem specific to hibernating bats and are most analogous to disease caused by chytrid fungus in amphibians.

Wing pathology of white-nose syndrome in bats suggests life-threatening disruption of physiology

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Boyles Justin G

2010-11-01

Full Text Available Abstract White-nose syndrome (WNS is causing unprecedented declines in several species of North American bats. The characteristic lesions of WNS are caused by the fungus Geomyces destructans, which erodes and replaces the living skin of bats while they hibernate. It is unknown how this infection kills the bats. We review here the unique physiological importance of wings to hibernating bats in relation to the damage caused by G. destructans and propose that mortality is caused by catastrophic disruption of wing-dependent physiological functions. Mechanisms of disease associated with G. destructans seem specific to hibernating bats and are most analogous to disease caused by chytrid fungus in amphibians.

Wing pathology of white-nose syndrome in bats suggests life-threatening disruption of physiology

Science.gov (United States)

Cryan, Paul M.; Meteyer, Carol U.; Boyles, Justin G.; Blehert, David S.

2010-01-01

White-nose syndrome (WNS) is causing unprecedented declines in several species of North American bats. The characteristic lesions of WNS are caused by the fungus Geomyces destructans, which erodes and replaces the living skin of bats while they hibernate. It is unknown how this infection kills the bats. We review here the unique physiological importance of wings to hibernating bats in relation to the damage caused by G. destructans and propose that mortality is caused by catastrophic disruption of wing-dependent physiological functions. Mechanisms of disease associated with G. destructans seem specific to hibernating bats and are most analogous to disease caused by chytrid fungus in amphibians.

Electron microscopy of Chytridiomycosis and the need to re-examine the disease from the gene to the cell

International Nuclear Information System (INIS)

Hyatt, A.; Siddon, N.; Speare, R.

2003-01-01

Full text: Over the past three decades there has been a global decline of amphibian populations. A variety of causative factors, including increased ultra violet radiation, habitat destruction and chemical pollution have been proposed; these, however, have not been correlated with all amphibian declines in the protected areas of Australia or overseas. During the past five years a network of electron microscopists, veterinary pathologists, molecular biologists and ecologists have been working on identifying the etiological agent. Examination of skin from a large number of dead and moribund frogs revealed 'a fungus belonging to the phylum Chytridiomycota and order Chytridiales. The fungus has been demonstrated to cause the disease chytridiomycosis which is now recognised as a fatal disease of amphibians and is the most common disease of Australian frogs. The fungus (Batrachochytrium dendrobatidis) was originally identified by electron microscopy, and is the only member of the Chytridiomycota that causes disease in vertebrates. The fungus has a broad amphibian host range and occurs worldwide. A total of 94 amphibian species from 15 families have been found infected with B. dendrobatidis, from Australia, South America, Central America, North America, Europe, New Zealand and Africa. Electron microscopy (transmission, scanning, immuno and cryo) provided pivotal information on pathogen identification and understanding of the life cycle of the organism. However, what light and electron microscopy has not been able to elucidate is the cause of death within the infected animals. Many veterinary pathologists have examined the 'pathology' of the disease but are unable to agree on the probable causes (physiological processes) associated with the death of the infected animals. Two hypotheses exist the chytrid irreversibly affects the osmoregulatory ability of the amphibians and the chytrid releases a toxin that over time leads to the death of the animals. The cause of death

Colony Size Affects the Efficacy of Bait Containing Chlorfluazuron Against the Fungus-Growing Termite Macrotermes gilvus (Blattodea: Termitidae).

Science.gov (United States)

Lee, Ching-Chen; Neoh, Kok-Boon; Lee, Chow-Yang

2014-12-01

The efficacy of chitin synthesis inhibitors (CSIs) against fungus-growing termites is known to vary. In this study, 0.1% chlorfluazuron (CFZ) cellulose bait was tested against medium and large field colonies of Macrotermes gilvus (Hagen). The termite mounds were dissected to determine the health of the colony. Individual termites (i.e., workers and larvae) and fungus combs were subjected to gas chromatography-mass spectrometry (GC-MS) analysis to detect the presence of CFZ. In this study, 540.0 ± 25.8 g (or equivalent to 540.0 ± 25.8 mg active ingredient) and 680.0 ± 49.0 g (680.0 ± 49.0 mg active ingredient) of bait matrix were removed by the medium- and large-sized colonies, respectively, after baiting. All treated medium-sized colonies were moribund. The dead termites were scattered in the mound, larvae were absent, population size had decreased by 90%, and the queens appeared unhealthy. In contrast, no or limited effects were found in large-sized colonies. Only trace amounts of CFZ were detected in workers, larvae, and fungus combs, and the population of large-sized colonies had declined by only up to 40%. This might be owing to the presence of large amount of basidiomycete fungus and a drastic decrease of CFZ content per unit fungus comb (a main food source of larvae) in the large-sized colonies, and hence reduced the toxic effect and longer time is required to accumulate the lethal dose in larvae. Nevertheless, we do not deny the possibility of CSI bait eliminating or suppressing the higher termite if the test colonies could pick up adequate lethal dose by installing more bait stations and prolonging the baiting period. © 2014 Entomological Society of America.

Coincidence-counting corrections for accidental coincidences, set dead time and intrinsic dead time

International Nuclear Information System (INIS)

Wyllie, H.A.

1998-01-01

An equation is derived for calculating the radioactivity of a source from the results of coincidence counting, taking into account dead-time losses and accidental coincidences. The corrections allow for the extension of the set dead time in the p channel by the intrinsic dead time. Experimental verification shows improvement over a previous equation. (author)

Geographically structured host specificity is caused by the range expansions and host shifts of a symbiotic fungus.

Science.gov (United States)

Wolfe, Benjamin E; Pringle, Anne

2012-04-01

The inability to associate with local species may constrain the spread of mutualists arriving to new habitats, but the fates of introduced, microbial mutualists are largely unknown. The deadly poisonous ectomycorrhizal fungus Amanita phalloides (the death cap) is native to Europe and introduced to the East and West Coasts of North America. By cataloging host associations across the two continents, we record dramatic changes in specificity among the three ranges. On the East Coast, where the fungus is restricted in its distribution, it associates almost exclusively with pines, which are rarely hosts of A. phalloides in its native range. In California, where the fungus is widespread and locally abundant, it associates almost exclusively with oaks, mirroring the host associations observed in Europe. The most common host of the death cap in California is the endemic coast live oak (Quercus agrifolia), and the current distribution of A. phalloides appears constrained within the distribution of Q. agrifolia. In California, host shifts to native plants are also associated with a near doubling in the resources allocated to sexual reproduction and a prolonged fruiting period; mushrooms are twice as large as they are elsewhere and mushrooms are found throughout the year. Host and niche shifts are likely to shape the continuing range expansion of A. phalloides and other ectomycorrhizal fungi introduced across the world.

Label-Free Differential Proteomics and Quantification of Exoenzymes from Isolates of the Entomopathogenic Fungus Beauveria bassiana

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Giuseppe Dionisio

2016-10-01

Full Text Available Beauveria bassiana is an entomopathogenic fungus that grows both in vivo and in vitro. In vivo it can colonize live insect hosts, and tissue digestion occurs by secreted hydrolytic exoenzymes. It can also colonize dead insect tissue provided this is free from competing microorganisms. Depending on whether the host is alive or dead the expression (quality/quantity of the exoenzymes may vary. We have grown several isolates of B. bassiana in shaking flasks for 120 h at 25 °C in order to evaluate the maximal exoenzyme production using two diet regimes. As sole carbon, nitrogen, and phosphate sources we used 1% shrimp chitin and either 0.5% w/v of dead intact American cockroach (Periplaneta americana or their isolated cuticles. This is the first report of a differential proteomics of B. bassiana exoenzymes performed by label-free nano-LC MS/MS. Total proteolytic enzyme activity was mainly due to Pr1A or Pr1B depending on the isolate and the diet regime. The most differentially secreted enzymes were: the cuticle-degrading subtilisin Pr1A, GH13 alpha-glycosidase, glucan endo-1,3-beta-glucosidase, subtilisin-like proteinase Spm1, lipase 1, beta-1,3 exoglucanase, and endo-1,3-beta-glucosidase. Among the B. bassiana isolates analyzed, Bb 678 and Bb BG were the most active in Pr1A secretion.

Label-Free Differential Proteomics and Quantification of Exoenzymes from Isolates of the Entomopathogenic Fungus Beauveria bassiana.

Science.gov (United States)

Dionisio, Giuseppe; Kryger, Per; Steenberg, Tove

2016-10-14

Beauveria bassiana is an entomopathogenic fungus that grows both in vivo and in vitro. In vivo it can colonize live insect hosts, and tissue digestion occurs by secreted hydrolytic exoenzymes. It can also colonize dead insect tissue provided this is free from competing microorganisms. Depending on whether the host is alive or dead the expression (quality/quantity) of the exoenzymes may vary. We have grown several isolates of B. bassiana in shaking flasks for 120 h at 25 °C in order to evaluate the maximal exoenzyme production using two diet regimes. As sole carbon, nitrogen, and phosphate sources we used 1% shrimp chitin and either 0.5% w / v of dead intact American cockroach ( Periplaneta americana ) or their isolated cuticles. This is the first report of a differential proteomics of B. bassiana exoenzymes performed by label-free nano-LC MS/MS. Total proteolytic enzyme activity was mainly due to Pr1A or Pr1B depending on the isolate and the diet regime. The most differentially secreted enzymes were: the cuticle-degrading subtilisin Pr1A, GH13 alpha-glycosidase, glucan endo-1,3-beta-glucosidase, subtilisin-like proteinase Spm1, lipase 1, beta-1,3 exoglucanase, and endo-1,3-beta-glucosidase. Among the B. bassiana isolates analyzed, Bb 678 and Bb BG were the most active in Pr1A secretion.

Dead time of dual detector tools

International Nuclear Information System (INIS)

Czubek, J.A.

1994-01-01

A theory of the dead time for the dual detector nuclear tool with the analogue signal transmission is given in the paper. At least two different times exist in such tools: the dead time of detectors (for final computation they assumed identical to each other) and the dead time of the signal transmission set-up. A method of two radioactive sources is proposed to measure these two different dead times. When the times used for measuring every countrate needed in the dead time determination algorithm are taken into account, the statistical accuracy of the dead time determination can be obtained. These estimations are performed by the computer simulation method. Two codes have been designed: DEADT2D (DEAD Time for 2 Detectors) and DEADT2DS (DEAD Time for 2 Detectors with Statistics). The first code calculates the dead time based on the recorded countrates only, the second is doing a 'simulation job' and provides information on the statistical distribution of the observed dead times. The theory and the numerical solutions were checked both by the simulation calculations and by the experiments performed with the ODSN-102 tool (the experiments were performed by T. Zorski). (Author)

The anaerobic chytridiomycete fungus Piromyces sp. E2 produces ethanol via pyruvate:formate lyase and an alcohol dehydrogenase E.

NARCIS (Netherlands)

Boxma, B.; Voncken, F.L.M.; Jannink, S.A.; Alen, T.A. van; Akhmanova, A.S.; Weelden, S.W. van; Hellemond, J.J. van; Ricard, G.N.S.; Huynen, M.A.; Tielens, A.G.; Hackstein, J.H.P.

2004-01-01

Anaerobic chytridiomycete fungi possess hydrogenosomes, which generate hydrogen and ATP, but also acetate and formate as end-products of a prokaryotic-type mixed-acid fermentation. Notably, the anaerobic chytrids Piromyces and Neocallimastix use pyruvate:formate lyase (PFL) for the catabolism of

Dead Man or Dead Hand?

DEFF Research Database (Denmark)

Ringe, Wolf-Georg

and potential takeover bids. Recent Delaware case-law suggests that the most extreme, ‘dead hand’ version of such clauses might violate directors’ fiduciary duties. This short article develops some initial thoughts on the phenomenon and evaluates how the new poison pills would be handled under European takeover...

Dead zone characteristics of a gas counter

International Nuclear Information System (INIS)

Nohtomi, Akihiro; Sakae, Takeji; Matoba, Masaru; Koori, Norihiko.

1990-01-01

The dead zone was recently defined as the product of dead length and dead time in order to describe the characteristics of the self-quenching streamer (SQS) mode of a gas counter. Investigation of the dead zone characteristics has been extended for the proportional and GM modes, and the measured dead zone has been compared with that of the SQS mode. Accurate values for the dead zone could be determined by means of a newly developed method with a pulse interval time to amplitude converter. Each operation mode indicates distinct dead zone characteristics. Properties of gas counters for high counting rates may be improved on the basis of measurements of the dead zone. (author)

Practicing on Newly Dead

Directory of Open Access Journals (Sweden)

Jewel Abraham

2015-07-01

Full Text Available A newly dead cadaver simulation is practiced on the physical remains of the dead before the onset of rigor mortis. This technique has potential benefits for providing real-life in-situ experience for novice providers in health care practices. Evolving ethical views in health care brings into question some of the ethical aspects associated with newly dead cadaver simulation in terms of justification for practice, autonomy, consent, and the need of disclosure. A clear statement of policies and procedures on newly dead cadaver simulation has yet to be implemented. Although there are benefits and disadvantages to an in-situ cadaver simulation, such practices should not be carried out in secrecy as there is no compelling evidence that suggests such training as imperative. Secrecy in these practices is a violation of honor code of nursing ethics. As health care providers, practitioners are obliged to be ethically honest and trustworthy to their patients. The author explores the ethical aspects of using newly dead cadaver simulation in training novice nursing providers to gain competency in various lifesaving skills, which otherwise cannot be practiced on a living individual. The author explores multiple views on cadaver simulation in relation to ethical theories and practices such as consent and disclosure to family.

The life of a dead ant: the expression of an adaptive extended phenotype.

Science.gov (United States)

Andersen, Sandra B; Gerritsma, Sylvia; Yusah, Kalsum M; Mayntz, David; Hywel-Jones, Nigel L; Billen, Johan; Boomsma, Jacobus J; Hughes, David P

2009-09-01

Specialized parasites are expected to express complex adaptations to their hosts. Manipulation of host behavior is such an adaptation. We studied the fungus Ophiocordyceps unilateralis, a locally specialized parasite of arboreal Camponotus leonardi ants. Ant-infecting Ophiocordyceps are known to make hosts bite onto vegetation before killing them. We show that this represents a fine-tuned fungal adaptation: an extended phenotype. Dead ants were found under leaves, attached by their mandibles, on the northern side of saplings approximately 25 cm above the soil, where temperature and humidity conditions were optimal for fungal growth. Experimental relocation confirmed that parasite fitness was lower outside this manipulative zone. Host resources were rapidly colonized and further secured by extensive internal structuring. Nutritional composition analysis indicated that such structuring allows the parasite to produce a large fruiting body for spore production. Our findings suggest that the osmotrophic lifestyle of fungi may have facilitated novel exploitation strategies.

Live and Dead Nodes

DEFF Research Database (Denmark)

Jørgensen, Sune Lehman; Jackson, A. D.

2005-01-01

In this paper, we explore the consequences of a distinction between `live' and `dead' network nodes; `live' nodes are able to acquire new links whereas `dead' nodes are static. We develop an analytically soluble growing network model incorporating this distinction and show that it can provide...

Oral chytridiomycosis in the mountain yellow-legged frog (Rana muscosa)

Science.gov (United States)

Fellers, G.M.; Green, E.D.; Longcore, J.E.

2001-01-01

The chytrid fungus Batrachochytrium dendrobatidis was originally reported in wild frog populations in Panama and Australia, and from captive frogs in the U.S. National Zoological Park (Washington, DC). This recently described fungus affects the keratinized epidermis of amphibians and has been implicated as a causative factor in the declines of frog populations. We report here the presence of B. dendrobatidis in larval and recently metamorphosed mountain yellow-legged frogs (Rana muscosa) in or near the Sierra Nevada Mountains of California, an area where declines have been documented in all five species of native anurans. Forty-one percent (158 of 387) of larval R. muscosa examined in the field with a hand lens and 18% (14 of 79) of preserved larvae had abnormalities of the oral disc. Twenty-eight larvae were collected from 10 sites where tadpoles had been observed with missing or abnormally keratinized mouthparts, and 24 of these were examined for infection. Sixty-seven percent (16 of 24) of these tadpoles were infected with B. dendrobatidis. Batrachochytrium dendrobatidis was cultured from both tadpoles and recent metamorphs from one of these sites. Tadpoles with mouthpart abnormalities or confirmed chytrid fungus infections were collected at 23 sites spanning a distance of > 440 km and an elevational range from 1658-3550 m. Life-history traits of R. muscosa may make this species particularly susceptible to infection by Batrachochytrium. We recommend that biologists examine tadpoles for oral disc abnormalities as a preliminary indication of chytridiomycosis. Further, we believe that biologists should take precautions to prevent spreading this and other amphibian diseases from one site to another.

The Dead Sea

Science.gov (United States)

2006-01-01

The Dead Sea is the lowest point on Earth at 418 meters below sea level, and also one of the saltiest bodies of water on Earth with a salinity of about 300 parts-per-thousand (nine times greater than ocean salinity). It is located on the border between Jordan and Israel, and is fed by the Jordan River. The Dead Sea is located in the Dead Sea Rift, formed as a result of the Arabian tectonic plate moving northward away from the African Plate. The mineral content of the Dead Sea is significantly different from that of ocean water, consisting of approximately 53% magnesium chloride, 37% potassium chloride and 8% sodium chloride. In the early part of the 20th century, the Dead Sea began to attract interest from chemists who deduced that the Sea was a natural deposit of potash and bromine. From the Dead Sea brine, Israel and Jordan produce 3.8 million tons potash, 200,000 tons elemental bromine, 45,000 tons caustic soda, 25, 000 tons magnesium metal, and sodium chloride. Both countries use extensive salt evaporation pans that have essentially diked the entire southern end of the Dead Sea. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining

Substrate-specific gene expression in Batrachochytrium dendrobatidis, the chytrid pathogen of amphibians.

Directory of Open Access Journals (Sweden)

Erica Bree Rosenblum

Full Text Available Determining the mechanisms of host-pathogen interaction is critical for understanding and mitigating infectious disease. Mechanisms of fungal pathogenicity are of particular interest given the recent outbreaks of fungal diseases in wildlife populations. Our study focuses on Batrachochytrium dendrobatidis (Bd, the chytrid pathogen responsible for amphibian declines around the world. Previous studies have hypothesized a role for several specific families of secreted proteases as pathogenicity factors in Bd, but the expression of these genes has only been evaluated in laboratory growth conditions. Here we conduct a genome-wide study of Bd gene expression under two different nutrient conditions. We compare Bd gene expression profiles in standard laboratory growth media and in pulverized host tissue (i.e., frog skin. A large proportion of genes in the Bd genome show increased expression when grown in host tissue, indicating the importance of studying pathogens on host substrate. A number of gene classes show particularly high levels of expression in host tissue, including three families of secreted proteases (metallo-, serine- and aspartyl-proteases, adhesion genes, lipase-3 encoding genes, and a group of phylogenetically unusual crinkler-like effectors. We discuss the roles of these different genes as putative pathogenicity factors and discuss what they can teach us about Bd's metabolic targets, host invasion, and pathogenesis.

9 CFR 314.8 - Dead animal carcasses.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Dead animal carcasses. 314.8 Section... Dead animal carcasses. (a) With the exception of dead livestock which have died en route and are received with livestock for slaughter at an official establishment, no dead animal or part of the carcass...

7 CFR 322.29 - Dead bees.

Science.gov (United States)

2010-01-01

... 7 Agriculture 5 2010-01-01 2010-01-01 false Dead bees. 322.29 Section 322.29 Agriculture..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation and Transit of Restricted Articles § 322.29 Dead bees. (a) Dead bees imported into or transiting the United States must be...

Measurement of the Dead-Time in a Multichannel Analyser

DEFF Research Database (Denmark)

Mortensen, L.; Olsen, J.

1973-01-01

By means of two simple measurements three different dead-times are determined: the normal dead-time, a dead-time coming from the pile-up, and a dead-time due to the finite width of the timing pulses.......By means of two simple measurements three different dead-times are determined: the normal dead-time, a dead-time coming from the pile-up, and a dead-time due to the finite width of the timing pulses....

Malaria mosquitoes attracted by fatal fungus.

Directory of Open Access Journals (Sweden)

Justin George

Full Text Available Insect-killing fungi such as Beauveria bassiana are being evaluated as possible active ingredients for use in novel biopesticides against mosquito vectors that transmit malaria. Fungal pathogens infect through contact and so applications of spores to surfaces such as walls, nets, or other resting sites provide possible routes to infect mosquitoes in and around domestic dwellings. However, some insects can detect and actively avoid fungal spores to reduce infection risk. If true for mosquitoes, such behavior could render the biopesticide approach ineffective. Here we find that the spores of B. bassiana are highly attractive to females of Anopheles stephensi, a major anopheline mosquito vector of human malaria in Asia. We further find that An. stephensi females are preferentially attracted to dead and dying caterpillars infected with B. bassiana, landing on them and subsequently becoming infected with the fungus. Females are also preferentially attracted to cloth sprayed with oil-formulated B. bassiana spores, with 95% of the attracted females becoming infected after a one-minute visit on the cloth. This is the first report of an insect being attracted to a lethal fungal pathogen. The exact mechanisms involved in this behavior remain unclear. Nonetheless, our results indicate that biopesticidal formulations comprising B. bassiana spores will be conducive to attraction and on-source visitation by malaria vectors.

Microsatellite primers for fungus-growing ants

DEFF Research Database (Denmark)

Villesen, Palle; Gertsch, P J; Boomsma, JJ

2002-01-01

We isolated five polymorphic microsatellite loci from a library of two thousand recombinant clones of two fungus-growing ant species, Cyphomyrmex longiscapus and Trachymyrmex cf. zeteki. Amplification and heterozygosity were tested in five species of higher attine ants using both the newly...... developed primers and earlier published primers that were developed for fungus-growing ants. A total of 20 variable microsatellite loci, developed for six different species of fungus-growing ants, are now available for studying the population genetics and colony kin-structure of these ants....

Microsatellite Primers for Fungus-Growing Ants

DEFF Research Database (Denmark)

Villesen Fredsted, Palle; Gertsch, Pia J.; Boomsma, Jacobus Jan (Koos)

2002-01-01

We isolated five polymorphic microsatellite loci from a library of two thousand recombinant clones of two fungus-growing ant species, Cyphomyrmex longiscapus and Trachymyrmex cf. zeteki. Amplification and heterozygosity were tested in five species of higher attine ants using both the newly...... developed primers and earlier published primers that were developed for fungus-growing ants. A total of 20 variable microsatellite loci, developed for six different species of fungus-growing ants, are now available for studying the population genetics and colony kin-structure of these ants....

STUDIES ON THE DYNAMICS OF DEHYDROGENASES KREBS CYCLE ACTIVITY AT MONILINIA LAXA (ADERH. & RUHL. HONEY FUNGUS GROWN ON MEDIA WITH DIFFERENT CARBOHYDRATES

Directory of Open Access Journals (Sweden)

Elena Ciornea

2010-09-01

Full Text Available As ubiquitous organisms, fungi grow on a large number of organic substrate, alive or dead, confronting therefore with a wide variety of carbohydrates and various physical factors, and their versatility to adapt and be able to use a large number of these compounds could provide them the chance to survive. Given that, these fungi have a rich enzyme equipment that allows them to operate on different metabolic pathways, this study aims to monitor the dynamics activity of some Krebs cycle dehydrogenases in Monilinia laxa (Aderh & Ruhl. Honey species parasitic on various species of plum trees. To this end, the fungus was cultivated in vitro on media enriched with different carbohydrates and the isocitrate dehydrogenase, �-cetoglutarate dehydrogenase, succinate dehydrogenase and malate dehydrogenase activity in the fungus mycelium was followed, at 7, respectively, 14 days after the inoculation of the culture medium and determined using the spectrophotometric Sîsoev and Krasna method (Cojocaru, D.C., 2009. Data revealed obvious differences depending on the type of carbohydrate introduced into the medium and the age of the culture mycelia.

STUDIES ON THE DYNAMICS OF DEHYDROGENASES KREBS CYCLE ACTIVITY AT MONILINIA LAXA (ADERH. & RUHL. HONEY FUNGUS GROWN ON MEDIA WITH DIFFERENT CARBOHYDRATES

Directory of Open Access Journals (Sweden)

Elena Ciornea

2011-11-01

Full Text Available As ubiquitous organisms, fungi grow on a large number of organic substrate, alive or dead, confronting therefore with a wide variety of carbohydrates and various physical factors, and their versatility to adapt and be able to use a large number of these compounds could provide them the chance to survive. Given that, these fungi have a rich enzyme equipment that allows them to operate on different metabolic pathways, this study aims to monitor the dynamics activity of some Krebs cycle dehydrogenases in Monilinia laxa (Aderh & Ruhl. Honey species parasitic on various species of plum trees. To this end, the fungus was cultivated in vitro on media enriched with different carbohydrates and the isocitrate dehydrogenase, �-cetoglutarate dehydrogenase, succinate dehydrogenase and malate dehydrogenase activity in the fungus mycelium was followed, at 7, respectively, 14 days after the inoculation of the culture medium and determined using the spectrophotometric Sîsoev and Krasna method (Cojocaru, D.C., 2009. Data revealed obvious differences depending on the type of carbohydrate introduced into the medium and the age of the culture mycelia.

Global Amphibian Extinction Risk Assessment for the Panzootic Chytrid Fungus

Directory of Open Access Journals (Sweden)

Matthew C. Fisher

2009-09-01

Full Text Available Species are being lost at increasing rates due to anthropogenic effects, leading to the recognition that we are witnessing the onset of a sixth mass extinction. Emerging infectious disease has been shown to increase species loss and any attempts to reduce extinction rates need to squarely confront this challenge. Here, we develop a procedure for identifying amphibian species that are most at risk from the effects of chytridiomycosis by combining spatial analyses of key host life-history variables with the pathogen's predicted distribution. We apply our rule set to the known global diversity of amphibians in order to prioritize pecies that are most at risk of loss from disease emergence. This risk assessment shows where limited conservation funds are best deployed in order to prevent further loss of species by enabling ex situ amphibian salvage operations and focusing any potential disease mitigation projects.

Global Amphibian Extinction Risk Assessment for the Panzootic Chytrid Fungus

OpenAIRE

Rödder, Dennis; Kielgast, Jos; Bielby, Jon; Schmidtlein, Sebastian; Bosch, Jaime; Garner, Trenton W. J.; Veith, Michael; Walker, Susan; Fisher, Matthew C.; Lötters, Stefan

2009-01-01

Species are being lost at increasing rates due to anthropogenic effects, leading to the recognition that we are witnessing the onset of a sixth mass extinction. Emerging infectious disease has been shown to increase species loss and any attempts to reduce extinction rates need to squarely confront this challenge. Here, we develop a procedure for identifying amphibian species that are most at risk from the effects of chytridiomycosis by combining spatial analyses of key host life-history varia...

Vivitron dead section pumping tests

International Nuclear Information System (INIS)

Heugel, J.; Bayet, J.P.; Brandt, C.; Delhomme, C.; Krieg, C.; Kustner, F.; Meiss, R.; Riehl, R.; Roth, C.; Schlewer, B.; Six, P.; Weber, A.

1990-10-01

Pumping tests have been conducted on a simulated accelerator dead section. The behavior of different pump types are compared and analyzed. Vacuum conditions to be expected in the Vivitron are reached and several parameters are verified. Selection of a pump for the Vivitron dead section is confirmed

And the Dead Remain Behind

Directory of Open Access Journals (Sweden)

Peter Read

2013-08-01

Full Text Available In most cultures the dead and their living relatives are held in a dialogic relationship. The dead have made it clear, while living, what they expect from their descendants. The living, for their part, wish to honour the tombs of their ancestors; at the least, to keep the graves of the recent dead from disrepair. Despite the strictures, the living can fail their responsibilities, for example, by migration to foreign countries. The peripatetic Chinese are one of the few cultures able to overcome the dilemma of the wanderer or the exile. With the help of a priest, an Australian Chinese migrant may summon the soul of an ancestor from an Asian grave to a Melbourne temple, where the spirit, though removed from its earthly vessel, will rest and remain at peace. Amongst cultures in which such practices are not culturally appropriate, to fail to honour the family dead can be exquisitely painful. Violence is the cause of most failure.

A hydrogenosomal [Fe]-hydrogenase from the anaerobic chytrid Neocallimastix sp L2

NARCIS (Netherlands)

Voncken, Frank G.J.; Boxma, Brigitte; Hoek, Angela H.A.M. van; Akhmanova, Anna S.; Vogels, Godfried D.; Huynen, Martijn; Veenhuis, Marten; Hackstein, Johannes H.P.

2002-01-01

The presence of a [Fe]-hydrogenase in the hydrogenosomes of the anaerobic chytridiomycete fungus Neocallimastix sp. L2 has been demonstrated by immunocytochemistry, subcellular fractionation, Western-blotting, and measurements of hydrogenase activity in the presence of various concentrations of

A new G-M counter dead time model

International Nuclear Information System (INIS)

Lee, S.H.; Gardner, R.P.

2000-01-01

A hybrid G-M counter dead time model was derived by combining the idealized paralyzable and non-paralyzable models. The new model involves two parameters, which are the paralyzable and non-paralyzable dead times. The dead times used in the model are very closely related to the physical dead time of the G-M tube and its resolving time. To check the validity of the model, the decaying source method with 56 Mn was used. The corrected counting rates by the new G-M dead time model were compared with the observed counting rates obtained from the measurement and gave very good agreement within 5% up to 7x10 4 counts/s for a G-M tube with a dead time of about 300 μs

Dentigerumycin: a bacterial mediator of an ant-fungus symbiosis

DEFF Research Database (Denmark)

Oh, Dong-Chan; Poulsen, Michael; Currie, Cameron R

2009-01-01

Fungus-growing ants engage in mutualistic associations with both the fungus they cultivate for food and actinobacteria (Pseudonocardia spp.) that produce selective antibiotics to defend that fungus from specialized fungal parasites. We have analyzed one such system at the molecular level and found...

Assessment and management of dead-wood habitat

Science.gov (United States)

Hagar, Joan

2007-01-01

The Bureau of Land Management (BLM) is in the process of revising its resource management plans for six districts in western and southern Oregon as the result of the settlement of a lawsuit brought by the American Forest Resource Council. A range of management alternatives is being considered and evaluated including at least one that will minimize reserves on O&C lands. In order to develop the bases for evaluating management alternatives, the agency needs to derive a reasonable range of objectives for key issues and resources. Dead-wood habitat for wildlife has been identified as a key resource for which decision-making tools and techniques need to be refined and clarified. Under the Northwest Forest Plan, reserves were to play an important role in providing habitat for species associated with dead wood (U.S. Department of Agriculture Forest Service and U.S. Department of the Interior Bureau of Land Management, 1994). Thus, the BLM needs to: 1) address the question of how dead wood will be provided if reserves are not included as a management strategy in the revised Resource Management Plan, and 2) be able to evaluate the effects of alternative land management approaches. Dead wood has become an increasingly important conservation issue in managed forests, as awareness of its function in providing wildlife habitat and in basic ecological processes has dramatically increased over the last several decades (Laudenslayer et al., 2002). A major concern of forest managers is providing dead wood habitat for terrestrial wildlife. Wildlife in Pacific Northwest forests have evolved with disturbances that create large amounts of dead wood; so, it is not surprising that many species are closely associated with standing (snags) or down, dead wood. In general, the occurrence or abundance of one-quarter to one-third of forest-dwelling vertebrate wildlife species, is strongly associated with availability of suitable dead-wood habitat (Bunnell et al., 1999; Rose et al., 2001). In

Carbon dioxide sensing in an obligate insect-fungus symbiosis: CO2 preferences of leaf-cutting ants to rear their mutualistic fungus.

Directory of Open Access Journals (Sweden)

Daniela Römer

Full Text Available Defense against biotic or abiotic stresses is one of the benefits of living in symbiosis. Leaf-cutting ants, which live in an obligate mutualism with a fungus, attenuate thermal and desiccation stress of their partner through behavioral responses, by choosing suitable places for fungus-rearing across the soil profile. The underground environment also presents hypoxic (low oxygen and hypercapnic (high carbon dioxide conditions, which can negatively influence the symbiont. Here, we investigated whether workers of the leaf-cutting ant Acromyrmex lundii use the CO2 concentration as an orientation cue when selecting a place to locate their fungus garden, and whether they show preferences for specific CO2 concentrations. We also evaluated whether levels preferred by workers for fungus-rearing differ from those selected for themselves. In the laboratory, CO2 preferences were assessed in binary choices between chambers with different CO2 concentrations, by quantifying number of workers in each chamber and amount of relocated fungus. Leaf-cutting ants used the CO2 concentration as a spatial cue when selecting places for fungus-rearing. A. lundii preferred intermediate CO2 levels, between 1 and 3%, as they would encounter at soil depths where their nest chambers are located. In addition, workers avoided both atmospheric and high CO2 levels as they would occur outside the nest and at deeper soil layers, respectively. In order to prevent fungus desiccation, however, workers relocated fungus to high CO2 levels, which were otherwise avoided. Workers' CO2 preferences for themselves showed no clear-cut pattern. We suggest that workers avoid both atmospheric and high CO2 concentrations not because they are detrimental for themselves, but because of their consequences for the symbiotic partner. Whether the preferred CO2 concentrations are beneficial for symbiont growth remains to be investigated, as well as whether the observed preferences for fungus

Determination of detection equipment dead time

International Nuclear Information System (INIS)

Sacha, J.

1980-01-01

A method is described of determining dead time by short-lived source measurement. It is based on measuring the sample count rates in different time intervals when only dead time correction is changed with the changing count of recorded pulses. The dead time may be determined from the measured values by a numerical-graphical method. The method is described. The advantage of the method is the minimization of errors and inaccuracies; the disadvantage is that the half-life of the source used should very accurately be known. (J.P.)

Cascades of pile-up and dead time

International Nuclear Information System (INIS)

Pomme, S.

2008-01-01

Count loss through a cascade of pile-up and dead time is studied. Time interval density-distribution functions and throughput factors are presented for counters with a series arrangement of pile-up and extending or non-extending dead time. A counter is considered, where an artificial dead time is imposed on every counted event, in order to control the length and type of dead time. For such a system, it is relatively easy to determine an average count-loss correction factor via a live-time clock gated by the imposed dead-time signal ('live-time mode'), or otherwise to apply a correction factor based on the inversion of the throughput function ('real-time mode'). However, these techniques do not account for additional loss through pulse pile-up. In this work, counting errors associated with neglecting cascade effects are calculated for measurements in live-time and real-time mode

White-Nose Syndrome Fungus (Geomyces destructans) in Bat, France

Science.gov (United States)

Puechmaille, Sébastien J.; Verdeyroux, Pascal; Fuller, Hubert; Gouilh, Meriadeg Ar; Bekaert, Michaël

2010-01-01

White-nose syndrome is caused by the fungus Geomyces destructans and is responsible for the deaths of >1,000,000 bats since 2006. This disease and fungus had been restricted to the northeastern United States. We detected this fungus in a bat in France and assessed the implications of this finding. PMID:20113562

Dead time corrections using the backward extrapolation method

Energy Technology Data Exchange (ETDEWEB)

Gilad, E., E-mail: gilade@bgu.ac.il [The Unit of Nuclear Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel); Dubi, C. [Department of Physics, Nuclear Research Center NEGEV (NRCN), Beer-Sheva 84190 (Israel); Geslot, B.; Blaise, P. [DEN/CAD/DER/SPEx/LPE, CEA Cadarache, Saint-Paul-les-Durance 13108 (France); Kolin, A. [Department of Physics, Nuclear Research Center NEGEV (NRCN), Beer-Sheva 84190 (Israel)

2017-05-11

Dead time losses in neutron detection, caused by both the detector and the electronics dead time, is a highly nonlinear effect, known to create high biasing in physical experiments as the power grows over a certain threshold, up to total saturation of the detector system. Analytic modeling of the dead time losses is a highly complicated task due to the different nature of the dead time in the different components of the monitoring system (e.g., paralyzing vs. non paralyzing), and the stochastic nature of the fission chains. In the present study, a new technique is introduced for dead time corrections on the sampled Count Per Second (CPS), based on backward extrapolation of the losses, created by increasingly growing artificially imposed dead time on the data, back to zero. The method has been implemented on actual neutron noise measurements carried out in the MINERVE zero power reactor, demonstrating high accuracy (of 1–2%) in restoring the corrected count rate. - Highlights: • A new method for dead time corrections is introduced and experimentally validated. • The method does not depend on any prior calibration nor assumes any specific model. • Different dead times are imposed on the signal and the losses are extrapolated to zero. • The method is implemented and validated using neutron measurements from the MINERVE. • Result show very good correspondence to empirical results.

Fungus-insect gall of Phlebopus portentosus.

Science.gov (United States)

Zhang, Chun-Xia; He, Ming-Xia; Cao, Yang; Liu, Jing; Gao, Feng; Wang, Wen-Bing; Ji, Kai-Ping; Shao, Shi-Cheng; Wang, Yun

2015-01-01

Phlebopus portentosus is a popular edible wild mushroom found in the tropical Yunnan, China, and northern Thailand. In its natural habitats, a gall often has been found on some plant roots, around which fungal fruiting bodies are produced. The galls are different from common insect galls in that their cavity walls are not made from plant tissue but rather from the hyphae of P. portentosus. Therefore we have termed this phenomenon "fungus-insect gall". Thus far six root mealy bug species in the family Pseudococcidae that form fungus-insect galls with P. portentosus have been identified: Formicococcus polysperes, Geococcus satellitum, Planococcus minor, Pseudococcus cryptus, Paraputo banzigeri and Rastrococcus invadens. Fungus-insect galls were found on the roots of more than 21 plant species, including Delonix regia, Citrus maxima, Coffea arabica and Artocarpus heterophyllus. Greenhouse inoculation trials showed that fungus-insect galls were found on the roots of A. heterophyllus 1 mo after inoculation. The galls were subglobose to globose, fulvous when young and became dark brown at maturation. Each gall harbored one or more mealy bugs and had a chimney-like vent for ventilation and access to the gall. The cavity wall had three layers. Various shaped mealy bug wax deposits were found inside the wall. Fungal hyphae invaded the epidermis of plant roots and sometimes even the cortical cells during the late stage of gall development. The identity of the fungus inside the cavity was confirmed by molecular methods. © 2015 by The Mycological Society of America.

9 CFR 82.6 - Interstate movement of dead birds and dead poultry from a quarantined area.

Science.gov (United States)

2010-01-01

... provided in paragraph (b) of this section for dressed carcasses, dead birds and dead poultry, including any... poultry at the destination listed on the permit required by paragraph (a)(1) of this section. (b) Dressed... quarantined area only if: (1) The dressed carcasses are from birds or poultry that were slaughtered in a...

Optimized integration of T-DNA in the taxol-producing fungus ...

African Journals Online (AJOL)

We previously reported a taxol-producing fungus Pestalotiopsis malicola. There, we described the transformation of the fungus mediated by Agrobacterium tumefaciens. T-DNA carrying the selection marker was transferred into the fungus and randomly integrated into the genome as shown by Southern blotting.

Towards an integrated understanding of the consequences of fungus domestication on the fungus-growing termite gut microbiota

DEFF Research Database (Denmark)

Thomas-Poulsen, Michael

2015-01-01

Approximately 30 million years ago (MYA), the subfamily of higher termites Macrotermitinae domesticated a fungus, Termitomyces, as the main plant decomposer and food source for the termite host. The origin of fungiculture shifted the composition of the termite gut microbiota, and some of the func......Approximately 30 million years ago (MYA), the subfamily of higher termites Macrotermitinae domesticated a fungus, Termitomyces, as the main plant decomposer and food source for the termite host. The origin of fungiculture shifted the composition of the termite gut microbiota, and some...... will be powerful, particularly if executed in comparative analyses across the well-established congruent termite-fungus phylogenies. This will allow for testing if gut communities have evolved in parallel with their hosts, with implications for our general understanding of the evolution of gut symbiont communities...

Dead pixel replacement in LWIR microgrid polarimeters.

Science.gov (United States)

Ratliff, Bradley M; Tyo, J Scott; Boger, James K; Black, Wiley T; Bowers, David L; Fetrow, Matthew P

2007-06-11

LWIR imaging arrays are often affected by nonresponsive pixels, or "dead pixels." These dead pixels can severely degrade the quality of imagery and often have to be replaced before subsequent image processing and display of the imagery data. For LWIR arrays that are integrated with arrays of micropolarizers, the problem of dead pixels is amplified. Conventional dead pixel replacement (DPR) strategies cannot be employed since neighboring pixels are of different polarizations. In this paper we present two DPR schemes. The first is a modified nearest-neighbor replacement method. The second is a method based on redundancy in the polarization measurements.We find that the redundancy-based DPR scheme provides an order-of-magnitude better performance for typical LWIR polarimetric data.

10 CFR 1047.7 - Use of deadly force.

Science.gov (United States)

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Use of deadly force. 1047.7 Section 1047.7 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) LIMITED ARREST AUTHORITY AND USE OF FORCE BY PROTECTIVE FORCE OFFICERS General Provisions § 1047.7 Use of deadly force. (a) Deadly force means that force which a...

Visualization of deuterium dead layer by atom probe tomography

KAUST Repository

Gemma, Ryota

2012-12-01

The first direct observation, by atom probe tomography, of a deuterium dead layer is reported for Fe/V multilayered film loaded with D solute atoms. The thickness of the dead layers was measured to be 0.4-0.5 nm. The dead layers could be distinguished from chemically intermixed layers. The results suggest that the dead layer effect occurs even near the interface of the mixing layers, supporting an interpretation that the dead layer effect cannot be explained solely by electronic charge transfer but also involves a modulation of rigidity. © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Visualization of deuterium dead layer by atom probe tomography

KAUST Repository

Gemma, Ryota; Al-Kassab, Talaat; Kirchheim, Reiner; Pundt, Astrid A.

2012-01-01

The first direct observation, by atom probe tomography, of a deuterium dead layer is reported for Fe/V multilayered film loaded with D solute atoms. The thickness of the dead layers was measured to be 0.4-0.5 nm. The dead layers could be distinguished from chemically intermixed layers. The results suggest that the dead layer effect occurs even near the interface of the mixing layers, supporting an interpretation that the dead layer effect cannot be explained solely by electronic charge transfer but also involves a modulation of rigidity. © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Dead Time in the LAr Calorimeter Front-End Readout

CERN Document Server

Gingrich, D M

2002-01-01

We present readout time, latency, buffering, and dead-time calculations for the switched capacitor array controllers of the LAr calorimeter. The dead time is compared with algorithms for the dead-time generation in the level-1 central trigger processor.

Mapping the global emergence of Batrachochytrium dendrobatidis, the amphibian chytrid fungus

Science.gov (United States)

Deanna H. Olson; David M. Aanensen; Kathryn L. Ronnenberg; Christopher I. Powell; Susan F. Walker; Jon Bielby; Trenton W.J. Garner; George Weaver; Matthew C. Fisher

2013-01-01

The rapid worldwide emergence of the amphibian pathogen Batrachochytrium dendrobatidis (Bd) is having a profound negative impact on biodiversity. However, global research efforts are fragmented and an overarching synthesis of global infection data is lacking. Here, we provide results from a community tool for the compilation of...

Predation by northern squawfish on live and dead juvenile chinook salmon

International Nuclear Information System (INIS)

Gadomski, D.M.; Hall-Griswold, J.A.

1992-01-01

Northern squawfish Ptychocheilus oregonensis is a major predator of juvenile salmonids Oncorhynchus spp. migrating downstream through the Columbia River. High predation rates occur just below dams. If northern squawfish selectively consume salmonids killed or injured during dam passage, previous estimates of predation mortality may be too high. We conducted laboratory experiments that indicate northern squawfish prefer dead juvenile chinook salmon O. tshawytscha over live individuals. When equal numbers of dead and live chinook salmon were offered to northern squawfish maintained on a natural photoperiod (15 h light: 9 h darkness), significantly more (P < 0.05) dead than live fish were consumed, both in 1,400-L circular tanks and in an 11,300-L raceway (62% and 79% of prey consumed were dead, respectively). When dead and live juvenile chinook salmon were provided in proportions more similar to those below dams (20% dead, 80% live), northern squawfish still selected for dead prey (36% of fish consumed were dead). In additional experiments, northern squawfish were offered a proportion of 20% dead juvenile chinook salmon during 4-h periods of either light or darkness. The predators were much more selective for dead chinook salmon during bright light (88% of fish consumed were dead) than during darkness (31% were dead)

CHARACTERIZATION OF AN ANAEROBIC FUNGUS FROM LLAMA FECES

NARCIS (Netherlands)

MARVINSIKKEMA, FD; LAHPOR, GA; KRAAK, MN; GOTTSCHAL, JC; PRINS, RA

1992-01-01

An anaerobic fungus was isolated from Hama faeces. Based on its morphological characteristics, polyflagellated zoospores, extensive rhizoid system and the formation of monocentric colonies, the fungus is assigned to the genus Neocallimastix. Neocallimastix sp. L2 is able to grow on several poly-,

Dead time effects in laser Doppler anemometry measurements

DEFF Research Database (Denmark)

Velte, Clara Marika; Buchhave, Preben; George, William K.

2014-01-01

frequency range, starting around the cutoff frequency due to the finite size of the MV. Using computer-generated data mimicking the LDA data, these effects have previously been shown to appear due to the effect of dead time, i.e., the finite time during which the system is not able to acquire new...... measurements. These dead times can be traced back to the fact that the burst-mode LDA cannot measure more than one signal burst at a time. Since the dead time is approximately equal to the residence time for a particle traversing a measurement volume, we are dealing with widely varying dead times, which...

Termite-egg mimicry by a sclerotium-forming fungus.

Science.gov (United States)

Matsuura, Kenji

2006-05-22

Mimicry has evolved in a wide range of organisms and encompasses diverse tactics for defence, foraging, pollination and social parasitism. Here, I report an extraordinary case of egg mimicry by a fungus, whereby the fungus gains competitor-free habitat in termite nests. Brown fungal balls, called 'termite balls', are frequently found in egg piles of Reticulitermes termites. Phylogenetic analysis illustrated that termite-ball fungi isolated from different hosts (Reticulitermes speratus, Reticulitermes flavipes and Reticulitermes virginicus) were all very similar, with no significant molecular differences among host species or geographical locations. I found no significant effect of termite balls on egg survivorship. The termite-ball fungus rarely kills termite eggs in natural colonies. Even a termite species (Reticulitermes okinawanus) with no natural association with the fungus tended termite balls along with its eggs when it was experimentally provided with termite balls. Dummy-egg bioassays using glass beads showed that both morphological and chemical camouflage were necessary to induce tending by termites. Termites almost exclusively tended termite balls with diameters that exactly matched their egg size. Moreover, scanning electron microscopic observations revealed sophisticated mimicry of the smooth surface texture of eggs. These results provide clear evidence that this interaction is beneficial only for the fungus, i.e. termite balls parasitically mimic termite eggs.

The ecosystem service value of living versus dead biogenic reef

Science.gov (United States)

Sheehan, E. V.; Bridger, D.; Attrill, M. J.

2015-03-01

Mixed maerl beds (corralline red algae) comprise dead thalli with varying amounts of live maerl fragments, but previously it was not known whether the presence of the live maerl increases the ecosystem service 'habitat provision' of the dead maerl for the associated epibenthos. A 'flying array' towed sled with high definition video was used to film transects of the epibenthos in dead maerl and mixed maerl beds in two locations to the north and south of the English Channel (Falmouth and Jersey). Mixed maerl beds supported greater number of taxa and abundance than dead beds in Falmouth, while in Jersey, mixed and dead beds supported similar number of taxa and dead beds had a greater abundance of epifauna. Scallops tended to be more abundant on mixed beds than dead beds. Tube worms were more abundant on mixed beds in Falmouth and dead beds in Jersey. An increasing percentage occurrence of live maerl thalli correlated with increasing number of taxa in Falmouth but not Jersey. It was concluded that while live thalli can increase the functional role of dead maerl beds for the epibenthos, this is dependent on location and response variable. As a result of this work, maerl habitat in SE Jersey has been protected from towed demersal fishing gear.

Mucormycosis (Mucor fungus ball) of the maxillary sinus.

Science.gov (United States)

Cho, Hang Sun; Yang, Hoon Shik; Kim, Kyung Soo

2014-01-01

A fungus ball is an extramucosal fungal proliferation that completely fills one or more paranasal sinuses and usually occurs as a unilateral infection. It is mainly caused by Aspergillus spp in an immunocompetent host, but some cases of paranasal fungal balls reportedly have been caused by Mucor spp. A Mucor fungus ball is usually found in the maxillary sinus and/or the sphenoid sinus and may be black in color. Patients with mucormycosis, or a Mucor fungal ball infection, usually present with facial pain or headache. On computed tomography, there are no pathognomonic findings that are conclusive for a diagnosis of mucormycosis. In this article we report a case of mucormycosis in a 56-year-old woman and provide a comprehensive review of the literature on the "Mucor fungus ball." To the best of our knowledge, 5 case reports (8 patients) have been published in which the fungus ball was thought to be caused by Mucor spp.

Solubilization of diabase and phonolite dust by filamentous fungus

Directory of Open Access Journals (Sweden)

Juliana Andréia Vrba Brandão

2014-10-01

Full Text Available The objective of this study was to evaluate the effect of the fungus Aspergillus niger strain CCT4355 in the release of nutrients contained in two types of rock powder (diabase and phonolite by means of in vitro solubilization trials. The experimental design was completely randomized in a 5 x 4 factorial design with three replications. It was evaluated five treatments (phonolite dust + culture medium; phonolite dust + fungus + culture medium; diabase powder + culture medium; diabase powder + fungus + culture medium and fungus + culture medium and four sampling dates (0, 10, 20 and 30 days. Rock dust (0.4% w/v was added to 125 mL Erlenmeyer flasks containing 50 mL of liquid culture medium adapted to A. niger. The flasks were incubated at 30°C for 30 days, and analysis of pH (in water, titratable acidity, and concentrations of soluble potassium, calcium, magnesium, zinc, iron and manganese were made. The fungus A. niger was able to produce organic acids that solubilized ions. This result indicates its potential to alter minerals contained in rock dust, with the ability to interact in different ways with the nutrients. A significant increase in the amount of K was found in the treatment with phonolite dust in the presence of the fungus. The strain CCT4355 of A. niger can solubilize minerals contained in these rocks dust.

COMPARATIVE ANALYSIS OF TECHNILOGIES OF CHITOSAN PRODUCTION FROM DEAD BEES

Directory of Open Access Journals (Sweden)

Marina Abramova

2017-07-01

Full Text Available Objective: The aim of this work is to study the characteristics of technology of chitosan obtaining from unconventional sources, namely from dead bees. Methods: The article considers three methods of chitosan obtaining from dead bees, namely the technology with the usage of dead bees with low degree of drying; the technology with the usage of dead bees with high degree of drying; the technology with the usage of dead bees with high degree of drying but without separation of deproteination and deacetylation stages. Results: It is proved that the technology with the usage of dead bees with high degree of drying but without separation of deproteination and deacetylation stages does not require high temperatures and long time. Yield of chitosan with the use of this technology is 21-24%. Discussion: The expediency of dead bees usage as raw material for the production of chitosan in Ukraine is shown. The technologies of chitosan obtaining from dead bees are compared, the most efficient one is chosen, which provide the highest yield of the finished product, so it is the most promising for the application in practice.

Trematodes enhance the development of the nematode-trapping fungus Arthrobotrys (Duddingtonia) flagrans.

Science.gov (United States)

Arias, María Sol; Suárez, José; Cazapal-Monteiro, Cristiana Filipa; Francisco, Iván; López-Arellano, María Eugenia; Piñeiro, Pablo; Suárez, José Luis; Sánchez-Andrade, Rita; Mendoza de Gives, Pedro; Paz-Silva, Adolfo

2013-01-01

The capability of helminth (nematode and trematode) parasites in stimulating nematode trap and chlamydospore development of the nematophagous fungus Arthrobotrys (formerly Duddingtonia) flagrans was explored. Dead adult specimens of trematodes (the liver fluke Fasciola hepatica and the rumen fluke Calicophoron daubneyi) and nematodes (the ascarid Parascaris equorum and the strongylid Oesophagostomum spp.), as well as their secretory products, were placed onto corn meal agar plates concurrently inoculated with A. flagrans. Trapping organs were observed after 5 d and chlamydospores after 16 d, including in the control plates in the absence of parasitic stimulus. However, our data shows that both nematodes and trematodes increase trap and chlamydospore production compared with controls. We show for the first time that significantly higher numbers of traps and chlamydospores were observed in the cultures coinoculated with adult trematodes. We conclude that both the traps and chlamydospores formation are not only related to nematode-specific stimuli. The addition of secretory products of the trematode C. daubneyi to culture medium has potential for use in the large scale production of chlamydospores. Copyright © 2013 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Dead sea transform fault system reviews

CERN Document Server

Garfunkel, Zvi; Kagan, Elisa

2014-01-01

The Dead Sea transform is an active plate boundary connecting the Red Sea seafloor spreading system to the Arabian-Eurasian continental collision zone. Its geology and geophysics provide a natural laboratory for investigation of the surficial, crustal and mantle processes occurring along transtensional and transpressional transform fault domains on a lithospheric scale and related to continental breakup. There have been many detailed and disciplinary studies of the Dead Sea transform fault zone during the last?20 years and this book brings them together.This book is an updated comprehensive coverage of the knowledge, based on recent studies of the tectonics, structure, geophysics, volcanism, active tectonics, sedimentology and paleo and modern climate of the Dead Sea transform fault zone. It puts together all this new information and knowledge in a coherent fashion.

14 CFR 1203b.106 - Use of deadly force.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Use of deadly force. 1203b.106 Section... AUTHORITY AND USE OF FORCE BY NASA SECURITY FORCE PERSONNEL § 1203b.106 Use of deadly force. Deadly force shall be used only in those circumstances where the security force officer reasonably believes that...

Resurrecting deadly carrots

DEFF Research Database (Denmark)

Weitzel, Corinna; Rønsted, Nina; Spalik, Krysztof

2014-01-01

Thapsia L. circumscribes a small genus of herbaceous perennials in the taxonomically difficult family Apiaceae. Thapsia occurs around the Mediterranean, extending from the Atlantic coasts of Portugal and Morocco to Crete and other Greek Islands in the East. Thapsia is commonly known as deadly...

Dead-Time Generation in Six-Phase Frequency Inverter

Directory of Open Access Journals (Sweden)

Aurelijus Pitrėnas

2016-06-01

Full Text Available In this paper control of multi-phase induction drives is discussed. Structure of six-phase frequency inverter is examined. The article deals with dead-time generation circuits in six-phase frequency inverter for transistor control signals. Computer models of dead-time circuits is created using LTspice software package. Simulation results are compared with experimental results of the tested dead-time circuits. Parameters obtained in simulation results are close to the parameters obtained in experimental results.

Isolation and identification of iron ore-solubilising fungus

Directory of Open Access Journals (Sweden)

Damase Khasa

2010-09-01

Full Text Available Potential mineral-solubilising fungi were successfully isolated from the surfaces of iron ore minerals. Four isolates were obtained and identified by molecular and phylogenetic methods as close relatives of three different genera, namely Penicillium (for isolate FO, Alternaria (for isolates SFC2 and KFC1 and Epicoccum (for isolate SFC2B. The use of tricalcium phosphate (Ca₃(PO₄₂in phosphate-solubilising experiments confirmed isolate FO as the only phosphate solubiliser among the isolated fungi. The bioleaching capabilities of both the fungus and its spent liquid medium were tested and compared using two types of iron ore materials, conglomerate and shale, from the Sishen Iron Ore Mine as sources of potassium (K and phosphorus (P. The spent liquid medium removed more K (a maximum of 32.94% removal, from conglomerate, than the fungus (a maximum of 21.36% removal, from shale. However, the fungus removed more P (a maximum of 58.33% removal, from conglomerate than the spent liquid medium (a maximum of 29.25% removal, from conglomerate. The results also indicated a potential relationship between the removal of K or P and the production of organic acids by the fungus. A high production of gluconic acid could be related to the ability of the fungus to reduce K and P. Acetic, citric and maleic acids were also produced by the fungus, but in lower quantities. In addition, particle size and iron ore type were also shown to have significant effects on the removal of potassium and phosphorus from the iron ore minerals. We therefore conclude that the spent liquid medium from the fungal isolate FO can potentially be used for biobeneficiation of iron ore minerals.

The zero inflation of standing dead tree carbon stocks

Science.gov (United States)

Christopher W. Woodall; David W. MacFarlane

2012-01-01

Given the importance of standing dead trees in numerous forest ecosystem attributes/processes such as carbon (C) stocks, the USDA Forest Service’s Forest Inventory and Analysis (FIA) program began consistent nationwide sampling of standing dead trees in 1999. Modeled estimates of standing dead tree C stocks are currently used as the official C stock estimates for the...

Various Stages of Pink Fungus (Upasia salmonicolor in Java

Directory of Open Access Journals (Sweden)

Ambarwati Harsojo Tjokrosoedarmo

1995-12-01

Full Text Available Pink fungus in Java is classified as Upasia salmonicolor (Basidiomycetes: Corticiaceae and its anamorph is Necator decretus. This fungus is a serious pathogen which attacks many woody plants. The pink fungus in Java exhibits five developmental stages on the surface of the host bark: I. An initial cobweb stage as thin, white, cobweb-like hyphal layer, which creeps over the surface of the bark, during which penetration of the host occurs; II. Pseudonodular stage, as conical white pustules occurring only on lenticels or cracks, and only on shady side of branches; III. Teleomorph, occurs as pink incrustation and pink pustules on shady side of branches; IV. Nodular stages, as globose white pustules occurring chiefly on intact bark, but also on the lenticels or cracks, on exposed side of branches; V. Anamorph, as small orange-red sporodochium, on exposed side of branches. Key words: pink fungus, Corticiaceae, Basidiomycetes, Necator

Effect of counting system dead time on thyroid uptake measurements

International Nuclear Information System (INIS)

Simpkin, D.J.

1984-01-01

Equations are derived and the results of numerical calculations shown that illustrate the effect of counting system dead time on measured thyroid uptake of radioiodine. It is predicted that the observed uptake is higher than the true uptake due to system dead time. This is shown for both paralyzing and nonparalyzing dead time. The effect of increasing the administered activity is shown to increase the measured uptake, in a manner predicted by the paralyzable and nonparalyzable dead time models

Chemical composition of metapleural gland secretions of fungus-growing and non-fungus-growing ants.

Science.gov (United States)

Vieira, Alexsandro S; Morgan, E David; Drijfhout, Falko P; Camargo-Mathias, Maria I

2012-10-01

The metapleural gland is exclusive to ants, and unusual among exocrine glands in having no mechanism for closure and retention of secretion. As yet, no clear conclusion has been reached as to the function of metapleural gland secretion. Metapleural gland secretions were investigated for fungus-growing ants representing the derived attines Trachymyrmex fuscus, Atta laevigata, and Acromyrmex coronatus, the basal attines Apterostigma pilosum and Mycetarotes parallelus, and non-fungus-growing ants of the tribes Ectatommini (Ectatomma brunneum) and Myrmicini (Pogonomyrmex naegeli). Our results showed that the secretions of leaf-cutting ants (A. laevigata and A. coronatus) and the derived attine, T. fuscus, contain a greater variety and larger quantities of volatile compounds than those of myrmicine and ectatommine ants. The most abundant compounds found in the metapleural glands of A. laevigata and A. coronatus were hydroxyacids, and phenylacetic acid (only in A. laevigata). Indole was present in all groups examined, while skatole was found in large quantities only in attines. Ketones and aldehydes are present in the secretion of some attines. Esters are present in the metapleural gland secretion of all species examined, although mainly in A. laevigata, A. coronatus, and T. fuscus. Compared with basal attines and non-fungus-growing ants, the metapleural glands of leaf-cutting ants produce more acidic compounds that may have an antibiotic or antifungal function.

Reciprocal genomic evolution in the ant-fungus agricultural symbiosis

DEFF Research Database (Denmark)

Nygaard, Sanne; Hu, Haofu; Li, Cai

2016-01-01

The attine ant-fungus agricultural symbiosis evolved over tens of millions of years, producing complex societies with industrial-scale farming analogous to that of humans. Here we document reciprocal shifts in the genomes and transcriptomes of seven fungus-farming ant species and their fungal...

Comparative studies of the secretome of fungus-growing ants

DEFF Research Database (Denmark)

Linde, Tore; Grell, Morten Nedergaard; Schiøtt, Morten

2009-01-01

Leafcutter ants of the species Acromyrmex echinatior live in symbiosis with the fungus Leucoagaricus gongylophorus. The ants harvest fragments of leaves and carry them to the nest where they place the material on the fungal colony. The fungus secretes a wide array of proteins to degrade the leaves...... into nutrients that the ants can feed on. The focus of this study is to discover, characterize and compare the secreted proteins. In order to do so cDNA libraries are constructed from mRNA extracted from the fungus material. The most efficient technology to screen cDNA libraries selectively for secreted...

Dead-ice environments

DEFF Research Database (Denmark)

Krüger, Johannes; Kjær, Kurt H.; Schomacker, Anders

2010-01-01

glacier environment. The scientific challenges are to answer the key questions. What are the conditions for dead-ice formation? From which sources does the sediment cover originate? Which melting and reworking processes act in the ice-cored moraines? What is the rate of de-icing in the ice-cored moraines...

Antibiotic Resistance and Fungus

Centers for Disease Control (CDC) Podcasts

2017-02-28

Dr. David Denning, President of the Global Action Fund for Fungal Infections and an infectious diseases clinician, discusses antimicrobial resistance and fungus.  Created: 2/28/2017 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 2/28/2017.

U.S. National Fungus Collections

Data.gov (United States)

Department of Agriculture — The U.S. National Fungus Collections (BPI) are the “Smithsonian for fungi” and are the repository for over one million fungal specimens worldwide - the largest such...

Evolutionary patterns of proteinase activity in attine ant fungus gardens

DEFF Research Database (Denmark)

Semenova, Tatyana; Hughes, David Peter; Boomsma, Jacobus Jan

2011-01-01

hypothesized that fungal proteinase activity may have been under selection for efficiency and that different classes of proteinases might be involved. Results: We determined proteinase activity profiles across a wide pH range for fungus gardens of 14 Panamanian species of fungus-growing ants, representing...... classes. Remarkably, the single symbiont that is shared by species of the crown group of Atta and Acromyrmex leaf-cutting ants mostly showed metalloproteinase activity, suggesting that recurrent changes in enzyme production may have occurred throughout the domestication history of fungus-garden symbionts......Background: Attine ants live in symbiosis with a basidiomycetous fungus that they rear on a substrate of plant material. This indirect herbivory implies that the symbiosis is likely to be nitrogen deprived, so that specific mechanisms may have evolved to enhance protein availability. We therefore...

Exploring the potential for actinobacteria as defensive symbionts in fungus-growing termites

DEFF Research Database (Denmark)

Visser, Anna A.; Nobre, Tânia; Currie, Cameron R.

2012-01-01

In fungus-growing termites, fungi of the subgenus Pseudoxylaria threaten colony health through substrate competition with the termite fungus (Termitomyces). The potential mechanisms with which termites suppress Pseudoxylaria have remained unknown. Here we explore if Actinobacteria potentially play...... a role as defensive symbionts against Pseudoxylaria in fungus-growing termites. We sampled for Actinobacteria from 30 fungus-growing termite colonies, spanning the three main termite genera and two geographically distant sites. Our isolations yielded 360 Actinobacteria, from which we selected subsets...... for morphological (288 isolates, grouped in 44 morphotypes) and for 16S rRNA (35 isolates, spanning the majority of morphotypes) characterisation. Actinobacteria were found throughout all sampled nests and colony parts and, phylogenetically, they are interspersed with Actinobacteria from origins other than fungus...

Electronic fingerprinting of the dead.

Science.gov (United States)

Rutty, G N; Stringer, K; Turk, E E

2008-01-01

To date, a number of methods exist for the capture of fingerprints from cadavers that can then be used in isolation as a primary method for the identification of the dead. We report the use of a handheld, mobile wireless unit used in conjunction with a personal digital assistant (PDA) device for the capture of fingerprints from the dead. We also consider a handheld single-digit fingerprint scanner that utilises a USB laptop connection for the electronic capture of cadaveric fingerprints. Both are single-operator units that, if ridge detail is preserved, can collect a 10-set of finger pad prints in approximately 45 and 90 s, respectively. We present our observations on the restrictions as to when such devices can be used with cadavers. We do, however, illustrate that the images are of sufficient quality to allow positive identification from finger pad prints of the dead. With the development of mobile, handheld, biometric, PDA-based units for the police, we hypothesize that, under certain circumstances, devices such as these could be used for the accelerated acquisition of fingerprint identification data with the potential for rapid near-patient identification in the future.

Another method of dead time correction

International Nuclear Information System (INIS)

Sabol, J.

1988-01-01

A new method of the correction of counting losses caused by a non-extended dead time of pulse detection systems is presented. The approach is based on the distribution of time intervals between pulses at the output of the system. The method was verified both experimentally and by using the Monte Carlo simulations. The results show that the suggested technique is more reliable and accurate than other methods based on a separate measurement of the dead time. (author) 5 refs

Correction for intrinsic and set dead-time losses in radioactivity counting

International Nuclear Information System (INIS)

Wyllie, H.A.

1992-12-01

Equations are derived for the determination of the intrinsic dead time of the components which precede the paralysis unit in a counting system for measuring radioactivity. The determination depends on the extension of the set dead time by the intrinsic dead time. Improved formulae are given for the dead-time correction of the count rate of a radioactive source in a single-channel system. A variable in the formulae is the intrinsic dead time which is determined concurrently with the counting of the source. The only extra equipment required in a conventional system is a scaler. 5 refs., 2 tabs., 21 figs

Virtually Dead: Digital Public Mortuary Archaeology

Directory of Open Access Journals (Sweden)

Howard Williams

2015-12-01

Full Text Available Over recent decades, the ethics, politics and public engagements of mortuary archaeology have received sustained scrutiny, including how we handle, write about and display the archaeological dead. Yet the burgeoning use of digital media to engage different audiences in the archaeology of death and burial have so far escaped attention. This article explores categories and strategies by which digital media create virtual communities engaging with mortuary archaeology. Considering digital public mortuary archaeology (DPMA as a distinctive theme linking archaeology, mortality and material culture, we discuss blogs, vlogs and Twitter as case studies to illustrate the variety of strategies by which digital media can promote, educate and engage public audiences with archaeological projects and research relating to death and the dead in the human past. The article then explores a selection of key critical concerns regarding how the digital dead are currently portrayed, identifying the need for further investigation and critical reflection on DPMA’s aims, objectives and aspired outcomes.

The Dead Walk

Directory of Open Access Journals (Sweden)

Bill Phillips

2014-02-01

Full Text Available Monsters have always enjoyed a significant presence in the human imagination, and religion was instrumental in replacing the physical horror they engendered with that of a moral threat. Zombies, however, are amoral – their motivation purely instinctive and arbitrary, yet they are, perhaps, the most loathed of all contemporary monsters. One explanation for this lies in the theory of the uncanny valley, proposed by robotics engineer Masahiro Mori. According to the theory, we reserve our greatest fears for those things which seem most human, yet are not – such as dead bodies. Such a reaction is most likely a survival mechanism to protect us from danger and disease – a mechanism even more essential when the dead rise up and walk. From their beginnings zombies have reflected western societies’ greatest fears – be they of revolutionary Haitians, women, or communists. In recent years the rise in the popularity of the zombie in films, books and television series reflects our fears for the planet, the economy, and of death itself

The Dead Sea, The Lake and Its Setting

Science.gov (United States)

Brink, Uri ten

I cannot think of a subject more befitting the description of interdisciplinary research with societal relevance than the study of the Dead Sea, a terminal lake of the Jordan River in Israel and Jordan. The scientific study of the Dead Sea is intimately connected with politics, religion, archeology, economic development, tourism, and environmental change.The Dead Sea is a relatively closed geologic and limnologic system with drastic physical changes often occurring on human timescales and with a long human history to observe these changes. Research in this unique area covers diverse aspects such as active subsidence and deformation along strike-slip faults; vertical stratification and stability of the water column; physical properties of extremely saline and dense (1234 kg/m3) water; spontaneous precipitation of minerals in an oversaturated environment; origin of the unusual chemical composition of the brine; existence of life in extreme environments; use of lake level fluctuations as a paleoclimatic indicator; and effects on the environment of human intervention versus natural climatic variability. Although the Dead Sea covers a small area on a global scale, it is nevertheless one of the largest natural laboratories for these types of research on Earth. These reasons make the Dead Sea a fascinating topic for the curious mind.

Traumatic cerrebral fungus: Experience from an institution in North East India

Directory of Open Access Journals (Sweden)

Binoy Kumar Singh

2017-01-01

Full Text Available Background: Traumatic brain fungus is manifestation of neglected head injury. Although rare it is not uncommon. The patients are usually intact with good Glasgow coma (GCS score inspite of complex injuries and exposed brain parenchyma but morbidity and mortality is very high with time if no proper and timely management is offered. There is very less study on traumatic brain fungus with no defined management protocols. So an attempt was made to explain in details the surgical strategies and other management techniques in patients with traumatic brain fungus. Aims: To study and evaluate the pattern of causation, clinical presentations, modalities of management of traumatic brain fungus and outcome after treatment. Methods: All patients with fungus cerebri, admitted to our centre from January 2012 to December 2015 were studied prospectively. All the patients were examined clinically and triaged urgently for surgery. CT head was done in all patients to look for any brain parenchymal injury. All patients were managed surgically. Outcome was assessed as per the Glassgow Outcome Score. Results: Total 10 patients were included in the study. 8 were men and 2 women. The patients' ages ranged from 3-48 years (mean 31.6 years. The interval between initial injury and protrusion ranged from 3 days to 6 days (mean 4.1 days. Mean GCS at the time of presentation was 13.2.60% of the patients (n = 6 sustained moderate head injury. (GCS-9-13. Size of the fungus ranged from 5cm×3cm to 8cm×10cm. Conclusion: Early and proper local wound treatment prevents fungus formation. Pre-emptive antibiotics, AEDs and cerebral decongestants are recommended. Loose water-tight duroplasty prevents CSF leak. But mortality and morbidity can be reduced significantly if brain fungus is managed properly by applying basic surgical principles and antibiotic protocols combined with newer surgical modalities.

Options for reducing HIV transmission related to the dead space in needles and syringes.

Science.gov (United States)

Zule, William A; Pande, Poonam G; Otiashvili, David; Bobashev, Georgiy V; Friedman, Samuel R; Gyarmathy, V Anna; Des Jarlais, Don C

2018-01-15

When shared by people who inject drugs, needles and syringes with different dead space may affect the probability of HIV and hepatitis C virus (HCV) transmission differently. We measured dead space in 56 needle and syringe combinations obtained from needle and syringe programs across 17 countries in Europe and Asia. We also calculated the amounts of blood and HIV that would remain in different combinations following injection and rinsing. Syringe barrel capacities ranged from 0.5 to 20 mL. Needles ranged in length from 8 to 38 mm. The average dead space was 3 μL in low dead space syringes with permanently attached needles, 13 μL in high dead space syringes with low dead space needles, 45 μL in low dead space syringes with high dead space needles, and 99 μL in high dead space syringes with high dead space needles. Among low dead space designs, calculated volumes of blood and HIV viral burden were lowest for low dead space syringes with permanently attached needles and highest for low dead space syringes with high dead space needles. The dead space in different low dead space needle and syringe combinations varied substantially. To reduce HIV transmission related to syringe sharing, needle and syringe programs need to combine this knowledge with the needs of their clients.

Experimental dead-time distortions of Poisson processes

International Nuclear Information System (INIS)

Faraci, G.; Pennisi, A.R.; Consiglio Nazionale delle Ricerche, Catania

1983-01-01

In order to check the distortions, introduced by a non-extended dead time on the Poisson statistics, accurate experiments have been made in single channel counting. At a given measuring time, the dependence on the choice of the time origin and on the width of the dead time has been verified. An excellent agreement has been found between the theoretical expressions and the experimental curves. (orig.)

ADR: An atypical presentation of rare dematiaceous fungus

Directory of Open Access Journals (Sweden)

J Karthika

2014-01-01

Full Text Available The association of fungus in allergic fungal rhino sinusitis has been around 200 times in the world literature. As per the available literature, the most common agent identified so far appears to be ASPERGILLUS, though the condition is increasingly associated with Dematiaceous fungi. Here we report for the first time the presence of unusual fungus in allergic rhino sinusitis, which has not been reported so far.

Degradation of Phenanthrene by a chilean white rot fungus Anthracophyllum discolor

International Nuclear Information System (INIS)

Acevedo, F.; Cuevas, R.; Rubilar, O.; Tortella, G.; Diez, M. C.

2009-01-01

Anthracophyllum discolor, a white rot fungus of southern Chile, has been an efficient degrader of clorophenols and azo dyes. This fungus produces ligninolytic enzymes being manganese peroxidase (Mn)) the major one produced. The main purpose of this study was to evaluate the effect of phenanthrene concentration of ligninolytic activity of A. Discolor measured by poly R-478 decolorazation, and to evaluate the potential of this fungus for degrading phenanthrene in liquid media. (Author)

Degradation of Phenanthrene by a chilean white rot fungus Anthracophyllum discolor

Energy Technology Data Exchange (ETDEWEB)

Acevedo, F.; Cuevas, R.; Rubilar, O.; Tortella, G.; Diez, M. C.

2009-07-01

Anthracophyllum discolor, a white rot fungus of southern Chile, has been an efficient degrader of clorophenols and azo dyes. This fungus produces ligninolytic enzymes being manganese peroxidase (Mn) the major one produced. The main purpose of this study was to evaluate the effect of phenanthrene concentration of ligninolytic activity of A. Discolor measured by poly R-478 decolorazation, and to evaluate the potential of this fungus for degrading phenanthrene in liquid media. (Author)

Comparative growth and development of spiders reared on live and dead prey.

Science.gov (United States)

Peng, Yu; Zhang, Fan; Gui, Shaolan; Qiao, Huping; Hose, Grant C

2013-01-01

Scavenging (feeding on dead prey) has been demonstrated across a number of spider families, yet the implications of feeding on dead prey for the growth and development of individuals and population is unknown. In this study we compare the growth, development, and predatory activity of two species of spiders that were fed on live and dead prey. Pardosa astrigera (Lycosidae) and Hylyphantes graminicola (Lyniphiidae) were fed live or dead fruit flies, Drosophila melanogaster. The survival of P. astrigera and H. graminicola was not affected by prey type. The duration of late instars of P. astrigera fed dead prey were longer and mature spiders had less protein content than those fed live prey, whereas there were no differences in the rate of H. graminicola development, but the mass of mature spiders fed dead prey was greater than those fed live prey. Predation rates by P. astrigera did not differ between the two prey types, but H. graminicola had a higher rate of predation on dead than alive prey, presumably because the dead flies were easier to catch and handle. Overall, the growth, development and reproduction of H. graminicola reared with dead flies was better than those reared on live flies, yet for the larger P. astrigera, dead prey may suit smaller instars but mature spiders may be best maintained with live prey. We have clearly demonstrated that dead prey may be suitable for rearing spiders, although the success of the spiders fed such prey appears size- and species specific.

Patterns of functional enzyme activity in fungus farming ambrosia beetles.

Science.gov (United States)

De Fine Licht, Henrik H; Biedermann, Peter H W

2012-06-06

In wood-dwelling fungus-farming weevils, the so-called ambrosia beetles (Curculionidae: Scolytinae and Platypodinae), wood in the excavated tunnels is used as a medium for cultivating fungi by the combined action of digging larvae (which create more space for the fungi to grow) and of adults sowing and pruning the fungus. The beetles are obligately dependent on the fungus that provides essential vitamins, amino acids and sterols. However, to what extent microbial enzymes support fungus farming in ambrosia beetles is unknown. Here we measure (i) 13 plant cell-wall degrading enzymes in the fungus garden microbial consortium of the ambrosia beetle Xyleborinus saxesenii, including its primary fungal symbionts, in three compartments of laboratory maintained nests, at different time points after gallery foundation and (ii) four specific enzymes that may be either insect or microbially derived in X. saxesenii adult and larval individuals. We discovered that the activity of cellulases in ambrosia fungus gardens is relatively small compared to the activities of other cellulolytic enzymes. Enzyme activity in all compartments of the garden was mainly directed towards hemicellulose carbohydrates such as xylan, glucomannan and callose. Hemicellulolytic enzyme activity within the brood chamber increased with gallery age, whereas irrespective of the age of the gallery, the highest overall enzyme activity were detected in the gallery dump material expelled by the beetles. Interestingly endo-β-1,3(4)-glucanase activity capable of callose degradation was identified in whole-body extracts of both larvae and adult X. saxesenii, whereas endo-β-1,4-xylanase activity was exclusively detected in larvae. Similar to closely related fungi associated with bark beetles in phloem, the microbial symbionts of ambrosia beetles hardly degrade cellulose. Instead, their enzyme activity is directed mainly towards comparatively more easily accessible hemicellulose components of the ray

Tourism development challenges on the Dead Sea shore

Directory of Open Access Journals (Sweden)

Wendt Jan A.

2016-12-01

Full Text Available The Dead Sea along with Jerusalem belongs to one of the most well-known spots visited by tourists in Israel. Because of many factors, such as the water level of the Dead Sea at a depth of 430 m b.s.l. (in 2015, average salinity of 26%, hot springs and many healing salts located there, it is a unique tourist attraction on a global level. Its attractiveness is heightened by its proximity to other sites of interest, such as the Jewish fortress at Masada, Jericho, Qumran, where the Dead Sea Scrolls were found, as well as Petra, Madaba and Al-Karak on the Jordanian side of the Dead Sea. High salinity and a microclimate create perfect conditions for the development of health resorts and medical tourism. Extracting healing salts from its waters for the needs of the chemical industry is important for both the economy and medical tourism. However, as a consequence of the agricultural and urban use of the waters of the River Jordan, which flows into the Dead Sea, a persistent decrease in the lake water level has been observed over the last century. This has created a number of economic and political issues. The problems which still have to be resolved are associated with the Red Sea-Dead Sea Conduit (Canal, the division of Jordan’s water resources, conservation of the unique reservoir of the Dead Sea and the threat of hindering the development of tourism within the region. The presentation of these issues is the main aim of this research paper. The study is based on the analysis of changes in tourism flows, results of research studies and the prognosis of changes in the water level of the Dead Sea. It presents an assessment of the effects of this phenomenon on the tourist economy. At the current level of tourism flows within the region, the tourist capacity of local beaches will be exceeded in areas where the most popular tourist resorts are located. Increased expenditure on development of tourism infrastructure in the coastal zone can also be observed

Proportional Derivative Control with Inverse Dead-Zone for Pendulum Systems

Directory of Open Access Journals (Sweden)

José de Jesús Rubio

2013-01-01

Full Text Available A proportional derivative controller with inverse dead-zone is proposed for the control of pendulum systems. The proposed method has the characteristic that the inverse dead-zone is cancelled with the pendulum dead-zone. Asymptotic stability of the proposed technique is guaranteed by the Lyapunov analysis. Simulations of two pendulum systems show the effectiveness of the proposed technique.

Simulation of Simple Controlled Processes with Dead-Time.

Science.gov (United States)

Watson, Keith R.; And Others

1985-01-01

The determination of closed-loop response of processes containing dead-time is typically not covered in undergraduate process control, possibly because the solution by Laplace transforms requires the use of Pade approximation for dead-time, which makes the procedure lengthy and tedious. A computer-aided method is described which simplifies the…

Are Brain Dead Individuals Dead? Grounds for Reasonable Doubt.

Science.gov (United States)

Brugger, E Christian

2016-06-01

According to the biological definition of death, a human body that has not lost the capacity to holistically organize itself is the body of a living human individual. Reasonable doubt against the conclusion that it has lost the capacity exists when the body appears to express it and no evidence to the contrary is sufficient to rule out reasonable doubt against the conclusion that the apparent expression is a true expression (i.e., when the conclusion that what appears to be holistic organization is in fact holistic organization remains a reasonable explanatory hypothesis in light of the best evidence to the contrary). This essay argues that the evidence and arguments against the conclusion that the signs of complex bodily integration exhibited in ventilated brain dead bodies are true expressions of somatic integration are unpersuasive; that is, they are not adequate to exclude reasonable doubt against the conclusion that BD bodies are dead. Since we should not treat as corpses what for all we know might be living human beings, it follows that we have an obligation to treat BD individuals as if they were living human beings. © The Author 2016. Published by Oxford University Press, on behalf of the Journal of Medicine and Philosophy Inc. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Metacridamides A and B from the biocontrol fungus metarhizium acridum

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Metarhizium acridum, an entomopathogenic fungus, has been commercialized and used successfully for biocontrol of grasshopper pests in Africa and Australia. As part of an effort to catalog the secondary metabolites of this fungus we discovered that its conidia produce two novel 17-membered macrocycl...

( Azadirachta Indica ) Leaf Extracts on the Rot Fungus ( Fusarium ...

African Journals Online (AJOL)

The storage lifespan of kola nuts is challenged by the problem of decay of nuts in storage as a result of the attack by the rot fungus (Fusarium spp). The effect of the neem leaf (Azadirachta indica) extracts on the rot fungus was investigated in order to aid extended kola nuts storage. The aqueous and ethanolic leaf extracts of ...

Biosynthesis of size-controlled gold nanoparticles using fungus, Penicillium sp.

Science.gov (United States)

Zhang, Xiaorong; He, Xiaoxiao; Wang, Kemin; Wang, Yonghong; Li, Huimin; Tan, Weihong

2009-10-01

The unique optoelectronic and physicochemical properties of gold nanoparticles are significantly dependent on the particle size, shape and structure. In this paper, biosynthesis of size-controlled gold nanoparticles using fungus Penicillium sp. is reported. Fungus Penicillium sp. could successfully bioreduce and nucleate AuCl4(-) ions, and lead to the assembly and formation of intracellular Au nanoparticles with spherical morphology and good monodispersity after exposure to HAuCl4 solution. Reaction temperature, as an important physiological parameter for fungus Penicillium sp. growth, could significantly control the size of the biosynthesized Au nanoparticles. The biological compositions and FTIR spectra analysis of fungus Penicillium sp. exposed to HAuCl4 solution indicated the intracellular reducing sugar played an important role in the occurrence of intracellular reduction of AuCl4(-) ions and the growth of gold nanoparticles. Furthermore, the intracellular gold nanoparticles could be easily separated from the fungal cell lysate by ultrasonication and centrifugation.

Biochemical Characterization of Fungus Isolated during In vitro Propagation of Bambusa balcooa.

Science.gov (United States)

Tyagi, Bhawna; Tewari, Salil; Dubey, Ashutosh

2018-01-01

Bambusa balcooa ( Poaceae: Bambusoideae ) is a multipurpose bamboo species, which is native of the Indian subcontinent. B. balcooa is regarded as one of the best species for scaffolding and building purposes because of its strong culm. Other uses include paper pulp, handicrafts, and products of the wood chip industry. Due to these various uses in industries, this species has been identified as one of the priority bamboos by the National Bamboo Mission. This study is designed to analyze the identification of fungus and develop the strategy to eliminate the contamination during in vitro establishment of B. balcooa through nodal part. Fungus contamination is a problem which is encountered during in vitro establishment of B. balcooa cultures. In the present study, fungus contamination from in vitro cultured plant has been isolated and subjected to partial sequence analysis of the 18S rRNA gene to identify the fungus strain. Experiments were designed to develop a strategy for removal of the fungus contamination with the help of antifungal compounds and commercial antimicrobial supplement supplied by HiMedia. Fusarium equiseti was identified as endophytic fungus. It was observed that antimicrobial supplement at concentration of 500 μl/l was more effective concentration to remove fungus contamination and not showed any detrimental effect on growth parameters of shoot. This experiment would help in identification and to get rid of fungal contamination and improve the in vitro establishment of B. balcooa cultures for large-scale propagation. Endogenous fungus was isolated from contaminated culture of B. balcooa , and it was identified as Fusarium equiseti and submitted to NCBI under accession no. KP274872. The endophytic fungus had shown substantial production of amylase, cellulase, and protease media. Gibberellic acid (GA 3 ) production by F. equiseti was maximum on the 7 th day on inoculation. Abbreviations used: B. balcooa : Bambusa balcooa , F. equiseti : Fusarium

Dead wood inventory and assessment in South Korea

Science.gov (United States)

Jong-Su Yim; Rae Hyun Kim; Sun-Jeong Lee; Yeongmo. Son

2015-01-01

Dead wood (DW) plays a critical role not only in maintaining biodiversity but also in stocking carbon under UNFCCC. From the 5th national forest inventory (NFI5; 2006-2010) in South Korea, field data relevant to the DW including standing and downed dead trees by four decay class, etc. were collected. Based on the NFI5 data,...

Exploring the potential for actinobacteria as defensive symbionts in fungus-growing termites.

Science.gov (United States)

Visser, Anna A; Nobre, Tânia; Currie, Cameron R; Aanen, Duur K; Poulsen, Michael

2012-05-01

In fungus-growing termites, fungi of the subgenus Pseudoxylaria threaten colony health through substrate competition with the termite fungus (Termitomyces). The potential mechanisms with which termites suppress Pseudoxylaria have remained unknown. Here we explore if Actinobacteria potentially play a role as defensive symbionts against Pseudoxylaria in fungus-growing termites. We sampled for Actinobacteria from 30 fungus-growing termite colonies, spanning the three main termite genera and two geographically distant sites. Our isolations yielded 360 Actinobacteria, from which we selected subsets for morphological (288 isolates, grouped in 44 morphotypes) and for 16S rRNA (35 isolates, spanning the majority of morphotypes) characterisation. Actinobacteria were found throughout all sampled nests and colony parts and, phylogenetically, they are interspersed with Actinobacteria from origins other than fungus-growing termites, indicating lack of specificity. Antibiotic-activity screening of 288 isolates against the fungal cultivar and competitor revealed that most of the Actinobacteria-produced molecules with antifungal activity. A more detailed bioassay on 53 isolates, to test the specificity of antibiotics, showed that many Actinobacteria inhibit both Pseudoxylaria and Termitomyces, and that the cultivar fungus generally is more susceptible to inhibition than the competitor. This suggests that either defensive symbionts are not present in the system or that they, if present, represent a subset of the community isolated. If so, the antibiotics must be used in a targeted fashion, being applied to specific areas by the termites. We describe the first discovery of an assembly of antibiotic-producing Actinobacteria occurring in fungus-growing termite nests. However, due to the diversity found, and the lack of both phylogenetic and bioactivity specificity, further work is necessary for a better understanding of the putative role of antibiotic-producing bacteria in the fungus

Patterns of functional enzyme activity in fungus farming ambrosia beetles

Directory of Open Access Journals (Sweden)

De Fine Licht Henrik H

2012-06-01

Full Text Available Abstract Introduction In wood-dwelling fungus-farming weevils, the so-called ambrosia beetles (Curculionidae: Scolytinae and Platypodinae, wood in the excavated tunnels is used as a medium for cultivating fungi by the combined action of digging larvae (which create more space for the fungi to grow and of adults sowing and pruning the fungus. The beetles are obligately dependent on the fungus that provides essential vitamins, amino acids and sterols. However, to what extent microbial enzymes support fungus farming in ambrosia beetles is unknown. Here we measure (i 13 plant cell-wall degrading enzymes in the fungus garden microbial consortium of the ambrosia beetle Xyleborinus saxesenii, including its primary fungal symbionts, in three compartments of laboratory maintained nests, at different time points after gallery foundation and (ii four specific enzymes that may be either insect or microbially derived in X. saxesenii adult and larval individuals. Results We discovered that the activity of cellulases in ambrosia fungus gardens is relatively small compared to the activities of other cellulolytic enzymes. Enzyme activity in all compartments of the garden was mainly directed towards hemicellulose carbohydrates such as xylan, glucomannan and callose. Hemicellulolytic enzyme activity within the brood chamber increased with gallery age, whereas irrespective of the age of the gallery, the highest overall enzyme activity were detected in the gallery dump material expelled by the beetles. Interestingly endo-β-1,3(4-glucanase activity capable of callose degradation was identified in whole-body extracts of both larvae and adult X. saxesenii, whereas endo-β-1,4-xylanase activity was exclusively detected in larvae. Conclusion Similar to closely related fungi associated with bark beetles in phloem, the microbial symbionts of ambrosia beetles hardly degrade cellulose. Instead, their enzyme activity is directed mainly towards comparatively more easily

Dead zone area at the downstream flow of barrages

Directory of Open Access Journals (Sweden)

Mohamed F. Sauida

2016-12-01

Full Text Available Flow separation is a natural phenomenon encountered at some cases downstream of barrages. The main flow is divided into current and dead zone flows. The percentage area of dead zone flow must be taken into consideration downstream of barrages, due to its negative effect on flow characteristics. Experimental studies were conducted in the Hydraulic Research Institute (HRI, on a physical regulator model with five vents. Theoretically the separation zone is described as a part of an ellipse which is practically verified by plotting velocity vectors. The results show that the percentage area of dead zone to the area through length of separation depends mainly on the expansion ratio [channel width to width of opened vents], with maximum value of 81% for operated side gates. A statistical analysis was derived, to predict the percentage area of dead zone flow to the area through length of separation.

Ex situ diet influences the bacterial community associated with the skin of red-eyed tree frogs (Agalychnis callidryas.

Directory of Open Access Journals (Sweden)

Rachael E Antwis

Full Text Available Amphibians support symbiotic bacterial communities on their skin that protect against a range of infectious pathogens, including the amphibian chytrid fungus. The conditions under which amphibians are maintained in captivity (e.g. diet, substrate, enrichment in ex situ conservation programmes may affect the composition of the bacterial community. In addition, ex situ amphibian populations may support different bacterial communities in comparison to in situ populations of the same species. This could have implications for the suitability of populations intended for reintroduction, as well as the success of probiotic bacterial inoculations intended to provide amphibians with a bacterial community that resists invasion by the chytrid fungus. We aimed to investigate the effect of a carotenoid-enriched diet on the culturable bacterial community associated with captive red-eyed tree frogs (Agalychnis callidryas and make comparisons to bacteria isolated from a wild population from the Chiquibul Rainforest in Belize. We successfully showed carotenoid availability influences the overall community composition, species richness and abundance of the bacterial community associated with the skin of captive frogs, with A. callidryas fed a carotenoid-enriched diet supporting a greater species richness and abundance of bacteria than those fed a carotenoid-free diet. Our results suggest that availability of carotenoids in the diet of captive frogs is likely to be beneficial for the bacterial community associated with the skin. We also found wild A. callidryas hosted more than double the number of different bacterial species than captive frogs with very little commonality between species. This suggests frogs in captivity may support a reduced and diverged bacterial community in comparison to wild populations of the same species, which could have particular relevance for ex situ conservation projects.

Noninvasive medical management of fungus ball uropathy in a premature infant.

Science.gov (United States)

Alkalay, A L; Srugo, I; Blifeld, C; Komaiko, M S; Pomerance, J J

1991-09-01

Unilateral renal obstruction secondary to fungus balls is described in a premature infant. Noninvasive medical management, which included amphotericin B and 5-flucytosine therapy and forced diuresis, resulted in disappearance of fungus balls and resolution of the obstruction.

Deadly Choices empowering Indigenous Australians through social networking sites.

Science.gov (United States)

McPhail-Bell, Karen; Appo, Nathan; Haymes, Alana; Bond, Chelsea; Brough, Mark; Fredericks, Bronwyn

2017-04-05

The potential for health promotion through social networking sites (SNSs) is widely recognized. However, while health promotion prides itself in focusing on the social determinants of health, its partiality for persuading individuals to comply with health behaviours dominates the way health promotion utilizes SNSs. This paper contributes to an understanding of collaborative ways SNSs can work for health promotion agendas of self-determination and empowerment in an Indigenous Australia context. An ethnographic study was undertaken with Deadly Choices, an Indigenous-led health promotion initiative. The study involved participant observation of interactions on Deadly Choices SNSs between Deadly Choices and its online community members. Deadly Choices provides an example of SNSs providing a powerful tool to create a safe, inclusive and positive space for Indigenous people and communities to profile their healthy choices, according to Indigenous notions of health and identity. The study found five principles that underpin Deadly Choices' use of SNSs for health promotion. These are: create a dialogue; build community online and offline; incentivise healthy online engagement; celebrate Indigenous identity and culture; and prioritize partnerships. Deadly Choices SNSs empowers Indigenous people and communities to be health promoters themselves, which represents a power shift from health promotion practitioner to Indigenous people and communities and more broadly, an enactment of Indigenous self-determination on SNSs. Mainstream health promotion can learn from Indigenous health promotion practice regarding the use of SNSs for health promotion agendas. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Isolation and Characterization of “Terrein” an Antimicrobial and Antitumor Compound from Endophytic Fungus Aspergillus terreus (JAS-2) Associated from Achyranthus aspera Varanasi, India

Science.gov (United States)

Goutam, Jyoti; Sharma, Gunjan; Tiwari, Vinod K.; Mishra, Amrita; Kharwar, Ravindra N.; Ramaraj, Vijayakumar; Koch, Biplob

2017-01-01

The present study aimed at characterizing biological potentials of endophyte Aspergillus terreus JAS-2 isolated from Achyranthus aspera. Crude extracted from endophytic fungus JAS-2 was purified and chemically characterized by chromatographic and spectroscopic studies respectively. Spectral assignment of NMR (nuclear magnetic resonance) data, 1H proton and 13C carbon analysis along with FTIR data elucidated the structure of compound as 4,5-Dihydroxy-3-(1-propenyl)-2-cyclopenten-1-one. After purification and identification a set of experiment was conducted to explore efficacy of compound. Results revealed that on accessing the antifungal activity of compound, growth diameter of tested phytopathogenic fungi was reduced to 50% at higher concentration taken (10 μgμl−1). Compound exhibited in-vitro bacterial cell inhibition at 20 μgml−1 concentration along with moderate antioxidant behavior. Evaluation of anticancer activity against human lung cancer cell line (A-549) exhibited its IC50 value to be 121.9 ± 4.821 μgml−1. Further cell cycle phase distribution were analyzed on the basis of DNA content and evaluated by FACS (Fluorescence Activated Cell Sorting) and it was revealed that at 150 μgml−1 of compound maximum cells were found in sub G1 phase which represents apoptotic dead cells. Terrein (4, 5-Dihydroxy-3-(1-propenyl)-2-cyclopenten-1-one) a multi-potential was isolated from endophytic fungus JAS-2, from well recognized medicinal herb A. aspera. To best of our knowledge, this is the first report of “Terrein” from endophytic derived fungus. This compound had also exhibited anticancer and antifungal activity against human lung cancer cell line A-549 and Bipolaris sorokiniana respectively which is causal organism of many plants disease. Hence endophytes are serving as alternative sources of drug molecules. PMID:28790982

Insect symbioses: a case study of past, present, and future fungus-growing ant research

DEFF Research Database (Denmark)

Caldera, Eric J; Poulsen, Michael; Suen, Garret

2009-01-01

's fungus garden, antibiotic-producing actinobacteria that help protect the fungus garden from the parasite, and a black yeast that parasitizes the ant-actinobacteria mutualism. The fungus-growing ant symbiosis serves as a particularly useful model system for studying insect-microbe symbioses, because...

Resonant power converter comprising adaptive dead-time control

DEFF Research Database (Denmark)

2017-01-01

The invention relates in a first aspect to a resonant power converter comprising: a first power supply rail for receipt of a positive DC supply voltage and a second power supply rail for receipt of a negative DC supply voltage. The resonant power converter comprises a resonant network with an input...... terminal for receipt of a resonant input voltage from a driver circuit. The driver circuit is configured for alternatingly pulling the resonant input voltage towards the positive and negative DC supply voltages via first and second semiconductor switches, respectively, separated by intervening dead......-time periods in accordance with one or more driver control signals. A dead-time controller is configured to adaptively adjusting the dead-time periods based on the resonant input voltage....

Are We the Walking Dead? Burnout as Zombie Apocalypse.

Science.gov (United States)

Doolittle, Benjamin R

2016-11-01

The Walking Dead , one of the most popular television shows in recent history, uses the plot of a zombie apocalypse as a lens into exploring the human condition. Amidst a particularly dangerous moment, the show's hero references the human struggle to survive by remarking, " We are the walking dead." This offhand comment sheds light upon physicians' struggles in medicine, in particular the high prevalence of burnout and the challenge to cultivate compassion and meaning. This is an important question for our age and for our profession. Are we the walking dead? © 2016 Annals of Family Medicine, Inc.

Phomalactone from a phytopathogenic fungus infecting Zinnia elegans (Asteraceae) leaves

Science.gov (United States)

Zinnia elegans plants are infected by a fungus that causes necrosis with dark red spots particularly in late spring to the middle of summer in the Mid-South part of the United States. This fungal disease when untreated causes the leaves to wilt and eventually kills the plant. The fungus was isolated...

"Dead in bed": a tragic complication of type 1 diabetes mellitus.

LENUS (Irish Health Repository)

O'Reilly, M

2010-12-01

"Dead in bed" is a tragic description of a particular type of sudden death in type 1 diabetes mellitus (DM). Patients are typically found dead in the early morning, lying in an undisturbed bed, having been well the previous evening. The incidence of "dead in bed" syndrome is not known but studies suggest figures of between 4.7 and 27.3% of all unexplained deaths in type 1 DM. The pathogenesis is unclear but patients typically have a preceding history of recurrent severe hypoglycaemia. We describe two cases of "dead in bed" syndrome which occurred at our institution within a 12-month period.

The dead donor rule, voluntary active euthanasia, and capital punishment.

Science.gov (United States)

Coons, Christian; Levin, Noah

2011-06-01

We argue that the dead donor rule, which states that multiple vital organs should only be taken from dead patients, is justified neither in principle nor in practice. We use a thought experiment and a guiding assumption in the literature about the justification of moral principles to undermine the theoretical justification for the rule. We then offer two real world analogues to this thought experiment, voluntary active euthanasia and capital punishment, and argue that the moral permissibility of terminating any patient through the removal of vital organs cannot turn on whether or not the practice violates the dead donor rule. Next, we consider practical justifications for the dead donor rule. Specifically, we consider whether there are compelling reasons to promulgate the rule even though its corresponding moral principle is not theoretically justified. We argue that there are no such reasons. In fact, we argue that promulgating the rule may actually decrease public trust in organ procurement procedures and medical institutions generally - even in states that do not permit capital punishment or voluntary active euthanasia. Finally, we examine our case against the dead donor rule in the light of common arguments for it. We find that these arguments are often misplaced - they do not support the dead donor rule. Instead, they support the quite different rule that patients should not be killed for their vital organs.

Dead wood for biodiversity - foresters torn between mistrust and commitment

International Nuclear Information System (INIS)

Deuffic, Philippe

2010-01-01

Dead wood is a key element in forest biodiversity, which is used as one of the indicators for sustainable development of forests. A survey was conducted among foresters and users in the Landes de Gascogne and ile-de-France areas so as to assess practises and social representations associated with dead wood. From the results of the survey, it appears that there is a diversity of practices and divergences about the implications connected with dead wood. The 64 respondents can be divided into roughly six groups (G1: 'industrial foresters', G2: the 'silvicultural foresters', G3: the 'remote foresters', G4: the 'environmentalist foresters', G5: the 'naturalists' and G6: the 'users'). Among other things, they can be differentiated by their management practises, their degree of knowledge about and concern with ecology, their social networks, their aesthetic judgment, their perception of risks and their economic requirements. While underscoring the scarce popularity on average of the biodiversity-related issues, this sociological survey also highlights: the need for a minimal regulatory framework to achieve integrated retention of dead wood, the serious concern of forest managers in the Landes with plant health risks associated with dead wood, and the need for a functional justification for keeping dead wood in the ecosystem. (authors)

Modeling decay rates of dead wood in a neotropical forest.

Science.gov (United States)

Hérault, Bruno; Beauchêne, Jacques; Muller, Félix; Wagner, Fabien; Baraloto, Christopher; Blanc, Lilian; Martin, Jean-Michel

2010-09-01

Variation of dead wood decay rates among tropical trees remains one source of uncertainty in global models of the carbon cycle. Taking advantage of a broad forest plot network surveyed for tree mortality over a 23-year period, we measured the remaining fraction of boles from 367 dead trees from 26 neotropical species widely varying in wood density (0.23-1.24 g cm(-3)) and tree circumference at death time (31.5-272.0 cm). We modeled decay rates within a Bayesian framework assuming a first order differential equation to model the decomposition process and tested for the effects of forest management (selective logging vs. unexploited), of mode of death (standing vs. downed) and of topographical levels (bottomlands vs. hillsides vs. hilltops) on wood decay rates. The general decay model predicts the observed remaining fraction of dead wood (R2 = 60%) with only two biological predictors: tree circumference at death time and wood specific density. Neither selective logging nor local topography had a differential effect on wood decay rates. Including the mode of death into the model revealed that standing dead trees decomposed faster than downed dead trees, but the gain of model accuracy remains rather marginal. Overall, these results suggest that the release of carbon from tropical dead trees to the atmosphere can be simply estimated using tree circumference at death time and wood density.

The Role of Dead Wood in Maintaining Arthropod Diversity on the Forest Floor

Energy Technology Data Exchange (ETDEWEB)

Hanula, James L. [Dept. of Agriculture Forest Service, Athens, GA (United States). Southern Research Station; Horn, Scott [Dept. of Agriculture Forest Service, Athens, GA (United States). Southern Research Station; Wade, Dale D. [Dept. of Agriculture Forest Service, Athens, GA (United States). Southern Research Station

2006-08-01

Dead wood is a major component of forests and contributes to overall diversity, primarily by supporting insects that feed directly on or in it. Further, a variety of organisms benefit by feeding on those insects. What is not well known is how or whether dead wood influences the composition of the arthropod community that is not solely dependent on it as a food resource, or whether woody debris influences prey available to generalist predators. One group likely to be affected by dead wood is ground-dwelling arthropods. We studied the effect of adding large dead wood to unburned and frequently burned pine stands to determine if dead wood was used more when the litter and understory plant community are removed. We also studied the effect of annual removal of dead wood from large (10-ha) plots over a 5-year period on ground-dwelling arthropods. In related studies, we examined the relationships among an endangered woodpecker that forages for prey on live trees, its prey, and dead wood in the forest. Finally, the results of these and other studies show that dead wood can influence the abundance and diversity of the ground-dwelling arthropod community and of prey available to generalist predators not foraging directly on dead trees.

Anthrax, People and Dead Hippos

Centers for Disease Control (CDC) Podcasts

2017-11-07

Epidemiologist, Dr. Melissa Marx, discuses anthrax deaths in people who ate dead hippos.  Created: 11/7/2017 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 11/7/2017.

Removal of phenanthrene in contaminated soil by combination of alfalfa, white-rot fungus, and earthworms.

Science.gov (United States)

Deng, Shuguang; Zeng, Defang

2017-03-01

The aim of this study was to investigate the removal of phenanthrene by combination of alfalfa, white-rot fungus, and earthworms in soil. A 60-day experiment was conducted. Inoculation with earthworms and/or white-rot fungus increased alfalfa biomass and phenanthrene accumulation in alfalfa. However, inoculations of alfalfa and white-rot fungus can significantly decrease the accumulation of phenanthrene in earthworms. The removal rates for phenanthrene in soil were 33, 48, 66, 74, 85, and 93% under treatments control, only earthworms, only alfalfa, earthworms + alfalfa, alfalfa + white-rot fungus, and alfalfa + earthworms + white-rot fungus, respectively. The present study demonstrated that the combination of alfalfa, earthworms, and white-rot fungus is an effective way to remove phenanthrene in the soil. The removal is mainly via stimulating both microbial development and soil enzyme activity.

Occurrence of organohalogens at the Dead Sea Basin

Science.gov (United States)

Tubbesing, Christoph; Kotte, Karsten; Keppler, Frank; Krause, Torsten; Bahlmann, Enno; Schöler, Heinfried

2013-04-01

Most arid and semi-arid regions are characterized by evaporites, which are assured sources for volatile organohalogens (VOX) [1]. These compounds play an important role in tropospheric and stratospheric chemistry. The Dead Sea between Israel and Jordan is the world's most famous and biggest all-season water covered salt lake. In both countries chemical plants like the Dead Sea Works and the Arab Potash Company are located at the southern part of the Dead Sea and mine various elements such as bromine and magnesium. Conveying sea water through constructed evaporation pans multifarious salts are enriched and precipitated. In contrast, the Northern basin and main part of the Dead Sea has remained almost untouched by industrial salt production. Its fresh water supply from the Jordan River is constantly decreasing, leading to further increased salinity. During a HALOPROC campaign (Natural Halogenation Processes in the Environment) we collected various samples including air, soils, sediments, halophytic plants, ground- and seawater from the Northern and Southern basin of the Israeli side of the Dead Sea. These samples were investigated for the occurrence of halocarbons using different analytical techniques. Most samples were analyzed for volatile organohalogens such as haloalkanes using gas chromatography- mass spectrometry (GC-MS). Interestingly, there is a strong enrichment of trihalomethanes (THM), especially all chlorinated and brominated ones and also the iodinated compound dichloroiodomethane were found in the Southern basin. In addition, volatile organic carbons (VOC) such as ethene and some other alkenes were analyzed by a gas chromatography-flame ionisation detector (GC-FID) to obtain further information about potential precursors of halogenated compounds. Halophytic plants were investigated for their potential to release chloromethane and bromomethane but also for their stable carbon and hydrogen isotope composition. For this purpose, a plant chamber was

Pulmonary Dead Space Fraction and Extubation Success in Children After Cardiac Surgery.

Science.gov (United States)

Devor, Renee L; Kang, Paul; Wellnitz, Chasity; Nigro, John J; Velez, Daniel A; Willis, Brigham C

2018-04-01

1) Determine the correlation between pulmonary dead space fraction and extubation success in postoperative pediatric cardiac patients; and 2) document the natural history of pulmonary dead space fractions, dynamic compliance, and airway resistance during the first 72 hours postoperatively in postoperative pediatric cardiac patients. A retrospective chart review. Cardiac ICU in a quaternary care free-standing children's hospital. Twenty-nine with balanced single ventricle physiology, 61 with two ventricle physiology. None. We collected data for all pediatric patients undergoing congenital cardiac surgery over a 14-month period during the first 72 hours postoperatively as well as prior to extubation. Overall, patients with successful extubations had lower preextubation dead space fractions and shorter lengths of stay. Single ventricle patients had higher initial postoperative and preextubation dead space fractions. Two-ventricle physiology patients had higher extubation failure rates if the preextubation dead space fraction was greater than 0.5, whereas single ventricle patients had similar extubation failure rates whether preextubation dead space fractions were less than or equal to 0.5 or greater than 0.5. Additionally, increasing initial dead space fraction values predicted prolonged mechanical ventilation times. Airway resistance and dynamic compliance were similar between those with successful extubations and those who failed. Initial postoperative dead space fraction correlates with the length of mechanical ventilation in two ventricle patients but not in single ventricle patients. Lower preextubation dead space fractions are a strong predictor of successful extubation in two ventricle patients after cardiac surgery, but may not be as useful in single ventricle patients.

Monitoring the Dead Sea Region by Multi-Parameter Stations

Science.gov (United States)

Mohsen, A.; Weber, M. H.; Kottmeier, C.; Asch, G.

2015-12-01

The Dead Sea Region is an exceptional ecosystem whose seismic activity has influenced all facets of the development, from ground water availability to human evolution. Israelis, Palestinians and Jordanians living in the Dead Sea region are exposed to severe earthquake hazard. Repeatedly large earthquakes (e.g. 1927, magnitude 6.0; (Ambraseys, 2009)) shook the whole Dead Sea region proving that earthquake hazard knows no borders and damaging seismic events can strike anytime. Combined with the high vulnerability of cities in the region and with the enormous concentration of historical values this natural hazard results in an extreme earthquake risk. Thus, an integration of earthquake parameters at all scales (size and time) and their combination with data of infrastructure are needed with the specific aim of providing a state-of-the-art seismic hazard assessment for the Dead Sea region as well as a first quantitative estimate of vulnerability and risk. A strong motivation for our research is the lack of reliable multi-parameter ground-based geophysical information on earthquakes in the Dead Sea region. The proposed set up of a number of observatories with on-line data access will enable to derive the present-day seismicity and deformation pattern in the Dead Sea region. The first multi-parameter stations were installed in Jordan, Israel and Palestine for long-time monitoring. All partners will jointly use these locations. All stations will have an open data policy, with the Deutsches GeoForschungsZentrum (GFZ, Potsdam, Germany) providing the hard and software for real-time data transmission via satellite to Germany, where all partners can access the data via standard data protocols.

Microbial transformation of (-)-isolongifolol by plant pathogenic fungus Glomerella cingulata.

Science.gov (United States)

Miyazawa, Mitsuo; Sakata, Kazuki; Ueda, Masashi

2010-01-01

The biotransformation of terpenoids using the plant pathogenic fungus as a biocatalyst to produce useful novel organic compounds was investigated. The biotransformation of sesquiterpen alcohol, (-)-isolongifolol (1) was investigated using plant pathogenic fungus Glomerella cingulata as a biocatalyst. Compound 1 was converted to (-)-(3R)-3-hydroxy-isolongifolol and (-)-(9R)-9-hydroxy-isolongifolol by G. cingulata.

The Physiology of Microbial Symbionts in Fungus-Farming Termites

DEFF Research Database (Denmark)

Rodrigues da Costa, Rafael

. The termites provide the fungus with optimal growth conditions (e.g., stable temperature and humidity), as well as with constant inoculation of growth substrate and protection against alien fungi. In reward, the fungus provides the termites with a protein-rich fungal biomass based diet. In addition...... with their symbionts are main decomposer of organic matter in Africa, and this is reflect of a metabolic complementarity to decompose plant biomass in the genome of the three organisms involved in this symbiosis. Many of the physiological aspects of this symbiosis remain obscure, and here I focus on physiology...... of microbial symbionts associated with fungus-growing termites. Firstly, by using a set of enzyme assays, plant biomass compositional analyses, and RNA sequencing we gained deeper understanding on what enzymes are produced and active at different times of the decomposition process. Our results show that enzyme...

DEF: an automated dead-end filling approach based on quasi-endosymbiosis.

Science.gov (United States)

Liu, Lili; Zhang, Zijun; Sheng, Taotao; Chen, Ming

2017-02-01

Gap filling for the reconstruction of metabolic networks is to restore the connectivity of metabolites via finding high-confidence reactions that could be missed in target organism. Current methods for gap filling either fall into the network topology or have limited capability in finding missing reactions that are indirectly related to dead-end metabolites but of biological importance to the target model. We present an automated dead-end filling (DEF) approach, which is derived from the wisdom of endosymbiosis theory, to fill gaps by finding the most efficient dead-end utilization paths in a constructed quasi-endosymbiosis model. The recalls of reactions and dead ends of DEF reach around 73% and 86%, respectively. This method is capable of finding indirectly dead-end-related reactions with biological importance for the target organism and is applicable to any given metabolic model. In the E. coli iJR904 model, for instance, about 42% of the dead-end metabolites were fixed by our proposed method. DEF is publicly available at http://bis.zju.edu.cn/DEF/. mchen@zju.edu.cn Supplementary data are available at Bioinformatics online.

Fungus-Growing Termites Originated in African Rain Forest

DEFF Research Database (Denmark)

Aanen, Duur Kornelis; Eggleton, Paul

2005-01-01

are consumed (cf. [ [1] and [2] ]). Fungus-growing termites are found throughout the Old World tropics, in rain forests and savannas, but are ecologically dominant in savannas [ 3 ]. Here, we reconstruct the ancestral habitat and geographical origin of fungus-growing termites. We used a statistical model...... of habitat switching [ 4 ] repeated over all phylogenetic trees sampled in a Bayesian analysis of molecular data [ 5 ]. Our reconstructions provide strong evidence that termite agriculture originated in African rain forest and that the main radiation leading to the extant genera occurred there. Because...

Development and validation of an LC-MS/MS method for the detection of phomopsin A in lupin and lupin-containing retail food samples from the Netherlands

NARCIS (Netherlands)

Nijs, de W.C.M.; Pereboom-de Fauw, D.P.K.H.; Dam, van R.C.J.; Rijk, de T.C.; Egmond, van H.P.; Mol, J.G.J.

2013-01-01

Phomopsins (PHO) are mycotoxins produced by the fungus Diaporthe toxica (also referred to as Phomopsis leptostromiformis). Lupin is the most important host crop for this fungus and PHO are suspected as cause of lupinosis, a deadly liver disease, in sheep. Lupin is currently in use to replace

Evaluating the links between climate, disease spread, and amphibian declines.

Science.gov (United States)

Rohr, Jason R; Raffel, Thomas R; Romansic, John M; McCallum, Hamish; Hudson, Peter J

2008-11-11

Human alteration of the environment has arguably propelled the Earth into its sixth mass extinction event and amphibians, the most threatened of all vertebrate taxa, are at the forefront. Many of the worldwide amphibian declines have been caused by the chytrid fungus, Batrachochytrium dendrobatidis (Bd), and two contrasting hypotheses have been proposed to explain these declines. Positive correlations between global warming and Bd-related declines sparked the chytrid-thermal-optimum hypothesis, which proposes that global warming increased cloud cover in warm years that drove the convergence of daytime and nighttime temperatures toward the thermal optimum for Bd growth. In contrast, the spatiotemporal-spread hypothesis states that Bd-related declines are caused by the introduction and spread of Bd, independent of climate change. We provide a rigorous test of these hypotheses by evaluating (i) whether cloud cover, temperature convergence, and predicted temperature-dependent Bd growth are significant positive predictors of amphibian extinctions in the genus Atelopus and (ii) whether spatial structure in the timing of these extinctions can be detected without making assumptions about the location, timing, or number of Bd emergences. We show that there is spatial structure to the timing of Atelopus spp. extinctions but that the cause of this structure remains equivocal, emphasizing the need for further molecular characterization of Bd. We also show that the reported positive multi-decade correlation between Atelopus spp. extinctions and mean tropical air temperature in the previous year is indeed robust, but the evidence that it is causal is weak because numerous other variables, including regional banana and beer production, were better predictors of these extinctions. Finally, almost all of our findings were opposite to the predictions of the chytrid-thermal-optimum hypothesis. Although climate change is likely to play an important role in worldwide amphibian declines

Functions of DEAD-box proteins in bacteria: current knowledge and pending questions.

Science.gov (United States)

Iost, Isabelle; Bizebard, Thierry; Dreyfus, Marc

2013-08-01

DEAD-box proteins are RNA-dependent ATPases that are widespread in all three kingdoms of life. They are thought to rearrange the structures of RNA or ribonucleoprotein complexes but their exact mechanism of action is rarely known. Whereas in yeast most DEAD-box proteins are essential, no example of an essential bacterial DEAD-box protein has been reported so far; at most, their absence results in cold-sensitive growth. Moreover, whereas yeast DEAD-box proteins are implicated in virtually all reactions involving RNA, in E. coli (the bacterium where DEAD-box proteins have been mostly studied) their role is limited to ribosome biogenesis, mRNA degradation, and possibly translation initiation. Plausible reasons for these differences are discussed here. In spite of their dispensability, E. coli DEAD-box proteins are valuable models for the mechanism of action of DEAD-box proteins in general because the reactions in which they participate can be reproduced in vitro. Here we review our present understanding of this mechanism of action. Using selected examples for which information is available: (i) we describe how, by interacting directly with a particular RNA motif or by binding to proteins that themselves recognize such a motif, DEAD-box proteins are brought to their specific RNA substrate(s); (ii) we discuss the nature of the structural transitions that DEAD-box proteins induce on their substrates; and (iii) we analyze the reasons why these proteins are mostly important at low temperatures. This article is part of a Special Issue entitled: The Biology of RNA helicases-Modulation for life. Copyright © 2013 Elsevier B.V. All rights reserved.

Co-evolution of enzyme function in the attine ant-fungus symbiosis

DEFF Research Database (Denmark)

de Fine Licht, Henrik Hjarvard; Schiøtt, Morten; Boomsma, Jacobus Jan

Introduction: Fungus-growing ants cultivate specialized fungi in the tribe Leucocoprineae (Lepiotaceae: Basidiomycota) inside their nests. The conspicuous leaf-cutting ants in the genus Atta build huge nests displacing several cubic meters of soil, whereas lower attine genera such as Cyphomyrmex ...... garden. This system can be viewed as ant induced crop optimization similar to human agricultural practices....... have small nests with a fungus garden the size of a table-tennis ball. Only the leaf-cutting ants are specialized on using fresh leaves as substrate for their fungus gardens, whereas the more basal attine genera use substrates such as dry plant material (leaf litter and small twigs) and also insect...... feces and insect carcasses. This diverse array of fungal substrates across the attine lineage implies that the symbiotic fungus needs different enzymes to break down the plant material that the ants provide or different efficiencies of enzyme function. Methods: (1.) We made a literature survey...

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...

Potential Evaporite Biomarkers from the Dead Sea

Science.gov (United States)

Morris, Penny A.; Wentworth, Susan J.; Thomas-Keprta, Kathie; Allen, Carlton C.; McKay, David S.

2001-01-01

The Dead Sea is located on the northern branch of the African-Levant Rift systems. The rift system, according to one model, was formed by a series of strike slip faults, initially forming approximately two million years ago. The Dead Sea is an evaporite basin that receives freshwater from springs and from the Jordan River. The Dead Sea is different from other evaporite basins, such as the Great Salt Lake, in that it possesses high concentrations of magnesium and has an average pH of 6.1. The dominant cation in the Great Salt Lake is sodium, and the pH is 7.7. Calcium concentrations are also higher in the Dead Sea than in the Great Salt Lake. Both basins are similar in that the dominant anion is chlorine and the salinity levels are approximately 20 %. Other common cations that have been identified from the waters of the Dead Sea and the Great Salt Lake include sodium and potassium. A variety of Archea, Bacteria, and a single genus of a green algal, Dunaliella, has been described from the Dead Sea. Earlier studies concentrated on microbial identification and analysis of their unique physiology that allows them to survive in this type of extreme environment. Potential microbial fossilization processes, microbial fossils, and the metallic ions associated with fossilization have not been studied thoroughly. The present study is restricted to identifying probable microbial morphologies and associated metallic ions. XRD (X Ray Diffraction) analysis indicates the presence of halite, quartz, and orthoclase feldspar. In addition to these minerals, other workers have reported potassium chloride, magnesium bromide, magnesium chloride, calcium chloride, and calcium sulfate. Halite, calcium sulfate, and orthoclase were examined in this report for the presence of microbes, microbially induced deposits or microbial alteration. Neither the gypsum nor the orthoclase surfaces possesses any obvious indications of microbial life or fossilization. The sand-sized orthoclase particles are

Effect of dead space on breathing stability at exercise in hypoxia.

Science.gov (United States)

Hermand, Eric; Lhuissier, François J; Richalet, Jean-Paul

2017-12-01

Recent studies have shown that normal subjects exhibit periodic breathing when submitted to concomitant environmental (hypoxia) and physiological (exercise) stresses. A mathematical model including mass balance equations confirmed the short period of ventilatory oscillations and pointed out an important role of dead space in the genesis of these phenomena. Ten healthy subjects performed mild exercise on a cycloergometer in different conditions: rest/exercise, normoxia/hypoxia and no added dead space/added dead space (aDS). Ventilatory oscillations (V˙E peak power) were augmented by exercise, hypoxia and aDS (Pspace. This underlines opposite effects observed in heart failure patients and normal subjects, in which added dead space drastically reduced periodic breathing and sleep apneas. It also points out that alveolar ventilation remains very close to metabolic needs and is not affected by an added dead space. Clinical Trial reg. n°: NCT02201875. Copyright © 2017 Elsevier B.V. All rights reserved.

Partial resistance of tomatoes against Phytophthora infestans, the late blight fungus

NARCIS (Netherlands)

Turkensteen, L.J.

1973-01-01

In the Netherlands, the source of inoculum of the late blight fungus on tomatoes is the late blight fungus on potato crops. In regions of Europe mentioned, where tomatoes are grown in the open, P. infestans on tomatoes is the main source of inoculum. Especially in

Comparative structural analysis of human DEAD-box RNA helicases.

Science.gov (United States)

Schütz, Patrick; Karlberg, Tobias; van den Berg, Susanne; Collins, Ruairi; Lehtiö, Lari; Högbom, Martin; Holmberg-Schiavone, Lovisa; Tempel, Wolfram; Park, Hee-Won; Hammarström, Martin; Moche, Martin; Thorsell, Ann-Gerd; Schüler, Herwig

2010-09-30

DEAD-box RNA helicases play various, often critical, roles in all processes where RNAs are involved. Members of this family of proteins are linked to human disease, including cancer and viral infections. DEAD-box proteins contain two conserved domains that both contribute to RNA and ATP binding. Despite recent advances the molecular details of how these enzymes convert chemical energy into RNA remodeling is unknown. We present crystal structures of the isolated DEAD-domains of human DDX2A/eIF4A1, DDX2B/eIF4A2, DDX5, DDX10/DBP4, DDX18/myc-regulated DEAD-box protein, DDX20, DDX47, DDX52/ROK1, and DDX53/CAGE, and of the helicase domains of DDX25 and DDX41. Together with prior knowledge this enables a family-wide comparative structural analysis. We propose a general mechanism for opening of the RNA binding site. This analysis also provides insights into the diversity of DExD/H- proteins, with implications for understanding the functions of individual family members.

Comparative structural analysis of human DEAD-box RNA helicases.

Directory of Open Access Journals (Sweden)

Patrick Schütz

2010-09-01

Full Text Available DEAD-box RNA helicases play various, often critical, roles in all processes where RNAs are involved. Members of this family of proteins are linked to human disease, including cancer and viral infections. DEAD-box proteins contain two conserved domains that both contribute to RNA and ATP binding. Despite recent advances the molecular details of how these enzymes convert chemical energy into RNA remodeling is unknown. We present crystal structures of the isolated DEAD-domains of human DDX2A/eIF4A1, DDX2B/eIF4A2, DDX5, DDX10/DBP4, DDX18/myc-regulated DEAD-box protein, DDX20, DDX47, DDX52/ROK1, and DDX53/CAGE, and of the helicase domains of DDX25 and DDX41. Together with prior knowledge this enables a family-wide comparative structural analysis. We propose a general mechanism for opening of the RNA binding site. This analysis also provides insights into the diversity of DExD/H- proteins, with implications for understanding the functions of individual family members.

Reductions in dead space ventilation with nasal high flow depend on physiological dead space volume: metabolic hood measurements during sleep in patients with COPD and controls.

Science.gov (United States)

Biselli, Paolo; Fricke, Kathrin; Grote, Ludger; Braun, Andrew T; Kirkness, Jason; Smith, Philip; Schwartz, Alan; Schneider, Hartmut

2018-05-01

Nasal high flow (NHF) reduces minute ventilation and ventilatory loads during sleep but the mechanisms are not clear. We hypothesised NHF reduces ventilation in proportion to physiological but not anatomical dead space.11 subjects (five controls and six chronic obstructive pulmonary disease (COPD) patients) underwent polysomnography with transcutaneous carbon dioxide (CO 2 ) monitoring under a metabolic hood. During stable non-rapid eye movement stage 2 sleep, subjects received NHF (20 L·min -1 ) intermittently for periods of 5-10 min. We measured CO 2 production and calculated dead space ventilation.Controls and COPD patients responded similarly to NHF. NHF reduced minute ventilation (from 5.6±0.4 to 4.8±0.4 L·min -1 ; pspace ventilation (from 2.5±0.4 to 1.6±0.4 L·min -1 ; pspace ventilation correlated with baseline physiological dead space fraction (r 2 =0.36; pspace volume.During sleep, NHF decreases minute ventilation due to an overall reduction in dead space ventilation in proportion to the extent of baseline physiological dead space fraction. Copyright ©ERS 2018.

Factors affecting fungus-induced larval mortality in Anopheles gambiae and Anopheles stephensi

Directory of Open Access Journals (Sweden)

Takken Willem

2010-01-01

Full Text Available Abstract Background Entomopathogenic fungi have shown great potential for the control of adult malaria vectors. However, their ability to control aquatic stages of anopheline vectors remains largely unexplored. Therefore, how larval characteristics (Anopheles species, age and larval density, fungus (species and concentration and environmental effects (exposure duration and food availability influence larval mortality caused by fungus, was studied. Methods Laboratory bioassays were performed on the larval stages of Anopheles gambiae and Anopheles stephensi with spores of two fungus species, Metarhizium anisopliae and Beauveria bassiana. For various larval and fungal characteristics and environmental effects the time to death was determined and survival curves established. These curves were compared by Kaplan Meier and Cox regression analyses. Results Beauveria bassiana and Metarhizium anisopliae caused high mortality of An. gambiae and An. stephensi larvae. However, Beauveria bassiana was less effective (Hazard ratio (HR Metarhizium anisopliae. Anopheles stephensi and An. gambiae were equally susceptible to each fungus. Older larvae were less likely to die than young larvae (HR Conclusions This study shows that both fungus species have potential to kill mosquitoes in the larval stage, and that mortality rate depends on fungus species itself, larval stage targeted, larval density and amount of nutrients available to the larvae. Increasing the concentration of fungal spores or reducing the exposure time to spores did not show a proportional increase and decrease in mortality rate, respectively, because the spores clumped together. As a result spores did not provide uniform coverage over space and time. It is, therefore, necessary to develop a formulation that allows the spores to spread over the water surface. Apart from formulation appropriate delivery methods are also necessary to avoid exposing non-target organisms to fungus.

White-Nose Syndrome Fungus in a 1918 Bat Specimen from France

OpenAIRE

Campana, Michael G.; Kurata, Naoko P.; Foster, Jeffrey T.; Helgen, Lauren E.; Reeder, DeeAnn M.; Fleischer, Robert C.; Helgen, Kristofer M.

2017-01-01

White-nose syndrome, first diagnosed in North America in 2006, causes mass deaths among bats in North America. We found the causative fungus, Pseudogymnoascus destructans, in a 1918 sample collected in Europe, where bats have now adapted to the fungus. These results are consistent with a Eurasian origin of the pathogen.

White-Nose Syndrome Fungus in a 1918 Bat Specimen from France.

Science.gov (United States)

Campana, Michael G; Kurata, Naoko P; Foster, Jeffrey T; Helgen, Lauren E; Reeder, DeeAnn M; Fleischer, Robert C; Helgen, Kristofer M

2017-09-01

White-nose syndrome, first diagnosed in North America in 2006, causes mass deaths among bats in North America. We found the causative fungus, Pseudogymnoascus destructans, in a 1918 sample collected in Europe, where bats have now adapted to the fungus. These results are consistent with a Eurasian origin of the pathogen.

Volatile antimicrobials from Muscodor crispans, a novel endophytic fungus.

Science.gov (United States)

Mitchell, Angela M; Strobel, Gary A; Moore, Emily; Robison, Richard; Sears, Joe

2010-01-01

Muscodor crispans is a recently described novel endophytic fungus of Ananas ananassoides (wild pineapple) growing in the Bolivian Amazon Basin. The fungus produces a mixture of volatile organic compounds (VOCs); some of the major components of this mixture, as determined by GC/MS, are propanoic acid, 2-methyl-, methyl ester; propanoic acid, 2-methyl-; 1-butanol, 3-methyl-;1-butanol, 3-methyl-, acetate; propanoic acid, 2-methyl-, 2-methylbutyl ester; and ethanol. The fungus does not, however, produce naphthalene or azulene derivatives as has been observed with many other members of the genus Muscodor. The mixture of VOCs produced by M. crispans cultures possesses antibiotic properties, as does an artificial mixture of a majority of the components. The VOCs of the fungus are effective against a wide range of plant pathogens, including the fungi Pythium ultimum, Phytophthora cinnamomi, Sclerotinia sclerotiorum and Mycosphaerella fijiensis (the black sigatoka pathogen of bananas), and the serious bacterial pathogen of citrus, Xanthomonas axonopodis pv. citri. In addition, the VOCs of M. crispans killed several human pathogens, including Yersinia pestis, Mycobacterium tuberculosis and Staphylococcus aureus. Artificial mixtures of the fungal VOCs were both inhibitory and lethal to a number of human and plant pathogens, including three drug-resistant strains of Mycobacterium tuberculosis. The gaseous products of Muscodor crispans potentially could prove to be beneficial in the fields of medicine, agriculture, and industry.

Exploring the Potential for Actinobacteria as Defensive Symbionts in Fungus-Growing Termites

NARCIS (Netherlands)

Visser, A.A.; Mesquita Nobre, T.; Currie, C.R.; Aanen, D.K.; Poulsen, M.

2012-01-01

In fungus-growing termites, fungi of the subgenus Pseudoxylaria threaten colony health through substrate competition with the termite fungus (Termitomyces). The potential mechanisms with which termites suppress Pseudoxylaria have remained unknown. Here we explore if Actinobacteria potentially play a

Once upon a time... Dead wood in french forests

International Nuclear Information System (INIS)

Bartoli, Michel; Geny, Bernard

2005-01-01

For many centuries in France, dead wood was an essential source of energy for households. Harvesting dead wood was both authorised - in particular, through allocation of rights of use - and highly regulated. Restrictions on its employment were established by texts ranging from the 1515 royal decree to an implementation decree of 1853 that is still applicable today - its owner must have formally released the wood. It must be dry and lying on the ground. It can be broken only by hand and no means other than human labour can be used to transport it. Furthermore, it cannot be the outcome of an act that caused a stem to dry while standing. In the 19. century, the huge number of trials, some of which went as far as the supreme court, shows just how important dead wood was socially, and much coveted by the paupers who were confronted with increasingly repressive forest police. These trials provide an excellent reflection of a society that harvested all the proceeds of felling. From the end of the 18. century to the middle of the 20., forestry treatises always dealt with removal of dead trees as a priority. Dead wood was for a long time and up to very recently abhorred but latterly has begun to be considered as an important compartment of biodiversity. History shows that it is no surprise that for the time being there is little of it to be found in our forests. (authors)

Children, death, and the dead: the Mebengokré-Xikrin case

Directory of Open Access Journals (Sweden)

Clarice Cohn

Full Text Available This article approaches the relations children entertain with the dead, as well as with their own death risk, among the Mebenkogré-Xikrin, an indigenous Jê-speaking Indigenous group living in the North of Brazil. These themes are developed by analyzing the fabrication of the body, the formation of the self and the person, and the relations with the dead, with a special focus on children. Mebengokré-Xikrin notions of childhood are therefore discussed in an innovative manner through the formation of the self and the child's relations with the cosmos and the dead, by looking at the eventuality of caputre by the spirits of the dead, their adoption in the after-life, the mourning of children, their bodily adornments and painting, how they should be taken care of in life in order to prevent death, and their bodies and social interactions.

Using copper sulfate to control egg fungus at Keo Fish Farm

Science.gov (United States)

Keo Fish Farm is the biggest producer of hybrid striped bass fry in the world. The hatchery manager asked about treatments to control fungus on eggs which occurred fairly often. Our lab has been working on gaining FDA-approval to use copper sulfate to control fungus on catfish eggs, so we were con...

The prevalence and challenges of abandoned dead neonates in an ...

African Journals Online (AJOL)

parents/caregivers' attitudes toward dead neonates. Hospital-based postbereavement programs should be organized to ... Dead neonates at the Neonatal Intensive Care Units,. Pediatric Emergency Department, Pediatric Surgical .... interventions and newborn survival. Niger J Med 2006; 15:108–114. 3 Kalkofen RW. After a ...

A method for the measurement of the intrinsic dead time of a counting system

International Nuclear Information System (INIS)

Wyllie, H.A.

1989-01-01

Equations are derived for (a) the determination of the intrinsic dead time of a counting system in the components preceding the paralysis unit which imposes the set dead time, and (b) a more accurate correction of count rates in a single-channel system, taking into account the extension of the set dead time by the intrinsic dead time. (author)

Dead space and slope indices from the expiratory carbon dioxide tension-volume curve

NARCIS (Netherlands)

A.H. Kars (Alice); J.M. Bogaard (Jan); Th. Stijnen (Theo); J. de Vries; A.F.M. Verbraak (Anton); C. Hilvering

1997-01-01

textabstractThe slope of phase 3 and three noninvasively determined dead space estimates derived from the expiratory carbon dioxide tension (PCO2) versus volume curve, including the Bohr dead space (VD,Bohr), the Fowler dead space (VD,Fowler) and pre-interface expirate

Treatment of bark beetle attacked trees with entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin

OpenAIRE

Jakuš, Rastislav; Blaženec, Miroslav

2011-01-01

We carried out an experiment with using the entomopathogenic fungus Beauveria bassiana (Bals.) Vuill. for sanitation of active infested trees. We used 15 active infested trees from which 5 stems were treated with an insecticide, 5 were treated with solution of the tested entomopathogenic fungus and 5 were left as control. The used insecticide was pyretroid Fury 10 EW. We used a biopreparation based on the entomopathogenic fungus B. bassiana in form of wettable powder. The material was diluted...

Smoking Out a Deadly Threat: Tobacco Use in the LGBT Community

Science.gov (United States)

... Out a Deadly Threat: Tobacco Use in the LGBT Community Disparities in Lung Health Series "Smoking Out a Deadly Threat: Tobacco Use in the LGBT Community" is part of the American Lung Association's ...

Biotransformation of (+)-cycloisolongifolol by plant pathogenic fungus Glomerella cingulata.

Science.gov (United States)

Miyazawa, Mitsuo; Sakata, Kazuki

2007-05-01

The biotransformation of terpenoids using the plant pathogenic fungus as a biocatalyst to produce useful novel organic compounds was investigated. The biotransformation of sesquiterpen alcohol, (+)-cycloisolongifolol (1) was investigated using plant pathogenic fungus Glomerella cingulata as a biocatalyst. Compound 1 gave one major metabolic product and a number of minor metabolic products. Major product was dehydration at the C-8 position to (+)-dehydrocycloisolongifolene (2). The structure of the product was determined by their spectroscopic data. Glomerella cingulata gave dehydration in the specifically and over 70% conversion.

Experimental dead time corrections for a linear position-sensitive proportional counter

International Nuclear Information System (INIS)

Yelon, W.B.; Tompson, C.W.; Mildner, D.F.R.; Berliner, R.; Missouri Univ., Columbia

1984-01-01

Two simple counters included in the charge-digitization circuitry of a position-sensitive proportional counter using the charge division method for position encoding have enabled us to determine the dead time losses for the system. An interesting positional dependence of the dead time tau is observed, which agrees with a simple model. The system enables us to correct the experimental data for dead time and to be indifferent to the relatively slow analog-to-digital converters used in the system. (orig.)

First localities in Poland of the recently described fungus Cordyceps bifusispora

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Anna Bujakiewicz

2014-08-01

Full Text Available Two localities of the entomopathogenic fungus Cordyceps bifusispora, hitherto not reported from Poland, are characterised by their site conditions and co-occurring macrofungi during the period of the appearance of its stromata. Description of this fungus culture is given and some remarks on the resemblance of its teleomorphs and anamorphs from different collections are discussed.

MTR2: a discriminator and dead-time module used in counting systems

International Nuclear Information System (INIS)

Bouchard, J.

2000-01-01

In the field of radioactivity measurement, there is a constant need for highly specialized electronic modules such as ADCs, amplifiers, discriminators, dead-time modules, etc. But sometimes it is almost impossible to find on the market the modules having the performances corresponding to our needs. The purpose of the module presented here, called MTR2 (Module de Temps-mort Reconductible), is to process, in terms of pulse height discrimination and dead-time corrections, the pulses delivered by the detectors used in counting systems. This dead-time, of the extendible type, is triggered by both the positive and negative parts of the incoming pulse and the dead-time corrections are made according to the live-time method. This module, which has been developed and tested at LPRI, can be used alone in simple counting channels or in more complex systems such as coincidence systems. The philosophy governing the choice and the implementation of this type of dead-time as well as the system used for the dead-time corrections is presented. The electronic scheme and the performances are also presented. This module is available in the NIM standard

Comparison between morphological and staining characteristics of live and dead eggs of Schistosoma mansoni

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AK Sarvel

2006-10-01

Full Text Available Schistosoma mansoni eggs are classified, according to morphological characteristics, as follows: viable mature and immature eggs; dead mature and immature eggs, shells and granulomas. The scope of this study was to compare the staining characteristics of different morphological types of eggs in the presence of fluorescent labels and vital dyes, aiming at differentiating live and dead eggs. The eggs were obtained from the intestines of infected mice, and put into saline 0.85%. The fluorescent labels were Hoechst 33258 and Acridine Orange + Ethidium Bromide and vital dyes (Trypan Blue 0.4% and Neutral Red 1%. When labelled with the probe Hoechst 33258, some immature eggs, morphologically considered viable, presented fluorescence (a staining characteristic detected only in dead eggs; mature eggs did not present fluorescence, and the other types of dead eggs, morphologically defined, showed fluorescence. As far as Acridine Orange + Ethidium Bromide are concerned, either the eggs considered to be live, or the dead ones, presented staining with green color, and only the hatched and motionless miracidium was stained with an orange color. Trypan Blue was not able to stain the eggs, considered to be dead but only dead miracidia which had emerged out of the shell. Neutral Red stained both live and dead eggs. Only the fluorescent Hoechst 33258 can be considered a useful tool for differentiation between dead and live eggs.

Nest enlargement in leaf-cutting ants: relocated brood and fungus trigger the excavation of new chambers.

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Daniela Römer

Full Text Available During colony growth, leaf-cutting ants enlarge their nests by excavating tunnels and chambers housing their fungus gardens and brood. Workers are expected to excavate new nest chambers at locations across the soil profile that offer suitable environmental conditions for brood and fungus rearing. It is an open question whether new chambers are excavated in advance, or will emerge around brood or fungus initially relocated to a suitable site in a previously-excavated tunnel. In the laboratory, we investigated the mechanisms underlying the excavation of new nest chambers in the leaf-cutting ant Acromyrmex lundi. Specifically, we asked whether workers relocate brood and fungus to suitable nest locations, and to what extent the relocated items trigger the excavation of a nest chamber and influence its shape. When brood and fungus were exposed to unfavorable environmental conditions, either low temperatures or low humidity, both were relocated, but ants clearly preferred to relocate the brood first. Workers relocated fungus to places containing brood, demonstrating that subsequent fungus relocation spatially follows the brood deposition. In addition, more ants aggregated at sites containing brood. When presented with a choice between two otherwise identical digging sites, but one containing brood, ants' excavation activity was higher at this site, and the shape of the excavated cavity was more rounded and chamber-like. The presence of fungus also led to the excavation of rounder shapes, with higher excavation activity at the site that also contained brood. We argue that during colony growth, workers preferentially relocate brood to suitable locations along a tunnel, and that relocated brood spatially guides fungus relocation and leads to increased digging activity around them. We suggest that nest chambers are not excavated in advance, but emerge through a self-organized process resulting from the aggregation of workers and their density

The Dead Sea: A model of a desiccating terminal salt lake

International Nuclear Information System (INIS)

Gat, J.R.

2001-01-01

The continuing decline in the water level of the Dead Sea and the commensurate increase in salinity and precipitation of evaporates results in an irreversible evolution of the structure of the sea. The Dead Sea has been switching from its holomictic regime to short meromictic phases of up to 4-year duration, following the particular rainy winters of 1980 and 1992. The massive precipitation of halite in recent years, as well as the re-introduction of the end-brines of the potash plant, is changing the ion composition of the Dead Sea waters. This necessitates the adjustment of the equation-of-state of the brine and the solubility curve of halite. One consequence is that the onset of halite precipitation during the summer occurs earlier and earlier in the annual cycle. New isotopic measurement of δ 37 Cl of the brine and evaporate deposits and of δ 18 O in dissolved oxygen in the water column have yielded new information on geochemical processes in the Dead Sea system. A systematic monitoring of the oxygen and hydrogen isotopes in the Dead Sea waters has, unfortunately, not been continued in recent years and should be encouraged for the future. (author)

Dead Zones in LX-17 and PBX 9502

Energy Technology Data Exchange (ETDEWEB)

Souers, P C; Andreski, H G; Batteux, J; Bratton, B; Cabacungan, C; Cook, III, C F; Fletcher, S; Garza, R; Grimsley, D; Handly, J; Hernandez, A; McMaster, P; Molitoris, J D; Palmer, R; Prindiville, J; Rodriguez, J; Schneberk, D; Wong, B; Vitello, P

2005-09-06

Pin and X-ray corner-turning data have been taken on ambient LX-17 and PBX 9052, and the results are listed in tables as an aid to future modeling. The results have been modeled at 4 zones/mm with a reactive flow approach that varies the burn rate as a function of pressure. A single rate format is used to simulate failure and detonation in different pressure regimes. A pressure cut-off must also be reached to initiate the burn. Corner-turning and failure are modeled using an intermediate pressure rate region, and detonation occurs at high pressure. The TATB booster is also modeled using reactive flow, and X-ray tomography is used to partition the ram-pressed hemisphere into five different density regions. The model reasonably fits the bare corner-turning experiment but predicts a smaller dead zone with steel confinement, in contradiction with experiment. The same model also calculates the confined and unconfined cylinder detonation velocities and predicts the failure of the unconfined cylinder at 3.75 mm radius. The PBX 9502 shows a smaller dead zone than LX-17. An old experiment that showed a large apparent dead zone in Comp B was repeated with X-ray transmission and no dead zone was seen. This confirms the idea that a variable burn rate is the key to modeling. The model also produces initiation delays, which are shorter than those found in time-to-detonation.

Entomology: A Bee Farming a Fungus.

Science.gov (United States)

Oldroyd, Benjamin P; Aanen, Duur K

2015-11-16

Farming is done not only by humans, but also by some ant, beetle and termite species. With the discovery of a stingless bee farming a fungus that provides benefits to its larvae, bees can be added to this list. Copyright © 2015 Elsevier Ltd. All rights reserved.

Death from Fungus in the Soil

Centers for Disease Control (CDC) Podcasts

2012-12-17

Dr. Shira Shafir, Assistant Professor of Epidemiology at the UCLA Fielding School of Public Health, discusses her study about fungus found in soil.  Created: 12/17/2012 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 12/18/2012.

Experimental evaluation of the extended Dytlewski-style dead time correction formalism for neutron multiplicity counting

Science.gov (United States)

Lockhart, M.; Henzlova, D.; Croft, S.; Cutler, T.; Favalli, A.; McGahee, Ch.; Parker, R.

2018-01-01

Over the past few decades, neutron multiplicity counting has played an integral role in Special Nuclear Material (SNM) characterization pertaining to nuclear safeguards. Current neutron multiplicity analysis techniques use singles, doubles, and triples count rates because a methodology to extract and dead time correct higher order count rates (i.e. quads and pents) was not fully developed. This limitation is overcome by the recent extension of a popular dead time correction method developed by Dytlewski. This extended dead time correction algorithm, named Dytlewski-Croft-Favalli(DCF), is detailed in reference Croft and Favalli (2017), which gives an extensive explanation of the theory and implications of this new development. Dead time corrected results can then be used to assay SNM by inverting a set of extended point model equations which as well have only recently been formulated. The current paper discusses and presents the experimental evaluation of practical feasibility of the DCF dead time correction algorithm to demonstrate its performance and applicability in nuclear safeguards applications. In order to test the validity and effectiveness of the dead time correction for quads and pents, 252Cf and SNM sources were measured in high efficiency neutron multiplicity counters at the Los Alamos National Laboratory (LANL) and the count rates were extracted up to the fifth order and corrected for dead time. In order to assess the DCF dead time correction, the corrected data is compared to traditional dead time correction treatment within INCC. The DCF dead time correction is found to provide adequate dead time treatment for broad range of count rates available in practical applications.

Draft Genome Sequence and Gene Annotation of the Entomopathogenic Fungus Verticillium hemipterigenum

OpenAIRE

Horn, Fabian; Habel, Andreas; Scharf, Daniel H.; Dworschak, Jan; Brakhage, Axel A.; Guthke, Reinhard; Hertweck, Christian; Linde, J?rg

2015-01-01

Verticillium hemipterigenum (anamorph Torrubiella hemipterigena) is an entomopathogenic fungus and produces a broad range of secondary metabolites. Here, we present the draft genome sequence of the fungus, including gene structure and functional annotation. Genes were predicted incorporating RNA-Seq data and functionally annotated to provide the basis for further genome studies.

Dead space variability of face masks for valved holding chambers.

Science.gov (United States)

Amirav, Israel; Newhouse, Michael T

2008-03-01

Valved holding chambers with masks are commonly used to deliver inhaled medications to young children with asthma. Optimal mask properties such as their dead space volume have received little attention. The smaller the mask the more likely it is that a greater proportion of the dose in the VHC will be inhaled with each breath, thus speeding VHC emptying and improving overall aerosol delivery efficiency and dose. Masks may have different DSV and thus different performance. To compare both physical dead space and functional dead space of different face masks under various applied pressures. The DSV of three commonly used face masks of VHCs was measured by water displacement both under various pressures (to simulate real-life application, dynamic DSV) and under no pressure (static DSV). There was a great variability of both static and dynamic dead space among various face mask for VHCs, which is probably related to their flexibility. Different masks have different DSV characteristics. This variability should be taken into account when comparing the clinical efficacy of various VHCs.

The nematophagous fungus Monacrosporium thaumasium and its nematicidal activity on Angiostrongylus vasorum.

Science.gov (United States)

Soares, Filippe Elias de Freitas; Braga, Fabio Ribeiro; de Araújo, Jackson Victor; Lima, Walter dos Santos; de Queiroz, José Humberto

2015-01-01

The dog acts as a reservoir and environmental disseminator of potentially zoonotic parasites. The objective of this work was to study the fungus Monacrosporium thaumasium regarding its nematicidal potential in laboratory trials and its proteolytic profile. The in vitro test was carried out through two assays (A and B). In assay A, conidia of the fungus N34a were added in positive coprocultures for Angiostrongylus vasorum. In assay B, crude extract (treated group) and distilled water (control group) were added to coprocultures. Next, the proteolytic profile of crude extract of the nematophagous fungus M. thaumasium (NF34a) was revealed by performing a zymogram. There was a reduction (p<0.01) in the averages of larvae recovered from the treated groups (conidia and crude extract) in relation to control groups. The zymogram suggested that the nematophagous fungus M. thaumasium produces a protease of approximately 40 kDa. The results of this work confirm that the conidia as well as the crude extract of the fungus M. thaumasium may be used to control A. vasorum L1. The proteolytic profile suggested the presence of one protease (Mt1) of approximately 40 kDa that in the future may be used in biological control of L1 of this nematode. Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

The yeast spectrum of the 'tea fungus Kombucha'.

Science.gov (United States)

Mayser, P; Fromme, S; Leitzmann, C; Gründer, K

1995-01-01

The tea fungus 'Kombucha' is a symbiosis of Acetobacter, including Acetobacter xylinum as a characteristic species, and various yeasts. A characteristic yeast species or genus has not yet been identified. Kombucha is mainly cultivated in sugared black tea to produce a slightly acidulous effervescent beverage that is said to have several curative effects. In addition to sugar, the beverage contains small amounts of alcohol and various acids, including acetic acid, gluconic acid and lactic acid, as well as some antibiotic substances. To characterize the yeast spectrum with special consideration given to facultatively pathogenic yeasts, two commercially available specimens of tea fungus and 32 from private households in Germany were analysed by micromorphological and biochemical methods. Yeasts of the genera Brettanomyces, Zygosaccharomyces and Saccharomyces were identified in 56%, 29% and 26% respectively. The species Saccharomycodes ludwigii and Candida kefyr were only demonstrated in isolated cases. Furthermore, the tests revealed pellicle-forming yeasts such as Candida krusei or Issatchenkia orientalis/occidentalis as well as species of the apiculatus yeasts (Kloeckera, Hanseniaspora). Thus, the genus Brettanomyces may be a typical group of yeasts that are especially adapted to the environment of the tea fungus. However, to investigate further the beneficial effects of tea fungus, a spectrum of the other typical genera must be defined. Only three specimens showed definite contaminations. In one case, no yeasts could be isolated because of massive contamination with Penicillium spp. In the remaining two samples (from one household), Candida albicans was demonstrated. The low rate of contamination might be explained by protective mechanisms, such as formation of organic acids and antibiotic substances. Thus, subjects with a healthy metabolism do not need to be advised against cultivating Kombucha. However, those suffering from immunosuppression should preferably

The active structure of the Dead Sea depression

Science.gov (United States)

Shamir, G.

2003-04-01

The ~220km long gravitational and structural Dead Sea Depression (DSD), situated along the southern section of the Dead Sea Transform (DST), is centered by the Dead Sea basin sensu strictu (DSB), which has been described since the 1960?s as a pull-apart basin over a presumed left-hand fault step. However, several observations, or their lack thereof, question this scheme, e.g. (i) It is not supported by recent seismological and geomorphic data; (ii) It does not explain the fault pattern and mixed sinistral and dextral offset along the DSB western boundary; (iii) It does not simply explain the presence of intense deformation outside the presumed fault step zone; (iv) It is inconsistent with the orientation of seismically active faults within the Dead Sea and Jericho Valley; (v); It is apparently inconsistent with the symmetrical structure of the DSD; (vi) The length of the DSB exceeds the total offset along the Dead Sea Transform, while its subsidence is about the age of the DST. Integration of newly acquired and analyzed data (high resolution and petroleum seismic reflection data, earthquake relocation and fault plane solutions) with previously published data (structural mapping, fracture orientation distribution, Bouguer anomaly maps, sinkhole distribution, geomorphic lineaments) now shows that the active upper crustal manifestation of the DSD is a broad shear zone dominated by internal fault systems oriented NNE and NNW. These fault systems are identified by earthquake activity, seismic reflection observations, alignment of recent sinkholes, and distribution of Bouguer anomaly gradients. Motion on the NNE system is normal-dextral, suggesting that counterclockwise rotation may have taken place within the shear zone. The overall sinistral motion between the Arabian and Israel-Sinai plates along the DSD is thus accommodated by distributed shear across the N-S extending DSD. The three-dimensionality of this motion at the DSD may be related to the rate of convergence

Transcriptome of an entomophthoralean fungus (Pandora formicae) shows molecular machinery adjusted for successful host exploitation and transmission

DEFF Research Database (Denmark)

Malagocka, Joanna; Grell, Morten Nedergaard; Lange, Lene

2015-01-01

Pandora formicae is an obligate entomopathogenic fungus from the phylum Entomophthoromycota, known to infect only ants from the genus Formica. In the final stages of infection, the fungus induces the so-called summit disease syndrome, manipulating the host to climb up vegetation prior to death......, but the fungus had not grown out through the cuticle and (2) when the fungus was growing out from host cadaver and producing spores. These phases mark the switch from within-host growth to reproduction on the host surface, after fungus outgrowth through host integument. In this first de novo transcriptome...... of an entomophthoralean fungus, we detected expression of many pathogenicity-related genes, including secreted hydrolytic enzymes and genes related to morphological reorganization and nutrition uptake. Differences in expression of genes in these two infection phases were compared and showed a switch in enzyme expression...

Quantifying carbon stores and decomposition in dead wood: A review

Science.gov (United States)

Matthew B. Russell; Shawn Fraver; Tuomas Aakala; Jeffrey H. Gove; Christopher W. Woodall; Anthony W. D’Amato; Mark J. Ducey

2015-01-01

The amount and dynamics of forest dead wood (both standing and downed) has been quantified by a variety of approaches throughout the forest science and ecology literature. Differences in the sampling and quantification of dead wood can lead to differences in our understanding of forests and their role in the sequestration and emissions of CO2, as...

Formulation of the endophytic fungus Cladosporium oxysporum Berk.

Directory of Open Access Journals (Sweden)

Bensaci Oussama Ali

2015-01-01

Full Text Available Two formulations containing culture filtrates and conidial suspensions of the endophytic fungus Cladosporium oxysporum Berk. & M.A. Curtis, isolated previously from stems of Euphorbia bupleuroides subsp. luteola (Kralik Maire, were experimentally tested for their aphicid activity against the black bean aphid Aphis fabae Scop. found in Algeria. It was shown that invert emulsions are more effective against aphids, than using aqueous suspensions. This was especially true for formulations containing culture filtrates. The relatively insignificant mortalities obtained by formulations containing conidial suspensions indicated a low infectious potential towards the aphids. The proteolytic activity seemed to be more important than the chitinolytic activity of the fungus against the black bean aphid A. fabae

Yarsagumba Fungus: Health Problems in the Himalayan Gold Rush.

Science.gov (United States)

Koirala, Pranawa; Pandit, Bidur; Phuyal, Pratibha; Zafren, Ken

2017-09-01

Seasonal migration of people in search of Yarsagumba fungus creates a population of collectors that faces hardship and health risks in austere high-altitude settings. In 2016, our 4-person team performed a 2-day health-needs survey of people collecting Yarsagumba fungus near the village of Yak Kharka (4020 m) in the Manang District of Nepal. There were approximately 800 people, both male and female, from age 10 to over 60, collecting Yarsagumba fungus. They had paid high prices for permits, hoping to recoup the cost and make a profit by selling specimens of Yarsagumba, but the fungus seemed scarce in 2016, resulting in a bleak economic forecast. Most collectors were living in austere conditions, walking long hours to the collection areas early in the morning and returning in the late afternoon. Most were subsisting on 1 daily meal. Health problems, including acute mountain sickness as well as respiratory and gastrointestinal illnesses, were common. Yarsagumba has become harder to find in recent years, increasing hardships and risk of injury. Medical care was almost nonexistent. As abundance decreases and demand increases, there is increasing pressure on collectors to find Yarsagumba. The collectors are an economically disadvantaged population who live in austere conditions at high altitude with poor shelter and sanitation, strenuous work, and limited availability of food. Health care resources are very limited. There are significant risks of illness, injury, and death. Targeted efforts by government entities and nongovernmental organizations might be beneficial in meeting the health needs. Copyright © 2017 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

A Brazilian social bee must cultivate fungus to survive.

Science.gov (United States)

Menezes, Cristiano; Vollet-Neto, Ayrton; Marsaioli, Anita Jocelyne; Zampieri, Davila; Fontoura, Isabela Cardoso; Luchessi, Augusto Ducati; Imperatriz-Fonseca, Vera Lucia

2015-11-02

The nests of social insects provide suitable microenvironments for many microorganisms as they offer stable environmental conditions and a rich source of food [1-4]. Microorganisms in turn may provide several benefits to their hosts, such as nutrients and protection against pathogens [1, 4-6]. Several examples of symbiosis between social insects and microorganisms have been found in ants and termites. These symbioses have driven the evolution of complex behaviors and nest structures associated with the culturing of the symbiotic microorganisms [5, 7, 8]. However, while much is known about these relationships in many species of ants and termites, symbiotic relationships between microorganisms and social bees have been poorly explored [3, 4, 9, 10]. Here, we report the first case of an obligatory relationship between the Brazilian stingless bee Scaptotrigona depilis and a fungus of the genus Monascus (Ascomycotina). Fungal mycelia growing on the provisioned food inside the brood cell are eaten by the larva. Larvae reared in vitro on sterilized larval food supplemented with fungal mycelia had a much higher survival rate (76%) compared to larvae reared under identical conditions but without fungal mycelia (8% survival). The fungus was found to originate from the material from which the brood cells are made. Since the bees recycle and transport this material between nests, fungus would be transferred to newly built cells and also to newly founded nests. This is the first report of a fungus cultivation mutualism in a social bee. Copyright © 2015 Elsevier Ltd. All rights reserved.

Non-Poisson counting statistics of a hybrid G-M counter dead time model

International Nuclear Information System (INIS)

Lee, Sang Hoon; Jae, Moosung; Gardner, Robin P.

2007-01-01

The counting statistics of a G-M counter with a considerable dead time event rate deviates from Poisson statistics. Important characteristics such as observed counting rates as a function true counting rates, variances and interval distributions were analyzed for three dead time models, non-paralyzable, paralyzable and hybrid, with the help of GMSIM, a Monte Carlo dead time effect simulator. The simulation results showed good agreements with the models in observed counting rates and variances. It was found through GMSIM simulations that the interval distribution for the hybrid model showed three distinctive regions, a complete cutoff region for the duration of the total dead time, a degraded exponential and an enhanced exponential regions. By measuring the cutoff and the duration of degraded exponential from the pulse interval distribution, it is possible to evaluate the two dead times in the hybrid model

Accuracy in gamma spectrometry: Pileup, dead time, and fast electornics

International Nuclear Information System (INIS)

Lindstrom, R.M.

1993-01-01

An important source of inaccuracy in neutron activation analysis is the nonlinear throughput of the counting system, especially at high counting rates. Losses, due to the finite time needed for events to happen, occur in all parts of the spectrometer system: the germanium detector crystal, preamplifier, amplifier, analog-digital converter (ADC), and MCA or computer. The slowest unbuffered units are the ADC and the amplifier, followed by the crystal. Even with modern fast electronics, losses can be important, although compensating circuits can greatly improve accuracy if they are used correctly. The ADC dead time is less of a problem than it was a decade ago. For example, a modern successive-approximation ADC in the author's laboratory takes 6 μs to digitize a gamma ray in the middle of an 8192-channel spectrum, compared with 60 μs for the Wilkinson device that it replaced. Dead-time circuits in MCAs for many years have compensated very well for this dead time. Pulse pileup is as important as ADC dead time. Random coincidence, the accidental arrival of the signal from two nonrelated gamma rays at the amplifier in a time short compared to the shaping time, results in a composite pulse that distorts the spectrum. For accurate spectrometry, each such random-sum pulse should be excluded from the spectrum (pileup rejection), and the system dead time must be adjusted to compensate for the time the system is busy analyzing this rejected event (pileup live-time correction)

Microsatellite variability in the entomopathogenic fungus Paeciolomyces fumosoroseus: genetic diversity and population structure

Science.gov (United States)

The hyphomycete Paecilomyces fumosoroseus (Pfr) is a geographically widespread fungus capable of infecting various insect hosts. The fungus has been used for the biological control of several important insect pests of agriculture. However knowledge of the fungus’ genetic diversity and population str...

The dynamics of plant cell-wall polysaccharide decomposition in leaf-cutting ant fungus gardens.

Directory of Open Access Journals (Sweden)

Isabel E Moller

Full Text Available The degradation of live plant biomass in fungus gardens of leaf-cutting ants is poorly characterised but fundamental for understanding the mutual advantages and efficiency of this obligate nutritional symbiosis. Controversies about the extent to which the garden-symbiont Leucocoprinus gongylophorus degrades cellulose have hampered our understanding of the selection forces that induced large scale herbivory and of the ensuing ecological footprint of these ants. Here we use a recently established technique, based on polysaccharide microarrays probed with antibodies and carbohydrate binding modules, to map the occurrence of cell wall polymers in consecutive sections of the fungus garden of the leaf-cutting ant Acromyrmex echinatior. We show that pectin, xyloglucan and some xylan epitopes are degraded, whereas more highly substituted xylan and cellulose epitopes remain as residuals in the waste material that the ants remove from their fungus garden. These results demonstrate that biomass entering leaf-cutting ant fungus gardens is only partially utilized and explain why disproportionally large amounts of plant material are needed to sustain colony growth. They also explain why substantial communities of microbial and invertebrate symbionts have evolved associations with the dump material from leaf-cutting ant nests, to exploit decomposition niches that the ant garden-fungus does not utilize. Our approach thus provides detailed insight into the nutritional benefits and shortcomings associated with fungus-farming in ants.

Experimental study of Aspergillus flavus fungus from uranium mines

Energy Technology Data Exchange (ETDEWEB)

Kusak, V. (Ceskoslovenska Akademie Ved, Prague. Ustav Experimentalni Mediciny)

1982-06-01

Cultivation is discussed of fungus strain Aspergillus flavus obtained from materials from uranium mines. It was found that an addition of 0.6 g of uranium in form of uranyl acetate or of 0.6 g of thorium in form on thorium nitrate in 1000 ml of the standard medium had stimulating effects on the growth and sporulation of Aspergillus flavus. Irradiating the cultivated fungus through a polyethylene foil did not show a stimulating effect. It is stated that uranium and its daughters must be directly present in the culture medium for their stimulating effect on growth and sporulation to manifest itself.

Breathing Life Into Dead-Zones

Directory of Open Access Journals (Sweden)

Gressel Oliver

2013-04-01

Full Text Available The terrestrial planet formation regions of protoplanetary disks are generally sufficiently cold to be con- sidered non-magnetized and, consequently, dynamically inactive. However, recent investigations of these so-called “Dead-Zones” indicate the possibility that disks with strong mean radial temperature gradients can support instabilities associated with disk-normal gradients of the basic Keplerian shear profile. This process, known as the Goldreich-Schubert-Fricke (GSF instability, is the instability of short radial wavelength inertial modes and depends wholly on the presence of vertical gradients of the mean Keplerian (zonal flow. We report here high resolution fully nonlinear axisymmetric numerical studies of this instability and find a number of features including how, in the nonlinear saturated state, unstable discs become globally distorted, with strong vertical oscillations occurring at all radii due to local instability. We find that nonaxisymmetric numerical experiments are accompanied by significant amounts angular momentum transport (α ~ 0001. This instability should be operating in the Dead-Zones of protoplanetary disks at radii greater than 10-15 AU in minimum mass solar nebula models.

Datasheet: Pseudogymnoascus destructans (white-nose syndrome fungus)

Science.gov (United States)

Blehert, David; Lankau, Emily W.

2017-01-01

Pseudogymnoascus destructans is a psychrophilic (cold-loving) fungus that causes white-nose syndrome (WNS), an emerging disease of North American bats that has caused unprecedented population declines. The fungus is believed to have been introduced to North America from Europe or Asia (where it is present but does not cause significant mortality), but the full extent of its native range is unknown. The route of introduction is also unknown. In North America, hibernating bats become infected with P. destructans when body temperature decreases during winter torpor into the range permissive for growth of this fungus. Infected bats may develop visible fungal growth on the nose or wings, awaken more frequently from torpor, and experience a cascade of physiologic changes that result in weight loss, dehydration, electrolyte imbalances, and death. P. destructans persists in the environments of underground bat hibernation sites (hibernacula) and is believed to spread primarily by natural movements of infected bats. The first evidence of WNS in North America is from a photograph of a hibernating bat taken during winter of 2005-2006 in a hibernaculum near Albany, New York. P. destructans subsequently spread rapidly from the northeastern United States throughout much of the eastern portions of the United States and Canada, and most recently (as of May 2017) was detected in Washington State. It has killed millions of bats, threatening some species with regional extirpation and putting at risk the valuable environmental services that bats provide by eating harmful insects.

Multifarious plant growth promotion by an entomopathogenic fungus Lecanicillium psalliotae.

Science.gov (United States)

Senthil Kumar, C M; Jacob, T K; Devasahayam, S; Thomas, Stephy; Geethu, C

2018-03-01

An entomopathogenic fungus, Lecanicillium psalliotae strain IISR-EPF-02 previously found infectious to cardamom thrips, Sciothrips cardamomi promoted plant growth in cardamom, Elettaria cardamomum. The isolate exhibited direct plant growth promoting traits by production of indole-3-acetic acid and ammonia and by solubilizing inorganic phosphate and zinc. It also showed indirect plant growth promoting traits by producing siderophores and cell wall-degrading enzymes like, α-amylases, cellulases and proteases. In pot culture experiments, application of the fungus at the root zone of cardamom seedlings significantly increased shoot and root length, shoot and root biomass, number of secondary roots and leaves and leaf chlorophyll content compared to untreated plants. This is the first report on the plant growth promoting traits of this fungus. The entomopathogenic and multifarious growth promoting traits of L. psalliotae strain IISR-EPF-02 suggest that it has great potential for exploitation in sustainable agriculture. Copyright © 2017 Elsevier GmbH. All rights reserved.

Thermodynamic analysis of a Stirling engine including regenerator dead volume

Energy Technology Data Exchange (ETDEWEB)

Puech, Pascal; Tishkova, Victoria [Universite de Toulouse, UPS, CNRS, CEMES, 29 rue Jeanne Marvig, F-31055 Toulouse (France)

2011-02-15

This paper provides a theoretical investigation on the thermodynamic analysis of a Stirling engine with linear and sinusoidal variations of the volume. The regenerator in a Stirling engine is an internal heat exchanger allowing to reach high efficiency. We used an isothermal model to analyse the net work and the heat stored in the regenerator during a complete cycle. We show that the engine efficiency with perfect regeneration doesn't depend on the regenerator dead volume but this dead volume strongly amplifies the imperfect regeneration effect. An analytical expression to estimate the improvement due to the regenerator has been proposed including the combined effects of dead volume and imperfect regeneration. This could be used at the very preliminary stage of the engine design process. (author)

Microbe Profile: Mycobacterium tuberculosis: Humanity's deadly microbial foe.

Science.gov (United States)

Gordon, Stephen V; Parish, Tanya

2018-04-01

Mycobacterium tuberculosis is an expert and deadly pathogen, causing the disease tuberculosis (TB) in humans. It has several notable features: the ability to enter non-replicating states for long periods and cause latent infection; metabolic remodelling during chronic infection; a thick, waxy cell wall; slow growth rate in culture; and intrinsic drug resistance and antibiotic tolerance. As a pathogen, M. tuberculosis has a complex relationship with its host, is able to replicate inside macrophages, and expresses diverse immunomodulatory molecules. M. tuberculosis currently causes over 1.8 million deaths a year, making it the world's most deadly human pathogen.

Spread of Rare Fungus from Vancouver Island

Centers for Disease Control (CDC) Podcasts

Cryptococcus gattii, a rare fungus normally found in the tropics, has infected people and animals on Vancouver Island, Canada. Dr. David Warnock, Director, Division of Foodborne, Bacterial, and Mycotic Diseases, CDC, discusses public health concerns about further spread of this organism

Perturbative search for dead-end CFTs

International Nuclear Information System (INIS)

Nakayama, Yu

2015-01-01

To explore the possibility of self-organized criticality, we look for CFTs without any relevant scalar deformations (a.k.a. dead-end CFTs) within power-counting renormalizable quantum field theories with a weakly coupled Lagrangian description. In three dimensions, the only candidates are pure (Abelian) gauge theories, which may be further deformed by Chern-Simons terms. In four dimensions, we show that there are infinitely many non-trivial candidates based on chiral gauge theories. Using the three-loop beta functions, we compute the gap of scaling dimensions above the marginal value, and it can be as small as O(10"−"5) and robust against the perturbative corrections. These classes of candidates are very weakly coupled and our perturbative conclusion seems difficult to refute. Thus, the hypothesis that non-trivial dead-end CFTs do not exist is likely to be false in four dimensions.

Microclimate and habitat heterogeneity as the major drivers of beetle diversity in dead wood

Science.gov (United States)

Sebastian Seibold; Claus Bassler; Roland Brandl; Boris Buche; Alexander Szallies; Simon Thorn; Michael D. Ulyshen; Jorg Muller; Christopher Baraloto

2016-01-01

1. Resource availability and habitat heterogeneity are principle drivers of biodiversity, but their individual roles often remain unclear since both factors are usually correlated. The biodiversity of species dependent on dead wood could be driven by either resource availability represented by dead-wood amount or habitat heterogeneity characterized by dead-wood...

Postfire Succession of Ants (Hymenoptera: Formicidae) Nesting in Dead Wood of Northern Boreal Forest.

Science.gov (United States)

Boucher, Philippe; Hébert, Christian; Francoeur, André; Sirois, Luc

2015-10-01

Dead wood decomposition begins immediately after tree death and involves a large array of invertebrates. Ecological successions are still poorly known for saproxylic organisms, particularly in boreal forests. We investigated the use of dead wood as nesting sites for ants along a 60-yr postfire chronosequence in northeastern coniferous forests. We sampled a total of 1,625 pieces of dead wood, in which 263 ant nests were found. Overall, ant abundance increased during the first 30 yr after wildfire, and then declined. Leptothorax cf. canadensis Provancher, the most abundant species in our study, was absent during the first 2 yr postfire, but increased steadily until 30 yr after fire, whereas Myrmica alaskensis Wheeler, second in abundance, was found at all stages of succession in the chronosequence. Six other species were less frequently found, among which Camponotus herculeanus (Linné), Formica neorufibarbis Emery, and Formica aserva Forel were locally abundant, but more scarcely distributed. Dead wood lying on the ground and showing numerous woodborer holes had a higher probability of being colonized by ants. The C:N ratio was lower for dead wood colonized by ants than for noncolonized dead wood, showing that the continuous occupation of dead wood by ants influences the carbon and nitrogen dynamics of dead wood after wildfire in northern boreal forests. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Novel fungus-Fe{sub 3}O{sub 4} bio-nanocomposites as high performance adsorbents for the removal of radionuclides

Energy Technology Data Exchange (ETDEWEB)

Ding, Congcong [Institute of Plasma Physics, Chinese Academy of Science, P.O. Box 1126, Hefei 230031 (China); University of Science and Technology of China, Hefei 230000 (China); Cheng, Wencai [Institute of Plasma Physics, Chinese Academy of Science, P.O. Box 1126, Hefei 230031 (China); Sun, Yubing, E-mail: sunyb@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Science, P.O. Box 1126, Hefei 230031 (China); School for Radiological and Interdisciplinary Sciences (RAD-X), Soochow University and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 215123 Suzhou (China); School of Environment and Chemical Engineering, North China Electric Power University, Beijing 102206 (China); Wang, Xiangke, E-mail: xkwang@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Science, P.O. Box 1126, Hefei 230031 (China); School for Radiological and Interdisciplinary Sciences (RAD-X), Soochow University and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 215123 Suzhou (China); School of Environment and Chemical Engineering, North China Electric Power University, Beijing 102206 (China); Faculty of Engineering, King Abdulaziz University, Jeddah 21589 (Saudi Arabia)

2015-09-15

Highlights: • Fungus was used as a template for the assembly of nano-Fe{sub 3}O{sub 4}. • Fungal template directed the nano-Fe{sub 3}O{sub 4} structure from the micro-scale level. • Fungal template enhanced the dispersity and stability of nano-Fe{sub 3}O{sub 4}. • Fungus-Fe{sub 3}O{sub 4} exhibited high sorption capacity for Sr(II), Th(IV) and U(VI). • Fungus-Fe{sub 3}O{sub 4} possessed satisfactory regeneration performance and reusability. - Abstract: The bio-nanocomposites of fungus-Fe{sub 3}O{sub 4} were successfully synthesized using a low-cost self-assembly technique. SEM images showed uniform decoration of nano-Fe{sub 3}O{sub 4} particles on fungus surface. The FTIR analysis indicated that nano-Fe{sub 3}O{sub 4} was combined to the fungus surface by chemical bonds. The sorption ability of fungus-Fe{sub 3}O{sub 4} toward Sr(II), Th(IV) and U(VI) was evaluated by batch techniques. Radionuclide sorption on fungus-Fe{sub 3}O{sub 4} was independent of ionic strength, indicating that inner-sphere surface complexion dominated their sorption. XPS analysis indicated that the inner-sphere radionuclide complexes were formed by mainly bonding with oxygen-containing functional groups (i.e., alcohol, acetal and carboxyl) of fungus-Fe{sub 3}O{sub 4}. The maximum sorption capacities of fungus-Fe{sub 3}O{sub 4} calculated from Langmuir isotherm model were 100.9, 223.9 and 280.8 mg/g for Sr(II) and U(VI) at pH 5.0, and Th(IV) at pH 3.0, respectively, at 303 K. Fungus-Fe{sub 3}O{sub 4} also exhibited excellent regeneration performance for the preconcentration of radionuclides. The calculated thermodynamic parameters showed that the sorption of radionuclides on fungus-Fe{sub 3}O{sub 4} was a spontaneous and endothermic process. The findings herein highlight the novel synthesis method of fungus-Fe{sub 3}O{sub 4} and its high sorption ability for radionuclides.

Dynamic optimum dead time in piezoelectric transformer-based switch-mode power supplies

DEFF Research Database (Denmark)

Ekhtiari, Marzieh; Andersen, Thomas; Andersen, Michael A. E.

2016-01-01

to charge and discharge the input capacitance of piezoelectric transformers in order to achieve zero-voltage switching. This paper proposes a method for detecting the optimum dead time in piezoelectric transformer-based switch-mode power supplies. The provision of sufficient dead time in every cycle......Soft switching is required to attain high efficiency in high-frequency power converters. Piezoelectric transformerbased converters can benefit from soft switching in terms of significantly diminished switching losses and stresses. Adequate dead time is needed in order to deliver sufficient energy...

Love letters to the dead: resurrecting an epistolary art.

Science.gov (United States)

Lander, Dorothy A; Graham-Pole, John R

This article explores the art of letter-writing, specifically to our beloved dead, as a form of autoethnographic research, pedagogy, and care work. As university teachers and qualitative researchers in palliative and end-of-life care, we review the literature and history of epistolary communications with the deceased, as a prelude to writing our own letters. John writes to his long-dead mother and Dorothy to her recently deceased spouse Patrick, each letter followed by a reflective dialogue between us. Through this dialogue, we highlight the potential application of this art, or handcraft, to formal and informal palliative care, and the implications for practice, pedagogy, policy, and research. We propose that such direct, non-mediated, communications can offer a valuable form of healing for bereaved people. The therapeutic potential of letter writing and the abundance of literary and popular culture exemplars of responses from the dead are also largely unexplored in death education and research.

Experimental study of Aspergillus flavus fungus from uranium mines

International Nuclear Information System (INIS)

Kusak, V.

1982-01-01

Cultivation is discussed of fungus strain Aspergillus flavus obtained from materials from uranium mines. It was found that an addition of 0.6 g of uranium in form of uranyl acetate or of 0.6 g of thorium in form on thorium nitrate in 1000 ml of the standard medium had stimulating effects on the growth and sporulation of Aspergillus flavus. Irradiating the cultivated fungus through a polyethylene foil did not show a stimulating effect. It is stated that uranium and its daughters must be directly present in the culture medium for their stimulating effect on growth and sporulation to manifest itself. (H.S.)

Infection of silkworm larvae by the entomopathogenic fungus Metarhizium anisopliae

Directory of Open Access Journals (Sweden)

Lucineia de Fátima Chasko Ribeiro

Full Text Available ABSTRACT: The isolate E9 of Metarhizium anisopliae was used in commercial hybrids of Bombyx mori larvae to evaluate its biological effect. Symptomatological analyses showed typical signs of fungal infection. Histopathology revealed the presence of large numbers of hemocytes in the hemocoel, and on the sixth dpi the bodies of the insects appeared to be colonised by the fungus. The isolate E9 is pathogenic to larvae B. mori and; therefore, death of the insects was caused by the colonization of fungus in the epidermal and mesodermal tissues.

Bibliography on dead-time effects

International Nuclear Information System (INIS)

1975-01-01

A BIPM (Bureau International des Poids et Mesures) Working Party has assembled a bibliography of the publications dealing with the measurement of dead times, the evaluation of the corresponding corrections and of other closely related subjects. It contains some 350 references, each of which is given with its full title; an author index is added. The search has been stopped in August 1975

Does origin of mycorrhizal fungus on mycorrhizal plant influence effectiveness of the mycorrhizal symbiosis?

NARCIS (Netherlands)

Heijden, van der E.W.; Kuyper, T.W.

2001-01-01

Mycorrhizal effectiveness depends on the compatibility between fungus and plant. Therefore, genetic variation in plant and fungal species affect the effectiveness of the symbiosis. The importance of mycorrhizal plant and mycorrhizal fungus origin was investigated in two experiments. In the first

Dead space and slope indices from the expiratory carbon dioxide tension-volume curve

OpenAIRE

Kars, Alice; Bogaard, Jan; Stijnen, Theo; Vries, J.; Verbraak, Anton; Hilvering, C.

1997-01-01

textabstractThe slope of phase 3 and three noninvasively determined dead space estimates derived from the expiratory carbon dioxide tension (PCO2) versus volume curve, including the Bohr dead space (VD,Bohr), the Fowler dead space (VD,Fowler) and pre-interface expirate (PIE), were investigated in 28 healthy control subjects, 12 asthma and 29 emphysema patients (20 severely obstructed and nine moderately obstructed) with the aim to establish diagnostic value. Because breath volume and frequenc...

The fungus gardens of leaf-cutter ants undergo a distinct physiological transition during biomass degradation

Energy Technology Data Exchange (ETDEWEB)

Huang, Eric L.; Aylward, Frank O.; Kim, Young-Mo; Webb-Robertson, Bobbie-Jo M.; Nicora, Carrie D.; Hu, Zeping; Metz, Thomas O.; Lipton, Mary S.; Smith, Richard D.; Currie, Cameron R.; Burnum-Johnson, Kristin E.

2014-08-01

Leaf-cutter ants are dominant herbivores in ecosystems throughout the Neotropics. Rather than directly consuming the fresh foliar biomass they harvest, these ants use it to cultivate specialized fungus gardens. Although recent investigations have shed light on how plant biomass is degraded in fungus gardens, the cycling of nutrients that takes place in these specialized microbial ecosystems is still not well understood. Here, using metametabolomics and metaproteomics techniques, we examine the dynamics of nutrient turnover and biosynthesis in these gardens. Our results reveal that numerous free amino acids and sugars are depleted throughout the process of biomass degradation, indicating that easily accessible nutrients from plant material are readily consumed by microbes in these ecosystems. Accumulation of cellobiose and lignin derivatives near the end of the degradation process is consistent with previous findings of cellulases and laccases produced by Leucoagaricus gongylophorus, the fungus cultivated by leaf-cutter ants. Our results also suggest that ureides may be an important source of nitrogen in fungus gardens, especially during nitrogen-limiting conditions. No free arginine was detected in our metametabolomics experiments despite evidence that the host ants cannot produce this amino acid, suggesting that biosynthesis of this metabolite may be tightly regulated in the fungus garden. These results provide new insights into the dynamics of nutrient cycling that underlie this important ant-fungus symbiosis.

Biodegradation of hazardous waste using white rot fungus: Project planning and concept development document

International Nuclear Information System (INIS)

Luey, J.; Brouns, T.M.; Elliott, M.L.

1990-11-01

The white rot fungus Phanerochaete chrysosporium has been shown to effectively degrade pollutants such as trichlorophenol, polychlorinated biphenyls (PCBs), dioxins and other halogenated aromatic compounds. These refractory organic compounds and many others have been identified in the tank waste, groundwater and soil of various US Department of Energy (DOE) sites. The treatment of these refractory organic compounds has been identified as a high priority for DOE's Research, Development, Demonstration, Testing, and Evaluation (RDDT ampersand E) waste treatment programs. Unlike many bacteria, the white rot fungus P. chrysosporium is capable of degrading these types of refractory organics and may be valuable for the treatment of wastes containing multiple pollutants. The objectives of this project are to identify DOE waste problems amenable to white rot fungus treatment and to develop and demonstrate white rot fungus treatment process for these hazardous organic compounds. 32 refs., 6 figs., 7 tabs

Multiple origins of hydrogenosomes: functional and phylogenetic evidence from the ADP/ATP carrier of the anaerobic chytrid Neocallimastix sp.

NARCIS (Netherlands)

Voncken, F.L.M.; Boxma, B.; Tjaden, J.; Akhmanova, A.S.; Huynen, M.A.; Verbeek, F.; Tielens, A.G.; Haferkamp, I.; Neuhaus, H.E.; Vogels, G.D.; Veenhuis, M.; Hackstein, J.H.P.

2002-01-01

A mitochondrial-type ADP/ATP carrier (AAC) has been identified in the hydrogenosomes of the anaerobic chytridiomycete fungus Neocallimastix sp. L2. Biochemical and immunocytochemical studies revealed that this ADP/ATP carrier is an integral component of hydrogenosomal membranes. Expression of the

Multiple origins of hydrogenosomes : functional and phylogenetic evidence from the ADP/ATP carrier of the anaerobic chytrid Neocallimastix sp.

NARCIS (Netherlands)

Voncken, F; Boxma, B; Tjaden, J; Akhmanova, A; Huynen, M; Tielens, AGM; Haferkamp, [No Value; Neuhaus, HE; Vogels, G; Veenhuis, M; Hackstein, JHP; Tielens, Aloysius G.M.; Haferkamp, Ilka; Hackstein, Johannes H.P.

A mitochondrial-type ADP/ATP carrier (AAC) has been identified in the hydrogenosomes of the anaerobic chytridiomycete fungus Neocallimastix sp. L2. Biochemical and immunocytochemical studies revealed that this ADP/ATP carrier is an integral component of hydrogenosomal membranes. Expression of the

32 CFR 632.4 - Deadly force.

Science.gov (United States)

2010-07-01

..., is substantially important to national security. (See paragraph (b) of this section.) (iii) Escape of... security or an essential national defense mission. (2) Substantially important to national security based... INVESTIGATIONS USE OF FORCE BY PERSONNEL ENGAGED IN LAW ENFORCEMENT AND SECURITY DUTIES § 632.4 Deadly force. (a...

The ability of fungus Mucor racemosus Fresenius to degrade high concentration of detergent

Directory of Open Access Journals (Sweden)

Jakovljević Violeta D.

2014-01-01

Full Text Available The ability of fungus Mucor racemosus Fresenius to decompose high concentration of commercial detergent (MERIX, Henkel, Serbia was investigated in this study. Fungus was cultivated in liquid growth medium by Czapek with addition of detergent at concentration 0.5% during 16 days. The biochemical changes of pH, redox potential, amount of free and total organic acids, and activity of alkaline phosphatase were evaluated by analysis of fermentation broth. Simultaneously, biodegradation percentage of anionic surfactant of tested detergent was confirmed by MBAS assay. At the same time, the influence of detergent on fungal growth and total dry weight biomass was determined. Detergent at concentration 0.5% influenced on decreasing of pH value and increasing of redox potential as well as increasing of free and total organic acids. Enzyme activity of alkaline phosphatase was reduced by detergent at concentration 0.5%. The fungus was decomposed about 62% of anionic surfactant during 16 day. Due to fungus was produced higher dry weight biomass (53% in relation to control. [Projekat Ministarstva nauke Republike Srbije, br. III 43004

The Kinome of Edible and Medicinal Fungus Wolfiporia cocos

Directory of Open Access Journals (Sweden)

Wei Wei

2016-09-01

Full Text Available Wolfiporia cocos is an edible and medicinal fungus that grows in association with pine trees, and its dried sclerotium, known as Fuling in China, has been used as a traditional medicine in East Asian countries for centuries. Nearly 10% of the traditional Chinese medicinal preparations contain W. cocos. Currently, the commercial production of Fuling is limited because of the lack of pine-based substrate and paucity of knowledge about the sclerotial development of the fungus. Since protein kinase (PKs play significant roles in the regulation of growth, development, reproduction and environmental responses in filamentous fungi, the kinome of W. cocos was analyzed by identifying the PKs genes, studying transcript profiles and assigning PKs to orthologous groups. Of the 10 putative PKs, 11 encode atypical PKs, and 13, 10, 2, 22, and 11 could encoded PKs from the AGC, CAMK, CK, CMGC, STE and TLK Groups, respectively. The level of transcripts from PK genes associated with sclerotia formation in the mycelium and sclerotium stages were analyzed by qRT-PCR. Based on the functions of the orthologues in Sclerotinia sclerotiorum (a sclerotia-formation fungus and Saccharomyces cerevisiae, the potential roles of these W. cocos PKs were assigned. To the best of our knowledge, our study is the first identification and functional discussion of the kinome in the edible and medicinal fungus W. cocos. Our study systematically suggests potential roles of W. cocos PKs and provide comprehensive and novel insights into W. cocos sclerotial development and other economically important traits. Additionally, based on our result, genetic engineering can be employed for over expression or interference of some significant PKs genes to promote sclerotial growth and the accumulation of active compounds.

Instrumental dead-time and its relationship with matrix corrections in X-ray fluorescence analysis

International Nuclear Information System (INIS)

Thomas, I.L.; Haukka, M.T.; Anderson, D.H.

1979-01-01

The relationship between instrumental dead-time and the self-absorption coefficients, αsub(ii) in x.r.f. matrix correction by means of influence coefficients, is not generally recognized but has important analytical consequences. Systematic errors of the order of 1% (relative) for any analyte result from experimental uncertainties in instrumental dead-time. Such errors are applied unevenly across a given range of concentration because the error depends on the calibration standards and on the instrumental conditions used. Refinement of the instrumental dead-time value and other calibration parameters to conform with influence coefficients determined elsewhere assumes exact knowledge of dead-time of the instrument used originally, and quite similar excitation conditions and spectrometer geometry for the two instruments. Though these qualifications may not be met, adjustment of any of the parameters (dead-time, reference concentration, background concentration, self-absorption and other influence coefficients) can be easily achieved. (Auth.)

A new taxol-producing fungus ( Pestalotiopsis malicola ) and ...

African Journals Online (AJOL)

A new taxol-producing fungus ( Pestalotiopsis malicola ) and evidence for taxol as a transient product in the culture. ... African Journal of Biotechnology. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives.

Serpula lacrymans, the dry rot fungus and tolerance towards copper-based wood preservatives

Science.gov (United States)

Anne Christine Steenkjaer Hastrup; Frederick Green; Carol Clausen; Bo Jensen

2005-01-01

Serpula lacrymans (Wulfen : Fries) Schröter, the dry rot fungus, is considered the most economically important wood decay fungus in temperate regions of the world i.e. northern Europe, Japan and Australia. Previously copper based wood preservatives were the most commonly used preservatives for pressure treatment of wood for building constructions. Because of a...

SnoRNAs from the filamentous fungus Neurospora crassa: structural, functional and evolutionary insights

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Chen Chun-Long

2009-11-01

Full Text Available Abstract Background SnoRNAs represent an excellent model for studying the structural and functional evolution of small non-coding RNAs involved in the post-transcriptional modification machinery for rRNAs and snRNAs in eukaryotic cells. Identification of snoRNAs from Neurospora crassa, an important model organism playing key roles in the development of modern genetics, biochemistry and molecular biology will provide insights into the evolution of snoRNA genes in the fungus kingdom. Results Fifty five box C/D snoRNAs were identified and predicted to guide 71 2'-O-methylated sites including four sites on snRNAs and three sites on tRNAs. Additionally, twenty box H/ACA snoRNAs, which potentially guide 17 pseudouridylations on rRNAs, were also identified. Although not exhaustive, the study provides the first comprehensive list of two major families of snoRNAs from the filamentous fungus N. crassa. The independently transcribed strategy dominates in the expression of box H/ACA snoRNA genes, whereas most of the box C/D snoRNA genes are intron-encoded. This shows that different genomic organizations and expression modes have been adopted by the two major classes of snoRNA genes in N. crassa . Remarkably, five gene clusters represent an outstanding organization of box C/D snoRNA genes, which are well conserved among yeasts and multicellular fungi, implying their functional importance for the fungus cells. Interestingly, alternative splicing events were found in the expression of two polycistronic snoRNA gene hosts that resemble the UHG-like genes in mammals. Phylogenetic analysis further revealed that the extensive separation and recombination of two functional elements of snoRNA genes has occurred during fungus evolution. Conclusion This is the first genome-wide analysis of the filamentous fungus N. crassa snoRNAs that aids in understanding the differences between unicellular fungi and multicellular fungi. As compared with two yeasts, a more complex

Inosine Released from Dying or Dead Cells Stimulates Cell Proliferation via Adenosine Receptors

Directory of Open Access Journals (Sweden)

Yi Zhao

2017-04-01

Full Text Available IntroductionMany antitumor therapies induce apoptotic cell death in order to cause tumor regression. Paradoxically, apoptotic cells are also known to promote wound healing, cell proliferation, and tumor cell repopulation in multicellular organisms. We aimed to characterize the nature of the regenerative signals concentrated in the micromilieu of dead and dying cells.MethodsCultures of viable melanoma B16F10 cells, mouse fibroblasts, and primary human fibroblast-like synoviocytes (FLS in the presence of dead and dying cells, their supernatants (SNs, or purified agonists and antagonists were used to evaluate the stimulation of proliferation. Viable cell quantification was performed by either flow cytometry of harvested cells or by crystal violet staining of adherent cells. High-performance liquid chromatography and liquid chromatography coupled with mass spectrometry of cell SNs were deployed to identify the nature of growth-promoting factors. Coimplantation of living cells in the presence of SNs collected from dead and dying cells and specific agonists was used to evaluate tumor growth in vivo.ResultsThe stimulation of proliferation of few surviving cells by bystander dead cells was confirmed for melanoma cells, mouse fibroblasts, and primary FLS. We found that small soluble molecules present in the protein-free fraction of SNs of dead and dying cells were responsible for the promotion of proliferation. The nucleoside inosine released by dead and dying cells acting via adenosine receptors was identified as putative inducer of proliferation of surviving tumor cells after irradiation and heat treatment.ConclusionInosine released by dead and dying cells mediates tumor cell proliferation via purinergic receptors. Therapeutic strategies surmounting this pathway may help to reduce the rate of recurrence after radio- and chemotherapy.

Microbial and chemical characterization of underwater fresh water springs in the Dead Sea.

Directory of Open Access Journals (Sweden)

Danny Ionescu

Full Text Available Due to its extreme salinity and high Mg concentration the Dead Sea is characterized by a very low density of cells most of which are Archaea. We discovered several underwater fresh to brackish water springs in the Dead Sea harboring dense microbial communities. We provide the first characterization of these communities, discuss their possible origin, hydrochemical environment, energetic resources and the putative biogeochemical pathways they are mediating. Pyrosequencing of the 16S rRNA gene and community fingerprinting methods showed that the spring community originates from the Dead Sea sediments and not from the aquifer. Furthermore, it suggested that there is a dense Archaeal community in the shoreline pore water of the lake. Sequences of bacterial sulfate reducers, nitrifiers iron oxidizers and iron reducers were identified as well. Analysis of white and green biofilms suggested that sulfide oxidation through chemolitotrophy and phototrophy is highly significant. Hyperspectral analysis showed a tight association between abundant green sulfur bacteria and cyanobacteria in the green biofilms. Together, our findings show that the Dead Sea floor harbors diverse microbial communities, part of which is not known from other hypersaline environments. Analysis of the water's chemistry shows evidence of microbial activity along the path and suggests that the springs supply nitrogen, phosphorus and organic matter to the microbial communities in the Dead Sea. The underwater springs are a newly recognized water source for the Dead Sea. Their input of microorganisms and nutrients needs to be considered in the assessment of possible impact of dilution events of the lake surface waters, such as those that will occur in the future due to the intended establishment of the Red Sea-Dead Sea water conduit.

Evolutionary transitions in enzyme activity of ant fungus gardens.

Science.gov (United States)

De Fine Licht, Henrik H; Schiøtt, Morten; Mueller, Ulrich G; Boomsma, Jacobus J

2010-07-01

Fungus-growing (attine) ants and their fungal symbionts passed through several evolutionary transitions during their 50 million year old evolutionary history. The basal attine lineages often shifted between two main cultivar clades, whereas the derived higher-attine lineages maintained an association with a monophyletic clade of specialized symbionts. In conjunction with the transition to specialized symbionts, the ants advanced in colony size and social complexity. Here we provide a comparative study of the functional specialization in extracellular enzyme activities in fungus gardens across the attine phylogeny. We show that, relative to sister clades, gardens of higher-attine ants have enhanced activity of protein-digesting enzymes, whereas gardens of leaf-cutting ants also have increased activity of starch-digesting enzymes. However, the enzyme activities of lower-attine fungus gardens are targeted primarily toward partial degradation of plant cell walls, reflecting a plesiomorphic state of nondomesticated fungi. The enzyme profiles of the higher-attine and leaf-cutting gardens appear particularly suited to digest fresh plant materials and to access nutrients from live cells without major breakdown of cell walls. The adaptive significance of the lower-attine symbiont shifts remains unclear. One of these shifts was obligate, but digestive advantages remained ambiguous, whereas the other remained facultative despite providing greater digestive efficiency.

Pigment Production by the Edible Filamentous Fungus Neurospora Intermedia

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Rebecca Gmoser

2018-02-01

Full Text Available The production of pigments by edible filamentous fungi is gaining attention as a result of the increased interest in natural sources with added functionality in the food, feed, cosmetic, pharmaceutical and textile industries. The filamentous fungus Neurospora intermedia, used for production of the Indonesian food “oncom”, is one potential source of pigments. The objective of the study was to evaluate the fungus’ pigment production. The joint effect from different factors (carbon and nitrogen source, ZnCl2, MgCl2 and MnCl2 on pigment production by N. intermedia is reported for the first time. The scale-up to 4.5 L bubble column bioreactors was also performed to investigate the effect of pH and aeration. Pigment production of the fungus was successfully manipulated by varying several factors. The results showed that the formation of pigments was strongly influenced by light, carbon, pH, the co-factor Zn2+ and first- to fourth-order interactions between factors. The highest pigmentation (1.19 ± 0.08 mg carotenoids/g dry weight biomass was achieved in a bubble column reactor. This study provides important insights into pigmentation of this biotechnologically important fungus and lays a foundation for future utilizations of N. intermedia for pigment production.

Effects of Small-Scale Dead Wood Additions on Beetles in Southeastern U.S. Pine Forests

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Chris E. Carlton

2012-08-01

Full Text Available Pitfall traps were used to sample beetles (Coleoptera in plots with or without inputs of dead loblolly pine (Pinus taeda L. wood at four locations (Louisiana, Mississippi, North Carolina and Texas on the coastal plain of the southeastern United States. The plots were established in 1998 and sampling took place in 1998, 1999, and 2002 (only 1998 for North Carolina. Overall, beetles were more species rich, abundant and diverse in dead wood addition plots than in reference plots. While these differences were greatest in 1998 and lessened thereafter, they were not found to be significant in 1998 due largely to interactions between location and treatment. Specifically, the results from North Carolina were inconsistent with those from the other three locations. When these data were excluded from the analyses, the differences in overall beetle richness for 1998 became statistically significant. Beetle diversity was significantly higher in the dead wood plots in 1999 but by 2002 there were no differences between dead wood added and control plots. The positive influence of dead wood additions on the beetle community can be largely attributed to the saproxylic fauna (species dependent on dead wood, which, when analyzed separately, were significantly more species rich and diverse in dead wood plots in 1998 and 1999. Ground beetles (Carabidae and other species, by contrast, were not significantly affected. These results suggest manipulations of dead wood in pine forests have variable effects on beetles according to life history characteristics.

Awakening the "Walking Dead": Zombie Pedagogy for Millennials

Directory of Open Access Journals (Sweden)

Nancy Dawn Wadsworth

2017-02-01

Full Text Available This article lays out the pedagogical benefits of using popular zombie productions, particularly AMC's The Walking Dead, to teach a critical introduction to modern political theory. Based on my undergraduate course: "Political Theory, Climate Change, and the Zombie Apocalypse," the article outlines how The Walking Dead can be used to critique the mythic assumptions built into modern social contract theory; to introduce other political ideologies, including conservatism, anarchism, fascism, and communism; and to consider the political challenges raised by a global problem such as climate change in an increasingly neoliberal environment. Zombie productions are offered as a particularly salient pedagogical tool that can help awaken critical political analysis for the Millennial Generation.

Pan-European distribution of white-nose syndrome fungus (Geomyces destructans not associated with mass mortality.

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Sébastien J Puechmaille

Full Text Available BACKGROUND: The dramatic mass mortalities amongst hibernating bats in Northeastern America caused by "white nose-syndrome" (WNS continue to threaten populations of different bat species. The cold-loving fungus, Geomyces destructans, is the most likely causative agent leading to extensive destruction of the skin, particularly the wing membranes. Recent investigations in Europe confirmed the presence of the fungus G. destructans without associated mass mortality in hibernating bats in six countries but its distribution remains poorly known. METHODOLOGY/PRINCIPAL FINDINGS: We collected data on the presence of bats with white fungal growth in 12 countries in Europe between 2003 and 2010 and conducted morphological and genetic analysis to confirm the identity of the fungus as Geomyces destructans. Our results demonstrate the presence of the fungus in eight countries spanning over 2000 km from West to East and provide compelling photographic evidence for its presence in another four countries including Romania, and Turkey. Furthermore, matching prevalence data of a hibernaculum monitored over two consecutive years with data from across Europe show that the temporal occurrence of the fungus, which first becomes visible around February, peaks in March but can still be seen in some torpid bats in May or June, is strikingly similar throughout Europe. Finally, we isolated and cultured G. destructans from a cave wall adjacent to a bat with fungal growth. CONCLUSIONS/SIGNIFICANCE: G. destructans is widely found over large areas of the European continent without associated mass mortalities in bats, suggesting that the fungus is native to Europe. The characterisation of the temporal variation in G. destructans growth on bats provides reference data for studying the spatio-temporal dynamic of the fungus. Finally, the presence of G. destructans spores on cave walls suggests that hibernacula could act as passive vectors and/or reservoirs for G. destructans and

Safety evaluation of traces of nickel and chrome in cosmetics: The case of Dead Sea mud.

Science.gov (United States)

Ma'or, Ze'evi; Halicz, Ludwik; Portugal-Cohen, Meital; Russo, Matteo Zanotti; Robino, Federica; Vanhaecke, Tamara; Rogiers, Vera

2015-12-01

Metal impurities such as nickel and chrome are present in natural ingredients-containing cosmetic products. These traces are unavoidable due to the ubiquitous nature of these elements. Dead Sea mud is a popular natural ingredient of cosmetic products in which nickel and chrome residues are likely to occur. To analyze the potential systemic and local toxicity of Dead Sea mud taking into consideration Dead Sea muds' natural content of nickel and chrome. The following endpoints were evaluated: (Regulation No. 1223/20, 21/12/2009) systemic and (SCCS's Notes of Guidance) local toxicity of topical application of Dead Sea mud; health reports during the last five years of commercial marketing of Dead Sea mud. Following exposure to Dead Sea mud, MoS (margin of safety) calculations for nickel and chrome indicate no toxicological concern for systemic toxicity. Skin sensitization is also not to be expected by exposure of normal healthy skin to Dead Sea mud. Topical application, however, is not recommended for already nickel-or chrome-sensitized persons. As risk assessment of impurities present in cosmetics may be a difficult exercise, the case of Dead Sea mud is taken here as an example of a natural material that may contain traces of unavoidable metals. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Temperature dependence of magnetically dead layers in ferromagnetic thin-films

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M. Tokaç

2017-11-01

Full Text Available Polarized neutron reflectometry has been used to study interface magnetism and magnetic dead layers in model amorphous CoFeB:Ta alloy thin-film multilayers with Curie temperatures tuned to be below room-temperature. This allows temperature dependent variations in the effective magnetic thickness of the film to be determined at temperatures that are a significant fraction of the Curie temperature, which cannot be achieved in the material systems used for spintronic devices. In addition to variation in the effective magnetic thickness due to compositional grading at the interface with the tantalum capping layer, the key finding is that at the interface between ferromagnetic film and GaAs(001 substrate local interfacial alloying creates an additional magnetic dead-layer. The thickness of this magnetic dead-layer is temperature dependent, which may have significant implications for elevated-temperature operation of hybrid ferromagnetic metal-semiconductor spintronic devices.

Efficacy of in-house fluorescent stain for fungus

Directory of Open Access Journals (Sweden)

K. R. L. Surya Kirani

2017-01-01

Full Text Available Context: Mycotic infections are gaining importance in the present day medicine, and definite demonstration of fungus is essential for diagnosis. Small numbers of organisms in the smear can be identified by fluorescence microscopy. Calcofluor white (CFW fluorescent stain is a textile brightener mixed with Evans blue. It is expensive and not easily available. Aims: (1 To assess the efficacy of in-house CFW fluorescent stain for fungus in relation to conventional CFW stain, histopathology, and culture. (2 To determine sensitivity, specificity, negative predictive value (NPV, and positive predictive value (PPV with culture as gold standard. Settings and Design: One hundred cases of suspected dermatophytosis and 15 cases of systemic mycosis were included in the study. Subjects and Methods: The local whitener Ranipal is added with Robin blue, another brightener, and was used to stain teased fungal cultures. Skin, hair, and nails require pretreatment with potassium hydroxide (KOH. Biopsy slides require deparaffinization and pretreatment with KOH before staining. Conventional calcofluor stain, histopathology, and culture were done. Statistical Analysis Used: Statistical analysis was performed using sensitivity, specificity, NPV, and PPV. Results: The results are consistently comparable with conventional stain. The sensitivity was 100%, specificity was 93.3%, NPV was 100%, and PPV was 85.7%. It is also cost effective when compared to commercial stains. Conclusions: In-house stain can be used for screening of fungus in direct samples, biopsies as alternative in resource-constrained laboratories.

Caste-specific symbiont policing by workers of Acromyrmex fungus-growing ants

DEFF Research Database (Denmark)

Ivens, Aniek B.F.; Nash, David R.; Poulsen, Michael

2009-01-01

The interaction between leaf-cutting ants and their fungus garden mutualists is ideal for studying the evolutionary stability of interspecific cooperation. Although the mutualism has a long history of diffuse coevolution, there is ample potential for conflicts between the partners over the mixing...... and transmission of symbionts. Symbiont transmission is vertical by default, and both the ants and resident fungus actively protect the fungal monoculture growing in their nest against secondary introductions of genetically dissimilar symbionts from other colonies. An earlier study showed that mixtures of major...

Chemically armed mercenary ants protect fungus-farming societies

DEFF Research Database (Denmark)

Adams, Rachelle Martha Marie; Liberti, Joanito; Illum, Anders A.

2013-01-01

guest ants are sufficient to kill raiders that invariably exterminate host nests without a cohabiting guest ant colony. We also show that the odor of guest ants discourages raider scouts from recruiting nestmates to host colonies. Our results imply that Sericomyrmex fungus-growers obtain a net benefit......The ants are extraordinary in having evolved many lineages that exploit closely related ant societies as social parasites, but social parasitism by distantly related ants is rare. Here we document the interaction dynamics among a Sericomyrmex fungus-growing ant host, a permanently associated...... parasitic guest ant of the genus Megalomyrmex, and a raiding agro-predator of the genus Gnamptogenys. We show experimentally that the guest ants protect their host colonies against agro-predator raids using alkaloid venom that is much more potent than the biting defenses of the host ants. Relatively few...

Nothing special in the specialist? Draft genome sequence of Cryomyces antarcticus, the most extremophilic fungus from Antarctica.

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Katja Sterflinger

Full Text Available The draft genome of the Antarctic endemic fungus Cryomyces antarcticus is presented. This rock inhabiting, microcolonial fungus is extremely stress tolerant and it is a model organism for exobiology and studies on stress resistance in Eukaryots. Since this fungus is a specialist in the most extreme environment of the Earth, the analysis of its genome is of important value for the understanding of fungal genome evolution and stress adaptation. A comparison with Neurospora crassa as well as with other microcolonial fungi shows that the fungus has a genome size of 24 Mbp, which is the average in the fungal kingdom. Although sexual reproduction was never observed in this fungus, 34 mating genes are present with protein homologs in the classes Eurotiomycetes, Sordariomycetes and Dothideomycetes. The first analysis of the draft genome did not reveal any significant deviations of this genome from comparative species and mesophilic hyphomycetes.

Smith predictor-based multiple periodic disturbance compensation for long dead-time processes

Science.gov (United States)

Tan, Fang; Li, Han-Xiong; Shen, Ping

2018-05-01

Many disturbance rejection methods have been proposed for processes with dead-time, while these existing methods may not work well under multiple periodic disturbances. In this paper, a multiple periodic disturbance rejection is proposed under the Smith predictor configuration for processes with long dead-time. One feedback loop is added to compensate periodic disturbance while retaining the advantage of the Smith predictor. With information of the disturbance spectrum, the added feedback loop can remove multiple periodic disturbances effectively. The robust stability can be easily maintained through the rigorous analysis. Finally, simulation examples demonstrate the effectiveness and robustness of the proposed method for processes with long dead-time.

Energy Balance, Evapo-transpiration and Dew deposition in the Dead Sea Valley

Science.gov (United States)

Metzger, Jutta; Corsmeier, Ulrich

2016-04-01

The Dead Sea is a unique place on earth. It is a terminal hypersaline lake, located at the lowest point on earth with a lake level of currently -429 m above mean sea level (amsl). It is located in a transition zone of semiarid to arid climate conditions, which makes it highly sensible to climate change (Alpert1997, Smiatek2011). The Virtual Institute DEad SEa Research Venue (DESERVE) is an international project funded by the German Helmholtz Association and was established to study coupled atmospheric hydrological, and lithospheric processes in the changing environment of the Dead Sea. At the moment the most prominent environmental change is the lake level decline of approximately 1 m / year due to anthropogenic interferences (Gertman, 2002). This leads to noticeable changes in the fractions of the existing terrestrial surfaces - water, bare soil and vegetated areas - in the valley. Thus, the partitioning of the net radiation in the valley changes as well. To thoroughly study the atmospheric and hydrological processes in the Dead Sea valley, which are driven by the energy balance components, sound data of the energy fluxes of the different surfaces are necessary. Before DESERVE no long-term monitoring network simultaneously measuring the energy balance components of the different surfaces in the Dead Sea valley was available. Therefore, three energy balance stations were installed at three characteristic sites at the coast-line, over bare soil, and within vegetation, measuring all energy balance components by using the eddy covariance method. The results show, that the partitioning of the energy into sensible and latent heat flux on a diurnal scale is totally different at the three sites. This results in gradients between the sites, which are e.g. responsible for the typical diurnal wind systems at the Dead Sea. Furthermore, driving forces of evapo-transpiration at the sites were identified and a detailed analysis of the daily evaporation and dew deposition rates

Entomopathogenicity and Biological Attributes of Himalayan Treasured Fungus Ophiocordyceps sinensis (Yarsagumba)

Science.gov (United States)

Baral, Bikash

2017-01-01

Members of the entomophagous fungi are considered very crucial in the fungal domain relative to their natural phenomenon and economic perspectives; however, inadequate knowledge of their mechanisms of interaction keeps them lagging behind in parallel studies of fungi associated with agro-ecology, forest pathology and medical biology. Ophiocordyceps sinensis (syn. Cordyceps sinensis), an intricate fungus-caterpillar complex after it parasitizes the larva of the moth, is a highly prized medicinal fungus known widely for ages due to its peculiar biochemical assets. Recent technological innovations have significantly contributed a great deal to profiling the variable clinical importance of this fungus and other related fungi with similar medicinal potential. However, a detailed mechanism behind fungal pathogenicity and fungal-insect interactions seems rather ambiguous and is poorly justified, demanding special attention. The goal of the present review is to divulge an update on the published data and provides promising insights on different biological events that have remained underemphasized in previous reviews on fungal biology with relation to life-history trade-offs, host specialization and selection pressures. The infection of larvae by a fungus is not a unique event in Cordyceps; hence, other fungal species are also reviewed for effective comparison. Conceivably, the rationale and approaches behind the inheritance of pharmacological abilities acquired and stored within the insect framework at a time when they are completely hijacked and consumed by fungal parasites, and the molecular mechanisms involved therein, are clearly documented. PMID:29371523

Relationship between γ detection dead-time and count correction factor

International Nuclear Information System (INIS)

Wu Huailong; Zhang Jianhua; Chu Chengsheng; Hu Guangchun; Zhang Changfan; Hu Gen; Gong Jian; Tian Dongfeng

2015-01-01

The relationship between dead-time and count correction factor was investigated by using interference source for purpose of high γ activity measurement. The count rates maintain several 10 s"-"l with γ energy of 0.3-1.3 MeV for 10"4-10"5 Bq radioactive source. It is proved that the relationship between count loss and dead-time is unconcerned at various energy and various count intensities. The same correction formula can be used for any nuclide measurement. (authors)

Rethinking crop-disease management in fungus-growing ants

NARCIS (Netherlands)

Boomsma, J.J.; Aanen, D.K.

2009-01-01

Ant fungus farming has become a prominent model for studying the evolution of mutualistic cooperation, with recent advances in reconstructing the evolutionary origin and elaborations of the symbiosis (1, 2), discovering additional partners and clarifying their interactions (3, 4), and analyzing

Consistent association of fungus Fusarium mangiferae Britz with ...

African Journals Online (AJOL)

Administrator

2011-06-15

Jun 15, 2011 ... F. mangiferae proved to be the dominant fungus hosting majority of the malformed tissues. Among the indigenous ... tion amongst fruit crops due to its specific nature, growth pattern and ... It is affected by various animate and ...

Symbiotic Fungus of Marine Sponge Axinella sp. Producing Antibacterial Agent

Science.gov (United States)

Trianto, A.; Widyaningsih, S.; Radjasa, OK; Pribadi, R.

2017-02-01

The emerging of multidrug resistance pathogenic bacteria cause the treatment of the diseaseshave become ineffective. There for, invention of a new drug with novel mode of action is an essential for curing the disease caused by an MDR pathogen. Marine fungi is prolific source of bioactive compound that has not been well explored. This study aim to obtain the marine sponges-associated fungus that producing anti-MDR bacteria substaces. We collected the sponge from Riung water, NTT, Indonesia. The fungus was isolated with affixed method, followed with purification with streak method. The overlay and disk diffusion agar methods were applied for bioactivity test for the isolate and the extract, respectively. Molecular analysis was employed for identification of the isolate. The sponge was identified based on morphological and spicular analysis. The ovelay test showed that the isolate KN15-3 active against the MDR Staphylococcus aureus and Eschericia coli. The extract of the cultured KN15-3 was also inhibited the S. aureus and E. coli with inhibition zone 2.95 mm and 4.13 mm, respectively. Based on the molecular analysis, the fungus was identified as Aspergillus sydowii. While the sponge was identified as Axinella sp.

Conditions for selective degradation of lignin by the fungus Ganoderma australis

Energy Technology Data Exchange (ETDEWEB)

Rios, S.; Eyzaguirre, J. (Universidad Catolica de Chile, Santiago (Chile). Lab. de Bioquimica)

1992-08-01

The white-rot fungus Ganoderma australis selectively degrades lignin in the ecosystem 'palo podrido'. Using conditions that simulate those of 'palo podrido' in the laboratory, it was found that low nitrogen content and low O{sub 2} tension stimulate the production of manganese peroxidase and lignin degradation, and depress cellulose degradation and cellulase production. The inverse is found at high nitrogen concentration and high O{sub 2} tension. This agrees with previous results indicating that low O{sub 2} tension and low nitrogen stimulate selective lignin degradation by this fungus. (orig.).

Lignocellulose pretreatment in a fungus-cultivating termite

Science.gov (United States)

Hongjie Li; Daniel J. Yelle; Chang Li; Mengyi Yang; Jing Ke; Ruijuan Zhang; Yu Liu; Na Zhu; Shiyou Liang; Xiaochang Mo; John Ralph; Cameron R. Currie; Jianchu Mo

2017-01-01

Depolymerizing lignin, the complex phenolic polymer fortifying plant cell walls, is an essential but challenging starting point for the lignocellulosics industries. The variety of ether– and carbon–carbon interunit linkages produced via radical coupling during lignification limit chemical and biological depolymerization efficiency. In an ancient fungus-cultivating...

Dynamic optimization of dead-end membrane filtration

NARCIS (Netherlands)

Blankert, B.; Betlem, Bernardus H.L.; Roffel, B.; Marquardt, Wolfgang; Pantelides, Costas

2006-01-01

An operating strategy aimed at minimizing the energy consumption during the filtration phase of dead-end membrane filtration has been formulated. A method allowing fast calculation of trajectories is used to allow incorporation in a hierarchical optimization scheme. The optimal trajectory can be

Dinosaurs of India: Dead but Alive

Indian Academy of Sciences (India)

Table of contents. Dinosaurs of India: Dead but Alive · Fossils · Evolution and O2 PAL · The Science in Dinosaurs · Origin/ Extinction of Dinosaurs · PowerPoint Presentation · India –94my + 50my · Icehouse /Greenhouse through time · Global Mean Annual Temperature Distributions at 100 my · Global Mean Annual ...

Giant, Voltage-Actuated Deformation of a Dielectric Elastomer under Dead Load

OpenAIRE

Huang, Jiangshui; Li, Tiefeng; Foo, Choon Chiang; Clarke, David R.; Zhu, Jian; Suo, Zhigang

2012-01-01

Far greater voltage-actuated deformation is achievable for a dielectric elastomer under equal-biaxial dead load than under rigid constraint usually employed. Areal strains of 488% are demonstrated. The dead load suppresses electric breakdown, enabling the elastomer to survive the snap-through electromechanical instability. The breakdown voltage is found to increase with the voltage ramp rate. A nonlinear model for viscoelastic dielectric elastomers is developed and shown to be consistent with...

Effects of Calcium Superphosphate Additive on Nitrogen Conservation During Dead-pig Composting

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LEI Ping

2017-05-01

Full Text Available To study the effects of calcium superphosphate additive on nitrogen conservation, an experiment of 30 days dead-pig composting was carried out. Three mixtures were treated with different amount of calcium superphosphate additive of 0%(CK, 5%(T1 and 10%(T2. The results showed that each composte temperature higher than 50 ℃ remained above 10 days, meeting the requirements of hygiene index about the compost rotten. The pH of composting with calcium superphosphate was significantly decreased, while NH4+-N, NH3-N, total nitrogen contents were significant higher than the control. 5% and 10% calcium superphosphate addition increased the total nitrogen contents by 10.7%, 10.1%, respectively. The seed germination index(GI of 5% calcium superphosphate addition was up to 101.4% on the 14th day, which was significant higher than the contrast. It demonstrated that calcium superphosphate could accelerate maturity during dead-pig compositng. Thus, calcium superphosphate as an additive in dead-pig composting could decrease nitrogen losses, which would bring prospects of application in dead-pig composting.

Reaction of some soybean mutant lines to natural rust fungus caused by (phakopsora pachyrhizi syd)

International Nuclear Information System (INIS)

Ratma, R.

1988-01-01

Reaction of some soybean mutant lines to natural rust fungus caused by (phakopsora pachyhizi syd). Eleven soybean mutant lines of orba variety derived from gamma fungus disease in the wet season 1985/86 at the experimental station of Citayam, Bogor. Based on IWGSR rating system, soybean mutant lines No 18/PsJ was moderately resistant to rust fungus disease. The other mutant lines, 14/PsJ, 15/PsJ, 20/PsJ, 102/PsJ, 106/PsJ, 111/PsJ, 118/PsJ, 119/PsJ and 220/PsJ were susceptible. (author). 4 figs.; 8 refs

Occurrence patterns of dead wood and wood-dependent lichens in managed boreal forest landscapes

OpenAIRE

Svensson, Måns

2013-01-01

Dead wood is a key resource for biodiversity, on which thousands of forest organisms are dependent. Because of current forest management, there has been a large-scale change in dead wood amounts and qualities, and consequently, many wood-dependent species are threatened. The general aim of this thesis is to increase our understanding of habitat requirements and occurrence patterns of wood-dependent lichens in managed, boreal forest landscapes. We surveyed dead wood and wood-dependent lichens ...

The Active Structure of the Greater Dead Sea Basin

Science.gov (United States)

Shamir, G.

2002-12-01

The Greater Dead Sea Basin (GDSB) is a 220km long depression situated along the southern section of the Dead Sea Transform (DST), between two structurally and gravitationally elevated points, Wadi Malih in the north and Paran fault zone in the south. In its center is the Dead Sea basin 'sensu strictu' (DSB), which has been described since the 1970s as a pull-apart basin at a left step-over along the DST. However, several observations, or their lack thereof, contradict this scheme, e.g. (i) It is not supported by recent seismological and geomorphic data; (ii) It does not explain the fault pattern and mixed sinistral and dextral offset along the DSB western boundary; (iii) It does not simply explain the presence of intense deformation outside the presumed fault step zone; (iv) It is inconsistent with the orientation of seismically active faults within the Dead Sea and Jericho Valley; (v) The length of the DSB exceeds the total offset along the Dead Sea Transform, while its subsidence is about the age of the DST. In this study, newly acquired and analyzed data (high resolution seismic reflection and earthquake relocation and fault plane solutions) has been integrated with previously published data (structural mapping, fracture orientation distribution, Bouguer anomaly maps, sinkhole distribution, geomorphic lineaments). The results show that the GDSB is dominated by two active fault systems, one trending NNE and showing normal-dextral motion, the other trending NW. These systems are identified by earthquake activity, seismic reflection observations, alignment of recent sinkholes, and distribution of Bouguer anomaly gradients. As a result, the intra-basin structure is of a series of rectangular blocks. The dextral slip component along NNE trending faults, the mixed sense of lateral offset along the western boundary of the DSB and temporal change in fracture orientation in the Jericho Valley suggest that the intra-basin blocks have rotated counterclockwise since the

Graveyards on the Move: The Spatio-Temporal Distribution of Dead Ophiocordyceps-Infected Ants

DEFF Research Database (Denmark)

Pontoppidan, Maj-Britt; Himaman, Winanda; Hywel-Jones, Nigel L.

2009-01-01

rainforest. We established that high density aggregations exist (up to 26 dead ants/m2), which we coined graveyards. We further established that graveyards are patchily distributed in a landscape with no or very few O. unilateralis-killed ants. At some, but not all, spatial scales of analysis the density...... unilateralis, which is pan-tropical in distribution, causes infected worker ants to leave their nest and die under leaves in the understory of tropical rainforests. Working in a forest dynamic plot in Southern Thailand we mapped the occurrence of these dead ants by examining every leaf in 1,360 m2 of primary...... of dead ants correlated with temperature, humidity and vegetation cover. Remarkably, having found 2243 dead ants inside graveyards we only found 2 live ants of the principal host, ant Camponotus leonardi, suggesting that foraging host ants actively avoid graveyards. We discovered that the principal host...

Botrallin from the endophytic fungus Hyalodendriella sp ...

African Journals Online (AJOL)

use

2011-12-12

Dec 12, 2011 ... Bioassay-guided fractionation of the crude methanol extract of the mycelia from the endophytic fungus. Hyalodendriella sp. Ponipodef12, associated with the hybrid 'Neva' of Populus deltoides Marsh × P. nigra L., led to the isolation of one compound coded as P12-1 which was identified as botrallin (1,7-.

Medical image of the week: fungus ball

Directory of Open Access Journals (Sweden)

Rosen S

2015-04-01

Full Text Available No abstract available. Article truncated at 150 words. A 69 year-old Asian woman living in Arizona with a past medical history of nephrotic syndrome on high-dose steroids had worsening pulmonary symptoms. A computed tomography (CT of the chest (Figure 1 showed a 4.7 cm thin walled cavitary lesion in the right middle lobe compatible with mycetoma. She underwent thoracotomy for mycetoma resection. Surgical pathology confirmed an epithelial-lined cavity containing dense mycelia (Figure 2. Given the patient lived in an endemic area; the cavity was thought to be likely due to coccidioidomycosis. However, the mycetoma was of unclear etiology. No spherules were noted on GMS stain and tissue culture was negative. While of unclear clinical significance which fungus colonizes a pre-existing cavity, a Coccidioides PCR was performed and no Coccidioides genes were amplified making a Coccidioides mycetoma very unlikely. Pulmonary mycetoma or “fungus ball” consists of dense fungal elements and amorphous cellular material within a pre-existing pulmonary cavity. Classically ...

Antimicrobial chemical constituents from endophytic fungus Phomasp.

Institute of Scientific and Technical Information of China (English)

Hidayat Hussain; Siegfried Draeger; Barbara Schulz; Karsten Krohn; Ines Kock; Ahmed Al-Harrasi; Ahmed Al-Rawahi; Ghulam Abbas; Ivan R Green; Afzal Shah; Amin Badshah; Muhammad Saleem

2014-01-01

Objective:To evaluate the antimicrobial potential of different extracts of the endophytic fungus Phomasp. and the tentative identification of their active constituents.Methods:The extract and compounds were screened for antimicrobial activity using theAgarWellDiffusionMethod. Four compounds were purified using column chromatography and their structures were assigned using1H and13CNMR spectra,DEPT,2DCOSY,HMQC andHMBC experiments.Results:The ethyl acetate fraction ofPhomasp. showed good antifungal, antibacterial, and algicidal properties.One new dihydrofuran derivative, named phomafuranol(1), together with three known compounds, phomalacton(2),(3R)-5-hydroxymellein(3) and emodin(4) were isolated from the ethyl acetate fraction ofPhomasp.Preliminary studies indicated that phomalacton(2) displayed strong antibacterial, good antifungal and antialgal activities.Similarly(3R)-5-hydroxymellein (3) and emodin(4) showed good antifungal, antibacterial and algicidal properties.Conclusions:Antimicrobial activities of the ethyl acetate fraction of the endophytic fungusPhomasp. and isolated compounds clearly demonstrate thatPhomasp. and its active compounds represent a great potential for the food, cosmetic and pharmaceutical industries.

The Blast Fungus Decoded: Genomes in Flux

Directory of Open Access Journals (Sweden)

Thorsten Langner

2018-04-01

Full Text Available Plant disease outbreaks caused by fungi are a chronic threat to global food security. A prime case is blast disease, which is caused by the ascomycete fungus Magnaporthe oryzae (syn. Pyricularia oryzae, which is infamous as the most destructive disease of the staple crop rice. However, despite its Linnaean binomial name, M. oryzae is a multihost pathogen that infects more than 50 species of grasses. A timely study by P. Gladieux and colleagues (mBio 9:e01219-17, 2018, https://doi.org/10.1128/mBio.01219-17 reports the most extensive population genomic analysis of the blast fungus thus far. M. oryzae consists of an assemblage of differentiated lineages that tend to be associated with particular host genera. Nonetheless, there is clear evidence of gene flow between lineages consistent with maintaining M. oryzae as a single species. Here, we discuss these findings with an emphasis on the ecologic and genetic mechanisms underpinning gene flow. This work also bears practical implications for diagnostics, surveillance, and management of blast diseases.

Ribonucleic acids in different tea fungus beverages

Directory of Open Access Journals (Sweden)

Malbaša Radomir V.

2003-01-01

Full Text Available In human nutrition, nucleic acids have to be balanced and limited up to 2 g/day because purines are degraded to urate, and excessive production of urate is a cause of gout which primarily affects adult males. Tea fungus beverage is a well known drink with high nutritional value and certain curative effects. Its benefits have been proved in a number of studies but it is still necessary to examine some potential harmful effects of this beverage. The aim of this paper was to investigate content of ribonucleic acids (RNA produced during tea fungus fermentation on a usual substrate sweetened black tea, and on Jerusalem artichoke tubers (J.A.T extract using method by Munro and Fleck (1966. pH, ribonucleic acids and also the production of proteins that affect purity of nucleic acids preparations were monitored. A higher value of RNA has been noticed in J.A.T. beverage (0.57 mg/ml and with observation of usual daily dose of the beverage it is completely safe and useful one.

The Blast Fungus Decoded: Genomes in Flux.

Science.gov (United States)

Langner, Thorsten; Białas, Aleksandra; Kamoun, Sophien

2018-04-17

Plant disease outbreaks caused by fungi are a chronic threat to global food security. A prime case is blast disease, which is caused by the ascomycete fungus Magnaporthe oryzae (syn. Pyricularia oryzae ), which is infamous as the most destructive disease of the staple crop rice. However, despite its Linnaean binomial name, M. oryzae is a multihost pathogen that infects more than 50 species of grasses. A timely study by P. Gladieux and colleagues (mBio 9:e01219-17, 2018, https://doi.org/10.1128/mBio.01219-17) reports the most extensive population genomic analysis of the blast fungus thus far. M. oryzae consists of an assemblage of differentiated lineages that tend to be associated with particular host genera. Nonetheless, there is clear evidence of gene flow between lineages consistent with maintaining M. oryzae as a single species. Here, we discuss these findings with an emphasis on the ecologic and genetic mechanisms underpinning gene flow. This work also bears practical implications for diagnostics, surveillance, and management of blast diseases. Copyright © 2018 Langner et al.

Contact with the Dead, Religion, and Death Anxiety among Older Mexican Americans

Science.gov (United States)

Krause, Neal; Bastida, Elena

2012-01-01

The purpose of this study is to see if contact with the dead is associated with lower death anxiety among older Mexican Americans. The data come from a nationwide survey of older Mexican Americans (N = 1,005). The study model specifies that (a) older Mexican Americans who have experienced contact with the dead are more likely to see the…

Dead of night.

Science.gov (United States)

Balter, Leon

2010-07-01

Dead of Night, the first psychoanalytic horror film, was produced in England in 1945, immediately after the end of World War II--that is, after the English population had suffered systematic Nazi terror from imminent invasion, incessant aerial bombing, and rocket-bombs. This film continued the prewar format of horror films based on themes of the supernatural and the hubris and excesses of science. However, it introduced psychoanalysis as the science in question. The film is structured on two levels: a genteel English country weekend to which witty and urbane guests have been invited; and five horror stories told by the guests. Psychoanalytic insights into this film structure are used here to explain how the film induces horror in the audience.

Dead Reckoning in the Desert Ant: A Defence of Connectionist Models.

Science.gov (United States)

Mole, Christopher

2014-01-01

Dead reckoning is a feature of the navigation behaviour shown by several creatures, including the desert ant. Recent work by C. Randy Gallistel shows that some connectionist models of dead reckoning face important challenges. These challenges are thought to arise from essential features of the connectionist approach, and have therefore been taken to show that connectionist models are unable to explain even the most primitive of psychological phenomena. I show that Gallistel's challenges are successfully met by one recent connectionist model, proposed by Ulysses Bernardet, Sergi Bermúdez i Badia, and Paul F.M.J. Verschure. The success of this model suggests that there are ways to implement dead reckoning with neural circuits that fall within the bounds of what many people regard as neurobiologically plausible, and so that the wholesale dismissal of the connectionist modelling project remains premature.

New perspectives on interdisciplinary earth science at the Dead Sea: The DESERVE project

International Nuclear Information System (INIS)

Kottmeier, Christoph; Agnon, Amotz; Al-Halbouni, Djamil; Alpert, Pinhas; Corsmeier, Ulrich; Dahm, Torsten; Eshel, Adam; Geyer, Stefan; Haas, Michael; Holohan, Eoghan; Kalthoff, Norbert; Kishcha, Pavel; Krawczyk, Charlotte; Lati, Joseph; Laronne, Jonathan B.; Lott, Friederike; Mallast, Ulf; Merz, Ralf; Metzger, Jutta; Mohsen, Ayman

2016-01-01

The Dead Sea region has faced substantial environmental challenges in recent decades, including water resource scarcity, ~ 1 m annual decreases in the water level, sinkhole development, ascending-brine freshwater pollution, and seismic disturbance risks. Natural processes are significantly affected by human interference as well as by climate change and tectonic developments over the long term. To get a deep understanding of processes and their interactions, innovative scientific approaches that integrate disciplinary research and education are required. The research project DESERVE (Helmholtz Virtual Institute Dead Sea Research Venue) addresses these challenges in an interdisciplinary approach that includes geophysics, hydrology, and meteorology. The project is implemented by a consortium of scientific institutions in neighboring countries of the Dead Sea (Israel, Jordan, Palestine Territories) and participating German Helmholtz Centres (KIT, GFZ, UFZ). A new monitoring network of meteorological, hydrological, and seismic/geodynamic stations has been established, and extensive field research and numerical simulations have been undertaken. For the first time, innovative measurement and modeling techniques have been applied to the extreme conditions of the Dead Sea and its surroundings. The preliminary results show the potential of these methods. First time ever performed eddy covariance measurements give insight into the governing factors of Dead Sea evaporation. High-resolution bathymetric investigations reveal a strong correlation between submarine springs and neo-tectonic patterns. Based on detailed studies of stratigraphy and borehole information, the extension of the subsurface drainage basin of the Dead Sea is now reliably estimated. Originality has been achieved in monitoring flash floods in an arid basin at its outlet and simultaneously in tributaries, supplemented by spatio-temporal rainfall data. Low-altitude, high resolution photogrammetry, allied to

New perspectives on interdisciplinary earth science at the Dead Sea: The DESERVE project

Energy Technology Data Exchange (ETDEWEB)

Kottmeier, Christoph, E-mail: Christoph.Kottmeier@kit.edu [Karlsruhe Institute of Technology, Hermann von Helmholtz Platz 1, Eggenstein-Leopoldshafen (Germany); Agnon, Amotz [The Hebrew University of Jerusalem, Jerusalem (Israel); Al-Halbouni, Djamil [GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam (Germany); Alpert, Pinhas [Tel Aviv University, Tel Aviv-Yafo (Israel); Corsmeier, Ulrich [Karlsruhe Institute of Technology, Hermann von Helmholtz Platz 1, Eggenstein-Leopoldshafen (Germany); Dahm, Torsten [GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam (Germany); Eshel, Adam [Tel Aviv University, Tel Aviv-Yafo (Israel); Geyer, Stefan [Helmholtz Centre for Environmental Research GmbH — UFZ, Theodor-Lieser-Strasse 4, 06120 Halle (Germany); Haas, Michael; Holohan, Eoghan [GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam (Germany); Kalthoff, Norbert [Karlsruhe Institute of Technology, Hermann von Helmholtz Platz 1, Eggenstein-Leopoldshafen (Germany); Kishcha, Pavel [Tel Aviv University, Tel Aviv-Yafo (Israel); Krawczyk, Charlotte [Leibniz Institute for Applied Geophysics (LIAG), Stilleweg 2, 30655 Hannover (Germany); Lati, Joseph [Tel Aviv University, Tel Aviv-Yafo (Israel); Laronne, Jonathan B. [Ben Gurion University of the Negev, Be' er Sheva (Israel); Lott, Friederike [Karlsruhe Institute of Technology, Hermann von Helmholtz Platz 1, Eggenstein-Leopoldshafen (Germany); Mallast, Ulf; Merz, Ralf [Helmholtz Centre for Environmental Research GmbH — UFZ, Theodor-Lieser-Strasse 4, 06120 Halle (Germany); Metzger, Jutta [Karlsruhe Institute of Technology, Hermann von Helmholtz Platz 1, Eggenstein-Leopoldshafen (Germany); Mohsen, Ayman [An-Najah National University, Nablus, Palestine (Country Unknown); and others

2016-02-15

The Dead Sea region has faced substantial environmental challenges in recent decades, including water resource scarcity, ~ 1 m annual decreases in the water level, sinkhole development, ascending-brine freshwater pollution, and seismic disturbance risks. Natural processes are significantly affected by human interference as well as by climate change and tectonic developments over the long term. To get a deep understanding of processes and their interactions, innovative scientific approaches that integrate disciplinary research and education are required. The research project DESERVE (Helmholtz Virtual Institute Dead Sea Research Venue) addresses these challenges in an interdisciplinary approach that includes geophysics, hydrology, and meteorology. The project is implemented by a consortium of scientific institutions in neighboring countries of the Dead Sea (Israel, Jordan, Palestine Territories) and participating German Helmholtz Centres (KIT, GFZ, UFZ). A new monitoring network of meteorological, hydrological, and seismic/geodynamic stations has been established, and extensive field research and numerical simulations have been undertaken. For the first time, innovative measurement and modeling techniques have been applied to the extreme conditions of the Dead Sea and its surroundings. The preliminary results show the potential of these methods. First time ever performed eddy covariance measurements give insight into the governing factors of Dead Sea evaporation. High-resolution bathymetric investigations reveal a strong correlation between submarine springs and neo-tectonic patterns. Based on detailed studies of stratigraphy and borehole information, the extension of the subsurface drainage basin of the Dead Sea is now reliably estimated. Originality has been achieved in monitoring flash floods in an arid basin at its outlet and simultaneously in tributaries, supplemented by spatio-temporal rainfall data. Low-altitude, high resolution photogrammetry, allied to

Dielectrophoretic Separation of Live and Dead Monocytes Using 3D Carbon-Electrodes

Directory of Open Access Journals (Sweden)

Yagmur Yildizhan

2017-11-01

Full Text Available Blood has been the most reliable body fluid commonly used for the diagnosis of diseases. Although there have been promising investigations for the development of novel lab-on-a-chip devices to utilize other body fluids such as urine and sweat samples in diagnosis, their stability remains a problem that limits the reliability and accuracy of readouts. Hence, accurate and quantitative separation and characterization of blood cells are still crucial. The first step in achieving high-resolution characteristics for specific cell subpopulations from the whole blood is the isolation of pure cell populations from a mixture of cell suspensions. Second, live cells need to be purified from dead cells; otherwise, dead cells might introduce biases in the measurements. In addition, the separation and characterization methods being used must preserve the genetic and phenotypic properties of the cells. Among the characterization and separation approaches, dielectrophoresis (DEP is one of the oldest and most efficient label-free quantification methods, which directly purifies and characterizes cells using their intrinsic, physical properties. In this study, we present the dielectrophoretic separation and characterization of live and dead monocytes using 3D carbon-electrodes. Our approach successfully removed the dead monocytes while preserving the viability of the live monocytes. Therefore, when blood analyses and disease diagnosis are performed with enriched, live monocyte populations, this approach will reduce the dead-cell contamination risk and achieve more reliable and accurate test results.

Contribution of arbuscular mycorrhizal fungus to red kidney and ...

African Journals Online (AJOL)

... fungus to red kidney and wheat plants tolerance grown in heavy metal-polluted soil. ... artificially contaminated with high oncentrations of zinc, copper, lead and cadmium. ... strategies of remediation of highly heavy metal contaminated soils.

Challenges to estimate surface- and groundwater flow in arid regions: the Dead Sea catchment.

Science.gov (United States)

Siebert, Christian; Rödiger, Tino; Mallast, Ulf; Gräbe, Agnes; Guttman, Joseph; Laronne, Jonathan B; Storz-Peretz, Yael; Greenman, Anat; Salameh, Elias; Al-Raggad, Marwan; Vachtman, Dina; Zvi, Arie Ben; Ionescu, Danny; Brenner, Asher; Merz, Ralf; Geyer, Stefan

2014-07-01

The overall aim of the this study, which was conducted within the framework of the multilateral IWRM project SUMAR, was to expand the scientific basement to quantify surface- and groundwater fluxes towards the hypersaline Dead Sea. The flux significance for the arid vicinity around the Dead Sea is decisive not only for a sustainable management in terms of water availability for future generations but also for the resilience of the unique ecosystems along its coast. Coping with different challenges interdisciplinary methods like (i) hydrogeochemical fingerprinting, (ii) satellite and airborne-based thermal remote sensing, (iii) direct measurement with gauging station in ephemeral wadis and a first multilateral gauging station at the river Jordan, (iv) hydro-bio-geochemical approach at submarine and shore springs along the Dead Sea and (v) hydro(geo)logical modelling contributed to the overall aim. As primary results, we deduce that the following: (i) Within the drainage basins of the Dead Sea, the total mean annual precipitation amounts to 300 mm a(−1) west and to 179 mm a(−1) east of the lake, respectively. (ii) The total mean annual runoff volumes from side wadis (except the Jordan River) entering the Dead Sea is approximately 58–66 × 10(6) m(3) a(−1) (western wadis: 7–15 × 10(6) m(3) a(−1); eastern wadis: 51 × 10(6) m(3) a(−1)). (iii) The modelled groundwater discharge from the upper Cretaceous aquifers in both flanks of the Dead Sea towards the lake amounts to 177 × 10(6) m(3) a(−1). (iv) An unexpected abundance of life in submarine springs exists, which in turn explains microbial moderated geo-bio-chemical processes in the Dead Sea sediments, affecting the highly variable chemical composition of on- and offshore spring waters.The results of this work show a promising enhancement of describing and modelling the Dead Sea basin as a whole. Copyright © 2014 Elsevier B.V. All rights reserved.

Ecology of Fungus Gnats (Bradysia spp.) in Greenhouse Production Systems Associated with Disease-Interactions and Alternative Management Strategies.

Science.gov (United States)

Cloyd, Raymond A

2015-04-09

Fungus gnats (Bradysia spp.) are major insect pests of greenhouse-grown horticultural crops mainly due to the direct feeding damage caused by the larvae, and the ability of larvae to transmit certain soil-borne plant pathogens. Currently, insecticides and biological control agents are being used successively to deal with fungus gnat populations in greenhouse production systems. However, these strategies may only be effective as long as greenhouse producers also implement alternative management strategies such as cultural, physical, and sanitation. This includes elimination of algae, and plant and growing medium debris; placing physical barriers onto the growing medium surface; and using materials that repel fungus gnat adults. This article describes the disease-interactions associated with fungus gnats and foliar and soil-borne diseases, and the alternative management strategies that should be considered by greenhouse producers in order to alleviate problems with fungus gnats in greenhouse production systems.

Ecology of Fungus Gnats (Bradysia spp. in Greenhouse Production Systems Associated with Disease-Interactions and Alternative Management Strategies

Directory of Open Access Journals (Sweden)

Raymond A. Cloyd

2015-04-01

Full Text Available Fungus gnats (Bradysia spp. are major insect pests of greenhouse-grown horticultural crops mainly due to the direct feeding damage caused by the larvae, and the ability of larvae to transmit certain soil-borne plant pathogens. Currently, insecticides and biological control agents are being used successively to deal with fungus gnat populations in greenhouse production systems. However, these strategies may only be effective as long as greenhouse producers also implement alternative management strategies such as cultural, physical, and sanitation. This includes elimination of algae, and plant and growing medium debris; placing physical barriers onto the growing medium surface; and using materials that repel fungus gnat adults. This article describes the disease-interactions associated with fungus gnats and foliar and soil-borne diseases, and the alternative management strategies that should be considered by greenhouse producers in order to alleviate problems with fungus gnats in greenhouse production systems.

Dead-time corrections on long-interval measurements of short-lived activities

International Nuclear Information System (INIS)

Irfan, M.

1977-01-01

A method has been proposed to make correction for counting losses due to dead time where the counting interval is comparable to or larger than the half-life of the activity under investigation. Counts due to background and any long-lived activity present in the source have been taken into consideration. The method is, under certain circumstances, capable of providing a valuable check on the accuracy of the dead time of the counting system. (Auth.)

Spread of Rare Fungus from Vancouver Island

Centers for Disease Control (CDC) Podcasts

2006-12-20

Cryptococcus gattii, a rare fungus normally found in the tropics, has infected people and animals on Vancouver Island, Canada. Dr. David Warnock, Director, Division of Foodborne, Bacterial, and Mycotic Diseases, CDC, discusses public health concerns about further spread of this organism.  Created: 12/20/2006 by Emerging Infectious Diseases.   Date Released: 12/29/2006.

EVOLUTIONARY TRANSITIONS IN ENZYME ACTIVITY OF ANT FUNGUS GARDENS

DEFF Research Database (Denmark)

De Fine Licht, Henrik H; Schiøtt, Morten; Mueller, Ulrich G

2010-01-01

an association with a monophyletic clade of specialized symbionts. In conjunction with the transition to specialized symbionts, the ants advanced in colony size and social complexity. Here we provide a comparative study of the functional specialization in extracellular enzyme activities in fungus gardens across...... the attine phylogeny. We show that, relative to sister clades, gardens of higher-attine ants have enhanced activity of protein-digesting enzymes, whereas gardens of leaf-cutting ants also have increased activity of starch-digesting enzymes. However, the enzyme activities of lower-attine fungus gardens...... are targeted primarily towards partial degradation of plant cell walls, reflecting a plesiomorphic state of non-domesticated fungi. The enzyme profiles of the higher-attine and leaf-cutting gardens appear particularly suited to digest fresh plant materials and to access nutrients from live cells without major...

Homer and the cult of the dead in Helladic times

Directory of Open Access Journals (Sweden)

Odysseus Tsagarakis

1980-12-01

Full Text Available This paper discusses the Homeric bothros (Odyssey X 517 ff. as a possible source of information for the ritual and function of various bothroi (grave pits which are considered to be an important archaeological source. It seems that the bothroi were, by their nature, best suited to a cult of the dead and served as altars. The paper also discusses the possible reasons for the existence of the cult and argues against the view that fear of the dead motivated the cult in Helladic times.

Si(Li) detectors with thin dead layers for low energy x-ray detection

International Nuclear Information System (INIS)

Rossington, C.S.; Walton, J.T.; Jaklevic, J.M.

1990-10-01

Regions of incomplete charge collection, or ''dead layers'', are compared for Si(Li) detectors fabricated with Au and Pd entrance window electrodes. The dead layers were measured by characterizing the detector spectral response to x-ray energies above and below the Si Kα absorption edge. It was found that Si(Li) detectors with Pd electrodes exhibit consistently thinner effective Si dead layers than those with Au electrodes. Furthermore, it is demonstrated that the minimum thickness required for low resistivity Pd electrodes is thinner than that required for low resistivity Au electrodes, which further reduces the signal attenuation in Pd/Si(Li) detectors. A model, based on Pd compensation of oxygen vacancies in the SiO 2 at the entrance window Si(Li) surface, is proposed to explain the observed differences in detector dead layer thickness. Electrode structures for optimum Si(Li) detector performance at low x-ray energies are discussed. 18 refs., 8 figs., 1 tab

Formation of Ramified Colony of Fungus Aspergillus Oryzae on Agar Media

Science.gov (United States)

Matsuura, Shu; Miyazima, Sasuke

Ramified colonies of fungus Aspergillus oryzae have been found to grow at a low growth rate on "liquid-like" agar media with low concentrations of agar and glucose. Box-counting fractal dimensions of the individual colony branches have been found to decrease with the time of incubation. Addition of glucose solution in the interior of branched colonies has brought about the production of the hyphal filaments almost only at the apical region of the colony branches. Active growth of the ramified colonies is localized in the peripheral zone, and this growth manner implies that the fungus is exhibiting a positive exploitation.

Tea fungus fermentation on a substrate with iron(ii-ions

Directory of Open Access Journals (Sweden)

Malbaša Radomir V.

2002-01-01

Full Text Available Iron is essential element for human metabolism and it is a constituent of both heme- containing and nonheme proteins. Its deficiency can cause serious diseases, i.e. iron-deficiency anemia, with some fatal consequences. Tea fungus beverage has high nutritional value and some pharmaceutical effects. It is widely consumed allover the world and its benefits were proved a number of times. The aim of this paper was to investigate tea fungus fermentation on a substrate containing iron(II-ions and the possibility of obtaining a beverage enriched with iron. We monitored pH, iron content and also the production of L-ascorbic acid, which is very important for iron absorption in humans.

Utilizing fungus myceliated grain for molt induction and performance in commercial laying hens.

Science.gov (United States)

Willis, W L; Isikhuemhen, O S; Allen, J W; Byers, A; King, K; Thomas, C

2009-10-01

Molting in poultry is used to rejuvenate hens for a second or third laying cycle. Feed withdrawal was once the most effective method used for molt induction; however, it has being phased out due to food safety and animal welfare concerns. This study evaluated the utilization of fungus myceliated grain as a safe and effective alternative for inducing molt, enhancing immunity, reducing Salmonella growth, and returning to egg production. Laying hens were subjected to 1 of 5 treatments: 1) nonfed (NF), 2) full-fed (FF), 3) fungus myceliated meal (FM), 4) 90% fungus myceliated meal+10% standard layer ration (FM-90), and 5) 90% alfalfa meal+10% fungus myceliated meal (AF-90). Each treatment condition was replicated 9 times during a 9-d molt period. The results revealed that egg production for treatments 1 and 3 ceased completely by d 5, whereas hens in treatments 4 and 5 ceased egg production by d 6. The percentage of BW loss decreased significantly (P<0.05) in treatments 1 (57%), 2 (8%), 3 (35%), 4 (37%), and 5 (44%). Ovary weights of hens fed all molting diets decreased significantly from the full-fed control but did not differ significantly (P<0.05) from each other. Salmonella population in the crop, ovary, and ceca from hens differed significantly (P<0.05) among treatments. Return to egg production differed between treatments with higher production beginning in treatment 3 and ending in treatment 5. Antibody titers did differ (P<0.05) among treatments. From these results, fungus myceliated meal appears to be a viable alternative to conventional feed withdrawal and other methods for the successful induction of molt and retention of postmolt performance.

Uranium and thorium uptake by live and dead cells of Pseudomonas Sp

International Nuclear Information System (INIS)

Siva Prasath, C.S.; Manikandan, N.; Prakash, S.

2010-01-01

This study presents uptake of uranium (U) and thorium (Th) by live and dead cells of Pseudomonas Sp. Increasing concentration of U and Tb showed decrease in absorption by Pseudomonas Sp. Dead cells of Pseudomonas Sp. exhibited same or more uptake of U and Th than living cells. Increasing temperature promotes uptake of U and Th by Pseudomonas Sp. (author)

Generalized projective synchronization of chaotic nonlinear gyros coupled with dead-zone input

International Nuclear Information System (INIS)

Hung, M.-L.; Yan, J.-J.; Liao, T.-L.

2008-01-01

This paper addresses the synchronization problem of drive-response chaotic gyros coupled with dead-zone nonlinear input. Using the sliding mode control technique, a novel control law is established which guarantees generalized projective synchronization even when the dead-zone nonlinearity is present. Numerical simulations are presented to verify that the synchronization can be achieved by using the proposed synchronization scheme

Analysis of neutron multiplicity measurements with allowance for dead-time losses between time-correlated detections

International Nuclear Information System (INIS)

Vincent, C.H.

1992-01-01

An exact solution is found for dead-time losses between detections occurring within a gate interval, with constant dead time and with allowance for time correlation between detections from the same spontaneous initial event. This is used to obtain a close approximation to the losses with a multi-channel detection system, with allowance for dead times briding the gate opening. This is applied, inversely, to calculate the true detection multiplicity rates from the distribution of the recorded counts within that interval. A suggestion is made for a circuit change to give a major reduction in dead-time effects. The unavoidable statistical errors that would remain are calculated. Their minimization and the limits of such minimization are discussed. (orig.)

Tunnel Diode Discriminator with Fixed Dead Time

DEFF Research Database (Denmark)

Diamond, J. M.

1965-01-01

A solid state discriminator for the range 0.4 to 10 V is described. Tunnel diodes are used for the discriminator element and in a special fixed dead time circuit. An analysis of temperature stability is presented. The regulated power supplies are described, including a special negative resistance...

Fungi colonizing dead leaves of herbs

Directory of Open Access Journals (Sweden)

Maria Kowalik

2013-04-01

Full Text Available The material was collected from the Botanical Garden and the Collegium Medicum Medicinal Plant Garden of the Jagiellonian University in Krakow. The investigated species were: lemon balm (Mellisa officinalis L., common lavender (Lavendula angustifolia Mill., horsemint (Mentha longifolia L., sage (Salvia officinalis L., sweet basil (Ocimum basilicum L., and wild marjoram (Origanum vulgare L.. The aim of the investigation was to identify fungi causing the death of leaf tissues of herbs from the mint family Lamiaceae. In mycological investigations, 180 fragments of each plant leaves (1,080 dead leaf fragments in total were placed in a 2% PDA medium. Over 970 colonies of fungi belonging to 48 species were isolated from the dead leaf tissues of the six herb species. Alternaria alternata (toxin-producing, Epicoccum nigrum and Sordaria fimicola were the most frequently isolated. The largest numbers of colonies and species of fungi were isolated from horsemint, while the lowest numbers were from wild marjoram leaves. It was shown that the death of leaves of selected herb species from the Lamiaceae family was caused by various fungi. The results of the mycological analysis confirmed the diversity of species colonizing the leaves of the herbs.

Control of Root-Knot Nematodes on Tomato by the Endoparasitic Fungus Meria coniospora

OpenAIRE

Jansson, Hans-Börje; Jeyaprakash, A.; Zuckerman, Bert M.

1985-01-01

The endoparasitic nematophagous fungus Meria coniospora reduced root-knot nematode galling on tomatoes in greenhouse pot trials. The fungus was introduced to pots by addition of conidia at several inoculum levels directly to the soil or addition of nematodes infected with M. coniospora to the soil; both methods reduced root galling by root-knot nematodes. These studies represent a part of a recently initiated effort to evaluate the potential of endoparasitic nematophagous fungi for biocontrol...

Defending against parasites: fungus-growing ants combine specialized behaviours and microbial symbionts to protect their fungus gardens.

Science.gov (United States)

Little, Ainslie E F; Murakami, Takahiro; Mueller, Ulrich G; Currie, Cameron R

2006-03-22

Parasites influence host biology and population structure, and thus shape the evolution of their hosts. Parasites often accelerate the evolution of host defences, including direct defences such as evasion and sanitation and indirect defences such as the management of beneficial microbes that aid in the suppression or removal of pathogens. Fungus-growing ants are doubly burdened by parasites, needing to protect their crops as well as themselves from infection. We show that parasite removal from fungus gardens is more complex than previously realized. In response to infection of their fungal gardens by a specialized virulent parasite, ants gather and compress parasitic spores and hyphae in their infrabuccal pockets, then deposit the resulting pellet in piles near their gardens. We reveal that the ants' infrabuccal pocket functions as a specialized sterilization device, killing spores of the garden parasite Escovopsis. This is apparently achieved through a symbiotic association with actinomycetous bacteria in the infrabuccal pocket that produce antibiotics which inhibit Escovopsis. The use of the infrabuccal pocket as a receptacle to sequester Escovopsis, and as a location for antibiotic administration by the ants' bacterial mutualist, illustrates how the combination of behaviour and microbial symbionts can be a successful defence strategy for hosts.

Communication media and the dead: from the Stone Age to Facebook.

Science.gov (United States)

Walter, Tony

2015-07-03

This article argues as follows: (i) The presence of the dead within a society depends in part on available communication technologies, specifically speech, stone, sculpture, writing, printing, photography and phonography (including the mass media), and most recently the internet. (ii) Each communication technology affords possibilities for the dead to construct and legitimate particular social groups and institutions - from the oral construction of kinship, to the megalithic legitimation of the territorial rights of chiefdoms, to the written word's construction of world religions and nations, to the photographic and phonographic construction of celebrity-based neo-tribalism, and to the digital reconstruction of family and friendship. (iii) Historically, concerns about the dead have on a number of occasions aided the development of new communication technologies - the causal connection between the two can go both ways. The argument is based primarily on critical synthesis of existing research literature.

Do saproxylic beetles respond numerically to rapid changes in dead wood availability following moth outbreaks?

OpenAIRE

Schultze, Sabrina

2012-01-01

Outbreaks of defoliating insects periodically cause mass mortality of trees, thereby generating pulses of dead wood resources for saproxylic (i.e. dead-wood dependent) organisms. This study investigated the responses of saproxylic beetles to a dead wood resource pulse caused by recent (2001-2009) outbreaks of geometrid moths in the subarctic mountain birch forest of the Varanger region in northern Norway. A large scale (20 km) transect design, implementing window (flight interception) traps a...

The relationship between an endangered North American tree and an endophytic fungus.

Science.gov (United States)

Lee, J C; Yang, X; Schwartz, M; Strobel, G; Clardy, J

1995-11-01

The Florida torreya (Torreya taxifolia) began a catastrophic decline in the late 1950s and is now the rarest tree in North America for which a full species designation has been established. The trees have common plant disease symptoms, but the reason for the decline has never been identified. T. taxifolia's imminent extinction gains special poignancy through its close relationship to the Pacific yew (Taxus brevifolia), which produces the potent anticancer agent, taxol. An examination of the endophytic fungal communities of wild torreyas consistently found a filamentous fungus, Pestalotiopsis microspora, associated with diseased trees and also with most symptomless trees. P. microspora can be cultured in the laboratory, and when it is introduced into greenhouse-grown torreyas, it causes disease symptoms similar to those seen in the field. The fungus can then be reisolated from these deliberately infected trees. The phytotoxins pestalopyrone, hydroxypestalopyrone and pestaloside have been isolated and characterized from axenic fungal cultures, and both pestalopyrone and hydroxypestalopyrone can be isolated from artificially infected torreyas. In addition, pestaloside has antifungal activity against other fungal endophytes of T. taxifolia. The filamentous fungus, P. microspora, has an endophytic-pathologic relationship with T. taxifolia. The fungus resides in the inner bark of symptomless trees, and physiological or environmental factors could trigger its pathological activity. P. microspora produces the phytotoxins pestalopyrone, hydroxypestalopyrone, and pestaloside which give rise to the disease. Pestaloside, which also has antifungal activity, could reduce competition from other fungal endophytes within the host.

ZnS semiconductor quantum dots production by an endophytic fungus Aspergillus flavus

Energy Technology Data Exchange (ETDEWEB)

Uddandarao, Priyanka, E-mail: uddandaraopriyanka@gmail.com; B, Raj Mohan, E-mail: rajmohanbala@gmail.com

2016-05-15

Graphical abstract: - Highlights: • Endophytic fungus Aspergillus flavus isolated from a medicinal plant Nothapodytes foetida was used for the synthesis of quantum dots. • Morris-Weber kinetic model and Lagergren's pseudo-first-order rate equation were used to study the biosorption kinetics. • Polycrystalline ZnS quantum dots of 18 nm and 58.9 nm from TEM and DLS, respectively. - Abstract: The development of reliable and eco-friendly processes for the synthesis of metal sulphide quantum dots has been considered as a major challenge in the field of nanotechnology. In the present study, polycrystalline ZnS quantum dots were synthesized from an endophytic fungus Aspergillus flavus. It is noteworthy that apart from being rich sources of bioactive compounds, endophytic fungus also has the ability to mediate the synthesis of nanoparticles. TEM and DLS revealed the formation of spherical particles with an average diameter of about 18 nm and 58.9 nm, respectively. The ZnS quantum dots were further characterized using SEM, EDAX, XRD, UV–visible spectroscopy and FTIR. The obtained results confirmed the synthesis of polycrystalline ZnS quantum dots and these quantum dots are used for studying ROS activity. In addition this paper explains kinetics of metal sorption to study the role of biosorption in synthesis of quantum dots by applying Morris-Weber kinetic model. Since Aspergillus flavus is isolated from a medicinal plant Nothapodytes foetida, quantum dots synthesized from this fungus may have great potential in broad environmental and medical applications.

Consistent association of fungus Fusarium mangiferae Britz with ...

African Journals Online (AJOL)

In exotic ones, maximum and minimum infections of 97.33 and 70.67% were noted in the cultivars Sensation and Pop, respectively. Light and transmission electron microscopy proved helpful in investigating the morphological matrix and ultrastructure of the propagules of fungus F. mangiferae. Key words: Mangifera indica, ...

Dead end metabolites--defining the known unknowns of the E. coli metabolic network.

Directory of Open Access Journals (Sweden)

Amanda Mackie

Full Text Available The EcoCyc database is an online scientific database which provides an integrated view of the metabolic and regulatory network of the bacterium Escherichia coli K-12 and facilitates computational exploration of this important model organism. We have analysed the occurrence of dead end metabolites within the database--these are metabolites which lack the requisite reactions (either metabolic or transport that would account for their production or consumption within the metabolic network. 127 dead end metabolites were identified from the 995 compounds that are contained within the EcoCyc metabolic network. Their presence reflects either a deficit in our representation of the network or in our knowledge of E. coli metabolism. Extensive literature searches resulted in the addition of 38 transport reactions and 3 metabolic reactions to the database and led to an improved representation of the pathway for Vitamin B12 salvage. 39 dead end metabolites were identified as components of reactions that are not physiologically relevant to E. coli K-12--these reactions are properties of purified enzymes in vitro that would not be expected to occur in vivo. Our analysis led to improvements in the software that underpins the database and to the program that finds dead end metabolites within EcoCyc. The remaining dead end metabolites in the EcoCyc database likely represent deficiencies in our knowledge of E. coli metabolism.

Bacteria associated with decomposing dead wood in a natural temperate forest.

Science.gov (United States)

Tláskal, Vojtech; Zrustová, Petra; Vrška, Tomáš; Baldrian, Petr

2017-12-01

Dead wood represents an important pool of organic matter in forests and is one of the sources of soil formation. It has been shown to harbour diverse communities of bacteria, but their roles in this habitat are still poorly understood. Here, we describe the bacterial communities in the dead wood of Abies alba, Picea abies and Fagus sylvatica in a temperate natural forest in Central Europe. An analysis of environmental factors showed that decomposing time along with pH and water content was the strongest drivers of community composition. Bacterial biomass positively correlated with N content and increased with decomposition along with the concurrent decrease in the fungal/bacterial biomass ratio. Rhizobiales and Acidobacteriales were abundant bacterial orders throughout the whole decay process, but many bacterial taxa were specific either for young (<15 years) or old dead wood. During early decomposition, bacterial genera able to fix N2 and to use simple C1 compounds (e.g. Yersinia and Methylomonas) were frequent, while wood in advanced decay was rich in taxa typical of forest soils (e.g. Bradyrhizobium and Rhodoplanes). Although the bacterial contribution to dead wood turnover remains unclear, the community composition appears to reflect the changing conditions of the substrate and suggests broad metabolic capacities of its members. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Dead time effects from linear amplifiers and discriminators in single detector systems

International Nuclear Information System (INIS)

Funck, E.

1986-01-01

The dead-time losses originating from a linear amplifier combined with a discriminator for pulse-height selection are investigated. Measurements are carried out to determine the type of dead time represented by the amplifier-discriminator combination. The corrections involved by feeding the discriminator output pulses into an electronic module producing a blocking time are discussed and practical hints are given to reduce them. (orig.)

Inhibition of Caused by Bacteria Isolated from the Skin of Boreal Toads, , from Grand Teton National Park, Wyoming, USA

Directory of Open Access Journals (Sweden)

Shawna T. Park

2014-01-01

Full Text Available The chytrid fungus Batrachochytrium dendrobatidis is a significant cause of the worldwide decline in amphibian populations; however, various amphibian species are capable of coexisting with B. dendrobatidis. Among them are boreal toads ( Anaxyrus ( Bufo boreas boreas located in Grand Teton National Park (GTNP in Wyoming, USA. The purpose of this study was to identify cultivable bacterial isolates from the skin microbiota of boreal toads from GTNP and determine if they were capable of inhibiting B. dendrobatidis in vitro, and therefore might be a factor in the toad's coexistence with this pathogen. Isolates from 6 of 21 genera tested were found to inhibit the growth of B. dendrobatidis. These bacteria represent diverse lineages such as the Gammaproteobacteria, the Betaproteobacteria, and the Bacteroidetes/Chlorobium groups. We propose that these bacteria compete via microbial antagonism with B. dendrobatidis.

The Influence Of Dead Layer Effect On The Characteristics Of The High Purity Germanium P-Type Detector

International Nuclear Information System (INIS)

Ngo Quang Huy

2011-01-01

The present work aims at reviewing the studies of the influence of dead layer effect on the characteristics of a high purity germanium (HPGe) p-type detector, obtained by the author and his colleagues in the recent years. The object for study was the HPGe GC1518 detector-based gamma spectrometer of the Center for Nuclear Techniques, Ho Chi Minh City. The studying problems were: The modeling of an HPGe detector-based gamma spectrometer with using the MCNP code; the method of determining the thickness of dead layer by experimental measurements of gamma spectra and the calculations using MCNP code; the influence of material parameters and dead layer on detector efficiency; the increase of dead layer thickness over the operating time of the GC1518 detector; the influence of dead layer thickness increase on the decrease of detector efficiency; the dead layer effect for the gamma spectra measured in the GC1518 detector. (author)

Process for producing ethanol from plant biomass using the fungus Paecilomyces sp

Science.gov (United States)

Wu, J.F.

1985-08-08

A process for producing ethanol from plant biomass is disclosed. The process includes forming a substrate from the biomass with the substrate including hydrolysates of cellulose and hemicellulose. A species of the fungus Paecilomyces which has the ability to ferment both cellobiose and xylose to ethanol is then selected and isolated. The substrate is inoculated with this fungus, and the inoculated substrate is then fermented under conditions favorable for cell viability and conversion of hydrolysates to ethanol. Finally, ethanol is recovered from the fermented substrate. 5 figs., 3 tabs.

Screening of potent anticancer drug taxol from Entophytic fungus ...

African Journals Online (AJOL)

Muthumary

2011-02-21

Feb 21, 2011 ... Isolation and detection of taxol, an anticancer drug produced from ... cancer cell line, taxol produced by the test fungus in MID culture medium was isolated for its .... then plotted on a graph. RESULTS AND ... Wavelength (nm).

Geosmithia-Ophiostoma: a New Fungus-Fungus Association.

Science.gov (United States)

Pepori, Alessia L; Bettini, Priscilla P; Comparini, Cecilia; Sarrocco, Sabrina; Bonini, Anna; Frascella, Arcangela; Ghelardini, Luisa; Scala, Aniello; Vannacci, Giovanni; Santini, Alberto

2018-04-01

In Europe as in North America, elms are devastated by Dutch elm disease (DED), caused by the alien ascomycete Ophiostoma novo-ulmi. Pathogen dispersal and transmission are ensured by local species of bark beetles, which established a novel association with the fungus. Elm bark beetles also transport the Geosmithia fungi genus that is found in scolytids' galleries colonized by O. novo-ulmi. Widespread horizontal gene transfer between O. novo-ulmi and Geosmithia was recently observed. In order to define the relation between these two fungi in the DED pathosystem, O. novo-ulmi and Geosmithia species from elm, including a GFP-tagged strain, were grown in dual culture and mycelial interactions were observed by light and fluorescence microscopy. Growth and sporulation of O. novo-ulmi in the absence or presence of Geosmithia were compared. The impact of Geosmithia on DED severity was tested in vivo by co-inoculating Geosmithia and O. novo-ulmi in elms. A close and stable relation was observed between the two fungi, which may be classified as mycoparasitism by Geosmithia on O. novo-ulmi. These results prove the existence of a new component in the complex of organisms involved in DED, which might be capable of reducing the disease impact.

The dynamics of plant cell-wall polysaccharide decomposition in leaf-cutting ant fungus gardens

DEFF Research Database (Denmark)

Moller, Isabel Eva; de Fine Licht, Henrik Hjarvard; Harholt, Jesper

2011-01-01

communities of microbial and invertebrate symbionts have evolved associations with the dump material from leaf-cutting ant nests, to exploit decomposition niches that the ant garden-fungus does not utilize. Our approach thus provides detailed insight into the nutritional benefits and shortcomings associated......The degradation of live plant biomass in fungus gardens of leaf-cutting ants is poorly characterised but fundamental for understanding the mutual advantages and efficiency of this obligate nutritional symbiosis. Controversies about the extent to which the garden-symbiont Leucocoprinus gongylophorus......, to map the occurrence of cell wall polymers in consecutive sections of the fungus garden of the leaf-cutting ant Acromyrmex echinatior. We show that pectin, xyloglucan and some xylan epitopes are degraded, whereas more highly substituted xylan and cellulose epitopes remain as residuals in the waste...

The Dead Sea Mud and Salt: A Review of Its Characterization, Contaminants, and Beneficial Effects

Science.gov (United States)

Bawab, Abeer Al; Bozeya, Ayat; Abu-Mallouh, Saida; Abu Irmaileh, Basha'er; Daqour, Ismail; Abu-Zurayk, Rund A.

2018-02-01

The Dead Sea has been known for its therapeutic and cosmetic properties. The unique climatic conditions in the Dead Sea area make it a renowned site worldwide for the field of climatotherapy, which is a natural approach for the provision of medications for many human diseases including unusual exclusive salt composition of the water, a special natural mud, thermal mineral springs, solar irradiation, oxygen-rich and bromine-rich haze. This review focuses on the physical, chemical, and biological characteristics of the Dead Sea mud and salts, in addition to their contaminants, allowing this review to serve as a guide to interested researchers to their risks and the importance of treatment. Beneficial effects of Dead Sea mud and salts are discussed in terms of therapy and cosmetics. Additional benefits of both Dead Sea mud and salts are also discussed, such as antimicrobial action of the mud in relation to its therapeutic properties, and the potency of mud and salts to be a good medium for the growth of a halophilic unicellular algae, used for the commercial production of β-carotene Dunaliella.

Unethical and Deadly Symbiosis in Higher Education

Science.gov (United States)

Crumbley, D. Larry; Flinn, Ronald; Reichelt, Kenneth J.

2012-01-01

As administrators are pressured to increase retention rates in accounting departments, and higher education in general, a deadly symbiosis is occurring. Most students and parents only wish for high grades, so year after year many educators engage in unethical grade inflation and course work deflation. Since administrators use the students to audit…

[Spatial pattern of land surface dead combustible fuel load in Huzhong forest area in Great Xing'an Mountains].

Science.gov (United States)

Liu, Zhi-Hua; Chang, Yu; Chen, Hong-Wei; Zhou, Rui; Jing, Guo-Zhi; Zhang, Hong-Xin; Zhang, Chang-Meng

2008-03-01

By using geo-statistics and based on time-lag classification standard, a comparative study was made on the land surface dead combustible fuels in Huzhong forest area in Great Xing'an Mountains. The results indicated that the first level land surface dead combustible fuel, i. e., 1 h time-lag dead fuel, presented stronger spatial auto-correlation, with an average of 762.35 g x m(-2) and contributing to 55.54% of the total load. Its determining factors were species composition and stand age. The second and third levels land surface dead combustible fuel, i. e., 10 h and 100 h time-lag dead fuels, had a sum of 610.26 g x m(-2), and presented weaker spatial auto-correlation than 1 h time-lag dead fuel. Their determining factor was the disturbance history of forest stand. The complexity and heterogeneity of the factors determining the quality and quantity of forest land surface dead combustible fuels were the main reasons for the relatively inaccurate interpolation. However, the utilization of field survey data coupled with geo-statistics could easily and accurately interpolate the spatial pattern of forest land surface dead combustible fuel loads, and indirectly provide a practical basis for forest management.

Greater taxol yield of fungus Pestalotiopsis hainanensis from dermatitic scurf of the giant panda (Ailuropoda melanoleuca).

Science.gov (United States)

Gu, Yu; Wang, Yanlin; Ma, Xiaoping; Wang, Chengdong; Yue, Guizhou; Zhang, Yuetian; Zhang, Yunyan; Li, Shanshan; Ling, Shanshan; Liu, Xiaomin; Wen, Xintian; Cao, Sanjie; Huang, Xiaobo; Deng, Junliang; Zuo, Zhicai; Yu, Shumin; Shen, Liuhong; Wu, Rui

2015-01-01

While taxol yields of fungi from non-animal sources are still low, whether Pestalotiopsis hainanensis isolated from the scurf of a dermatitic giant panda, Ailuropoda melanoleuca, provides a greater taxol yield remains unknown. The objective of the study was to determine the corresponding taxol yield. The structure of the taxol produced by the fungus was evaluated by thin layer chromatography (TLC), ultraviolet (UV) spectroscopy, high-performance liquid chromatography (HPLC), (1)H and (13)C nuclear magnetic resonance spectroscopy ((1)H-NMR and (13)C-NMR), and time-of-flight mass spectrometry (TOF-MS), with standard taxol as a control. The results demonstrated that the P. hainanensis fungus produced taxol, which had the same structure as the standard taxol and yield of 1,466.87 μg/L. This fungal taxol yield from the dermatitic giant panda was significantly greater than those of fungus from non-animal sources. The taxol-producing fungus may be a potential candidate for the production of taxol on an industrial scale.

Arbuscular mycorrhizal fungus inoculation reduces the drought-resistance advantage of endophyte-infected versus endophyte-free Leymus chinensis.

Science.gov (United States)

Liu, Hui; Chen, Wei; Wu, Man; Wu, Rihan; Zhou, Yong; Gao, Yubao; Ren, Anzhi

2017-11-01

Grasses can be infected simultaneously by endophytic fungi and arbuscular mycorrhizal (AM) fungi. In this study, we tested the hypothesis that endophyte-associated drought resistance of a native grass was affected by an AM fungus. In a greenhouse experiment, we compared the performance of endophyte-infected (EI) and endophyte-free (EF) Leymus chinensis, a dominant species native to the Inner Mongolia steppe, under altered water and AM fungus availability. The results showed that endophyte infection significantly increased drought resistance of the host grass, but the beneficial effects were reduced by AM fungus inoculation. In the mycorrhizal-non-inoculated (MF) treatment, EI plants accumulated significantly more biomass, had greater proline and total phenolic concentration, and lower malondialdehyde concentration than EF plants. In the mycorrhizal-inoculation (MI) treatment, however, no significant difference occurred in either growth or physiological characters measured between EI and EF plants. AM fungus inoculation enhanced drought resistance of EF plants but had no significant effect on drought resistance of EI plants, thus AM fungus inoculation reduced the difference between EI and EF plants. Our findings highlight the importance of interactions among multiple microorganisms for plant performance under drought stress.

Empirical formulae for excess noise factor with dead space for single carrier multiplication

KAUST Repository

Dehwah, Ahmad H.

2011-09-01

In this letter, two empirical equations are presented for the calculation of the excess noise factor of an avalanche photodiode for single carrier multiplication including the dead space effect. The first is an equation for calculating the excess noise factor when the multiplication approaches infinity as a function of parameters that describe the degree of the dead space effect. The second equation can be used to find the minimum value of the excess noise factor for any multiplication when the dead space effect is completely dominant, the so called "deterministic" limit. This agrees with the theoretically known equation for multiplications less than or equal to two. © 2011 World Scientific Publishing Company.

Empirical formulae for excess noise factor with dead space for single carrier multiplication

KAUST Repository

Dehwah, Ahmad H.; Ajia, Idris A.; Marsland, John S.

2011-01-01

In this letter, two empirical equations are presented for the calculation of the excess noise factor of an avalanche photodiode for single carrier multiplication including the dead space effect. The first is an equation for calculating the excess noise factor when the multiplication approaches infinity as a function of parameters that describe the degree of the dead space effect. The second equation can be used to find the minimum value of the excess noise factor for any multiplication when the dead space effect is completely dominant, the so called "deterministic" limit. This agrees with the theoretically known equation for multiplications less than or equal to two. © 2011 World Scientific Publishing Company.

A Unified Approach to Adaptive Neural Control for Nonlinear Discrete-Time Systems With Nonlinear Dead-Zone Input.

Science.gov (United States)

Liu, Yan-Jun; Gao, Ying; Tong, Shaocheng; Chen, C L Philip

2016-01-01

In this paper, an effective adaptive control approach is constructed to stabilize a class of nonlinear discrete-time systems, which contain unknown functions, unknown dead-zone input, and unknown control direction. Different from linear dead zone, the dead zone, in this paper, is a kind of nonlinear dead zone. To overcome the noncausal problem, which leads to the control scheme infeasible, the systems can be transformed into a m -step-ahead predictor. Due to nonlinear dead-zone appearance, the transformed predictor still contains the nonaffine function. In addition, it is assumed that the gain function of dead-zone input and the control direction are unknown. These conditions bring about the difficulties and the complicacy in the controller design. Thus, the implicit function theorem is applied to deal with nonaffine dead-zone appearance, the problem caused by the unknown control direction can be resolved through applying the discrete Nussbaum gain, and the neural networks are used to approximate the unknown function. Based on the Lyapunov theory, all the signals of the resulting closed-loop system are proved to be semiglobal uniformly ultimately bounded. Moreover, the tracking error is proved to be regulated to a small neighborhood around zero. The feasibility of the proposed approach is demonstrated by a simulation example.

THE QUANTITY AND TURNOVER OF DEAD WOOD IN PERMANENT FOREST PLOTS IN SIX LIFE ZONES OF VENEZUELA

Science.gov (United States)

Dead wood can be an important component of the carbon pool in many forests, but few measurements have been made of this pool in tropical forests. To fill this gap, we determined the quantity of dead wood (downed and standing dead) in 25 long-term (up to 30 yr) permanent forest pl...

The Hidden Habit of the Entomopathogenic Fungus Beauveria bassiana: First Demonstration of Vertical Plant Transmission

Science.gov (United States)

Quesada-Moraga, Enrique; López-Díaz, Cristina; Landa, Blanca Beatriz

2014-01-01

Beauveria bassiana strain 04/01-Tip, obtained from a larva of the opium poppy stem gall wasp Iraella luteipes (Hymenoptera; Cynipidae), endophytically colonizes opium poppy (Papaver somniferum L.) plants and protects them against this pest. The goal of this study was to monitor the dynamics of endophytic colonization of opium poppy by B. bassiana after the fungus was applied to the seed and to ascertain whether the fungus is transmitted vertically via seeds. Using a species-specific nested PCR protocol and DNA extracted from surface-sterilised leaf pieces or seeds of B. bassiana-inoculated opium poppy plants, the fungus was detected within the plant beginning at the growth stage of rosette building and them throughout the entire plant growth cycle (about 120–140 days after sowing). The fungus was also detected in seeds from 50% of the capsules sampled. Seeds that showed positive amplification for B. bassiana were planted in sterile soil and the endophyte was again detected in more than 42% of the plants sampled during all plant growth stages. Beauveria bassiana was transmitted to seeds in 25% of the plants from the second generation that formed a mature capsule. These results demonstrate for the first time the vertical transmission of an entomopathogenic fungus from endophytically colonised maternal plants. This information is crucial to better understand the ecological role of entomopathogenic fungi as plant endophytes and may allow development of a sustainable and cost effective strategy for I. luteipes management in P. somniferum. PMID:24551242

The hidden habit of the entomopathogenic fungus Beauveria bassiana: first demonstration of vertical plant transmission.

Science.gov (United States)

Quesada-Moraga, Enrique; López-Díaz, Cristina; Landa, Blanca Beatriz

2014-01-01

Beauveria bassiana strain 04/01-Tip, obtained from a larva of the opium poppy stem gall wasp Iraella luteipes (Hymenoptera; Cynipidae), endophytically colonizes opium poppy (Papaver somniferum L.) plants and protects them against this pest. The goal of this study was to monitor the dynamics of endophytic colonization of opium poppy by B. bassiana after the fungus was applied to the seed and to ascertain whether the fungus is transmitted vertically via seeds. Using a species-specific nested PCR protocol and DNA extracted from surface-sterilised leaf pieces or seeds of B. bassiana-inoculated opium poppy plants, the fungus was detected within the plant beginning at the growth stage of rosette building and them throughout the entire plant growth cycle (about 120-140 days after sowing). The fungus was also detected in seeds from 50% of the capsules sampled. Seeds that showed positive amplification for B. bassiana were planted in sterile soil and the endophyte was again detected in more than 42% of the plants sampled during all plant growth stages. Beauveria bassiana was transmitted to seeds in 25% of the plants from the second generation that formed a mature capsule. These results demonstrate for the first time the vertical transmission of an entomopathogenic fungus from endophytically colonised maternal plants. This information is crucial to better understand the ecological role of entomopathogenic fungi as plant endophytes and may allow development of a sustainable and cost effective strategy for I. luteipes management in P. somniferum.

Integrated 3D density modelling and segmentation of the Dead Sea

OpenAIRE

H.-J. Götze; R. El-Kelani; Sebastian Schmidt; M. Rybakov; M. Hassouneh; Hans-Jürgen Förster; J. Ebbing; DESERT Group;  ;  ;  

2007-01-01

A 3D interpretation of the newly compiled Bouguer anomaly in the area of the '‘Dead Sea Rift’’ is presented. A high-resolution 3D model constrained with the seismic results reveals the crustal thickness and density distribution beneath the Arava/Araba Valley (AV), the region between the Dead Sea and the Gulf of Aqaba/Elat. The Bouguer anomalies along the axial portion of the AV, as deduced from the modelling results, are mainly caused by deep-seated sedimentary basins (D > 10 km). An inferred...

Structure, dynamics and domain organization of the repeat protein Cin1 from the apple scab fungus

NARCIS (Netherlands)

Mesarich, C.H.; Schmitz, M.; Tremouilhac, P.; McGillivray, D.J.; Templeton, M.D.; Dingley, A.J.

2012-01-01

Venturia inaequalis is a hemi-biotrophic fungus that causes scab disease of apple. A recently-identified gene from this fungus, cin1 (cellophane-induced 1), is up-regulated over 1000-fold in planta and considerably on cellophane membranes, and encodes a cysteine-rich secreted protein of 523 residues

Dead wood biomass and turnover time, measured by radiocarbon, along a subalpine elevation gradient.

Science.gov (United States)

Kueppers, Lara M; Southon, John; Baer, Paul; Harte, John

2004-12-01

Dead wood biomass can be a substantial fraction of stored carbon in forest ecosystems, and coarse woody debris (CWD) decay rates may be sensitive to climate warming. We used an elevation gradient in Colorado Rocky Mountain subalpine forest to examine climate and species effects on dead wood biomass, and on CWD decay rate. Using a new radiocarbon approach, we determined that the turnover time of lodgepole pine CWD (340+/-130 years) was roughly half as long in a site with 2.5-3 degrees C warmer air temperature, as that of pine (630+/-400 years) or Engelmann spruce CWD (800+/-960 and 650+/-410 years) in cooler sites. Across all sites and both species, CWD age ranged from 2 to 600 years, and turnover time was 580+/-180 years. Total standing and fallen dead wood biomass ranged from 4.7+/-0.2 to 54+/-1 Mg ha(-1), and from 2.8 to 60% of aboveground live tree biomass. Dead wood biomass increased 75 kg ha(-1) per meter gain in elevation and decreased 13 Mg ha(-1) for every degree C increase in mean air temperature. Differences in biomass and decay rates along the elevation gradient suggest that climate warming will lead to a loss of dead wood carbon from subalpine forest.

Nonlinear dead water resistance at subcritical speed

Science.gov (United States)

Grue, John

2015-08-01

The dead water resistance F 1 = /1 2 C d w ρ S U 2 (ρ fluid density, U ship speed, S wetted body surface, Cdw resistance coefficient) on a ship moving at subcritical speed along the upper layer of a two-layer fluid is calculated by a strongly nonlinear method assuming potential flow in each layer. The ship dimensions correspond to those of the Polar ship Fram. The ship draught, b0, is varied in the range 0.25h0-0.9h0 (h0 the upper layer depth). The calculations show that Cdw/(b0/h0)2 depends on the Froude number only, in the range close to critical speed, Fr = U/c0 ˜ 0.875-1.125 (c0 the linear internal long wave speed), irrespective of the ship draught. The function Cdw/(b0/h0)2 attains a maximum at subcritical Froude number depending on the draught. Maximum Cdw/(b0/h0)2 becomes 0.15 for Fr = 0.76, b0/h0 = 0.9, and 0.16 for Fr = 0.74, b0/h0 = 1, where the latter extrapolated value of the dead water resistance coefficient is about 60 times higher than the frictional drag coefficient and relevant for the historical dead water observations. The nonlinear Cdw significantly exceeds linear theory (Fr < 0.85). The ship generated waves have a wave height comparable to the upper layer depth. Calculations of three-dimensional wave patterns at critical speed compare well to available laboratory experiments. Upstream solitary waves are generated in a wave tank of finite width, when the layer depths differ, causing an oscillation of the force. In a wide ocean, a very wide wave system develops at critical speed. The force approaches a constant value for increasing time.

Asteroid 'Bites the Dust' Around Dead Star

Science.gov (United States)

2009-01-01

NASA's Spitzer Space Telescope set its infrared eyes upon the dusty remains of shredded asteroids around several dead stars. This artist's concept illustrates one such dead star, or 'white dwarf,' surrounded by the bits and pieces of a disintegrating asteroid. These observations help astronomers better understand what rocky planets are made of around other stars. Asteroids are leftover scraps of planetary material. They form early on in a star's history when planets are forming out of collisions between rocky bodies. When a star like our sun dies, shrinking down to a skeleton of its former self called a white dwarf, its asteroids get jostled about. If one of these asteroids gets too close to the white dwarf, the white dwarf's gravity will chew the asteroid up, leaving a cloud of dust. Spitzer's infrared detectors can see these dusty clouds and their various constituents. So far, the telescope has identified silicate minerals in the clouds polluting eight white dwarfs. Because silicates are common in our Earth's crust, the results suggest that planets similar to ours might be common around other stars.

Thermodynamics of the dead zone inner edge in protoplanetary disks

International Nuclear Information System (INIS)

Faure, Julien

2014-01-01

The dead zone, a quiescent region enclosed in the turbulent flow of a protoplanetary disk, seems to be a promising site for planet formation. Indeed, the development of a density maximum at the dead zone inner edge, that has the property to trap the infalling dust, is a natural outcome of the accretion mismatch at this interface. Moreover, the flow here may be unstable and organize itself into vortical structures that efficiently collect dust grains. The inner edge location is however loosely constrained. In particular, it depends on the thermodynamical prescriptions of the disk model that is considered. It has been recently proposed that the inner edge is not static and that the variations of young stars accretion luminosity are the signature of this interface displacements. This thesis address the question of the impact of the gas thermodynamics onto its dynamics around the dead zone inner edge. MHD simulations including the complex interplay between thermodynamical processes and the dynamics confirmed the dynamical behaviour of the inner edge. A first measure of the interface velocity has been realised. This result has been compared to the predictions of a mean field model. It revealed the crucial role of the energy transport by density waves excited at the interface. These simulations also exhibit a new intriguing phenomenon: vortices forming at the interface follow a cycle of formation-migration-destruction. This vortex cycle may compromise the formation of planetesimals at the inner edge. This thesis claims that thermodynamical processes are at the heart of how the region around the dead zone inner edge in protoplanetary disks works. (author) [fr

Increasing incidence of Geomyces destructans fungus in bats from the Czech Republic and Slovakia.

Directory of Open Access Journals (Sweden)

Natália Martínková

Full Text Available BACKGROUND: White-nose syndrome is a disease of hibernating insectivorous bats associated with the fungus Geomyces destructans. It first appeared in North America in 2006, where over a million bats died since then. In Europe, G. destructans was first identified in France in 2009. Its distribution, infection dynamics, and effects on hibernating bats in Europe are largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: We screened hibernacula in the Czech Republic and Slovakia for the presence of the fungus during the winter seasons of 2008/2009 and 2009/2010. In winter 2009/2010, we found infected bats in 76 out of 98 surveyed sites, in which the majority had been previously negative. A photographic record of over 6000 hibernating bats, taken since 1994, revealed bats with fungal growths since 1995; however, the incidence of such bats increased in Myotis myotis from 2% in 2007 to 14% by 2010. Microscopic, cultivation and molecular genetic evaluations confirmed the identity of the recently sampled fungus as G. destructans, and demonstrated its continuous distribution in the studied area. At the end of the hibernation season we recorded pathologic changes in the skin of the affected bats, from which the fungus was isolated. We registered no mass mortality caused by the fungus, and the recorded population decline in the last two years of the most affected species, M. myotis, is within the population trend prediction interval. CONCLUSIONS/SIGNIFICANCE: G. destructans was found to be widespread in the Czech Republic and Slovakia, with an epizootic incidence in bats during the most recent years. Further development of the situation urgently requires a detailed pan-European monitoring scheme.

The potential application of fungus Trichoderma harzianum Rifai in biodegradation of detergent and industry

Directory of Open Access Journals (Sweden)

Jakovljević Violeta D.

2015-01-01

Full Text Available The potential application of fungus Trichoderma harzianum Rifai in biodegradation of commercial detergent (MERIX, Henkel, Serbia was in the focus of this study. The fungus was isolated from wastewater samples of the Rasina River, downstream where the industrial wastewaters of factory Henkel (Krusevac, Serbia discharge into river. The fungus was cultivated in liquid growth medium by Czapek with addition of detergent at a concentration of 0.3% during 16 days. Analysis of fermentation broth evaluated the chemical and biochemical changes of pH, redox potential, activity of alkaline and acid invertase as well as activity of alkaline protease. In addition, the influence of detergent on fungal growth and total dry weight biomass was determined. At the same time, detergent disappearance in terms of methylene blue active substances in the medium was measured. The detergent at a concentration of 0.3% influenced significant decrease of pH value and increase of redox potential. The detergent showed inhibitory effect on acid invertase activity and stimulatory effect on alkaline invertase and protease activity. The fungus decomposed about 74.24% of tested detergent during 16 days, but total dry weight biomass reduced about 20% in relation to control. [Projekat Ministarstva nauke Republike Srbije, br. III 43004

Synthesis of regional wildlife and vegetation field studies to guide management of standing and down dead trees

Science.gov (United States)

Bruce G. Marcot; Janet L. Ohmann; Kim L. Mellen-McLean; Karen L. Waddell

2010-01-01

We used novel methods for combining information from wildlife and vegetation field studies to develop guidelines for managing dead wood for wildlife and biodiversity. The DecAID Decayed Wood Adviser presents data on wildlife use of standing and down dead trees (snags and down wood) and summaries of regional vegetation plot data depicting dead wood conditions, for...

Preparation of 'dead water' for low background liquid scintillation counting

International Nuclear Information System (INIS)

Morishima, Hiroshige; Koga, Taeko; Niwa, Takeo; Kawai, Hiroshi

1987-01-01

'Dead water', low level tritiated water is indispensable to measure tritium concentration in environmental waters using a low background liquid scintillation counter. Water produced by combustion of natural gas, or deep sea water etc. are usually used for the above purpose. A new method of reducing tritium concentration in natural water has been introduced for preparation of 'dead water'. This method is to combine hydrogen-oxygen mixture produced by water electrolysis with hopcalite catalyzer at 700 deg C. Deep well water was electrolized up to 2/3 volume, and tritium concentration of recombined water was reduced to be about one third of that of the original one. (author)

Levels of specificity of Xylaria species associated with fungus-growing termites: a phylogenetic approach

DEFF Research Database (Denmark)

Visser, Andre; Ros, V I D; De Beer, Z. W.

2009-01-01

of the ascomycete genus Xylaria appear and rapidly cover the fungus garden. This raises the question whether certain Xylaria species are specialised in occupying termite nests or whether they are just occasional visitors. We tested Xylaria specificity at four levels: (1) fungus-growing termites, (2) termite genera...... of the ITS region revealed 16 operational taxonomic units of Xylaria, indicating high levels of Xylaria species richness. Not much of this variation was explained by termite genus, species, or colony; thus, at level 2-4 the specificity is low. Analysis of the large subunit rDNA region, showed that all...... termite-associated Xylaria belong to a single clade, together with only three of the 26 non-termite-associated strains. Termite-associated Xylaria thus show specificity for fungus-growing termites (level 1). We did not find evidence for geographic or temporal structuring in these Xylaria phylogenies...

Fungus mediated biosynthesis of WO3 nanoparticles using Fusarium solani extract

Science.gov (United States)

Kavitha, N. S.; Venkatesh, K. S.; Palani, N. S.; Ilangovan, R.

2017-05-01

Currently nanoparticles were synthesized by emphasis bioremediation process due to less hazardous, eco-friendly and imperative applications on biogenic process. Fungus mediated biosynthesis strategy has been developed to prepare tungsten oxide nanoflakes (WO3, NFs) using the plant pathogenic fungus F.solani. The powder XRD pattern revealed the monoclinic crystal structure with improved crystalline nature of the synthesized WO3 nanoparticles. FESEM images showed the flake-like morphology of WO3, with average thickness and length around 40 nm and 300 nm respectively. The Raman spectrum of WO3 NFs showed their characteristic vibration modes that revealed the defect free nature of the WO3 NFs. Further, the elemental analysis indicated the stoichiometric composition of WO3 phase.

Laccase production by Monotospora sp., an endophytic fungus in Cynodon dactylon.

Science.gov (United States)

Wang, J W; Wu, J H; Huang, W Y; Tan, R X

2006-03-01

The effects of the carbon and nitrogen sources, initial pH and incubation temperature on laccase production by the endophytic fungus Monotospora sp. were evaluated. The optimal temperature and initial pH for laccase production by Monotospora sp. in submerged culture were found to be 30 degrees C and 8.5, respectively. Maltose (2 g l(-1)) and ammonium tartrate (10 g l(-1)) were the most suitable carbon and nitrogen source for laccase production. Under optimal culture medium, the maximum laccase activity was determined to be 13.55 U ml(-1), which was approximately four times higher than that in basal medium. This is the first report on laccase production by an endophytic fungus.

Integrated 3D density modelling and segmentation of the Dead Sea Transform

Science.gov (United States)

Götze, H.-J.; El-Kelani, R.; Schmidt, S.; Rybakov, M.; Hassouneh, M.; Förster, H.-J.; Ebbing, J.

2007-04-01

A 3D interpretation of the newly compiled Bouguer anomaly in the area of the “Dead Sea Rift” is presented. A high-resolution 3D model constrained with the seismic results reveals the crustal thickness and density distribution beneath the Arava/Araba Valley (AV), the region between the Dead Sea and the Gulf of Aqaba/Elat. The Bouguer anomalies along the axial portion of the AV, as deduced from the modelling results, are mainly caused by deep-seated sedimentary basins ( D > 10 km). An inferred zone of intrusion coincides with the maximum gravity anomaly on the eastern flank of the AV. The intrusion is displaced at different sectors along the NNW-SSE direction. The zone of maximum crustal thinning (depth 30 km) is attained in the western sector at the Mediterranean. The southeastern plateau, on the other hand, shows by far the largest crustal thickness of the region (38-42 km). Linked to the left lateral movement of approx. 105 km at the boundary between the African and Arabian plate, and constrained with recent seismic data, a small asymmetric topography of the Moho beneath the Dead Sea Transform (DST) was modelled. The thickness and density of the crust suggest that the AV is underlain by continental crust. The deep basins, the relatively large intrusion and the asymmetric topography of the Moho lead to the conclusion that a small-scale asthenospheric upwelling could be responsible for the thinning of the crust and subsequent creation of the Dead Sea basin during the left lateral movement. A clear segmentation along the strike of the DST was obtained by curvature analysis: the northern part in the neighbourhood of the Dead Sea is characterised by high curvature of the residual gravity field. Flexural rigidity calculations result in very low values of effective elastic lithospheric thickness ( t e < 5 km). This points to decoupling of crust in the Dead Sea area. In the central, AV the curvature is less pronounced and t e increases to approximately 10 km

14 CFR 1203b.105 - Use of non-deadly physical force when making an arrest.

Science.gov (United States)

2010-01-01

... Use of non-deadly physical force when making an arrest. When a security force officer has the right to... believes to be the use or threat of imminent use of non-deadly physical force by the offender. Verbal abuse...

Leaf-Cutter Ant Fungus Gardens Are Biphasic Mixed Microbial Bioreactors That Convert Plant Biomass to Polyols with Biotechnological Applications

Science.gov (United States)

Somera, Alexandre F.; Lima, Adriel M.; dos Santos-Neto, Álvaro J.; Lanças, Fernando M.

2015-01-01

Leaf-cutter ants use plant matter to culture the obligate mutualistic basidiomycete Leucoagaricus gongylophorus. This fungus mediates ant nutrition on plant resources. Furthermore, other microbes living in the fungus garden might also contribute to plant digestion. The fungus garden comprises a young sector with recently incorporated leaf fragments and an old sector with partially digested plant matter. Here, we show that the young and old sectors of the grass-cutter Atta bisphaerica fungus garden operate as a biphasic solid-state mixed fermenting system. An initial plant digestion phase occurred in the young sector in the fungus garden periphery, with prevailing hemicellulose and starch degradation into arabinose, mannose, xylose, and glucose. These products support fast microbial growth but were mostly converted into four polyols. Three polyols, mannitol, arabitol, and inositol, were secreted by L. gongylophorus, and a fourth polyol, sorbitol, was likely secreted by another, unidentified, microbe. A second plant digestion phase occurred in the old sector, located in the fungus garden core, comprising stocks of microbial biomass growing slowly on monosaccharides and polyols. This biphasic operation was efficient in mediating symbiotic nutrition on plant matter: the microbes, accounting for 4% of the fungus garden biomass, converted plant matter biomass into monosaccharides and polyols, which were completely consumed by the resident ants and microbes. However, when consumption was inhibited through laboratory manipulation, most of the plant polysaccharides were degraded, products rapidly accumulated, and yields could be preferentially switched between polyols and monosaccharides. This feature might be useful in biotechnology. PMID:25911490

Optimal linear filtering of Poisson process with dead time

International Nuclear Information System (INIS)

Glukhova, E.V.

1993-01-01

The paper presents a derivation of an integral equation defining the impulsed transient of optimum linear filtering for evaluation of the intensity of the fluctuating Poisson process with allowance for dead time of transducers

Fluorescent probes as a tool for labelling and tracking the amphibian chytrid fungus Batrachochytrium dendrobatidis.

Science.gov (United States)

Herbert, Sarah M; Leung, Tommy L F; Bishop, Phillip J

2011-09-09

The dissemination of the virulent pathogen Batrachochytrium dendrobatidis (Bd) has contributed to the decline and extinction of many amphibian species worldwide. Several different strains have been identified, some of which are sympatric. Interactions between co-infecting strains of a pathogen can have significant influences on disease epidemiology and evolution; therefore the dynamics of multi-strain infections is an important area of research. We stained Bd cells with 2 fluorescent BODIPY fatty acid probes to determine whether these can potentially be used to distinguish and track Bd cell lines in multi-strain experiments. Bd cells in broth culture were stained with 5 concentrations of green-fluorescent BODIPY FL and red-fluorescent BODIPY 558/568 and visualised under an epifluorescent microscope for up to 16 d post-dye. Dyed strains were also assessed for growth inhibition. The most effective concentration for both dyes was 10 pM. This concentration of dye produced strong fluorescence for 12 to 16 d in Bd cultures held at 23 degrees C (3 to 4 generations), and did not inhibit Bd growth. Cells dyed with BODIPY FL and BODIPY 558/568 can be distinguished from each other on the basis of their fluorescence characteristics. Therefore, it is likely that this technique will be useful for research into multi-strain dynamics of Bd infections.

Leucopaxillus lepistoides, a new steppe fungus in Poland

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Janusz Łuszczyński

2013-12-01

Full Text Available The paper presents information on Leucopaxillus lepistoides (Maire Singer, a new species for Poland. This fungus was found in two localities: the neighbourhood of Busko Zdrój and Chęciny (Little Polish Upland, S-Poland. Both localities were in the xerothermic grasslands belonging to the Cirsio-Brachypodion Order, Festuco-Brometea Class.

A new polyoxygenated farnesylcyclohexenone from Fungus Penicillium sp.

Science.gov (United States)

Yang, Yabin; Yang, Fangfang; Zhao, Lixing; Duang, Rongting; Chen, Guangyi; Li, Xiaozhan; Li, Qiling; Qin, Shaohuan; Ding, Zhongtao

2016-01-01

A new polyoxygenated farnesylcyclohexenone, peniginsengin A (1), was isolated from the fermentation of Penicillium sp. YIM PH30003, an endophytic fungus associated with Panax notoginseng (Burk.) F. H. Chen. The structure was assigned based on a combination of 1 D and 2 D NMR and mass spectral data. The cytotoxicity and antimicrobial activities of compound 1 were investigated.

A Rare Case of Intracavitary Fungus Ball (Aspergilloma in the Old Pulmonary Tuberculosis

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Majzoobi MM

2017-06-01

Full Text Available Introduction: Pulmonary fungus ball is a rare complication in pre-existing pulmonary cavitary lesions, due to some chronic pulmonary diseases including tuberculosis, lung abscess and sarcoidosis. Fungus ball is mostly caused by aspergillus. In many patients, fungus ball is asymptomatic, but in a significant number of them it can develop cough and hemoptysis, which may be massive and fatal. The cornerstone of assessment is chest imaging, along with sputum culture or aspergillus antibody in patient's serum. The purpose of this report is increment in attention to this complication in patients with previous pulmonary tuberculosis (TB. Case Presentation: The patient was a 23-year-old woman with chief complaint of fever, cough and hemoptysis, who was hospitalized in the Infectious Diseases Ward of Farshchian Sina hospital in March 2016. She had a history of anti-TB therapy from two years before. Sputum and bronchoalveolar lavage (BAL were negative for cytology and Mycobacterium tuberculosis, but cultures of both samples were positive for Aspergillus niger. Her lung contrast-enhanced computerized tomography (CECT scan revealed the presence of a fungus ball inside the upper lobe cavity of right lung. After lobectomy, fungal mass was confirmed by histopathology. Conclusions: In patients with pulmonary complaints (especially hemoptysis and history of cavitary pulmonary tuberculosis, the differential diagnosis of community-acquired pneumonia, lung abscess, reactivation of tuberculosis and lung cancer as well as fungal infections should be considered.

Spiritual bonds to the dead in cross-cultural and historical perspective: comparative religion and modern grief.

Science.gov (United States)

Klass, D; Goss, R

1999-09-01

Contemporary spirituality within continuing bonds with the dead is placed into the comparative context of Western Christianity and Japanese Buddhism. Throughout history, humans have maintained interaction with two kinds of dead: ancestors and sacred dead, the first characterized by symmetrical relationships and the second by asymmetrical. Continuing bonds are deeply connected with, and are often in conflict with, bonds to the nation and (in the West) to God. In this framework, the authors find that continuing bonds in the present function within the private sphere and have very limited functions within the larger society, resemble traditional bonds with the sacred dead, and, at this time, offer a mild critique of the values and lifestyles on which consumer capitalism is based.

The World of The Walking Dead – Transmediality and Transmedial Intermediality

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Beil Benjamin

2015-08-01

Full Text Available As transmedia franchises increasingly populate our cultural environment, many questions arise about the effect of the different media involved in the depiction of storyworlds. Through the analysis of different examples, with special emphasis on the particular case of The Walking Dead, and drawing primarily from Henry Jenkins’s concept of “transmedia storytelling” and Jens Schroter’s concept of intermediality, this paper aims to show how different media aesthetics contribute to the process of storytelling and enrich the experience of the consumer. Usually overlooked in other analyses, we argue that these formal and aesthetical characteristics, such as the interactive nature of video games, call for a broader approach that transcends the accustomed search of common narrative aspects. This will be exemplified by a closer comparative look at the adventure game The Walking Dead: The Ganie (Telltale Games, 2012 and The Walking Dead: Survival Instiiict (Terminal Reality, 2013. The transformations that the different media demand contribute not only to the narrative, but also provide different tools for the construction of storyworlds and different ways to engage with it.

The role of enzymes in fungus-growing ant evolution

DEFF Research Database (Denmark)

de Fine Licht, Henrik Hjarvard

behaviour. Here we report the first large-scale comparative study on fungus garden enzyme profiles and show that various interesting changes can be documented. A more detailed analysis of laccase expression, an enzyme that is believed to oxidize phenols in defensive secondary plant compounds such as tannins...

Leucoagaricus gongylophorus Produces Diverse Enzymes for the Degradation of Recalcitrant Plant Polymers in Leaf-Cutter Ant Fungus Gardens

Energy Technology Data Exchange (ETDEWEB)

Aylward, Frank O. [Univ. of Wisconsin, Madison, WI (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Burnum-Johnson, Kristin E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tringe, Susannah G. [Dept. of Energy Joint Genome Inst., Walnut Creek, CA (United States); Teiling, Clotilde [Roche Diagnostics, Indianapolis, IN (United States); Tremmel, Daniel [Univ. of Wisconsin, Madison, WI (United States); Moeller, Joseph [Univ. of Wisconsin, Madison, WI (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Scott, Jarrod J. [Univ. of Wisconsin, Madison, WI (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Barry, Kerrie W. [Dept. of Energy Joint Genome Inst., Walnut Creek, CA (United States); Piehowski, Paul D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Nicora, Carrie D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Malfatti, Stephanie [Dept. of Energy Joint Genome Inst., Walnut Creek, CA (United States); Monroe, Matthew E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Purvine, Samuel O. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Goodwin, Lynne A. [Dept. of Energy Joint Genome Inst., Walnut Creek, CA (United States); Smith, Richard D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Weinstock, George [Washington Univ. School of Medicine, St. Louis, MS (United States); Gerardo, Nicole [Emory Univ., Atlanta, GA (United States); Suen, Garret [Dept. of Energy Joint Genome Inst., Walnut Creek, CA (United States); Lipton, Mary S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Currie, Cameron R. [Univ. of Wisconsin, Madison, WI (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Smothsonian Tropical Research Inst., Balboa (Panama)

2013-06-12

Plants represent a large reservoir of organic carbon comprised largely of recalcitrant polymers that most metazoans are unable to deconstruct. Many herbivores gain access to nutrients in this material indirectly by associating with microbial symbionts, and leaf-cutter ants are a paradigmatic example. These ants use fresh foliar biomass as manure to cultivate fungus gardens composed primarily of Leucoagaricus gongylophorus, a basidiomycetous symbiont that produces specialized hyphal swellings that serve as a food source for the host ant colony. Although leaf-cutter ants are conspicuous herbivores that contribute substantially to carbon turnover in Neotropical ecosystems, the process through which plant biomass is degraded in their fungus gardens is not well understood. Here we present the first draft genome of L. gongylophorus, and using genomic, metaproteomic, and phylogenetic tools we investigate its role in lignocellulose degradation in the fungus gardens of both Atta cephalotes and Acromyrmex echinatior leaf-cutter ants. We show that L. gongylophorus produces a diversity of lignocellulases in fungus gardens, and is likely the primary driver of plant biomass degradation in these ecosystems. We also show that this fungus produces distinct sets of lignocellulases throughout the different stages of biomass degradation, including numerous cellulases and laccases that may be playing an important but previously uncharacterized role in lignocellulose degradation. Our study provides a comprehensive analysis of plant biomass degradation in leaf-cutter ant fungus gardens and provides insight into the molecular dynamics underlying the symbiosis between these dominant herbivores and their obligate fungal cultivar.

White-nose syndrome fungus (Geomyces destructans) in bats, Europe

Science.gov (United States)

Wibbelt, G.; Kurth, A.; Hellmann, D.; Weishaar, M.; Barlow, A.; Veith, M.; Pruger, J.; Gorfol, T.; Grosche, T.; Bontadina, F.; Zophel, U.; Seidl, Hans-Peter; Cryan, P.M.; Blehert, D.S.

2010-01-01

White-nose syndrome is an emerging disease in North America that has caused substantial declines in hibernating bats. A recently identified fungus (Geomyces destructans) causes skin lesions that are characteristic of this disease. Typical signs of this infection were not observed in bats in North America before white-nose syndrome was detected. However, unconfirmed reports from Europe indicated white fungal growth on hibernating bats without associated deaths. To investigate these differences, hibernating bats were sampled in Germany, Switzerland, and Hungary to determine whether G. destructans is present in Europe. Microscopic observations, fungal culture, and genetic analyses of 43 samples from 23 bats indicated that 21 bats of 5 species in 3 countries were colonized by G. destructans. We hypothesize that G. destructans is present throughout Europe and that bats in Europe may be more immunologically or behaviorally resistant to G. destructans than their congeners in North America because they potentially coevolved with the fungus.

White-nose syndrome fungus (Geomyces destructans) in bats, Europe.

Science.gov (United States)

Wibbelt, Gudrun; Kurth, Andreas; Hellmann, David; Weishaar, Manfred; Barlow, Alex; Veith, Michael; Prüger, Julia; Görföl, Tamás; Grosche, Lena; Bontadina, Fabio; Zöphel, Ulrich; Seidl, Hans Peter; Seidl, Hans Peter; Blehert, David S

2010-08-01

White-nose syndrome is an emerging disease in North America that has caused substantial declines in hibernating bats. A recently identified fungus (Geomyces destructans) causes skin lesions that are characteristic of this disease. Typical signs of this infection were not observed in bats in North America before white-nose syndrome was detected. However, unconfirmed reports from Europe indicated white fungal growth on hibernating bats without associated deaths. To investigate these differences, hibernating bats were sampled in Germany, Switzerland, and Hungary to determine whether G. destructans is present in Europe. Microscopic observations, fungal culture, and genetic analyses of 43 samples from 23 bats indicated that 21 bats of 5 species in 3 countries were colonized by G. destructans. We hypothesize that G. destructans is present throughout Europe and that bats in Europe may be more immunologically or behaviorally resistant to G. destructans than their congeners in North America because they potentially coevolved with the fungus.

Metabolism of carbohydrates in the fungus Aspergillus niger under the action of light

International Nuclear Information System (INIS)

Chebotarev, L.N.; Yaremina, Y.A.

1988-01-01

Effect of visible light with 410, 520 and 610 nm wave lengths on carbonhydrate transformation and absorption by Aspergillus niger fungus is studied. It is shown that the light stimulates the absorption by the fungus of the medium carbohydrates and their biochemical modifications. This leads to amplification of biomass accumulation and citric acid liberation to the medium. An increase of citric acid content in the cultural liquid is counected either with producer biomass growth or with amplification of biomass unit ability to citrate biosynthesis or with simultaneous realization of the both ways indicated

Bioactive Constituents from an Endophytic Fungus, Penicillium polonicum NFW9, Associated with Taxus fauna.

Science.gov (United States)

Fatima, Nighat; Sripisut, Tawanun; Youn, Ui J; Ahmed, Safia; Ul-Haq, Ihsan; Munoz-Acuna, Ulyana; Simmons, Charles J; Qazi, Muneer A; Jadoon, Muniba; Tan, Ghee T; de Blanco, Esperanza J C; Chang, Leng C

2017-01-01

Endophytic fungi are being recognized as vital and untapped sources of a variety of structurally novel and unique bioactive secondary metabolites in the field of natural products drug discovery. Herein, this study reports the isolation and characterization of secondary metabolites from an endophytic fungus Penicillium polonicum (NFW9) associated with Taxus fuana. The extracts of the endophytic fungus cultured on potato dextrose agar were purified using several chromatographic techniques. Biological evaluation was performed based on their abilities to inhibit tumor necrosis factor-alpha (TNF-α)-induced nuclear factor-kappa B (NF-κB) and cytotoxicity assays. Bioactivity-directed fractionation of the ethyl acetate extract of a fermentation culture of an endophytic fungus, Penicillium polonicum led to the isolation of a dimeric anthraquinone, (R)- 1,1',3,3',5,5'-hexahydroxy-7,7'-dimethyl[2,2'-bianthracene]-9,9',10,10'-tetraone (1), a steroidal furanoid (-)-wortmannolone (2), along with three other compounds (3-4). Moreover, this is the first report on the isolation of compound 1 from an endophytic fungus. All purified metabolites were characterized by NMR and MS data analyses. The stereo structure of compound 1 was determined by the measurement of specific optical rotation and CD spectrum. The relative stereochemistry of 2 was confirmed by single-crystal X-ray diffraction. Compounds 2-3 showed inhibitory activities in the TNF-α-induced NF-κB assay with IC50 values in the range of 0.47-2.11 µM. Compounds 1, 4 and 5 showed moderate inhibition against NF-κB and cancer cell lines. The endophytic fungus Penicillium polonicum of Taxus fuana is capable of producing biologically active natural compounds. Our results provide a scientific rationale for further chemical investigations into endophyte-producing natural products, drug discovery and development. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Comparative EST analysis provides insights into the basal aquatic fungus Blastocladiella emersonii

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Gomes Suely L

2006-07-01

Full Text Available Abstract Background Blastocladiella emersonii is an aquatic fungus of the Chytridiomycete class, which is at the base of the fungal phylogenetic tree. In this sense, some ancestral characteristics of fungi and animals or fungi and plants could have been retained in this aquatic fungus and lost in members of late-diverging fungal species. To identify in B. emersonii sequences associated with these ancestral characteristics two approaches were followed: (1 a large-scale comparative analysis between putative unigene sequences (uniseqs from B. emersonii and three databases constructed ad hoc with fungal proteins, animal proteins and plant unigenes deposited in Genbank, and (2 a pairwise comparison between B. emersonii full-length cDNA sequences and their putative orthologues in the ascomycete Neurospora crassa and the basidiomycete Ustilago maydis. Results Comparative analyses of B. emersonii uniseqs with fungi, animal and plant databases through the two approaches mentioned above produced 166 B. emersonii sequences, which were identified as putatively absent from other fungi or not previously described. Through these approaches we found: (1 possible orthologues of genes previously identified as specific to animals and/or plants, and (2 genes conserved in fungi, but with a large difference in divergence rate in B. emersonii. Among these sequences, we observed cDNAs encoding enzymes from coenzyme B12-dependent propionyl-CoA pathway, a metabolic route not previously described in fungi, and validated their expression in Northern blots. Conclusion Using two different approaches involving comparative sequence analyses, we could identify sequences from the early-diverging fungus B. emersonii previously considered specific to animals or plants, and highly divergent sequences from the same fungus relative to other fungi.

Dead Sea deep cores: A window into past climate and seismicity

Science.gov (United States)

Stein, Mordechai; Ben-Avraham, Zvi; Goldstein, Steven L.

2011-12-01

The area surrounding the Dead Sea was the locus of humankind's migration out of Africa and thus has been the home of peoples since the Stone Age. For this reason, understanding the climate and tectonic history of the region provides valuable insight into archaeology and studies of human history and helps to gain a better picture of future climate and tectonic scenarios. The deposits at the bottom of the Dead Sea are a geological archive of the environmental conditions (e.g., rains, floods, dust storms, droughts) during ice ages and warm ages, as well as of seismic activity in this key region. An International Continental Scientific Drilling Program (ICDP) deep drilling project was performed in the Dead Sea between November 2010 and March 2011. The project was funded by the ICDP and agencies in Israel, Germany, Japan, Norway, Switzerland, and the United States. Drilling was conducted using the new Large Lake Drilling Facility (Figure 1), a barge with a drilling rig run by DOSECC, Inc. (Drilling, Observation and Sampling of the Earth's Continental Crust), a nonprofit corporation dedicated to advancing scientific drilling worldwide. The main purpose of the project was to recover a long, continuous core to provide a high resolution record of the paleoclimate, paleoenvironment, paleoseismicity, and paleomagnetism of the Dead Sea Basin. With this, scientists are beginning to piece together a record of the climate and seismic history of the Middle East during the past several hundred thousand years in millennial to decadal to annual time resolution.

Measurement-based modeling of bromine chemistry in the boundary layer: 1. Bromine chemistry at the Dead Sea

Science.gov (United States)

Tas, E.; Peleg, M.; Pedersen, D. U.; Matveev, V.; Pour Biazar, A.; Luria, M.

2006-12-01

The Dead Sea is an excellent natural laboratory for the investigation of Reactive Bromine Species (RBS) chemistry, due to the high RBS levels observed in this area, combined with anthropogenic air pollutants up to several ppb. The present study investigated the basic chemical mechanism of RBS at the Dead Sea using a numerical one-dimensional chemical model. Simulations were based on data obtained from comprehensive measurements performed at sites along the Dead Sea. The simulations showed that the high BrO levels measured frequently at the Dead Sea could only partially be attributed to the highly concentrated Br- present in the Dead Sea water. Furthermore, the RBS activity at the Dead Sea cannot solely be explained by a pure gas phase mechanism. This paper presents a chemical mechanism which can account for the observed chemical activity at the Dead Sea, with the addition of only two heterogeneous processes: the "Bromine Explosion" mechanism and the heterogeneous decomposition of BrONO2. Ozone frequently dropped below a threshold value of ~1 to 2 ppbv at the Dead Sea evaporation ponds, and in such cases, O3 became a limiting factor for the production of BrOx (BrO+Br). The entrainment of O3 fluxes into the evaporation ponds was found to be essential for the continuation of RBS activity, and to be the main reason for the jagged diurnal pattern of BrO observed in the Dead Sea area, and for the positive correlation observed between BrO and O3 at low O3 concentrations. The present study has shown that the heterogeneous decomposition of BrONO2 has a great potential to affect the RBS activity in areas influenced by anthropogenic emissions, mainly due to the positive correlation between the rate of this process and the levels of NO2. Further investigation of the influence of the decomposition of BrONO2 may be especially important in understanding the RBS activity at mid-latitudes.

Measurement-based modeling of bromine chemistry in the boundary layer: 1. Bromine chemistry at the Dead Sea

Directory of Open Access Journals (Sweden)

E. Tas

2006-01-01

Full Text Available The Dead Sea is an excellent natural laboratory for the investigation of Reactive Bromine Species (RBS chemistry, due to the high RBS levels observed in this area, combined with anthropogenic air pollutants up to several ppb. The present study investigated the basic chemical mechanism of RBS at the Dead Sea using a numerical one-dimensional chemical model. Simulations were based on data obtained from comprehensive measurements performed at sites along the Dead Sea. The simulations showed that the high BrO levels measured frequently at the Dead Sea could only partially be attributed to the highly concentrated Br− present in the Dead Sea water. Furthermore, the RBS activity at the Dead Sea cannot solely be explained by a pure gas phase mechanism. This paper presents a chemical mechanism which can account for the observed chemical activity at the Dead Sea, with the addition of only two heterogeneous processes: the "Bromine Explosion" mechanism and the heterogeneous decomposition of BrONO2. Ozone frequently dropped below a threshold value of ~1 to 2 ppbv at the Dead Sea evaporation ponds, and in such cases, O3 became a limiting factor for the production of BrOx (BrO+Br. The entrainment of O3 fluxes into the evaporation ponds was found to be essential for the continuation of RBS activity, and to be the main reason for the jagged diurnal pattern of BrO observed in the Dead Sea area, and for the positive correlation observed between BrO and O3 at low O3 concentrations. The present study has shown that the heterogeneous decomposition of BrONO2 has a great potential to affect the RBS activity in areas influenced by anthropogenic emissions, mainly due to the positive correlation between the rate of this process and the levels of NO2. Further investigation of the influence of the decomposition of BrONO2 may be especially important in understanding the RBS activity at mid-latitudes.

Geiger-Mueller haloid counter dead time dependence on counting rate

International Nuclear Information System (INIS)

Onishchenko, A.M.; Tsvetkov, A.A.

1980-01-01

The experimental dependences of the dead time of Geiger counters (SBM-19, SBM-20, SBM-21 and SGM-19) on the loading, are presented. The method of two sources has been used to determine the dead time counters of increased stability. The counters are switched on according to the usually used circuit of discrete counting with loading resistance of 50 MOhm and the separating capacity of 10 pF. Voltage pulses are given to the counting device with the time of resolution of 100 ns, discrimenation threshold 3 V, input resistance 3.6 Ω and the input capacity-15 pF. The time constant of the counter RC-circuit is 50 μs

Direct ethanol production from starch, wheat bran and rice straw by the white rot fungus Trametes hirsuta

NARCIS (Netherlands)

Okamoto, Kenji; Nitta, Yasuyuki; Maekawa, Nitaro; Yanase, Hideshi

2011-01-01

The white rot fungus Trametes hirsuta produced ethanol from a variety of hexoses: glucose, mannose, cellobiose and maltose, with yields of 0.49. 0.48, 0.47 and 0.47 g/g of ethanol per sugar utilized, respectively. In addition, this fungus showed relatively favorable xylose consumption and ethanol

Detector dead-time effects and paralyzability in high-speed quantum key distribution

International Nuclear Information System (INIS)

Rogers, Daniel J; Bienfang, Joshua C; Nakassis, Anastase; Xu Hai; Clark, Charles W

2007-01-01

Recent advances in quantum key distribution (QKD) have given rise to systems that operate at transmission periods significantly shorter than the dead times of their component single-photon detectors. As systems continue to increase in transmission rate, security concerns associated with detector dead times can limit the production rate of sifted bits. We present a model of high-speed QKD in this limit that identifies an optimum transmission rate for a system with given link loss and detector response characteristics

A high-resolution and intelligent dead pixel detection scheme for an electrowetting display screen

Science.gov (United States)

Luo, ZhiJie; Luo, JianKun; Zhao, WenWen; Cao, Yang; Lin, WeiJie; Zhou, GuoFu

2018-02-01

Electrowetting display technology is realized by tuning the surface energy of a hydrophobic surface by applying a voltage based on electrowetting mechanism. With the rapid development of the electrowetting industry, how to analyze efficiently the quality of an electrowetting display screen has a very important significance. There are two kinds of dead pixels on the electrowetting display screen. One is that the oil of pixel cannot completely cover the display area. The other is that indium tin oxide semiconductor wire connecting pixel and foil was burned. In this paper, we propose a high-resolution and intelligent dead pixel detection scheme for an electrowetting display screen. First, we built an aperture ratio-capacitance model based on the electrical characteristics of electrowetting display. A field-programmable gate array is used as the integrated logic hub of the system for a highly reliable and efficient control of the circuit. Dead pixels can be detected and displayed on a PC-based 2D graphical interface in real time. The proposed dead pixel detection scheme reported in this work has promise in automating electrowetting display experiments.

Meroterpenoids and isoberkedienolactone from endophytic fungus Penicillium sp. associated with Dysosma versipellis.

Science.gov (United States)

Li, Jun-Wei; Duan, Rui-Gang; Zou, Jian-Hua; Chen, Ri-Dao; Chen, Xiao-Guang; Dai, Jun-Gui

2014-06-01

Seven meroterpenoids and five small-molecular precursors were isolated from Penicillium sp., an endophytic fungus from Dysosma versipellis. The structures of new compounds, 11beta-acetoxyisoaustinone (1) and isoberkedienolactone (2) were elucidated based on analysis of the spectral data, and the absolute configuration of 2 was established by TDDFT ECD calculation with satisfactory match to its experimental ECD data. Meroterpenoids originated tetraketide and pentaketide precursors, resepectively, were found to be simultaneously produced in specific fungus of Penicillium species. These compounds showed weak cytotoxicity in vitro against HCT-116, HepG2, BGC-823, NCI-H1650, and A2780 cell lines with IC 50 > 10 micromol x L(-1).

Diversity of dead wood inhabiting fungal and bryophytes in semi-natural beech forests in Europe

NARCIS (Netherlands)

Ódor, P.; Heilmann-Clausen, J.; Christensen, M.; Aude, E.; Dort, van K.W.; Piltaver, A.; Siller, I.; Veerkamp, M.T.; Walleyn, R.; Standovár, T.; Hees, van A.F.M.; Kosec, J.; Matocec, N.; Kraigher, H.; Grebenc, T.

2006-01-01

Saproxylic organisms are among the most threatened species in Europe and constitute a major conservation problem because they depend on the most important forestry product - dead wood. Diversity of fungal and bryophyte communities occurring on dead beech trees was analyzed in five European countries

Foehn-induced effects on dust pollution, frontal clouds and solar radiation in the Dead Sea valley

Science.gov (United States)

Kishcha, Pavel; Starobinets, Boris; Alpert, Pinhas; Kaplan, Michael

2017-04-01

The significant drying up of the Dead Sea over the past 40 years has led to an increase in an exposed area contributing to local dust pollution. Measurements show that, sometimes, in the Dead Sea valley, dust pollution can reach extreme concentrations up to several thousands of micrograms per cubic meters. Our analysis of a meteorological situation shows that a foehn phenomenon can be a causal factor for the aforementioned extreme local dust concentration. This foehn phenomenon creates strong warm and dry winds, which are accompanied by air turbulence and temperature inversion. In our study, foehn-induced effects on dust pollution, frontal clouds and solar radiation were analyzed over the Judean Mountains ( 1000 m) and over the Dead Sea valley (-420 m), using high-resolution numerical simulations and in-situ observations at meteorological stations located across the mountain ridge. An extreme dust episode occurring on March 22, 2013, was analyzed, which was characterized by measured surface dust concentrations of up to 7000 µg m-3 in the Dead Sea valley. We simulated this foehn phenomenon with the 3-km resolution COSMO-ART model. Our analysis has shown that the foehn phenomenon could be observed even over the relatively low Judean Mountains. This analysis was based on various meteorological, pyranometer, radar, and aerosol measurements together with high-resolution model data. In the Dead Sea valley, the maximum aerosol optical depth (AOD) did not coincide with the maximum surface dust concentration. This lack of coincidence indicates difficulties in using satellite-based AOD for initializing dust concentration within numerical forecast systems over this region with complex terrain. In the western Dead Sea valley, strong foehn winds of over 20 m/s were accompanied by maximal air turbulence leading to maximal local dust emissions. Thus, the model showed that, by creating significant turbulence, the foehn phenomenon intensified the saltation (bombardment) mechanism

Absolute dose calibration of an X-ray system and dead time investigations of photon-counting techniques

CERN Document Server

Carpentieri, C; Ludwig, J; Ashfaq, A; Fiederle, M

2002-01-01

High precision concerning the dose calibration of X-ray sources is required when counting and integrating methods are compared. The dose calibration for a dental X-ray tube was executed with special dose calibration equipment (dosimeter) as function of exposure time and rate. Results were compared with a benchmark spectrum and agree within +-1.5%. Dead time investigations with the Medipix1 photon-counting chip (PCC) have been performed by rate variations. Two different types of dead time, paralysable and non-paralysable will be discussed. The dead time depends on settings of the front-end electronics and is a function of signal height, which might lead to systematic defects of systems. Dead time losses in excess of 30% have been found for the PCC at 200 kHz absorbed photons per pixel.

A method for the determination of detector channel dead time for a neutron time-of-flight spectrometer

International Nuclear Information System (INIS)

Adib, M.; Salama, M.; Abd-Kawi, A.; Sadek, S.; Hamouda, I.

1975-01-01

A new method is developed to measure the dead time of a detector channel for a neutron time-of-flight spectrometer. The method is based on the simultaneous use of two identical BF 3 detectors but with two different efficiencies, due to their different enrichment in B 10 . The measurements were performed using the T.O.F. spectrometer installed at channel No. 6 of the ET-RR-1 reactor. The main contribution to the dead time was found to be due to the time analyser and the neutron detector used. The analyser dead time has been determined using a square wave pulse generator with frequency of 1 MC/S. For channel widths of 24.4 us, 48.8 ud and 97.6 us, the weighted dead times for statistical pulse distribution were found to be 3.25 us, 1.87 us respectively. The dead time of the detector contributes mostly to the counting losses and its value was found to be (33+-3) us

Pathogenicity of the bioherbicide fungus chondrostereum purpureum to some trees and shrubs of southern Vancouver Island. FRDA report No. 246

Energy Technology Data Exchange (ETDEWEB)

Wall, R.E.

1996-11-01

Chondrostereum purpureum is a common stem-invading fungus of trees and shrubs. The fungus has attracted interest as a bioherbicide, but a better understanding of its biology is required. This study was undertaken to determine the range of virulence of isolates of C. purpureum from a given region on major hardwood species in British Columbia. The investigators inoculated wounds of stems of standing red alder (Alnus rubra) and bigleaf maple (Acer macrophyllum) saplings with 11 isolates of the fungus and measured the resulting stem cankers as an index of virulence. They also inoculated eight hardwood and shrub species with two isolates to demonstrate the range of susceptibility of species to the fungus, as well as the intraspecific variation.

Ecology, environmental requirements and conservation of corticioid fungi occupying small diameter dead wood

OpenAIRE

Juutilainen, Katja

2016-01-01

The increasing human impact upon the biosphere of earth is causing profound changes across all spatial scales. The ability to cope with human-induced disturbance varies among organisms; specialist species are more negatively affected than generalist species. Forests are among the most heavily affected ecosystems; especially the dead wood associated organisms are in peril. The earlier research has strongly focused on large diameter dead wood and associated species. The ...

Quantitative Proteomics of an Amphibian Pathogen, Batrachochytrium dendrobatidis, following Exposure to Thyroid Hormone.

Science.gov (United States)

Thekkiniath, Jose; Zabet-Moghaddam, Masoud; Kottapalli, Kameswara Rao; Pasham, Mithun R; San Francisco, Susan; San Francisco, Michael

2015-01-01

Batrachochytrium dendrobatidis (Bd), a chytrid fungus, has increasingly been implicated as a major factor in the worldwide decline of amphibian populations. The fungus causes chytridiomycosis in susceptible species leading to massive die-offs of adult amphibians. Although Bd infects the keratinized mouthparts of tadpoles and negatively affects foraging behavior, these infections are non-lethal. An important morphogen controlling amphibian metamorphosis is thyroid hormone (T3). Tadpoles may be infected with Bd and the fungus may be exposed to T3 during metamorphosis. We hypothesize that exposure of Bd to T3 may induce the expression of factors associated with host colonization and pathogenicity. We utilized a proteomics approach to better understand the dynamics of the Bd-T3 interaction. Using liquid chromatography-mass spectrometry (LC-MS), we generated a data set of a large number of cytoplasmic and membrane proteins following exposure of Bd to T3. From these data, we identified a total of 263 proteins whose expression was significantly changed following T3 exposure. We provide evidence for expression of an array of proteins that may play key roles in both genomic and non-genomic actions of T3 in Bd. Additionally, our proteomics study shows an increase in several proteins including proteases and a class of uncommon crinkler and crinkler-like effector proteins suggesting their importance in Bd pathogenicity as well as those involved in metabolism and energy transfer, protein fate, transport and stress responses. This approach provides insights into the mechanistic basis of the Bd-amphibian interaction following T3 exposure.

Quantitative Proteomics of an Amphibian Pathogen, Batrachochytrium dendrobatidis, following Exposure to Thyroid Hormone.

Directory of Open Access Journals (Sweden)

Jose Thekkiniath

Full Text Available Batrachochytrium dendrobatidis (Bd, a chytrid fungus, has increasingly been implicated as a major factor in the worldwide decline of amphibian populations. The fungus causes chytridiomycosis in susceptible species leading to massive die-offs of adult amphibians. Although Bd infects the keratinized mouthparts of tadpoles and negatively affects foraging behavior, these infections are non-lethal. An important morphogen controlling amphibian metamorphosis is thyroid hormone (T3. Tadpoles may be infected with Bd and the fungus may be exposed to T3 during metamorphosis. We hypothesize that exposure of Bd to T3 may induce the expression of factors associated with host colonization and pathogenicity. We utilized a proteomics approach to better understand the dynamics of the Bd-T3 interaction. Using liquid chromatography-mass spectrometry (LC-MS, we generated a data set of a large number of cytoplasmic and membrane proteins following exposure of Bd to T3. From these data, we identified a total of 263 proteins whose expression was significantly changed following T3 exposure. We provide evidence for expression of an array of proteins that may play key roles in both genomic and non-genomic actions of T3 in Bd. Additionally, our proteomics study shows an increase in several proteins including proteases and a class of uncommon crinkler and crinkler-like effector proteins suggesting their importance in Bd pathogenicity as well as those involved in metabolism and energy transfer, protein fate, transport and stress responses. This approach provides insights into the mechanistic basis of the Bd-amphibian interaction following T3 exposure.

The Dead Mother, the Uncanny, and the Holy Ghost

Directory of Open Access Journals (Sweden)

Gal Ventura

2015-01-01

Full Text Available Recurrent portrayals of dead mothers frequently appeared in French art from 1800 to 1850. This essay focuses on one of the latest manifestations of this image, namely, the French Realist Jules Breton's (1827-1906 painting The Hunger of 1850, in order to examine the psycho-historical elements associated with the mother's death. Through an analysis of the "Uncanny" as formulated by both Ernst Jentsch and Sigmund Freud, we will address the undissolvable link between the structuralization of "homeliness" in the late eighteenth century and the dread it evoked in the early nineteenth century, as two sides of the same coin. We will simultaneously consider the inherent conflictuality embodied by the dead mother according to the French psychoanalyst André Green, who dealt with the experience of "nothingness" that characterizes children of mothers-who-refuse-to-die.

Theory of precipitation effects on dead cylindrical fuels

Science.gov (United States)

Michael A. Fosberg

1972-01-01

Numerical and analytical solutions of the Fickian diffusion equation were used to determine the effects of precipitation on dead cylindrical forest fuels. The analytical solution provided a physical framework. The numerical solutions were then used to refine the analytical solution through a similarity argument. The theoretical solutions predicted realistic rates of...

9 CFR 325.20 - Transportation and other transactions concerning dead, dying, disabled, or diseased livestock...

Science.gov (United States)

2010-01-01

... concerning dead, dying, disabled, or diseased livestock, and parts of carcasses of livestock that died... other transactions concerning dead, dying, disabled, or diseased livestock, and parts of carcasses of livestock that died otherwise than by slaughter. No person engaged in the business of buying, selling, or...

Fingerprints of a forest fungus: Swiss needle cast, carbon isotopes, carbohydrates, and growth in Douglas-fir

Science.gov (United States)

Andrea Watts; Frederick Meinzer; Brandy J. Saffell

2014-01-01

Swiss needle cast is caused by a fungus native to the Pacific Northwest. Its host is Douglas-fir, an iconic evergreen tree in the region. The fungus does not kill its host, but it adversely affects the tree's growth. The fungal fruiting bodies block the stomata, small openings on the underside of the needle where carbon dioxide, water vapor, and other gases are...

The origin of Ceratocystis fagacearum, the oak wilt fungus

Science.gov (United States)

Jennifer Juzwik; Thomas C. Harrington; William L. MacDonald; David N. Appel

2008-01-01

The oak wilt pathogen, Ceratocystis fagacearum, may be another example of a damaging, exotic species in forest ecosystems in the United States. Though C. fagacearum has received much research attention, the origin of the fungus is unknown. The pathogen may have been endemic at a low incidence until increased disturbances, changes...

Identification of a taxol-producing endophytic fungus EFY-36

African Journals Online (AJOL)

STORAGESEVER

2009-06-03

Jun 3, 2009 ... Morphological and molecular methods were used to identify the statues of an isolate, EFY-36, a taxol- ... of the spores. The analysis of endophytic fungus. 18S ribosome RNA sequence used PCR cloning technology. DNA was extracted by the CTAB method. ... of the fungal mycelium (magnification: 400 ×).

The SVX3D integrated circuit for dead-timeless silicon strip readout

Energy Technology Data Exchange (ETDEWEB)

Garcia-Sciveres, M. E-mail: mgs@lbl.gov; Milgrome, O.; Zimmerman, T.; Volobouev, I.; Ely, R.P.; Connolly, A.; Fish, D.; Affolder, T.; Sill, A

1999-10-01

The revision D of the SVX3 readout IC has been fabricated in the Honeywell radiation-hard 0.8 {mu}m bulk CMOS process, for instrumenting 712,704 silicon strips in the upgrade to the Collider Detector at Fermilab. This final revision incorporates new features and changes to the original architecture that were added to meet the goal of dead-timeless operation. This paper describes the features central to dead-timeless operation, and presents test data for un-irradiated and irradiated SVX3D chips. (author)

Resistance of some early mutant lines of soybean to rust fungus (Phakospora pachyrhizi Syd)

International Nuclear Information System (INIS)

Ratma, Rivaie

1984-01-01

A trial for resistance to rust fungus (Phakospora pachyrhizi Syd.) was conducted on 11 early mutant lines of soybean M6 (derived from Orba variety with a dose of 0.4 kGy of Co-60) at Citayam Experimental Station, Bogor, in the wet season of 80/81. Based on IWGSR rating system, soybean mutant lines number M6/40/6 was moderately susceptible to rust fungus (Phakospora pachyrhizi Syd). While 10 other soybean mutant lines M6/40/1, M6/40/2, M6/40/3, M6/40/4, M6/40/5, M6/40/7, M6/40/8, M6/40/9, M6/40/10 and M6/40/11 were susceptible to rust fungus. Significant differences in yield were observed between the early mutant lines M6/40/6 (moderate susceptible), 10 other mutant lines (susceptible) and ringgit variety (susceptible). However, a significant lower yield was produced by those mutant lines compared with the yield of orba variety. (author)

Active pharmaceutical ingredient (api) from an estuarine fungus, Microdochium nivale (Fr.)

Digital Repository Service at National Institute of Oceanography (India)

Bhosale, S.H.; Patil, K.B.; Parameswaran, P.S.; Jagtap, T.G.

Various marine habitats sustain variety of bio-sources of ecological and biotech potentials. Pharmaceutical potential compound Cyclosporine A was reported from marine fungus Microdochium nivale associated with Porteresia coarctata, a marine salt...

Biodiversity of Cryptofauna (Decapods) and Their Correlation with Dead Coral Pocillopora sp. Volume at Bunaken Island, North Sulawesi

Science.gov (United States)

Malik, Muhammad Danie Al; Kholilah, Nenik; Kurniasih, Eka Maya; Sembiring, Andrianus; Pertiwi, Ni Putu Dian; Ambariyanto, Ambariyanto; Munasik, Munasik; Meyer, Christopher

2018-02-01

Decapod is known as cryptofauna which is also important component of coral reef biodiversity. Dead corals are one of the area which usually used by decapods to live. This research aims to observe the diversity of cryptofauna (decapods) and the correlation between the number of decapods with the volume of dead corals. Ten dead corals, Pocillopora sp., were collected at 5 m depth at Bunaken Island. These dead corals were measured their volume and all decapods found were counted and identified up to family level. The richness and abundance were analyzed using ACE (Abundance-Based Coverage Estimates) and Chao 1. The results show that there were in total 474 decapods from 13 families found within all ten dead corals. Xanthidae was showed as the most abundance family among all, with 161 individual. Diversity index of decapods was found at medium category with value of 2.01. Rarefaction curve based on richness and abundance showed an estimation of 13 families. The result also indicated that the asymptote stage was reached on the 10th dead coral samples. The correlation between decapod with the volume of dead coral were showed significant positive correlation (r = 0.673, p<0.05). This result provides benefits to basic knowledge about diversity of decapod which one of cryptofauna as component fauna have a habitat on coral reef ecosystem.

Load structure seismites in the Dead Sea Area, Israel : Chronological benchmarking with C-14 dating

NARCIS (Netherlands)

Bowman, D; Bruins, HJ; van der Plicht, J; Boaretto, E.; Bruins, Hendrik J.; Carmi, I.

2001-01-01

The Dead Sea is a terminal lake located in the seismically active zone of the Syro-African Rift Valley. The water level of the Dead Sea has been receding dramatically during the last decades, resulting in significant entrenchment of wadis towards its shores. Exposed sections in fan deltas reveal

Foehn-induced effects on local dust pollution, frontal clouds and solar radiation in the Dead Sea valley

Science.gov (United States)

Kishcha, Pavel; Starobinets, Boris; Savir, Amit; Alpert, Pinhas; Kaplan, Michael

2018-06-01

Despite the long history of investigation of foehn phenomena, there are few studies of the influence of foehn winds on air pollution and none in the Dead Sea valley. For the first time the foehn phenomenon and its effects on local dust pollution, frontal cloudiness and surface solar radiation were analyzed in the Dead Sea valley, as it occurred on 22 March 2013. This was carried out using both numerical simulations and observations. The foehn winds intensified local dust emissions, while the foehn-induced temperature inversion trapped dust particles beneath this inversion. These two factors caused extreme surface dust concentration in the western Dead Sea valley. The dust pollution was transported by west winds eastward, to the central Dead Sea valley, where the speed of these winds sharply decreased. The transported dust was captured by the ascending airflow contributing to the maximum aerosol optical depth (AOD) over the central Dead Sea valley. On the day under study, the maximum surface dust concentration did not coincide with the maximum AOD: this being one of the specific effects of the foehn phenomenon on dust pollution in the Dead Sea valley. Radar data showed a passage of frontal cloudiness through the area of the Dead Sea valley leading to a sharp drop in noon solar radiation. The descending airflow over the downwind side of the Judean Mountains led to the formation of a cloud-free band followed by only the partial recovery of solar radiation because of the extreme dust pollution caused by foehn winds.

Occurrence of termites (Isoptera on living and standing dead trees in a tropical dry forest in Mexico

Directory of Open Access Journals (Sweden)

Nancy Calderón-Cortés

2018-05-01

Full Text Available Termites play a key role as ecosystem engineers in numerous ecological processes though their role in the dynamics of wood degradation in tropical dry forests, particularly at the level of the crown canopy, has been little studied. In this study, we analysed the occurrence of termites in the forest canopy by evaluating the density and proportion of living and standing dead trees associated with termites in deciduous and riparian habitats of the tropical dry forest in Chamela, Mexico. The results indicated that 60–98% of standing dead trees and 23–59% of living trees in Chamela were associated with termites. In particular, we found that the density of standing dead trees was higher in deciduous forests (0.057–0.066 trees/m2 than in riparian forests (0.022 and 0.027 trees/m2, even though the proportion of trees was not significantly different among habitats. Additionally, we found a higher density of trees associated with termites in trees of smaller size classes (0.01–0.09 trees/m2 than in larger class sizes (0–0.02 trees/m2. Interestingly, 72% of variation in the density of trees associated with termites is explained by the density of standing dead trees. Overall, these results indicate that standing dead tree availability might be the main factor regulating termite populations in Chamela forest and suggest that termites could play a key role in the decomposition of above-ground dead wood, mediating the incorporation of suspended and standing dead wood into the soil.

Occurrence of termites (Isoptera) on living and standing dead trees in a tropical dry forest in Mexico.

Science.gov (United States)

Calderón-Cortés, Nancy; Escalera-Vázquez, Luis H; Oyama, Ken

2018-01-01

Termites play a key role as ecosystem engineers in numerous ecological processes though their role in the dynamics of wood degradation in tropical dry forests, particularly at the level of the crown canopy, has been little studied. In this study, we analysed the occurrence of termites in the forest canopy by evaluating the density and proportion of living and standing dead trees associated with termites in deciduous and riparian habitats of the tropical dry forest in Chamela, Mexico. The results indicated that 60-98% of standing dead trees and 23-59% of living trees in Chamela were associated with termites. In particular, we found that the density of standing dead trees was higher in deciduous forests (0.057-0.066 trees/m 2 ) than in riparian forests (0.022 and 0.027 trees/m 2 ), even though the proportion of trees was not significantly different among habitats. Additionally, we found a higher density of trees associated with termites in trees of smaller size classes (0.01-0.09 trees/m 2 ) than in larger class sizes (0-0.02 trees/m 2 ). Interestingly, 72% of variation in the density of trees associated with termites is explained by the density of standing dead trees. Overall, these results indicate that standing dead tree availability might be the main factor regulating termite populations in Chamela forest and suggest that termites could play a key role in the decomposition of above-ground dead wood, mediating the incorporation of suspended and standing dead wood into the soil.

Design and analysis of a dead volume control for a solar Stirling engine with induction generator

International Nuclear Information System (INIS)

Beltrán-Chacon, Ricardo; Leal-Chavez, Daniel; Sauceda, D.; Pellegrini-Cervantes, Manuel; Borunda, Mónica

2015-01-01

In this work, a power generation system dish/Stirling with cavity receiver and an electrical induction generator was simulated. We propose a control system using a variable-dead-volume and analyze its influence on the mechanical performance. A system with a dead volume of 160 cm"3 was designed to control the power and speed of the engine considering annual insolation, mechanical properties of the heater and the limits of frequency and voltage for the systems interconnected to the electricity network. The designed system achieves net efficient solar conversion to electric of 23.38% at an irradiance of 975 W/m"2 and allows an annual increase of 18% of the useful electrical energy compared to a system without control. - Highlights: • Numerical simulation of a nitrogen charged solar Stirling engine for electric power generation. • Design and analysis of a dead volume control for performance increase and power modulation. • Effect of dead space on average working pressure and mass flow rate. • Comparison between dead volume and average pressure control methods. • Impact of Stirling engine control settings on annual generated electric power.

Antiangiogenic, wound healing and antioxidant activity of Cladosporium cladosporioides (Endophytic Fungus isolated from seaweed (Sargassum wightii

Directory of Open Access Journals (Sweden)

Manjunath M. Hulikere

2016-10-01

Full Text Available Endophytic fungi from marine seaweeds are the less studied group of organisms with vast medical applications. The aim of the present study was to evaluate antioxidant, antiangiogenic as well as wound healing potential of the endophytic fungus isolated from the seaweed Sargassum wightii. The morphological characters and the rDNA internal transcribed spacer sequence analysis (BLAST search in Gen Bank database was used for the identification of endophytic fungus. The antioxidant potential of the ethyl acetate extract of endophytic fungus was assessed by, 1,1-diphenyl-2-picryl-hydrazyl radical scavenging method. The fungal extract was also analysed for reducing power, total phenolic and flavonoid content. Antiangiogenic activity of the fungal extract was studied in vitro by inhibition of wound healing scratch assay and in vivo by Chick chorioallantoic membrane assay. The endophytic fungus was identified as Cladosporium cladosporioides (Gen Bank ID – KT384175. The ethyl acetate extract of C. cladosporioides showed a significant antioxidant and angiosuppressive activity. The ESI-LC-MS analysis of the extract revealed the presence of wide range of secondary metabolites. Results suggest that C. cladosporioides extract could be exploited as a potential source for angiogenic modulators.

The Brain Dead Patient Is Still Sentient: A Further Reply to Patrick Lee and Germain Grisez.

Science.gov (United States)

Austriaco, Nicanor Pier Giorgio

2016-06-01

Patrick Lee and Germain Grisez have argued that the total brain dead patient is still dead because the integrated entity that remains is not even an animal, not only because he is not sentient but also, and more importantly, because he has lost the radical capacity for sentience. In this essay, written from within and as a contribution to the Catholic philosophical tradition, I respond to Lee and Grisez's argument by proposing that the brain dead patient is still sentient because an animal with an intact but severed spinal cord can still perceive and respond to external stimuli. The brain dead patient is an unconscious sentient organism. © The Author 2016. Published by Oxford University Press, on behalf of the Journal of Medicine and Philosophy Inc. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Influence of arbuscular mycorrhizal fungus Glomus intraradices on accumulation of radiocaesium by plant species

International Nuclear Information System (INIS)

Dubchak, S.V.

2012-01-01

The role of arbuscular mycorrhizal fungus Glomus intraradices in 134 Cs isotope by different plant species is studied. The impact of radiocaesium on mycorrhizal development and functioning of plant photosynthetic apparatus is considered. The possibility of mycorrhizal symbiosis application in phyto remediation of radioactively contaminated areas is analyzed. It is found that colonization pf plants with arbuscular mycorrhizal fungus resulted in significant decrease of radiocesium concentration in their aboveground parts, while it did not have considerable impact on the radionuclide uptake by plant root system

New Cytochalasin from Rosellinia sanctae-cruciana, an Endophytic Fungus of Albizia lebbeck.

Science.gov (United States)

Sharma, Nisha; Kushwaha, Manoj; Arora, Divya; Jain, Shreyans; Singamaneni, Venugopal; Sharma, Sonia; Shankar, Ravi; Bhushan, Shashi; Gupta, Prasoon; Jaglan, Sundeep

2018-03-24

To explore the potential of Rosellinia sanctae-cruciana an endophytic fungus associated with Albizia lebbeck for pharmaceutically important cytotoxic compounds. One novel cytochalasin, named Jammosporin A (1) and four known analogues (2-5) were isolated from the culture of the endophytic fungus Rosellinia sanctae-cruciana, harbored from the leaves of medicinal plant Albizia lebbeck. Their structures were elucidated by extensive spectroscopic analyses including 1D and 2D NMR data along with MS data and by comparison with literature reports. In preliminary screening the ethyl acetate extract of the fungal culture was tested for the cytotoxic activity against a panel of four cancer cell lines (MOLT-4, A549, MIA PaCa -2 and MDA-MB-231), was found to be active against MOLT-4 with IC 50 value of 10 μg/mL. Owing to the remarkable cytotoxic activity of the extract the isolated compounds (1-5) were evaluated for their cytototoxicity against MOLT-4 cell line by MTT assay. Interestingly, compounds 1-2, 4 and 5 showed considerable cytotoxic potential against the human leukemia cancer cell line (MOLT-4) with IC 50 values of 20.0, 10.0, 8.0 and 6.0 μM, respectively, while compound 3 showed IC 50 value of 25 μM. This is the first report of existence of this class of secondary metabolites in Rosellinia sanctae-cruciana fungus. This study discovered a novel compound, named Jammosporin A, isolated for the first time from Rosellinia sanctae-cruciana, an endophytic fungus of Albizia lebbeck with anticancer activity against MOLT-4 cell line. Rosellinia sanctae-cruciana represents an interesting source of a new compound with bioactive potential as a therapeutic agent against human leukemia cancer cell line (MOLT-4). This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Microbial community structure of leaf-cutter ant fungus gardens and refuse dumps.

Science.gov (United States)

Scott, Jarrod J; Budsberg, Kevin J; Suen, Garret; Wixon, Devin L; Balser, Teri C; Currie, Cameron R

2010-03-29

Leaf-cutter ants use fresh plant material to grow a mutualistic fungus that serves as the ants' primary food source. Within fungus gardens, various plant compounds are metabolized and transformed into nutrients suitable for ant consumption. This symbiotic association produces a large amount of refuse consisting primarily of partly degraded plant material. A leaf-cutter ant colony is thus divided into two spatially and chemically distinct environments that together represent a plant biomass degradation gradient. Little is known about the microbial community structure in gardens and dumps or variation between lab and field colonies. Using microbial membrane lipid analysis and a variety of community metrics, we assessed and compared the microbiota of fungus gardens and refuse dumps from both laboratory-maintained and field-collected colonies. We found that gardens contained a diverse and consistent community of microbes, dominated by Gram-negative bacteria, particularly gamma-Proteobacteria and Bacteroidetes. These findings were consistent across lab and field gardens, as well as host ant taxa. In contrast, dumps were enriched for Gram-positive and anaerobic bacteria. Broad-scale clustering analyses revealed that community relatedness between samples reflected system component (gardens/dumps) rather than colony source (lab/field). At finer scales samples clustered according to colony source. Here we report the first comparative analysis of the microbiota from leaf-cutter ant colonies. Our work reveals the presence of two distinct communities: one in the fungus garden and the other in the refuse dump. Though we find some effect of colony source on community structure, our data indicate the presence of consistently associated microbes within gardens and dumps. Substrate composition and system component appear to be the most important factor in structuring the microbial communities. These results thus suggest that resident communities are shaped by the plant degradation

An entomopathogenic fungus for control of adult African malaria mosquitoes

NARCIS (Netherlands)

Scholte, E.J.; Ng'habi, K.R.N.; Kihonda, J.; Takken, W.; Paaijmans, K.P.; Abdulla, S.; Killeen, G.F.; Knols, B.G.J.

2005-01-01

Biological control of malaria mosquitoes in Africa has rarely been used in vector control programs. Recent developments in this field show that certain fungi are virulent to adult Anopheles mosquitoes. Practical delivery of an entomopathogenic fungus that infected and killed adult Anopheles gambiae,

Mycelium cultivation, chemical composition and antitumour activity of a Tolypocladium sp. fungus isolated from wild Cordyceps sinensis.

Science.gov (United States)

Leung, P H; Zhang, Q X; Wu, J Y

2006-08-01

To examine and illustrate the morphological characteristics and growth kinetics of Cs-HK1, a Tolypocladium fungus, isolated from wild Cordyceps sinensis in solid and liquid cultures, and the major chemical constituents and antitumour effects of Cs-HK1 mycelium. The Cs-HK1 fungus was isolated from the fruiting body of a wild C. sinensis and identified as a Tolypocladium sp. fungus. It grew rapidly at 22-25 degrees C on a liquid medium containing glucose, yeast extract, peptone and major inorganic salts, with a specific growth rate of 1.1 day(-1), reaching a cell density of 23.0 g dw l(-1) in 7-9 days. Exopolysaccharides accumulated in the liquid culture to about 0.3 g l(-1) glucose equivalent. In comparison with natural C. sinensis, the fungal mycelium had similar contents of protein (11.7-microg) and carbohydrate (654.6-microg) but much higher contents of polysaccharide (244.2 mg vs 129.5 mg), adenosine (1116.8-microg vs 264.6 microg) and cordycepin (65.7 microg vs 20.8 microg) (per gram dry weight). Cyclosporin A, an antibiotic commonly produced by Tolypocladium sp., was also detected from the mycelium extract. The hot water extract of mycelium showed low cytotoxic effect on B16 melanoma cells in culture (about 25% inhibition) but significant antitumour effect in animal tests, causing 50% inhibition of B16 cell-induced tumour growth in mice. The Tolypocladium sp. fungus, Cs-HK1, can be easily cultivated by liquid fermentation. The mycelium biomass contained the major bioactive compounds of C. sinensis, and the mycelium extract had significant antitumour activity. The Cs-HK1 fungus may be a new and promising medicinal fungus and an effective and economical substitute of the wild C. sinensis for health care.

Comparative nutritional evaluation of fungus and alkali treated rice ...

African Journals Online (AJOL)

Feeding trial was conducted with growing white albino rats (Rattus norvegicus) for 56 days to determine whether alkali (NaOH) or fungus (Mushroom) treatment of rice husk would affect rat's performance. The treated rice husk comprised 10% of the rat's diets, the rests of which were 50% maize, 20% soybeans, 19% ...

Ethanol effect on metabolic activity of the ethalogenic fungus Fusarium oxysporum.

Science.gov (United States)

Paschos, Thomas; Xiros, Charilaos; Christakopoulos, Paul

2015-03-12

Fusarium oxysporum is a filamentous fungus which has attracted a lot of scientific interest not only due to its ability to produce a variety of lignocellulolytic enzymes, but also because it is able to ferment both hexoses and pentoses to ethanol. Although this fungus has been studied a lot as a cell factory, regarding applications for the production of bioethanol and other high added value products, no systematic study has been performed concerning its ethanol tolerance levels. In aerobic conditions it was shown that both the biomass production and the specific growth rate were affected by the presence of ethanol. The maximum allowable ethanol concentration, above which cells could not grow, was predicted to be 72 g/L. Under limited aeration conditions the ethanol-producing capability of the cells was completely inhibited at 50 g/L ethanol. The lignocellulolytic enzymatic activities were affected to a lesser extent by the presence of ethanol, while the ethanol inhibitory effect appears to be more severe at elevated temperatures. Moreover, when the produced ethanol was partially removed from the broth, it led to an increase in fermenting ability of the fungus up to 22.5%. The addition of F. oxysporum's system was shown to increase the fermentation of pretreated wheat straw by 11%, in co-fermentation with Saccharomyces cerevisiae. The assessment of ethanol tolerance levels of F. oxysporum on aerobic growth, on lignocellulolytic activities and on fermentative performance confirmed its biotechnological potential for the production of bioethanol. The cellulolytic and xylanolytic enzymes of this fungus could be exploited within the biorefinery concept as their ethanol resistance is similar to that of the commercial enzymes broadly used in large scale fermentations and therefore, may substantially contribute to a rational design of a bioconversion process involving F. oxysporum. The SSCF experiments on liquefied wheat straw rich in hemicellulose indicated that the

Simple circuit for precise measurement of live dead or clock time in gamma-ray spectrometry

International Nuclear Information System (INIS)

Hammer, W.; Sterlinski, S.

1976-01-01

The basic design features and characteristics of circuit are described in the paper. The circuit coupled to a multichannel analyser (MCA) enables one of times: live(Tsub(iota)), dead (Tsub(d)) or clock(Tsub(c)) to be measured precisely. Second one is measured by a built-in timer of MCA. Having the Tsub(c)/Tsub(iota) ratio and utilizing suitable mathematical formulas one can make the corrections for both main effects (dead-time and pile-up) which yield counting losses in gamma-ray spectrometry at high and/or variable activities. Two examples of the dead-time and pile-up corrections by using the new circuit are presented in this paper. (author)

Symbiont diversification in ambrosia beetles: Diversity of fungi associated with exotic scolytine beetles

Science.gov (United States)

In virtually every forest habitat, ambrosia beetles (Coleoptera: Curculionidae: Scolytinae, Platypodinae) plant and maintain symbiotic fungus gardens inside dead or dying wood. Some introduced ambrosia beetles aggressively attack live trees and can damage tree crops, lumber, and native woody plant t...

Impact of climate change on potential distribution of Chinese caterpillar fungus (Ophiocordyceps sinensis) in Nepal Himalaya.

Science.gov (United States)

Shrestha, Uttam Babu; Bawa, Kamaljit S

2014-01-01

Climate change has already impacted ecosystems and species and substantial impacts of climate change in the future are expected. Species distribution modeling is widely used to map the current potential distribution of species as well as to model the impact of future climate change on distribution of species. Mapping current distribution is useful for conservation planning and understanding the change in distribution impacted by climate change is important for mitigation of future biodiversity losses. However, the current distribution of Chinese caterpillar fungus, a flagship species of the Himalaya with very high economic value, is unknown. Nor do we know the potential changes in suitable habitat of Chinese caterpillar fungus caused by future climate change. We used MaxEnt modeling to predict current distribution and changes in the future distributions of Chinese caterpillar fungus in three future climate change trajectories based on representative concentration pathways (RCPs: RCP 2.6, RCP 4.5, and RCP 6.0) in three different time periods (2030, 2050, and 2070) using species occurrence points, bioclimatic variables, and altitude. About 6.02% (8,989 km2) area of the Nepal Himalaya is suitable for Chinese caterpillar fungus habitat. Our model showed that across all future climate change trajectories over three different time periods, the area of predicted suitable habitat of Chinese caterpillar fungus would expand, with 0.11-4.87% expansion over current suitable habitat. Depending upon the representative concentration pathways, we observed both increase and decrease in average elevation of the suitable habitat range of the species.

Laboratory evolution of the entomopathogenic fungus Beauveria bassiana against Anopheles stephensi larvae (Diptera: Culicidae

Directory of Open Access Journals (Sweden)

Rahele Veys-Behbahani

2014-09-01

Full Text Available Objective: To examine Beauveria bassiana (B. bassiana fungus bioassay against the larval stages of Anopheles stephensi in Iran. Methods: The fungal suspension by the concentrations of 1伊1 09, 5伊1 08, 1 08, 5伊1 07 and 1伊 107 conidia per milliliter have been prepared in different volumes (2, 4 and 6 mL and each concentration were added to containers containing 25 Anopheles larva instars 1 and 2. The mortality of the dead larvae with abnormal symptoms was recorded as a result of the fungal infection after 24, 48 and 72 h. Results: Comparison between the mean mortality rate of Anopheles stephensi larva at different concentrations of B. bassiana strain Iran 429C at 2, 4 and 6 mL showed that there was no significant relation of the mean mortality rate of larvae at concentrations of 1伊109 and 5伊108, and after 48 h resulted in 100% mortality rate of the larvae populations. In addition, there is no significant differences in the amounts of lethal times (LT (LT50 and LT90 as LT90 values calculated at a concentration of 5伊108 and in volumes 2, 4 and 6 mL were 1.46, 1.36 and 1.08 d, respectively. Conclusions: B. bassiana strain Iran 429C in 2 mL of 5伊108 concentration or the concentration of a 1伊109 mL per 100 mL of water is recommended as the optimal concentration for the control of Anopheles larvae. The development of suitable formulations of entomopathogenic fungi may be a promising prospect in the mosquito control programs.

Diversity of macro-detritivores in dead wood is influenced by tree species, decay stage and environment

NARCIS (Netherlands)

Zuo, Juan; Fonck, Myrthe; van Hal, Jurgen; Cornelissen, J. Hans C.; Berg, Matty P.

Diplopoda (millipedes) and Isopoda (woodlice) are among the most abundant macro-detritivores in temperate forests. These key regulators of plant litter decomposition are influenced by habitat and substrate quality, including that of dead wood. Dead wood provides shelter and resources to

Diversity of macro-detritivores in dead wood is influenced by tree species, decay stage and environment

NARCIS (Netherlands)

Zuo, J.; Fonck, M.; van Hal, J.R.; Cornelissen, J.H.C.; Berg, M.P.

2014-01-01

Diplopoda (millipedes) and Isopoda (woodlice) are among the most abundant macro-detritivores in temperate forests. These key regulators of plant litter decomposition are influenced by habitat and substrate quality, including that of dead wood. Dead wood provides shelter and resources to

Oak protein profile alterations upon root colonization by an ectomycorrhizal fungus

DEFF Research Database (Denmark)

Sebastiana, Mónica; Martins, Joana; Figueiredo, Andreia

2017-01-01

in the roots. Consistent with the results of the biochemical analysis, the proteome analysis of the mycorrhizal roots suggests a decreasing utilization of sucrose for the metabolic activity of mycorrhizal roots which is consistent with an increased allocation of carbohydrates from the plant to the fungus...... to ectomycorrhizae formation using a proteomics approach complemented by biochemical analysis of carbohydrate levels. Comparative proteome analysis between mycorrhizal and nonmycorrhizal cork oak plants revealed no differences at the foliar level. However, the protein profile of 34 unique oak proteins was altered...... in order to sustain the symbiosis. In addition, a promotion of protein unfolding mechanisms, attenuation of defense reactions, increased nutrient mobilization from the plant-fungus interface (N and P), as well as cytoskeleton rearrangements and induction of plant cell wall loosening for fungal root...

Production of cellulases by a thermophilic fungus, Thermoascus aurantiacus A-131

Energy Technology Data Exchange (ETDEWEB)

Kawamori, M; Takayama, K; Takasawa, S

1987-01-01

A thermophilic fungus, strain A-131, isolated from a soil sample produced cellulases in the culture fluid. The fungus (strain A-131) was identified as Thermoascus aurantiacus Miehe from its taxonomical characteristics. The cellulases of T. aurantiacus A-131 were produced constitutively without cellulase inducers. Moreover, their production was induced markedly by amorphous polysaccharides containing beta-1, 4 linkages such as alkali-treated bagasse and xylan rather than crystalline cellulose. The cultivation of T. aurantiacus A-131 at 45 degrees C with 4% alkali-treated bagasse led to the production of about 70 U/ml of CMCase after four days. The thermostability of the cellulolytic enzymes of T. aurantiacus A-131 was excellent and virtually no decreases in their activities were seen after preincubation at 60 degrees C for 24 hours. (Refs. 21).

Dead Metaphor in Selected Advertisements in Nigerian Dailies ...

African Journals Online (AJOL)

Dead metaphors and images are often enlivened and empowered by advertisers to help their commUlzication and to achieve bewitching effects. It is interesting to see words and phrases that may be presumed to have been drained of their linguistic strength being brought back to currency and made to act fast in aiding ...

Treatment of a Textile Effluent from Dyeing with Cochineal Extracts Using Trametes versicolor Fungus

Directory of Open Access Journals (Sweden)

Gabriela Arroyo-Figueroa

2011-01-01

Full Text Available Trametes versicolor (Tv fungus can degrade synthetic dyes that contain azo groups, anthraquinone, triphenylmethane polymers, and heterocyclic groups. However, no references have been found related to the degradation of natural dyes, such as the carminic acid that is contained in the cochineal extract. Experiments to determine the decolorization of the effluent used in the cotton dyeing process with cochineal extract by means of Tv fungus were done. Treatments to determine decolorization in the presence or absence of Kirk's medium, glucose, and fungus, with an addition of 50% (v v-1 of nonsterilized effluent were performed. Physicochemical characterization was performed at the start and end of the treatment. Degradation kinetics were determined. A direct relationship was found between the dry weight of fungi, pH, and the decolorization system, with higher decolorization at lower pH levels (pH ~4.3. High decolorization (81% ± 0.09; 88% ± 0.17; and 99% ± 0.04 for three of the eight treatments (Kirk's medium without glucose, Kirk's medium with glucose, and without medium with glucose, respectively was found. Toxicity tests determined an increase in the initial effluent toxicity (7.33 TU compared with the final treatment (47.73 TU in a period of 11 days. For this system, a degradation sequence of the carminic acid structure present in the effluent by the Tv fungus is suggested, in which it is seen that metabolites still containing aromatic structures are generated.

Treatment of a textile effluent from dyeing with cochineal extracts using Trametes versicolor fungus.

Science.gov (United States)

Arroyo-Figueroa, Gabriela; Ruiz-Aguilar, Graciela M L; López-Martínez, Leticia; González-Sánchez, Guillermo; Cuevas-Rodríguez, Germán; Rodríguez-Vázquez, Refugio

2011-05-05

Trametes versicolor (Tv) fungus can degrade synthetic dyes that contain azo groups, anthraquinone, triphenylmethane polymers, and heterocyclic groups. However, no references have been found related to the degradation of natural dyes, such as the carminic acid that is contained in the cochineal extract. Experiments to determine the decolorization of the effluent used in the cotton dyeing process with cochineal extract by means of Tv fungus were done. Treatments to determine decolorization in the presence or absence of Kirk's medium, glucose, and fungus, with an addition of 50% (v v-1) of nonsterilized effluent were performed. Physicochemical characterization was performed at the start and end of the treatment. Degradation kinetics were determined. A direct relationship was found between the dry weight of fungi, pH, and the decolorization system, with higher decolorization at lower pH levels (pH ~4.3). High decolorization (81% ± 0.09; 88% ± 0.17; and 99% ± 0.04) for three of the eight treatments (Kirk's medium without glucose, Kirk's medium with glucose, and without medium with glucose, respectively) was found. Toxicity tests determined an increase in the initial effluent toxicity (7.33 TU) compared with the final treatment (47.73 TU) in a period of 11 days. For this system, a degradation sequence of the carminic acid structure present in the effluent by the Tv fungus is suggested, in which it is seen that metabolites still containing aromatic structures are generated.

Using palynology to re-assess the Dead Sea laminated sediments - Indeed varves?

Science.gov (United States)

Bookman, Revital; Lopez-Merino, Lourdes; Belmaker, Reuven; Eshel, Amram; Epshtein Epshtein, Valentina; Leroy, Suzanne

2017-04-01

Lacustrine laminated sediments are often varves representing annual rhythmic deposition. The Dead Sea high-stand laminated sections consist of mm-scale alternating detrital and authigenic aragonite laminae. Previous studies assumed these laminae were varves; detritus deposition during the winter and aragonite in the summer. These sequences were used for varve counting and chronology, however this assumption has never been robustly validated. Here, we report an examination of the seasonal deposition of detrital and aragonite couplets from two well-known Late Holocene laminated sections at the Ze'elim fan-delta using palynology and grain-size distribution analyses. These analyses are complemented by the study of contemporary flash-flood samples and multivariate statistical analysis. Because transport affects the pollen preservation state, well-preserved (mostly) air-borne transported pollen was analysed separately from badly-preserved pollen and fungal spores, which are more indicative of water transport and reworking from soils. Our results indicate that (i) both detrital and aragonite laminae were deposited during the rainy season; (ii) aragonite laminae have significantly lower reworked pollen and fungal spore concentrations than detrital and flash-flood samples; and (iii) detrital laminae are composed of recycling of local and distal sources, with coarser particles that were initially deposited in the Dead Sea watershed and later transported via run-off to the lake. The conclusions suggest that detrital and aragonite couplets in the Dead Sea laminated sediments are most likely not varves and that the laminae deposition is related to the occurrence of flash-flood events. Consequently, at least for the Holocene sequences, laminated sediments cannot be considered as varves and Quaternary laminated sequences should be re-evaluated. The Dead Sea Basin laminated sequences (as the ICDP Dead Sea Deep Drilling Project record) should be used for the reconstruction of

New perspectives on interdisciplinary earth science at the Dead Sea: The DESERVE project.

Science.gov (United States)

Kottmeier, Christoph; Agnon, Amotz; Al-Halbouni, Djamil; Alpert, Pinhas; Corsmeier, Ulrich; Dahm, Torsten; Eshel, Adam; Geyer, Stefan; Haas, Michael; Holohan, Eoghan; Kalthoff, Norbert; Kishcha, Pavel; Krawczyk, Charlotte; Lati, Joseph; Laronne, Jonathan B; Lott, Friederike; Mallast, Ulf; Merz, Ralf; Metzger, Jutta; Mohsen, Ayman; Morin, Efrat; Nied, Manuela; Rödiger, Tino; Salameh, Elias; Sawarieh, Ali; Shannak, Benbella; Siebert, Christian; Weber, Michael

2016-02-15

The Dead Sea region has faced substantial environmental challenges in recent decades, including water resource scarcity, ~1m annual decreases in the water level, sinkhole development, ascending-brine freshwater pollution, and seismic disturbance risks. Natural processes are significantly affected by human interference as well as by climate change and tectonic developments over the long term. To get a deep understanding of processes and their interactions, innovative scientific approaches that integrate disciplinary research and education are required. The research project DESERVE (Helmholtz Virtual Institute Dead Sea Research Venue) addresses these challenges in an interdisciplinary approach that includes geophysics, hydrology, and meteorology. The project is implemented by a consortium of scientific institutions in neighboring countries of the Dead Sea (Israel, Jordan, Palestine Territories) and participating German Helmholtz Centres (KIT, GFZ, UFZ). A new monitoring network of meteorological, hydrological, and seismic/geodynamic stations has been established, and extensive field research and numerical simulations have been undertaken. For the first time, innovative measurement and modeling techniques have been applied to the extreme conditions of the Dead Sea and its surroundings. The preliminary results show the potential of these methods. First time ever performed eddy covariance measurements give insight into the governing factors of Dead Sea evaporation. High-resolution bathymetric investigations reveal a strong correlation between submarine springs and neo-tectonic patterns. Based on detailed studies of stratigraphy and borehole information, the extension of the subsurface drainage basin of the Dead Sea is now reliably estimated. Originality has been achieved in monitoring flash floods in an arid basin at its outlet and simultaneously in tributaries, supplemented by spatio-temporal rainfall data. Low-altitude, high resolution photogrammetry, allied to

Not to declare dead someone still alive: Case reports

Directory of Open Access Journals (Sweden)

Anđelić Slađana

2015-01-01

Full Text Available Introduction. Diagnosing death represents an activity that carries a great deal of public responsibility for medical professionals and is continually exposed to the control of citizens and media. Although this is a taboo subject in medical circles, unfortunately in medical practice there are situations when the physician issues a death diagnosis form without even examining the person or for an already buried person. Such physician’s action is impermissible and it leads to the possibility of professional and criminal law punishment. Case Outline. By giving examples from practice, we wish to point out the need for exceptional caution when confirming and diagnosing death in order to diagnose the true, i.e. rule out apparent death and consequently avoid the mistake of declaring dead someone still alive. Conclusion. When confirming and declaring death, exceptional caution of the physician is necessary so as not to declare dead someone still alive!

Effect of plant extracts and a disinfectant on biological parameters and pathogenicity of the fungus Beauveria bassiana (Bals. Vuill. (Ascomycota: Cordycipitaceae

Directory of Open Access Journals (Sweden)

C. C. Martins

Full Text Available Abstract The fungus Beauveria bassiana is naturally found in poultry houses and causes high rates of mortality in Alphitobius diaperinus. Laboratory and field experiments have shown the potential of this fungus as an insect control agent. However, in poultry houses, bacteria as Salmonella, can be found and have been studied alternative control methods for this pathogen. Thus, this study aimed to evaluate the effect of plant extracts and a disinfectant on the fungus Beauveria bassiana (strain Unioeste 4. Conidial viability, colony-forming unit (CFU counts, vegetative growth, conidia production, insecticidal activity of the fungus and compatibility were used as parameters in the evaluation of the effect of these products on the fungus. Alcoholic and aqueous extracts of jabuticaba (Myrciaria cauliflora (Mart., guava (Psidium guajava (L., and jambolan (Syzygium cumini (L., at concentrations of 10% as well as the commercial disinfectant, Peroxitane® 1512 AL, were evaluated at the recommended concentrations (RC, 1:200 (RC, 0.5 RC and 2 RC. There was a negative influence of alcoholic and aqueous extracts of jabuticaba, guava and three dilutions of Peroxitane on the viability of conidia. The CFUs and vegetative growth of the fungus were affected only by the Peroxitane (all dilutions. For conidial production, the aqueous extract of guava had a positive effect, increasing production, while the Peroxitane at the R and RC concentrations resulted in a negative influence. The mortality of A. diaperinus, caused by the fungus after exposure to these products, was 60% for the peracetic acid at 0.5 RC, and above 80% for the extracts. Thus, the results showed that all the extracts and Peroxitane at RC 0.5 are compatible with the fungus B. bassiana Unioeste 4, however only the extracts had a low impact on inoculum potential.

Reconstructing the early evolution of the fungi using a six gene phylogeny

NARCIS (Netherlands)

James, T.Y.; Kauff, F.; Schoch, C.L.; Matheny, P.B.; Hofstetter, V.; Cox, C.J.; Celio, G.; Gueidan, C.; Fraker, E.; Miadlikowska, J.; Lumbsch, H.T.; Rauhut, A.; Reeb, V.; Arnold, A.E.; Amtoft, A.; Stajich, J.E.; Hosaka, K.; Sung, G.H.; Johnson, D.; O'Rourke, B.; Binder, M.; Curtis, J.M.; Slot, J.C.; Wang, Z.; Wilson, A.W.; Schüßler, A.; Longcore, J.E.; O'Donnell, K.; Mozley-Standridge, S.; Porter, D.; Letcher, P.M.; Powell, M.J.; Taylor, J.W.; White, M.M.; Griffith, G.W.; Davies, D.R.; Sugiyama, J.; Rossman, A.Y.; Rogers, J.D.; Pfister, D.H.; Hewitt, D.; Hansen, K.; Hambleton, S.; Shoemaker, R.A.; Kohlmeyer, J.; Volkmann-Kohlmeyer, B.; Spotts, R.A.; Serdani, M.; Crous, P.W.; Hughes, K.W.; Matsuura, K.; Langer, E.; Langer, G.; Untereiner, W.A.; Lücking, R.; Büdel, B.; Geiser, D.M.; Aptroot, A.; Diederich, P.; Schmitt, I.; Schultz, M.; Yahr, R.; Hibbett, D.S.; Lutzoni, F.; McLaughlin, D.J.; Spatafora, J.W.; Vilgalys, R.

2006-01-01

The ancestors of fungi are believed to be simple aquatic forms with flagellated spores, similar to members of the extant phylum Chytridiomycota (chytrids). Current classifications assume that chytrids form an early-diverging clade within the kingdom Fungi and imply a single loss of the spore

75 FR 7536 - Culturally Significant Objects Imported for Exhibition Determinations: “The Dead Sea Scrolls...

Science.gov (United States)

2010-02-19

... Determinations: ``The Dead Sea Scrolls: Words That Changed the World'' Summary: Notice is hereby given of the... included in the exhibition ``The Dead Sea Scrolls: Words That Changed the World,'' imported from abroad for... pursuant to a loan agreement with the foreign owner or custodian. I also determine that the exhibition or...

Identification and characterization of glucoamylase from the fungus, Thermomyces lanuginosus

DEFF Research Database (Denmark)

Thorsen, Thor Seneca; Johnsen, Anders; Josefsen, K.

2006-01-01

the thermophilic fungus Talaromyces emersonii. cDNA encoding Thermomyces lanuginosus glucoamylase was expression cloned into Pichia pastoris, producing approximately 7.4 U/ml. It was concluded that alternative mRNA splicing as it might occur in Aspergillus niger glucoamylase is not responsible for the occurrence...

Cyclodepsipeptides, sesquiterpenoids, and other cytotoxic metabolites from the filamentous fungus Trichothecium sp. (MSX 51320).

Science.gov (United States)

Sy-Cordero, Arlene A; Graf, Tyler N; Adcock, Audrey F; Kroll, David J; Shen, Qi; Swanson, Steven M; Wani, Mansukh C; Pearce, Cedric J; Oberlies, Nicholas H

2011-10-28

Two new cyclodepsipeptides (1 and 2), two new sesquiterpenoids (3 and 4), and the known compounds guangomide A (5), roseotoxin S, and three simple trichothecenes were isolated from the cytotoxic organic extract of a terrestrial filamentous fungus, Trichothecium sp. The structures were determined using NMR spectroscopy and mass spectrometry. Absolute configurations of the cyclodepsipeptides were established by employing chiral HPLC, while the relative configurations of 3 and 4 were determined via NOESY data. The isolation of guangomide A was of particular interest, since it was reported previously from a marine-derived fungus.

The use of Amazon fungus ( Trametes sp.) in the production of ...

African Journals Online (AJOL)

The use of Amazon fungus (Trametes sp.) in the production of cellulase and xylanase. Salony Aquino Pereira, Rafael Lopes e Oliveira, Sergio Duvoisin Jr, Leonor Alves de Oliveira da Silva, Patrícia Melchionna Albuquerque ...

Necrotizing fasciitis: A deadly disease | Cree | East and Central ...

African Journals Online (AJOL)

Background: Knowledge of the diagnosis, cause, course and required treatment of this deadly disease among physicians and surgeons around the world is limited. Methods: A study was undertaken at University Teaching Hospital (UTH), Lusaka Zambia to review the incidence, associated pathology, management given, ...

Gamma radiation effects on the frequency of toxigenic fungus on sene (Cassia angustifolia) and green tea (Camelia sinensis) samples

International Nuclear Information System (INIS)

Aquino, S.; Villavicencio, A.L.C.H.

2006-01-01

The levels of contamination and gamma radiation effects were analyzed in the reduction of toxigenic filamentous fungus in two types of medicinal plants. Aspergillus and Penicillium were the predominant genders and 73,80% of the samples showed high levels of fungus contamination

Copper sulfate controls fungus on mat-spawned largemouth bass eggs

Science.gov (United States)

Copper sulfate (CuSO4) is widely used by the catfish and hybrid striped bass industries as an economical treatment to control fungus (Saprolegnia spp.) on eggs; these industries use hatching troughs and McDonald jars, respectively, in moderate alkalinity waters. This study determined the effectivene...

Accurate live and dead bacterial cell enumeration using flow cytometry (Conference Presentation)

Science.gov (United States)

Ou, Fang; McGoverin, Cushla; Swift, Simon; Vanholsbeeck, Frédérique

2017-03-01

Flow cytometry (FCM) is based on the detection of scattered light and fluorescence to identify cells with particular characteristics of interest. However most FCM cannot precisely control the flow through its interrogation point and hence the volume and concentration of the sample cannot be immediately obtained. The easiest, most reliable and inexpensive way of obtaining absolute counts with FCM is by using reference beads. We investigated a method of using FCM with reference beads to measure live and dead bacterial concentration over the range of 106 to 108 cells/mL and ratio varying from 0 to 100%. We believe we are the first to use this method for such a large cell concentration range while also establishing the effect of varying the live/dead bacteria ratios. Escherichia coli solutions with differing ratios of live:dead cells were stained with fluorescent dyes SYTO 9 and propidium iodide (PI), which label live and dead cells, respectively. Samples were measured using a LSR II Flow Cytometer (BD Biosciences); using 488 nm excitation with 20 mW power. Both SYTO 9 and PI fluorescence were collected and threshold was set to side scatter. Traditional culture-based plate count was done in parallel to the FCM analysis. The concentration of live bacteria from FCM was compared to that obtained by plate counts. Preliminary results show that the concentration of live bacteria obtained by FCM and plate counts correlate well with each other and indicates this may be extended to a wider concentration range or for studying other cell characteristics.

Maternal parentage influences spore production but not spore pigmentation in the anisogamous and hermaphroditic fungus Neurospora crassa

DEFF Research Database (Denmark)

Zimmerman, Kolea; Levitis, Daniel; Pringle, Anne

2014-01-01

. In this fungus, pigmented spores are viable and unpigmented spores are inviable. These results show that while both parents influence all these traits, maternal influence is strongest on both fertility and mortality traits until the spores are physiologically independent of the maternal cytoplasm.......In this study, we tested the hypothesis that maternal effects on offspring production and quality are greater than paternal effects in both offspring number (fertility) and offspring viability (mortality). We used the model filamentous fungus Neurospora crassa. This fungus is anisogamous......, and various ascospore characteristics. Mixed effects models of these data show that the female parent accounts for the majority of variation in perithecial production, number of spores produced, and spore germination. Surprisingly, both sexes equally influence the percentage of spores that are pigmented...

Dead-wood addition promotes non-saproxylic epigeal arthropods but effects are mediated by canopy openness

Science.gov (United States)

Sebastian Seibold; Claus Bässler; Petr Baldrian; Lena Reinhard; Simon Thorn; Michael D. Ulyshen; Ingmar Weiß; Jörg Müller

2016-01-01

Restoring dead-wood amounts in forests is an increasingly and successfully applied conservation measure to counteract negative effects of intensive logging on biodiversity of saproxylic taxa. By contrast, if and how dead-wood addition benefits the vast number of non-saproxylic forest taxa, and how this varies with contextual factors like canopy openness, remains poorly...

G.M. counter and pre-determined dead time; Compteur G.M. et temps mort impose

Energy Technology Data Exchange (ETDEWEB)

Lamotte, R; Le Baud, P [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1959-07-01

This paper is divided into two main parts. - The first section recalls the principle on which a G.M. counter works, and examines the factors which lead to inaccuracies in counting. The concept of dead time, although simple risen associated with the counter alone, becomes complicated as soon as an electronic dead time is introduced to meet the demands of a measurement or an experiment. The resulting dead time, due to the coexistence of these dead times created by a single motivating factor, shows up as a function of certain laws of probability. From the analysis of the various cases of possible combinations, the conditions which must be fulfilled by a system with pre-determined dead time may be determined. This leads to a method for measuring the dead time of a G.M. counter, and the possibility of studying the latter under the utilisation conditions foreseen. - In the second part the principle, construction and characteristics of two systems with pre-determined dead time are discussed. To conclude, a comparison of several experimental results justifies an extension of the possibilities of a G.M. counter used in conjunction with such a system. (author) [French] Deux parties essentielles scindent cet expose. - La premiere partie rappelle le principe de fonctionnement d'un compteur G.M. et examine les facteurs d'imprecisions affectant les comptages. La notion de temps mort, simple quand elle est associee au compteur seul, se complique des qu'intervient un temps mort electronique introduit pour les besoins d'une mesure ou d'une experience. Le temps mort resultant, du a la coexistence de ces temps morts engendres par une meme cause, se manifeste en fonction de certaines lois de probabilites. L'analyse des differents cas de combinaisons possibles permet de preciser les imperatifs auxquels doit repondre un systeme a temps mort impose. Il en decoule une methode de mesure du temps mort d'un compteur G.M. et la possibilite d'etudier celui-ci dans les conditions d

Monitoring persistence of the entomopathogenic fungus Metarhizium anisopliae under simulated field conditions with the aim of controlling adult Aedes aegypti (Diptera: Culicidae).

Science.gov (United States)

Carolino, Aline T; Paula, Adriano R; Silva, Carlos P; Butt, Tariq M; Samuels, Richard I

2014-04-25

Entomopathogenic fungi are potential candidates for use in integrated vector management, with recent emphasis aimed at developing adult mosquito control methods. Here we investigated the persistence of the fungus Metarhizium anisopliae when tested against female A. aegypti under field conditions. Black cotton cloths impregnated with M. anisopliae conidia, formulated in vegetable oil + isoparaffin, were maintained on a covered veranda for up to 30 days. At specific times, pieces of the cloths were removed, placed in Tween 80 and the resuspended conidia were sprayed directly onto mosquitoes. The persistence of conidia impregnated on black cloths using three different carriers was evaluated in test rooms. Fifty mosquitoes were released into each room and after a 5 day period, the surviving insects were captured. Another 50 insects were then released into each room. The capacity of the fungus at reducing mosquito survival was evaluated over a total of 35 days. Conidia extracted from cloths maintained on the veranda for 2 to 18 days remained virulent, with 28 to 60% mosquito survival observed. Mosquito survival following exposure to fungus impregnated cloths showed that fungus + Tween caused similar reductions to that of fungus + vegetable oil. Mosquitoes exposed to the formulation fungus + vegetable oil had survival rates of 36% over the first 5 days of the experiment. Following the release of the second cohort of mosquitoes (6-11days), survival increased to 50%. The survival of the 12-17 day cohort (78%) was statistically equal to that of the controls (84%). Formulation of the fungus in vegetable oil + isoparaffin increased the persistence of the fungus, with the 18-23 day cohort (64% survival) still showing statistical differences to that of the controls (87% survival). The potential of entomopathogenic fungi for the control of adult A. aegypti was confirmed under field conditions. Vegetable oil + isoparaffin formulations of M. anisopliae significantly increased the

Mathematical modeling on obligate mutualism: Interactions between leaf-cutter ants and their fungus garden.

Science.gov (United States)

Kang, Yun; Clark, Rebecca; Makiyama, Michael; Fewell, Jennifer

2011-11-21

We propose a simple mathematical model by applying Michaelis-Menton equations of enzyme kinetics to study the mutualistic interaction between the leaf cutter ant and its fungus garden at the early stage of colony expansion. We derive sufficient conditions on the extinction and coexistence of these two species. In addition, we give a region of initial condition that leads to the extinction of two species when the model has an interior attractor. Our global analysis indicates that the division of labor by worker ants and initial conditions are two important factors that determine whether leaf cutter ants' colonies and their fungus garden can survive and grow or not. We validate the model by comparing model simulations and data on fungal and ant colony growth rates under laboratory conditions. We perform sensitive analysis of the model based on the experimental data to gain more biological insights on ecological interactions between leaf-cutter ants and their fungus garden. Finally, we give conclusions and discuss potential future work. Published by Elsevier Ltd.

Detection of wood discoloration in a canker fungus-inoculated Japanese cedar by neutron radiography

International Nuclear Information System (INIS)

Yamada, T.; Aoki, Y.; Yamato, M.; Komatsu, M.; Kusumoto, D.; Suzuki, K.; Nakanishi, T.M.

2005-01-01

Neutron radiography (NRG) was applied to trace the development of discolored tissue in the wood of Japanese cedar (Cryptomeria japonica) after being infected with a canker fungus. Japanese cedar seedlings were wound inoculated with a virulent and avirulent isolate of a canker fungus, Guignardia cryptomeriae. Three, 7, 13 and 22 days after the inoculation, the seedlings were irradiated with thermal neutrons. The image on the X-ray film showed that the whiteness in the image corresponded to the water content in the sample. Discolored tissue and surrounding dry zones induced by the fungal inoculation were detected as dark areas, indicating water deficiency with a high resolution. Through image analysis, the dry zones were detected as early as 3 days after inoculation. Neutron images also showed the difference in the size of water deficient parts due to the tissue damage among the treatments. The neutron beam dose used in this experiment had no effect on the growth rate of the fungus on a medium, showing that NRG is an effective method for pathological research of trees. (author)

Phenanthrene uptake by Medicago sativa L. under the influence of an arbuscular mycorrhizal fungus

Energy Technology Data Exchange (ETDEWEB)

Wu Naiying [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, PO Box 2871, Beijing 100085 (China); Department of Chemistry, Shangqiu Normal College, Shangqiu 476000 (China); Huang Honglin [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, PO Box 2871, Beijing 100085 (China); Zhang Shuzhen, E-mail: szzhang@rcees.ac.c [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, PO Box 2871, Beijing 100085 (China); Zhu Yongguan [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, PO Box 2871, Beijing 100085 (China); Christie, Peter [Agri-Environment Branch, Agriculture Food and Environmental Science Division, Agri-Food and Biosciences Institute, Newforge Lane, Belfast BT9 5PX (United Kingdom); Zhang Yong [State Key Laboratory of Marine Environmental Science, Environmental Science Research Centre, Xiamen University, Xiamen 361005 (China)

2009-05-15

Phenanthrene uptake by Medicago sativa L. was investigated under the influence of an arbuscular mycorrhizal fungus. Inoculation of lucerne with the arbuscular mycorrhizal fungus Glomus etunicatum L. resulted in higher phenanthrene accumulation in the roots and lower accumulation in the shoots compared to non-mycorrhizal controls. Studies on sorption and desorption of phenanthrene by roots and characterization of heterogeneity of mycorrhizal and non-mycorrhizal roots using solid-state {sup 13}C nuclear magnetic resonance spectroscopy ({sup 13}C NMR) demonstrated that increased aromatic components due to mycorrhizal inoculation resulted in enhanced phenanthrene uptake by the roots but lower translocation to the shoots. Direct visualization using two-photon excitation microscopy (TPEM) revealed higher phenanthrene accumulation in epidermal cells of roots and lower transport into the root interior and stem in mycorrhizal plants than in non-mycorrhizal controls. These results provide some insight into the mechanisms by which arbuscular mycorrhizal inoculation may influence the uptake of organic contaminants by plants. - Colonization by an arbuscular mycorrhizal fungus promoted root uptake and decreased shoot uptake of phenanthrene by Medicago sativa L.

Phenanthrene uptake by Medicago sativa L. under the influence of an arbuscular mycorrhizal fungus

International Nuclear Information System (INIS)

Wu Naiying; Huang Honglin; Zhang Shuzhen; Zhu Yongguan; Christie, Peter; Zhang Yong

2009-01-01

Phenanthrene uptake by Medicago sativa L. was investigated under the influence of an arbuscular mycorrhizal fungus. Inoculation of lucerne with the arbuscular mycorrhizal fungus Glomus etunicatum L. resulted in higher phenanthrene accumulation in the roots and lower accumulation in the shoots compared to non-mycorrhizal controls. Studies on sorption and desorption of phenanthrene by roots and characterization of heterogeneity of mycorrhizal and non-mycorrhizal roots using solid-state 13 C nuclear magnetic resonance spectroscopy ( 13 C NMR) demonstrated that increased aromatic components due to mycorrhizal inoculation resulted in enhanced phenanthrene uptake by the roots but lower translocation to the shoots. Direct visualization using two-photon excitation microscopy (TPEM) revealed higher phenanthrene accumulation in epidermal cells of roots and lower transport into the root interior and stem in mycorrhizal plants than in non-mycorrhizal controls. These results provide some insight into the mechanisms by which arbuscular mycorrhizal inoculation may influence the uptake of organic contaminants by plants. - Colonization by an arbuscular mycorrhizal fungus promoted root uptake and decreased shoot uptake of phenanthrene by Medicago sativa L.

Cuticle hydrolysis in four medically important fly species by enzymes of the entomopathogenic fungus Conidiobolus coronatus.

Science.gov (United States)

Boguś, M I; Włóka, E; Wrońska, A; Kaczmarek, A; Kazek, M; Zalewska, K; Ligęza-Żuber, M; Gołębiowski, M

2017-03-01

Entomopathogenic fungi infect insects via penetration through the cuticle, which varies remarkably in chemical composition across species and life stages. Fungal infection involves the production of enzymes that hydrolyse cuticular proteins, chitin and lipids. Host specificity is associated with fungus-cuticle interactions related to substrate utilization and resistance to host-specific inhibitors. The soil fungus Conidiobolus coronatus (Constantin) (Entomophthorales: Ancylistaceae) shows virulence against susceptible species. The larvae and pupae of Calliphora vicina (Robineau-Desvoidy) (Diptera: Calliphoridae), Calliphora vomitoria (Linnaeus), Lucilia sericata (Meigen) (Diptera: Calliphoridae) and Musca domestica (Linnaeus) (Diptera: Muscidae) are resistant, but adults exposed to C. coronatus quickly perish. Fungus was cultivated for 3 weeks in a minimal medium. Cell-free filtrate, for which activity of elastase, N-acetylglucosaminidase, chitobiosidase and lipase was determined, was used for in vitro hydrolysis of the cuticle from larvae, puparia and adults. Amounts of amino acids, N-glucosamine and fatty acids released were measured after 8 h of incubation. The effectiveness of fungal enzymes was correlated with concentrations of compounds detected in the cuticles of tested insects. Positive correlations suggest compounds used by the fungus as nutrients, whereas negative correlations may indicate compounds responsible for insect resistance. Adult deaths result from the ingestion of conidia or fungal excretions. © 2016 The Royal Entomological Society.

There Is No Structural Relationship between Nasal Septal Deviation, Concha Bullosa, and Paranasal Sinus Fungus Balls

Directory of Open Access Journals (Sweden)

Tung-Lung Tsai

2012-01-01

Full Text Available This study aims to determine the relationship between nasal septal deviation, concha bullosa, and chronic rhinosinusitis by using a definitive pathological and simplified model. Fifty-two consecutive sinus computed tomography scans were performed on patients who received endoscopic sinus surgery and whose final diagnosis was paranasal sinus fungus balls. The incidences of nasal septal deviation and concha bullosa for patients diagnosed with paranasal sinus fungus balls among the study group were 42.3% and 25%, respectively. About 63.6% sinuses with fungus balls were located on the ipsilateral side of the nasal septal deviation, and 46.2% were located on the ipsilateral side of the concha bullosa. When examined by Pearson’s chi-square test and the chi-squared goodness-of-fit test, no significant statistical difference for the presence of paranasal sinus fungus balls between ipsilateral and contralateral sides of nasal septal deviation and concha bullosa was noted (P=0.292 and P=0.593, resp.. In conclusion, we could not demonstrate any statistically significant correlation between the location of infected paranasal sinus, the direction of nasal septal deviation, and the location of concha bullosa, in location-limited rhinosinusitis lesions such as paranasal sinus fungal balls. We conclude that the anatomical variants discussed herein do not predispose patients to rhinosinusitis.

Influenza A(H10N7) Virus in Dead Harbor Seals, Denmark

DEFF Research Database (Denmark)

Krog, Jesper Schak; Hansen, Mette Sif; Holm, Elisabeth

2015-01-01

Since April 2014, an outbreak of influenza in harbor seals has been ongoing in northern Europe. In Denmark during June-August, 152 harbor seals on the island of Anholt were found dead from severe pneumonia. We detected influenza A(H10N7) virus in 2 of 4 seals examined.......Since April 2014, an outbreak of influenza in harbor seals has been ongoing in northern Europe. In Denmark during June-August, 152 harbor seals on the island of Anholt were found dead from severe pneumonia. We detected influenza A(H10N7) virus in 2 of 4 seals examined....

[Wood transformation in dead-standing trees in the forest-tundra of Central Siberia].

Science.gov (United States)

Mukhortova, L V; Kirdianov, A V; Myglan, V S; Guggenberger, G

2009-01-01

Changes in the composition of wood organic matter in dead-standing spruce and larch trees depending on the period after their death have been studied in the north of Central Siberia. The period after tree death has been estimated by means of cross-dating. The results show that changes in the composition of wood organic matter in 63% of cases are contingent on tree species. Wood decomposition in dead-standing trees is accompanied by an increase in the contents of alkali-soluble organic compounds. Lignin oxidation in larch begins approximately 80 years after tree death, whereas its transformation in spruce begins not earlier than after 100 years. In the forest-tundra of Central Siberia, the rate of wood organic matter transformation in dead-standing trees is one to two orders of magnitude lower than in fallen wood, which accounts for their role as a long-term store of carbon and mineral elements in these ecosystems.

Switching Device Dead Time Optimization of Resonant Double-Sided LCC Wireless Charging System for Electric Vehicles

Directory of Open Access Journals (Sweden)

Xi Zhang

2017-11-01

Full Text Available Aiming at the reduction of the influence of the dead time setting on power level and efficiency of the inverter of double-sided LCC resonant wireless power transfer (WPT system, a dead time soft switching optimization method for metal–oxide–semiconductor field-effect transistor (MOSFET is proposed. At first, the mathematic description of double-sided LCC resonant wireless charging system is established, and the operating mode is analyzed as well, deducing the quantitative characteristic that the secondary side compensation capacitor C2 can be adjusted to ensure that the circuit is inductive. A dead time optimization design method is proposed, contributing to achieving zero-voltage switching (ZVS of the inverter, which is closely related to the performance of the WPT system. In the end, a prototype is built. The experimental results verify that dead time calculated by this optimized method can ensure the soft switching of the inverter MOSFET and promote the power and efficiency of the WPT.

Enzyme activities at different stages of plant biomass decomposition in three species of fungus-growing termites

DEFF Research Database (Denmark)

da Costa, Rafael R.; Hu, Haofu; Pilgaard, Bo

2018-01-01

contributing to the success of the termites as the main plant decomposers in the Old World. Here we evaluate which plant polymers are decomposed and which enzymes are active during the decomposition process in two major genera of fungus-growing termites. We find a diversity of active enzymes at different...... stages of decomposition and a consistent decrease in plant components during the decomposition process. Furthermore, our findings are consistent with the hypothesis that termites transport enzymes from the older mature parts of the fungus comb through young worker guts to freshly inoculated plant...... substrate. However, preliminary fungal RNAseq analyses suggest that this likely transport is supplemented with enzymes produced in situ Our findings support that the maintenance of an external fungus comb, inoculated with an optimal mix of plant material, fungal spores, and enzymes, is likely the key...

The genome sequence of the model ascomycete fungus Podospora anserina

NARCIS (Netherlands)

Espagne, Eric; Lespinet, Olivier; Malagnac, Fabienne; Da Silva, Corinne; Jaillon, Olivier; Porcel, Betina M; Couloux, Arnaud; Aury, Jean-Marc; Ségurens, Béatrice; Poulain, Julie; Anthouard, Véronique; Grossetete, Sandrine; Khalili, Hamid; Coppin, Evelyne; Déquard-Chablat, Michelle; Picard, Marguerite; Contamine, Véronique; Arnaise, Sylvie; Bourdais, Anne; Berteaux-Lecellier, Véronique; Gautheret, Daniel; de Vries, Ronald P; Battaglia, Evy; Coutinho, Pedro M; Danchin, Etienne Gj; Henrissat, Bernard; Khoury, Riyad El; Sainsard-Chanet, Annie; Boivin, Antoine; Pinan-Lucarré, Bérangère; Sellem, Carole H; Debuchy, Robert; Wincker, Patrick; Weissenbach, Jean; Silar, Philippe

2008-01-01

BACKGROUND: The dung-inhabiting ascomycete fungus Podospora anserina is a model used to study various aspects of eukaryotic and fungal biology, such as ageing, prions and sexual development. RESULTS: We present a 10X draft sequence of P. anserina genome, linked to the sequences of a large expressed

[Biochemical basis of tolerance to osmotic stress in phytopathogenic fungus: The case of Macrophomina phaseolina (Tassi) Goid.

Science.gov (United States)

Martínez-Villarreal, Rodolfo; Garza-Romero, Tamar S; Moreno-Medina, Víctor R; Hernández-Delgado, Sanjuana; Mayek-Pérez, Netzahualcoyotl

Fungus Macrophomina phaseolina (Tassi) Goid. is the causative agent of charcoal rot disease which causes significant yield losses in major crops such as maize, sorghum, soybean and common beans in Mexico. This fungus is a facultative parasite which shows broad ability to adapt itself to stressed environments where water deficits and/or high temperature stresses commonly occur. These environmental conditions are common for most cultivable lands throughout Mexico. Here we describe some basic facts related to the etiology and epidemiology of the fungus as well as to the importance of responses to stressed environments, particularly to water deficits, based on morphology and growth traits, as well as on physiology, biochemistry and pathogenicity of fungus M. phaseolina. To conclude, we show some perspectives related to future research into the genus, which emphasize the increasing need to improve the knowledge based on the application of both traditional and biotechnological tools in order to elucidate the mechanisms of resistance to environmental stress which can be extrapolated to other useful organisms to man. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Down dead wood statistics for Maine timberlands, 1995

Science.gov (United States)

Linda S. Heath; David C. Chojnacky; David C. Chojnacky

2001-01-01

Down dead wood (DDW) is important for its role in carbon and nutrient cycling, carbon sequestration, wildfire behavior, plant reproduction, and wildlife habitat. DDW was measured for the first time during a forest inventory of Maine by the USDA Forest Service in 1994-1996. Pieces greater than 3 feet long and greater than 3 inches in diameter at point of intersection...

Scenes of Devastation: Chasing Hawaii's Deadly Ohia Fungus | Hawaii Public

Science.gov (United States)

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Phytoplankton chytridiomycosis: fungal parasites of phytoplankton and their imprints on the food web dynamics

Directory of Open Access Journals (Sweden)

Télesphore eSIME - NGANDO

2012-10-01

Full Text Available Parasitism is one of the earlier and common ecological interactions in the nature, occurring in almost all environments. Microbial parasites typically are characterized by their small size, short generation time, and high rates of reproduction, with simple life cycle occurring generally within a single host. They are diverse and ubiquitous in aquatic ecosystems, comprising viruses, prokaryotes and eukaryotes. Recently, environmental 18S-rDNA surveys of microbial eukaryotes have unveiled major infecting agents in pelagic systems, consisting primarily of the fungal order of Chytridiales (chytrids. Chytrids are considered the earlier branch of the Eumycetes and produce motile, flagellated zoospores, characterized by a small size (2-6 µm and a single, posterior flagellum. The existence of these dispersal propagules includes chytrids within the so-called group of zoosporic fungi, which are particularly adapted to the plankton lifestyle where they infect a wide variety of hosts, including fishes, eggs, zooplankton, algae, and other aquatic fungi but primarily freshwater phytoplankton. Related ecological implications are huge because chytrids can killed their hosts, release substrates for microbial processes, and provide nutrient-rich particles as zoospores and short fragments of filamentous inedible hosts for the grazer food chain. Furthermore, based on the observation that phytoplankton chytridiomycosis preferentially impacts the larger size species, blooms of such species (e.g. filamentous cyanobacteria may not totally represent trophic bottlenecks. Besides, chytrid epidemics represent an important driving factor in phytoplankton seasonal successions. In this review, I summarize the knowledge on the diversity, community structure, quantitative importance, and functional roles of fungal chytrids, primarily those who are parasites of phytoplankton, and infer the ecological implications and potentials for the food web dynamics and properties.

Influence of arbuscular mycorrhizal fungus Glomus intra-radices on accumulation of radiocaesium by plant species

International Nuclear Information System (INIS)

Dudchak, S.V.

2012-01-01

The role of arbuscular mycorrhizal fungus Glomus intra-radices in 134 Cs isotope uptake by different plant species is studied. The impact of radiocaesium on mycorrhizal development and functioning of plant photosynthetic apparatus is considered. The possibility of mycorrhizal symbiosis application in phytoremediation of radioactively contaminated areas is analyzed.It is found that colonization of plants with arbuscular mycorrhizal fungus resulted in significant decrease of radiocaesium concentration in their aboveground parts, while it did not have considerable impact on the radionuclide uptake by plant root system

Fungal metabolites: Tetrahydroauroglaucin and isodihydroauroglaucin from the marine fungus,iEurotium sp.

Digital Repository Service at National Institute of Oceanography (India)

Gawas, D.; PrabhaDevi; Tilvi, S.; Naik, C.G.; Parameswaran, P.S.

Two poly substituted aromatic compounds: tetrahydroauroglaucin 1 and isodihydroauroglaucin 2 were identified from a marine fungus, Eurotium sp. isolated from leaves of the mangrove, Porteresia coarctata (Roxb). These compounds were reported earlier...

Solution of the Markov chain for the dead time problem

International Nuclear Information System (INIS)

Degweker, S.B.

1997-01-01

A method for solving the equation for the Markov chain, describing the effect of a non-extendible dead time on the statistics of time correlated pulses, is discussed. The equation, which was derived in an earlier paper, describes a non-linear process and is not amenable to exact solution. The present method consists of representing the probability generating function as a factorial cumulant expansion and neglecting factorial cumulants beyond the second. This results in a closed set of non-linear equations for the factorial moments. Stationary solutions of these equations, which are of interest for calculating the count rate, are obtained iteratively. The method is applied to the variable dead time counter technique for estimation of system parameters in passive neutron assay of Pu and reactor noise analysis. Comparisons of results by this method with Monte Carlo calculations are presented. (author)

Corrections for the combined effects of decay and dead time in live-timed counting of short-lived radionuclides

International Nuclear Information System (INIS)

Fitzgerald, R.

2016-01-01

Studies and calibrations of short-lived radionuclides, for example "1"5O, are of particular interest in nuclear medicine. Yet counting experiments on such species are vulnerable to an error due to the combined effect of decay and dead time. Separate decay corrections and dead-time corrections do not account for this issue. Usually counting data are decay-corrected to the start time of the count period, or else instead of correcting the count rate, the mid-time of the measurement is used as the reference time. Correction factors are derived for both those methods, considering both extending and non-extending dead time. Series approximations are derived here and the accuracy of those approximations are discussed. - Highlights: • Derived combined effects of decay and dead time. • Derived for counting systems with extending or non-extending dead times. • Derived series expansions for both midpoint and decay-to-start-time methods. • Useful for counting experiments with short-lived radionuclides. • Examples given for "1"5O, used in PET scanning.

Organismal death, the dead-donor rule and the ethics of vital organ procurement.

Science.gov (United States)

Symons, Xavier; Chua, Reginald Mary

2018-06-19

Several bioethicists have recently discussed the complexity of defining human death, and considered in particular how our definition of death affects our understanding of the ethics of vital organ procurement. In this brief paper, we challenge the mainstream medical definition of human death-namely, that death is equivalent to total brain failure-and argue with Nair-Collins and Miller that integrated biological functions can continue even after total brain failure has occurred. We discuss the implications of Nair-Collins and Miller's argument and suggest that it may be necessary to look for alternative biological markers that reliably indicate the death of a human being. We reject the suggestion that we should abandon the dead-donor criteria for organ donation. Rather than weaken the ethical standards for vital organ procurement, it may be necessary to make them more demanding. The aim of this paper is not to justify the dead donor rule. Rather, we aim to explore the perspective of those who agree with critiques of the whole brain and cardiopulmonary definitions of death but yet disagree with the proposal that we should abandon the dead-donor rule. We will consider what those who want to retain the dead-donor rule must argue in light of Nair-Collins and Miller's critique. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

A Laboratory Maintenance Regime for a Fungus-Growing Termite Macrotermes gilvus (Blattodea: Termitidae).

Science.gov (United States)

Lee, Ching-Chen; Lee, Chow-Yang

2015-06-01

The optimum maintenance conditions of the fungus-growing termite, Macrotermes gilvus (Hagen) (Blattodea: Termitidae), in the laboratory were studied. Termites were kept on a matrix of moist sand and with fungus comb as food. The survival of groups of termites was measured when maintained at different population densities by changing group size and container volume. Larger groups (≥0.6 g) were more vigorous and had significant higher survival rates than smaller groups (≤0.3 g). The population density for optimal survival of M. gilvus is 0.0025 g per container volume (ml) or 0.0169 g per matrix volume (cm(3)), i.e., 1.2 g of termites kept in a 480-ml container filled with 71 cm3 of sand. In termite groups of smaller size (i.e., 0.3 g) or groups maintained in smaller container (i.e., 100 ml) the fungus comb was overgrown with Xylaria spp., and subsequently all termites died within the study period. The insufficient number of workers for regulating the growth of unwanted fungi other than Termitomyces spp. in the fungus comb is the most likely reason. Unlike some other mound-building termite species, M. gilvus showed satisfactory survival when maintained in non-nutritious matrix (i.e., sand). There was no significant difference in the survival rate between different colonies of M. gilvus (n=5), with survival in the range of 78.5-84.4% after 4 wk. Advances in the maintenance of Macrotermes will enable researchers to study with more biological relevance many aspects of the biology, behavior, and management of this species. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Rapid shifts in Atta cephalotes fungus-garden enzyme activity after a change in fungal substrate (Attini, Formicidae)

DEFF Research Database (Denmark)

Kooij, P W; Schiøtt, M; Boomsma, J J

2011-01-01

Fungus gardens of the basidiomycete Leucocoprinus gongylophorus sustain large colonies of leaf-cutting ants by degrading the plant material collected by the ants. Recent studies have shown that enzyme activity in these gardens is primarily targeted toward starch, proteins and the pectin matrix......, we measured the changes in enzyme activity after a controlled shift in fungal substrate offered to six laboratory colonies of Atta cephalotes. An ant diet consisting exclusively of grains of parboiled rice rapidly increased the activity of endo-proteinases and some of the pectinases attacking...... from the rice diet, relative to the leaf diet controls. Enzyme activity in the older, bottom sections of fungus gardens decreased, indicating a faster processing of the rice substrate compared to the leaf diet. These results suggest that leaf-cutting ant fungus gardens can rapidly adjust enzyme...

Adaptive NN tracking control of uncertain nonlinear discrete-time systems with nonaffine dead-zone input.

Science.gov (United States)

Liu, Yan-Jun; Tong, Shaocheng

2015-03-01

In the paper, an adaptive tracking control design is studied for a class of nonlinear discrete-time systems with dead-zone input. The considered systems are of the nonaffine pure-feedback form and the dead-zone input appears nonlinearly in the systems. The contributions of the paper are that: 1) it is for the first time to investigate the control problem for this class of discrete-time systems with dead-zone; 2) there are major difficulties for stabilizing such systems and in order to overcome the difficulties, the systems are transformed into an n-step-ahead predictor but nonaffine function is still existent; and 3) an adaptive compensative term is constructed to compensate for the parameters of the dead-zone. The neural networks are used to approximate the unknown functions in the transformed systems. Based on the Lyapunov theory, it is proven that all the signals in the closed-loop system are semi-globally uniformly ultimately bounded and the tracking error converges to a small neighborhood of zero. Two simulation examples are provided to verify the effectiveness of the control approach in the paper.

Accounting for density reduction and structural loss in standing dead trees: Implications for forest biomass and carbon stock estimates in the United States

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Domke Grant M

2011-11-01

Full Text Available Abstract Background Standing dead trees are one component of forest ecosystem dead wood carbon (C pools, whose national stock is estimated by the U.S. as required by the United Nations Framework Convention on Climate Change. Historically, standing dead tree C has been estimated as a function of live tree growing stock volume in the U.S.'s National Greenhouse Gas Inventory. Initiated in 1998, the USDA Forest Service's Forest Inventory and Analysis program (responsible for compiling the Nation's forest C estimates began consistent nationwide sampling of standing dead trees, which may now supplant previous purely model-based approaches to standing dead biomass and C stock estimation. A substantial hurdle to estimating standing dead tree biomass and C attributes is that traditional estimation procedures are based on merchantability paradigms that may not reflect density reductions or structural loss due to decomposition common in standing dead trees. The goal of this study was to incorporate standing dead tree adjustments into the current estimation procedures and assess how biomass and C stocks change at multiple spatial scales. Results Accounting for decay and structural loss in standing dead trees significantly decreased tree- and plot-level C stock estimates (and subsequent C stocks by decay class and tree component. At a regional scale, incorporating adjustment factors decreased standing dead quaking aspen biomass estimates by almost 50 percent in the Lake States and Douglas-fir estimates by more than 36 percent in the Pacific Northwest. Conclusions Substantial overestimates of standing dead tree biomass and C stocks occur when one does not account for density reductions or structural loss. Forest inventory estimation procedures that are descended from merchantability standards may need to be revised toward a more holistic approach to determining standing dead tree biomass and C attributes (i.e., attributes of tree biomass outside of sawlog

The improvement of precision for estimating the abundance of standing dead trees using auxiliary information under the FIA pot design

Science.gov (United States)

Hong Su An; David W. MacFarlane; Christopher W. Woodall

2012-01-01

Standing dead trees are an important component of forest ecosystems. However, reliable estimates of standing dead tree population parameters can be difficult to obtain due to their low abundance and spatial and temporal variation. After 1999, the Forest Inventory and Analysis (FIA) Program began collecting data for standing dead trees at the Phase 2 stage of sampling....

Caste-specific symbiont policing by workers of Acromyrmex fungus-growing ants

NARCIS (Netherlands)

Ivens, Aniek B. F.; Nash, David R.; Poulsen, Michael; Boomsma, Jacobus J.

2009-01-01

The interaction between leaf-cutting ants and their fungus garden mutualists is ideal for studying the evolutionary stability of interspecific cooperation. Although the mutualism has a long history of diffuse coevolution, there is ample potential for conflicts between the partners over the mixing

An in vivo transcriptome for entomopathogenic fungus Metarhizium robertsii ARSEF 2575

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Molecular mechanisms underlying the pathogenic process of the insect pathogen Metarhizium robertsii ARSEF 2575 in its host are only partially understood. To probe the transcriptional responses of the fungus during the interaction with insects, we have developed a method to specifically recover patho...

Presumptive horizontal symbiont transmission in the fungus-growing termite Macrotermes natalensis

NARCIS (Netherlands)

Fine Licht, de H.H.; Boomsma, J.J.; Aanen, D.K.

2006-01-01

All colonies of the fungus-growing termite Macrotermes natalensis studied so far are associated with a single genetically variable lineage of Termitomyces symbionts. Such limited genetic variation of symbionts and the absence of sexual fruiting bodies (mushrooms) on M. natalensis mounds would be

The telomerase reverse transcriptase subunit from the dimorphic fungus Ustilago maydis.

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Dolores Bautista-España

Full Text Available In this study, we investigated the reverse transcriptase subunit of telomerase in the dimorphic fungus Ustilago maydis. This protein (Trt1 contains 1371 amino acids and all of the characteristic TERT motifs. Mutants created by disrupting trt1 had senescent traits, such as delayed growth, low replicative potential, and reduced survival, that were reminiscent of the traits observed in est2 budding yeast mutants. Telomerase activity was observed in wild-type fungus sporidia but not those of the disruption mutant. The introduction of a self-replicating plasmid expressing Trt1 into the mutant strain restored growth proficiency and replicative potential. Analyses of trt1 crosses in planta suggested that Trt1 is necessary for teliospore formation in homozygous disrupted diploids and that telomerase is haploinsufficient in heterozygous diploids. Additionally, terminal restriction fragment analysis in the progeny hinted at alternative survival mechanisms similar to those of budding yeast.

Correction of the counting up number by dead time in detector systems for radiograph images

International Nuclear Information System (INIS)

Cerdeira E, A.; Cicuttin, A.; Cerdeira, A.; Estrada, M.; Luca, A. de

2002-01-01

The effect of the dead time in a detection system by counting up of particles and the contribution of this error in the final image resolution is analysed. It is given a statistical criteria for the optimization of electronic parameters such as dead time and counting up memory which help in the implementation of these systems with the minimum necessary characteristics which satisfy the resolution requirements. (Author)

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.

Global amphibian declines: perspectives from the United States and beyond

Science.gov (United States)

Densmore, Christine L.; Cipriano, R.C.; Bruckner, A.W.; Shchelkunov, I.S.

2011-01-01

Over recent decades, amphibians have experienced population declines, extirpations and species-level extinctions at an alarming rate. Numerous potential etiologies for amphibian declines have been postulated including climate and habitat degradation. Other potential anthropogenic causes including overexploitation and the frequent introductions of invasive predatory species have also been blamed for amphibian declines. Still other underlying factors may include infectious diseases caused by the chytrid fungus Batrachochytrium dendrobatidis, pathogenic viruses (Ranavirus), and other agents. It is nearly certain that more than one etiology is to blame for the majority of the global amphibian declines, and that these causal factors include some combination of climatological or physical habitat destabilization and infectious disease, most notably chytridiomycosis. Scientific research efforts are aimed at elucidating these etiologies on local, regional, and global scales that we might better understand and counteract the driving forces behind amphibian declines. Conservation efforts as outlined in the Amphibian Conservation Action Plan of 2005 are also being made to curtail losses and prevent further extinctions wherever possible.

Population size, survival, growth, and movements of Rana sierrae

Science.gov (United States)

Fellers, Gary M.; Kleeman, Patrick M.; Miller, David A. W.; Halstead, Brian J.; Link, William

2013-01-01

Based on 2431 captures of 757 individual frogs over a 9-yr period, we found that the population of R. sierrae in one meadow–stream complex in Yosemite National Park ranged from an estimated 45 to 115 adult frogs. Rana sierrae at our relatively low elevation site (2200 m) grew at a fast rate (K = 0.73–0.78), had high overwintering survival rates (44.6–95%), lived a long time (up to 16 yr), and tended to be fairly sedentary during the summer (100% minimum convex polygon annual home ranges of 139 m2) but had low year-to-year site fidelity. Even though the amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) has been present in the population for at least 13 yr, there was no clear downward trend as might be expected from reports of R. sierrae population declines associated with Bd or from reports of widespread population decline of R. sierrae throughout its range.

Introduced bullfrogs are associated with increased Batrachochytrium dendrobatidis prevalence and reduced occurrence of Korean treefrogs.

Directory of Open Access Journals (Sweden)

Amaël Borzée

Full Text Available Bullfrogs, Lithobates catesbeianus, have been described as major vectors of the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd. Bd is widespread throughout the range of amphibians yet varies considerably within and among populations in prevalence and host impact. In our study, the presence of L. catesbeianus is correlated with a 2.5 increase in Bd prevalence in treefrogs, and the endangered Dryophytes suweonensis displays a significantly higher Bd prevalence than the more abundant D. japonicus for the 37 sites surveyed. In addition, the occurrence of L. catesbeianus was significantly correlated with a decrease in presence of D. suweonensis at sites. We could not determine if it is the presence of bullfrogs as competitors or predators that is limiting the distribution of D. suweonensis or whether this is caused by bullfrogs acting as a reservoir for Bd. However, L. catesbeianus can now be added to the list of factors responsible for the decline of D. suweonensis populations.

Deadly progress

International Nuclear Information System (INIS)

Nader, R.; Abbotts, J.

1978-01-01

Nuclear power plants are safe, they help to get through the future bottle-neck in the field of energy, nuclear power plants provide for cheap electrical power and support economic growth - these are the sedative formulae which have been used for years to close the populations eyes towards the real problems. In this book, the American lawyer Ralph Nader and the nuclear chemist John Abbots not only oppose this myth of atomic safety, but they also defeat this theory with numerous technical, economic, and political details. Having realized the fact that the development of atomic energy can no longer be prevented by warnings of independent experts, but only by massive protests by the population - i.e. the protest by informed persons-, they give an understandable introduction to the techniques of atomic energy, construction of nuclear power plants, radioactive radiation, safety, etc. Furthermore, they inform about the social, political, and economic background of the nuclear power forcing. Nader and Abbots show the uncertainty of science, they bring secret documents about failures already occured and point out the catastrophic consequences of possible defects. The result of the thorough study: A 'technologic Vietnam' impends both USA and all other nuclear power countries, if the population won't struggle against this dead-end programme of the governments. (orig./HP) [de

Exploring the binding properties and structural stability of an opsin in the chytrid Spizellomyces punctatus using comparative and molecular modeling

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Steven R. Ahrendt

2017-04-01

Full Text Available Background Opsin proteins are seven transmembrane receptor proteins which detect light. Opsins can be classified into two types and share little sequence identity: type 1, typically found in bacteria, and type 2, primarily characterized in metazoa. The type 2 opsins (Rhodopsins are a subfamily of G-protein coupled receptors (GPCRs, a large and diverse class of seven transmembrane proteins and are generally restricted to metazoan lineages. Fungi use light receptors including opsins to sense the environment and transduce signals for developmental or metabolic changes. Opsins characterized in the Dikarya (Ascomycetes and Basidiomycetes are of the type 1 bacteriorhodopsin family but the early diverging fungal lineages have not been as well surveyed. We identified by sequence similarity a rhodopsin-like GPCR in genomes of early diverging chytrids and examined the structural characteristics of this protein to assess its likelihood to be homologous to animal rhodopsins and bind similar chromophores. Methods We used template-based structure modeling, automated ligand docking, and molecular modeling to assess the structural and binding properties of an identified opsin-like protein found in Spizellomyces punctatus, a unicellular, flagellated species belonging to Chytridiomycota, one of the earliest diverging fungal lineages. We tested if the sequence and inferred structure were consistent with a solved crystal structure of a type 2 rhodopsin from the squid Todarodes pacificus. Results Our results indicate that the Spizellomyces opsin has structural characteristics consistent with functional animal type 2 rhodopsins and is capable of maintaining a stable structure when associated with the retinaldehyde chromophore, specifically the 9-cis-retinal isomer. Together, these results support further the homology of Spizellomyces opsins to animal type 2 rhodopsins. Discussion This represents the first test of structure/function relationship of a type 2 rhodopsin

Preliminary data on growth and enzymatic abilities of soil fungus Humicolopsis cephalosporioides at different incubation temperatures.

Science.gov (United States)

Elíades, Lorena Alejandra; Cabello, Marta N; Pancotto, Verónica; Moretto, Alicia; Rago, María Melisa; Saparrat, Mario C N

2015-01-01

Nothofagus pumilio (Poepp & Endl.) Krasser, known as "lenga" is the most important timber wood species in southernmost Patagonia (Argentina). Humicolopsis cephalosporioides Cabral & Marchand is a soil fungus associated with Nothofagus pumilio forests, which has outstanding cellulolytic activity. However, there is no information about the ability of this fungus to use organic substrates other than cellulose, and its ability to produce different enzyme systems, as well as its response to temperature. The aim of this study was to examine the role of H. cephalosporioides in degradation processes in N. pumilio forests in detail by evaluating the in vitro ability of four isolates of this fungus to grow and produce different lytic enzyme systems, and their response to incubation temperature. The ability of the fungi to grow and produce enzyme systems was estimated by inoculating them on agar media with specific substrates, and the cultures were incubated at three temperatures. A differential behavior of each strain in levels of growth and enzyme activity was found according to the medium type and/or incubation temperature. A intra-specific variability was found in H. cephalosporioides. Likewise a possible link between the saprotrophic role of this fungus in N. pumilio forests and the degradation of organic matter under stress conditions, such as those from frosty environments, was also discussed. Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

Changes in down dead wood volume across a chronosequence of silvicultural openings in southern Indiana forests

Science.gov (United States)

Michael A. Jenkins; George R. Parker

1997-01-01

The volume and decay stages of down dead wood were evaluated across a chronosequence of 46 silvicultural openings and 10 uncut control stands to determine how down dead wood volume changes with stand development. Openings ranged in age from 8 to 26 years and were divided into three age groups: (1) 16 years. Individual logs...

Assessment of biofuel potential of dead neem leaves ( Azadirachta ...

African Journals Online (AJOL)

Unfortunately, the lack of information on the biomass and energy potentials of these wastes empedes any initiative for its industrial biomethanization. This study was investigated with the aim of evaluating the biofuel potentials of dead neem leaves in Maroua town. The number of neem trees, as well as biomass produced by ...

Dressing the dead body

Directory of Open Access Journals (Sweden)

Birgitta Nordström

2016-12-01

Full Text Available My current research focuses on textiles and rites, especially woven textiles for funerals and moments of loss. What active role can a textile such as an infant-wrapping cloth or a funeral pall play in the mourning process? This article will describe the development and current questions that address 1 the infant-wrapping cloth – the textile that is used to dress, clothe, or cover the dead body with particular attention to the question of infant mortality and the material practices of care. 2 The funeral pall that is used at funerals, draped over the coffin or as a body cover at hospital viewing rooms. One example to be presented is Kortedalakrönika (‘The Chronicle of Kortedala’, a collaborative project, woven for a church in Gothenburg. My work is based in artistic practice but opens up several scientific and existential questions.

Effect of the presence of brood and fungus on the nest architecture and digging activity of Acromyrmex subterraneus Forel (Hymenoptera, Formicidae

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Carlos Magno dos Santos

Full Text Available ABSTRACT This study investigated the stimuli that trigger digging behavior in Acromyrmex subterraneus during nest building. The hypothesis was that the presence of the fungus garden and/or brood triggers the excavation of tunnels and chambers. For the experiment, the excavation rate of individually marked workers kept in plastic cylinders filled with soil was recorded. Four treatments were applied: (1 30 medium-sized workers, 5 g fungus garden and 30 brood items (larvae and pupae; (2 30 medium-sized workers and 5 g fungus garden; (3 30 medium-sized workers and 30 brood items; (4 30 medium-sized workers without fungus and brood. After 24 h, morphological parameters of nest structure (length and width of the chambers and tunnels in cm and the volume of excavated soil were recorded. In contrast to the expected findings, no change in morphological structure, rate of excavation by workers, or volume of excavated soil was observed between treatments, except for tunnel width, which was greater, when no brood or fungus garden was present. Thus, the results do not support the hypothesis that the fungus garden and/or brood are local stimuli for nest excavation or that they mold the internal architecture of the nest. Although this hypothesis was confirmed for Acromyrmex lundii and Atta sexdens rubropilosa, the same does not apply to A. subterraneus. The digging behavior of workers is probably the result of adaptation during nest building in different habitats.

Effects of selenium oxyanions on the white-rot fungus Phanerochaete chrysosporium

KAUST Repository

Espinosa-Ortiz, Erika J.; Gonzalez-Gil, Graciela; Saikaly, Pascal; van Hullebusch, Eric D.; Lens, Piet N L

2014-01-01

and substrate consumption when supplied at 10 mg L−1 in the growth medium, whereas selenate did not have such a strong influence on the fungus. Biological removal of selenite was achieved under semi-acidic conditions (pH 4.5) with about 40 % removal efficiency