WorldWideScience

Sample records for bracken fern carcinogen

  1. Bracken fern poisoning

    Science.gov (United States)

    Bracken fern (Pteridium aquilinum) has worldwide distribution and in some areas dominated plant communities replacing desirable forages. Poisoning is identified as enzootic hematuria, bright blindness, and bracken staggers. This chapter reviews updates new information on the plant, the various poi...

  2. Genotoxic activity and inhibition of soil respiration by ptaquiloside, a bracken fern carcinogen

    DEFF Research Database (Denmark)

    Schmidt, Bjørn; Rasmussen, L.H.; Svendsen, Gitte Winkel

    2005-01-01

    Ptaquiloside (PTA) is a natural toxin produced by bracken (Pteridium aquilinum [L.] Kuhn). Assessment of PTA toxicity is needed because PTA deposited from bracken to soil may leach to surface and groundwater. Inhibition of soil respiration and genotoxic activity of PTA was determined by a soil...... microbial carbon transformation test and an umu test, respectively. In the carbon transformation test, sandy loam soil was incubated at five different initial concentrations of PTA for a period of 28 d, after which glucose was added and respiration measured for 12 consecutive hours. The tests were performed...... at 20 degrees C and Soil moisture content of approximately 15%. For soil material sampled in the autumn, initial PTA concentrations ranging from 0.008 to 40.6 mu g PTA/g dry soil were tested. From fitting of data by a sigmoidal function, a 10% effect dose (ED10) was estimated to 13 jig PTA/g dry soil...

  3. Environmental Fate and Analysis of Ptaquiloside from the Bracken Fern

    DEFF Research Database (Denmark)

    Clauson-Kaas, Frederik

    The naturally occurring phytotoxin ptaquiloside (PTA) has long been known to be both acute toxic and carcinogenic. Contents of more than 1% ptaquiloside on dry weight has been detected in bracken (Pteridium spp.), a fern distributed across the globe in often dense populations. This work focused...... fronds (the leaves of ferns) in concentrations up to 169 µ/L during rainfall events. Rainfall further determined the concentration in a stream that drained a bracken-covered catchment, suggesting that this is a potent driver of ptaquiloside exposure in the environment. In both pure and natural waters, p...

  4. Environmental Fate and Analysis of Ptaquiloside from the Bracken Fern

    DEFF Research Database (Denmark)

    Clauson-Kaas, Frederik

    fronds (the leaves of ferns) in concentrations up to 169 µ/L during rainfall events. Rainfall further determined the concentration in a stream that drained a bracken-covered catchment, suggesting that this is a potent driver of ptaquiloside exposure in the environment. In both pure and natural waters, p...

  5. Human gastric cancer, Helicobacter pylori and bracken carcinogens: A connecting hypothesis.

    Science.gov (United States)

    Oliveros-Bastidas, Alberto; Calcagno-Pissarelli, María Pía; Naya, Marlene; Ávila-Núñez, Jorge Luis; Alonso-Amelot, Miguel E

    2016-03-01

    Long term infection of Helicobacter pylori (Hp) virulent strains is a key factor in the genesis of human gastric cancer, and so are certain dietary proinflammatory and genotoxic compounds. Carcinogenic bracken fern (Pteridium spp.) is one of these. Toxins from this plant are consumed as bracken culinary preparations, through milk and meat of bracken-exposed livestock, and drain waters from bracken swards. Bracken toxin ptaquiloside (PtQ), a suspected human carcinogen, elicits complex responses in animals leading to death. PtQ and Hp might cooperate in gastric pathologies. This paper presents an hypothesis on PtQ-Hp association leading to the enhancement of carcinogenesis in the human gastric environment that might explain the high gastric cancer incidence and death rates among Hp-infected people living in bracken zones at two levels: (1) The macroscopic scale comprising the flow of PtQ in the human diet. (2) the microscopic scale encompassing (A) gastric luminal medium; (B) gastric mucus structure and mucin degradation elicited by Hp; (C) bacterial pH gradient modification of the gastric mucosa that favors PtQ survival and its penetration into epithelial tissue; (D) combined PtQ/Hp effects on gastric immune and inflammatory responses; (E) PtQ-Hp complementary activity at selected cell signaling cascades and genome disturbance.

  6. The effect of nitrogen additions on bracken fern and its insect herbivores at sites with high and low atmospheric pollution

    Science.gov (United States)

    M.E. Jones; M.E. Fenn; T.D. Paine

    2011-01-01

    The impact of atmospheric pollution, including nitrogen deposition, on bracken fern herbivores has never been studied. Bracken fern is globally distributed and has a high potential to accumulate nitrogen in plant tissue. We examined the response of bracken fern and its herbivores to N fertilization at a high and low pollution site in forests downwind of Los Angeles,...

  7. Clastogenic effect of bracken fern (Pteridium aquilinum v. arachnoideum) diet in peripheral lymphocytes of human consumers: preliminary data.

    Science.gov (United States)

    Recouso, R C; Stocco dos Santos, R C; Freitas, R; Santos, R C; de Freitas, A C; Brunner, O; Beçak, W; Lindsey, C J

    2003-03-01

    Ingestion of bracken fern (Pteridium aquilinum v. arachnoideum) is associated with digestive tract cancer in different regions of Japan, Venezuela and Brazil. In view of reports that dietary bracken fern causes chromosomal instability in cattle, the clastogenic effect of bracken fern was investigated, in a preliminary study, in peripheral lymphocytes obtained from habitual consumers and a control group of non-consumers, which were carefully investigated about cancer history or family cancer history, negative in both cases, using protocols comparable to those previously described in studies in cattle raised on bracken pastures. Cytogenetic analysis showed significant increased levels of chromosomal abnormalities, such as chromatid breaks, in cultured peripheral lymphocytes of the consumer group. There was no correlation with subjects, gender, smoking habits or alcohol consumption, and the only correlation was with prolonged exposure to dietary bracken.

  8. Land management of bracken needs to account for bracken carcinogens - a case study from Britain

    DEFF Research Database (Denmark)

    Rasmussen, Lars Holm; Donnelly, Eric; Strobel, Bjarne W.

    2015-01-01

    in bracken stands at any given time is difficult to predict and did not show any correlations with edaphic growth factors. The content of ptaquiloside turned out to be higher in fronds emerging after cutting compared to uncut fronds. Environmental risk assessment and bracken management must therefore...... with ptaquiloside may be the cause. The aim of this study was to monitor the content of ptaquiloside in 20 bracken stands from Britain to obtain a better understanding of the ptaquiloside dynamics and to evaluate the environmental implications of using different cutting regimes in bracken management...

  9. Distribution of the carcinogenic terpene ptaquiloside in Bracken fronds, rhizomes (Pteridium aquilinum) and litter in Denmark

    DEFF Research Database (Denmark)

    Rasmussen, Lars Holm; Jensen, Lasse Sander; Hansen, Hans Christian Bruun

    2003-01-01

    The distribution of ptaquiloside (PTA) was studied in four Danish bracken populations in order to evaluate the transfer of PTA from ferns to soil. Populations showed statistically significant differences in PTAcontents of fronds and rhizomes despite large in-site variations. The highest concentra...

  10. Physicochemical characterisation of the ubiquitous bracken fern as useful biomaterial for preconcentration of heavy metals.

    Science.gov (United States)

    Barriada, Jose L; Caridad, Sergio; Lodeiro, Pablo; Herrero, Roberto; Sastre de Vicente, Manuel E

    2009-02-01

    Batch experiments with dry bracken fern have been done to determine cadmium and lead sequestering capacity of this biomaterial. Biomass characterisation was done by infrared spectroscopy and potentiometric analysis. The effect of pH of the metal containing solution, contact time and initial metal concentration has been studied, together with the acid-base properties of the biomaterial. Results obtained have been analysed using mathematical and modelling techniques. Effect of pH on metal sequestration has been correlated with observed acid-base properties of the natural substrate. Kinetic data analysis provided relevant information about metal sequestration rate, showing important differences between lead and cadmium. Maximum uptake was found to be the same for both metals 0.410 mmol/g. This value was also clearly correlated to the number of acidic groups determined for this material which was found to be 0.432 mmol of acidic groups per gram of fern. Results obtained indicate that acidic groups are the functional groups responsible of the sequestration of metal ions and that bracken fern is a promising material for metal preconcentration.

  11. Sorption, degradation and mobility of ptaquiloside, a carcinogenic Bracken (Pteridium sp.) constituent, in the soil environment

    DEFF Research Database (Denmark)

    Rasmussen, Lars Holm; Lauren, Denis; Hansen, Hans Christian Bruun

    2005-01-01

    very low sorption affinity with distribution coefficients in the range 0.01–0.22 l kg1 at a solution concentration of 1 mg l1 except for the most acid soil; Freundlich affinity coefficients increased linearly with clay and organic matter contents. Negligible sorption was also observed in column studies......Ptaquiloside (PTA) is a carcinogenic norsesquiterpene glucoside produced by Bracken in amounts up to at least 13 500 mg m2. The toxin is transferred from Bracken to the underlying soil from where it may leach to surface and groundwaters impairing the quality of drinking water. The objectives...

  12. Possible association between gastric cancer and bracken fern in Venezuela: an epidemiologic study.

    Science.gov (United States)

    Alonso-Amelot, M E; Avendaño, M

    2001-01-15

    To explore a possible connection between specific environmental factors that might explain the high rates of stomach cancer in people living in the highlands of western Venezuela, an epidemiologic study was conducted in 2 regions of contrasting topography. The regions embrace 3 Andean states, Mérida, Táchira and Trujillo, and the vicinal lowland surrounding the Maracaibo lake basin of Zulia State. Statistical sanitary records from 1986 to 1996 comprising 5.5 million people in the study area indicated that age-sex-adjusted gastric cancer death rate per 100,000 people (DR) was up to 3.64 times higher in highland than lowland areas, although total cancer-related DRs were comparable in both regions. DRs of other less frequent cancers from the upper alimentary tract [esophagous (1.18/0.99) and mouth-throat (1.39/2.64)] showed comparable values in both regions as well as colorectal, breast, and uterus-cervix cancers, suggesting that the stomach cancer DRs were related to geographically determined factors. Comparison of some nutrition issues, incidence of Helicobacter pylori infection in selected areas, the discovery of the bracken carcinogen ptaquiloside in milk from bracken-fed cows, the prevalence of this plant in mountain cattle households and pasturelands and the rates of bracken-evoked bovine enzootic hematuria led us to conclude that consumption of ptaquiloside-contaminated milk may contribute to human gastric cancer in the Andean states of Venezuela.

  13. Ferns and lycopods--a potential treasury of anticancer agents but also a carcinogenic hazard.

    Science.gov (United States)

    Tomšík, Pavel

    2014-06-01

    Many species of seedless vascular plants-ferns and lycopods-have been used as food and folk medicine since ancient times. Some of them have become the focus of intensive research concerning their anticancer properties. Studies on the anticancer effect of crude extracts are being increasingly replaced by bioactivity-guided fractionation, as well as detailed assessment of the mechanism of action. Numerous compounds-especially flavonoids such as amentoflavone and protoapigenone, and also simpler phenolic compounds, steroids, alkaloids and terpenoids-were isolated and found to be cytotoxic, particularly pro-apoptotic, or to induce cell cycle arrest in cancer cell lines in vitro. In in vivo experiments, some fern-derived compounds inhibited tumour growth with little toxicity. On the other hand, many ferns-not only the well-known Bracken (Pteridium)-may pose a significant hazard to human health due to the fact that they contain carcinogenic sesquiterpenoids and their analogues. The objective of this review is to summarise the recent state of research on the anticancer properties of ferns and lycopods, with a focus on their characteristic bioactive constituents. The carcinogenic hazard posed by ferns is also mentioned.

  14. Detection and mapping the spatial distribution of bracken fern weeds using the Landsat 8 OLI new generation sensor

    Science.gov (United States)

    Matongera, Trylee Nyasha; Mutanga, Onisimo; Dube, Timothy; Sibanda, Mbulisi

    2017-05-01

    Bracken fern is an invasive plant that presents serious environmental, ecological and economic problems around the world. An understanding of the spatial distribution of bracken fern weeds is therefore essential for providing appropriate management strategies at both local and regional scales. The aim of this study was to assess the utility of the freely available medium resolution Landsat 8 OLI sensor in the detection and mapping of bracken fern at the Cathedral Peak, South Africa. To achieve this objective, the results obtained from Landsat 8 OLI were compared with those derived using the costly, high spatial resolution WorldView-2 imagery. Since previous studies have already successfully mapped bracken fern using high spatial resolution WorldView-2 image, the comparison was done to investigate the magnitude of difference in accuracy between the two sensors in relation to their acquisition costs. To evaluate the performance of Landsat 8 OLI in discriminating bracken fern compared to that of Worldview-2, we tested the utility of (i) spectral bands; (ii) derived vegetation indices as well as (iii) the combination of spectral bands and vegetation indices based on discriminant analysis classification algorithm. After resampling the training and testing data and reclassifying several times (n = 100) based on the combined data sets, the overall accuracies for both Landsat 8 and WorldView-2 were tested for significant differences based on Mann-Whitney U test. The results showed that the integration of the spectral bands and derived vegetation indices yielded the best overall classification accuracy (80.08% and 87.80% for Landsat 8 OLI and WorldView-2 respectively). Additionally, the use of derived vegetation indices as a standalone data set produced the weakest overall accuracy results of 62.14% and 82.11% for both the Landsat 8 OLI and WorldView-2 images. There were significant differences {U (100) = 569.5, z = -10.8242, p < 0.01} between the classification accuracies

  15. Allelopathy of Bracken Fern (Pteridium arachnoideum): New Evidence from Green Fronds, Litter, and Soil

    Science.gov (United States)

    Juliano Gualtieri, Sonia Cristina; Rodrigues-Filho, Edson; Macías, Francisco Antonio

    2016-01-01

    The neotropical bracken fern Pteridium arachnoideum (Kaulf.) Maxon. (Dennstaedtiaceae) is described as an aggressive pioneer plant species. It invades abandoned or newly burned areas and represents a management challenge at these invaded sites. Native to the Atlantic Forest and Cerrado (Tropical Savanna) Brazilian biomes, P. arachnoideum has nevertheless become very problematic in these conservation hotspots. Despite some reports suggesting a possible role of allelopathy in this plant’s dominance, until now there has been little evidence of isolated and individually identified compounds with phytotoxic activities present in its tissues or in the surrounding environment. Thus, the aim of this study was to investigate the allelopathic potential of P. arachnoideum by isolating and identifying any secondary metabolites with phytotoxic activity in its tissues, litter, and soil. Bioguided phytochemical investigation led to the isolation and identification of the proanthocyanidin selligueain A as the major secondary compound in the green fronds and litter of this fern. It is produced by P. arachnoideum in its green fronds, remains unaltered during the senescence process, and is the major secondary compound present in litter. Selligueain A showed phytotoxic activity against the selected target species sesame (Sesamum indicum) early development. In particular, the compound inhibited root and stem growth, and root metaxylem cell size but did not affect chlorophyll content. This compound can be considered as an allelochemical because it is present in the soil under P. arachnoideum patches as one of the major compounds in the soil solution. This is the first report of the presence of selligueain A in any member of the Dennstaedtiaceae family and the first time an isolated and identified allelochemical produced by members of the Pteridium species complex has been described. This evidence of selligueain A as a putative allelochemical of P. arachnoideum reinforces the role of

  16. Allelopathy of Bracken Fern (Pteridium arachnoideum): New Evidence from Green Fronds, Litter, and Soil.

    Science.gov (United States)

    de Jesus Jatoba, Luciana; Varela, Rosa Maria; Molinillo, José Maria Gonzalez; Ud Din, Zia; Juliano Gualtieri, Sonia Cristina; Rodrigues-Filho, Edson; Macías, Francisco Antonio

    2016-01-01

    The neotropical bracken fern Pteridium arachnoideum (Kaulf.) Maxon. (Dennstaedtiaceae) is described as an aggressive pioneer plant species. It invades abandoned or newly burned areas and represents a management challenge at these invaded sites. Native to the Atlantic Forest and Cerrado (Tropical Savanna) Brazilian biomes, P. arachnoideum has nevertheless become very problematic in these conservation hotspots. Despite some reports suggesting a possible role of allelopathy in this plant's dominance, until now there has been little evidence of isolated and individually identified compounds with phytotoxic activities present in its tissues or in the surrounding environment. Thus, the aim of this study was to investigate the allelopathic potential of P. arachnoideum by isolating and identifying any secondary metabolites with phytotoxic activity in its tissues, litter, and soil. Bioguided phytochemical investigation led to the isolation and identification of the proanthocyanidin selligueain A as the major secondary compound in the green fronds and litter of this fern. It is produced by P. arachnoideum in its green fronds, remains unaltered during the senescence process, and is the major secondary compound present in litter. Selligueain A showed phytotoxic activity against the selected target species sesame (Sesamum indicum) early development. In particular, the compound inhibited root and stem growth, and root metaxylem cell size but did not affect chlorophyll content. This compound can be considered as an allelochemical because it is present in the soil under P. arachnoideum patches as one of the major compounds in the soil solution. This is the first report of the presence of selligueain A in any member of the Dennstaedtiaceae family and the first time an isolated and identified allelochemical produced by members of the Pteridium species complex has been described. This evidence of selligueain A as a putative allelochemical of P. arachnoideum reinforces the role of

  17. Comparison between WorldView-2 and SPOT-5 images in mapping the bracken fern using the random forest algorithm

    Science.gov (United States)

    Odindi, John; Adam, Elhadi; Ngubane, Zinhle; Mutanga, Onisimo; Slotow, Rob

    2014-01-01

    Plant species invasion is known to be a major threat to socioeconomic and ecological systems. Due to high cost and limited extents of urban green spaces, high mapping accuracy is necessary to optimize the management of such spaces. We compare the performance of the new-generation WorldView-2 (WV-2) and SPOT-5 images in mapping the bracken fern [Pteridium aquilinum (L) kuhn] in a conserved urban landscape. Using the random forest algorithm, grid-search approaches based on out-of-bag estimate error were used to determine the optimal ntree and mtry combinations. The variable importance and backward feature elimination techniques were further used to determine the influence of the image bands on mapping accuracy. Additionally, the value of the commonly used vegetation indices in enhancing the classification accuracy was tested on the better performing image data. Results show that the performance of the new WV-2 bands was better than that of the traditional bands. Overall classification accuracies of 84.72 and 72.22% were achieved for the WV-2 and SPOT images, respectively. Use of selected indices from the WV-2 bands increased the overall classification accuracy to 91.67%. The findings in this study show the suitability of the new generation in mapping the bracken fern within the often vulnerable urban natural vegetation cover types.

  18. Detection of Ptaquilosides in different phenologic stages of Bracken fern (Pteridium aquilinum) and analysis of milk samples in farms with hematuria in Tolima, Colombia

    Science.gov (United States)

    Bracken fern or “Helecho Macho” (Pteridium aquilinum) is one of the most common weeds in the meadows of the mountain ranges of Colombia. Consumption of this palatable plant by bovines causes a disease known as bovine enzootic hematuria and esophageal neoplasia. The toxic effect of the plant in bovin...

  19. Ptaquiloside in Irish Bracken Ferns and Receiving Waters, with Implications for Land Managers

    Directory of Open Access Journals (Sweden)

    Connie O’Driscoll

    2016-04-01

    Full Text Available Ptaquiloside, along with other natural phytotoxins, is receiving increased attention from scientists and land use managers. There is an urgent need to increase empirical evidence to understand the scale of phytotoxin mobilisation and potential to enter into the environment. In this study the risk of ptaquiloside to drinking water was assessed by quantifying ptaquiloside in the receiving waters at three drinking water abstraction sites across Ireland and in bracken fronds surrounding the abstraction sites. We also investigated the impact of different management regimes (spraying, cutting and rolling on ptaquiloside concentrations at plot-scale in six locations in Northern Ireland, UK. Ptaquiloside concentrations were determined using recent advances in the use of LC-MS for the detection and quantification of ptaquiloside. The results indicate that ptaquiloside is present in bracken stands surrounding drinking water abstractions in Ireland, and ptaquiloside concentrations were also observed in the receiving waters. Furthermore, spraying was found to be the most effective bracken management regime observed in terms of reducing ptaquiloside load. Increased awareness is vital on the implications of managing land with extensive bracken stands.

  20. Microbial degradation and impact of Bracken toxin ptaquiloside on microbial communities in soil

    DEFF Research Database (Denmark)

    Engel, Pernille; Brandt, Kristian Koefoed; Rasmussen, Lars Holm

    2007-01-01

    The carcinogenic and toxic ptaquiloside (PTA) is a major secondary metabolite in Bracken fern (Pteridium aquilinum (L.) Kuhn) and was hypothesized to influence microbial communities in soil below Bracken stands. Soil and Bracken tissue were sampled at field sites in Denmark (DK) and New Zealand (......-level physiological profiles. Our results demonstrate that PTA stimulates microbial activity and that microorganisms play a predominant role for rapid PTA degradation in Bracken-impacted soils.......The carcinogenic and toxic ptaquiloside (PTA) is a major secondary metabolite in Bracken fern (Pteridium aquilinum (L.) Kuhn) and was hypothesized to influence microbial communities in soil below Bracken stands. Soil and Bracken tissue were sampled at field sites in Denmark (DK) and New Zealand (NZ......). PTA contents of 2.1 ± 0.5 mg g1 and 37.0 ± 8.7 mg g1 tissue were measured in Bracken fronds from DK and NZ, respectively. In the two soils the PTA levels were similar (0–5 lg g1 soil); a decrease with depth could be discerned in the deeper B and C horizons of the DK soil (weak acid sandy Spodosol...

  1. Ptaquiloside in bracken spores from Britain

    DEFF Research Database (Denmark)

    Rasmussen, Lars Holm; Schmidt, Bjørn; Sheffield, Elizabeth

    2013-01-01

    Secondary metabolites from bracken fern (Pteridium aquilinum (L.) Kuhn) are suspected of causing cancer in humans. The main carcinogen is the highly water-soluble norsesquiterpene glucoside ptaquiloside, which may be ingested by humans through food, e.g. via contaminated water, meat or milk. It has...... in a collection of spores from Britain. Ptaquiloside was present in all samples, with a maximum of 29μgg−1, which is very low compared to other parts of the fern. Considering the low abundance of spores in breathing air under normal conditions, this exposure route is likely to be secondary to milk or drinking...

  2. Occurrence of the carcinogenic Bracken constituent ptaquiloside in fronds, topsoils and organic soil layers in Denmark

    DEFF Research Database (Denmark)

    Rasmussen, L.H.; Kroghsbo, S.; Frisvad, Jens Christian

    2003-01-01

    ). The ptaquiloside-content in the standing biomass, which could be transferred to the soil by the end of the growing season, ranged between 10 and 260 mg m(-2), with nine sites having ptaquiloside loads over 100 mg m(-2). The carbon-content in the O-horizon, the precipitation, the amount of Bracken-litter...

  3. Studies on phytoremediation of copper using Pteridium aquilinum (bracken fern) in the presence of biostimulants and bioassay using Clarias gariepinus juveniles.

    Science.gov (United States)

    Olaifa, Flora Eyibio; Omekam, Anamese Jennifer

    2014-01-01

    A study was carried out to evaluate the uptake of copper from water containing 10 mg/L copper by Pteridium aquilinum (bracken fern) and Clarias gariepinus in the presence of five plant growth stimulants: Nitrogen: phosphorus: potassium (15-15-15: an inorganic fertilizer), pig, cattle, poultry, and a mixture of pig/cattle manures. A plant growth stimulant differentiated each treatment. A 96-hour bioassay using C. gariepinus was carried out at the end of the experiment to test the efficacy of the clean up by P. aquilinum. The control experiment contained no copper or plant growth stimulant. Fish survival, uptake of copper by P. aquilinum, C. gariepinus, concentration of copper in water, hematology and histopathology of the fish were assessed. Higher concentrations of copper were reported in P. aquilinum than in water or C. gariepinus. Low fish mortality was reported with the highest being 20% in the cattle manure-containing treatment.

  4. Dissipation of pterosin B in acid soils - tracking the fate of the bracken fern carcinogen ptaquiloside

    DEFF Research Database (Denmark)

    Skourti-Stathaki, Eirini; Clauson-Kaas, Frederik; Brandt, Kristian Koefoed

    2016-01-01

    -free areas. Soil samples were incubated with pterosin B at 3 and 8 μg g(-1) for 10 days, whereas sterile (autoclaved) samples were incubated for 23 days. Pterosin B showed unexpected fast degradation in soils with full degradation in topsoils in 2-5 days. Pterosin B dissipation followed the sum of two...

  5. Ferns.

    Science.gov (United States)

    Russell, Helen Ross

    1991-01-01

    Contains several study methods using ferns. Includes exercises on fern propagation, gametophytes and fern hybrids, fern collection, microscope use, asexual reproduction, and fern photography. Background information describes identification techniques and the alternation of generations phenomenon. (MCO)

  6. The role of bracken (Pteridium aquilinum) in forest dynamics

    NARCIS (Netherlands)

    Ouden, den J.

    2000-01-01

    Bracken fern ( Pteridium aquilinum ) causes stagnation in forest succession in many parts of the world. The mechanisms by which bracken affects the establishment and growth of plant species are studied, focusing on the regeneration of tree species in forest habitats.Bracken is well adapted to the fo

  7. Carcinogenic ptaquiloside in stream water at base flow and during storm events

    DEFF Research Database (Denmark)

    Strobel, Bjarne W.; Clauson-Kaas, Frederik; Hansen, Hans Chr. Bruun

    2017-01-01

    The globally occurring bracken fern (Pteridium sp.) is widespread in the broadleaf forests of Denmark, and densely populates several vegetation types in the Americas, Australia and on the British Isles. Bracken is toxic to livestock when consumed, and a group of potent carcinogens have been...... are crucial to measure these 1-2 hours pulses of natural toxins in the stream. Collected canopy through fall showed high amounts of PTA (up to 169 µg/L) leached from bracken fronds during rainfall, with no apparent deterioration of this source throughout the storm event. The results are important...

  8. Ptaquiloside from bracken in stream water at base flow and during storm events.

    Science.gov (United States)

    Clauson-Kaas, Frederik; Ramwell, Carmel; Hansen, Hans Chr B; Strobel, Bjarne W

    2016-12-01

    The bracken fern (Pteridium spp.) densely populates both open and woodland vegetation types around the globe. Bracken is toxic to livestock when consumed, and a group of potent illudane-type carcinogens have been identified, of which the compound ptaquiloside (PTA) is the most abundant. The highly water soluble PTA has been shown to be leachable from bracken fronds, and present in the soil and water below bracken stands. This has raised concerns over whether the compound might pose a risk to drinking water sources. We investigated PTA concentrations in a small stream draining a bracken-infested catchment at base flow and in response to storm events during a growth season, and included sampling of the bracken canopy throughfall. Streams in other bracken-dominated areas were also sampled at base flow for comparison, and a controlled pulse experiment was conducted in the field to study the in-stream dynamics of PTA. Ptaquiloside concentrations in the stream never exceeded 61 ng L(-1) in the base flow samples, but peaked at 2.2 μg L(-1) during the studied storm events. The mass of PTA in the stream, per storm event, was 7.5-93 mg from this catchment. A clear temporal connection was observed between rainfall and PTA concentration in the stream, with a reproducible time lag of approx. 1 h from onset of rain to elevated concentrations, and returning rather quickly (about 2 h) to base flow concentration levels. The concentration of PTA behaved similar to an inert tracer (Cl(-)) in the pulse experiment over a relative short time scale (minutes-hours) reflecting no PTA sorption, and dispersion and dilution considerably lowered the observed PTA concentrations downstream. Bracken throughfall revealed a potent and lasting source of PTA during rainfall, with concentrations up to 169 μg L(-1), that did not decrease over the course of the event. In the stream, the throughfall contribution to PTA cannot be separated from a possible below-ground input from litter, rhizomes

  9. Neoplasias do trato alimentar superior de bovinos associadas ao consumo espontâneo de samambaia (Pteridium aquilinum Neoplasms of the upper digestive tract of cattle associated with spontaneous ingestion of bracken fern (Pteridium aquilinum

    Directory of Open Access Journals (Sweden)

    Marione A. Moreira Souto

    2006-06-01

    of disease and necropsied. The main gross and microscopic alterations were found in identical areas of the UDT. They consisted of papillomas, transforming papillomas, and squamous cell carcinomas (SCCs. Metastases of SCCs to regional lymph nodes and other organs, such as liver and lungs, were also observed (18/30. Twenty-nine bovine had papillomas of various sizes in several areas of the UDT. The digestive papillomatosis ranged from mild (45%, to moderate (38%, to severe (17%. Three developing phases were observed microscopically in the examined papillomas: an early growing phase, a developing phase, and a regressing phase. In 16 cases, there was malignant transformation of papillomas into SCCs. The SCCs were solitary (12/30 or multiple (18/30 and were histologically well, moderately, or poorly differentiated. Grouping the distribution of SCCs of larger extension in the UDT into cranial region (base of the tongue, pharynx/oropharynx, and epiglottis, medial region (esophagus, and caudal region (cardia and rumen, the distribution was cranial in 39%, middle in 16%, and caudal in 45% of the cases. By the same grouping criteria, but considering the total number of times SCCs of varied extensions were diagnosed in the cranial, middle, and caudal regions, the percentages changed to 34%, 26%, and 40%, respectively. The epidemiological and histomorphological evidences found in this study are in agreement with the observations that point out the co-carcinogenesis between bovine papillomavirus type 4 infection and chemicals of bracken fern in the pathogenesis of the SCCs in the UDT of cattle. However, the presence of pre-neoplastic changes and SCCs in situ or in early stages of development, independently of the presence of papillomas, clearly indicates the possibility of development of SCCs from normal epithelium, probably due to the direct action of the chemical carcinogens contained in bracken fern.

  10. 昆虫幼虫对凤尾蕨属植物孢子囊群的拟态%Soral crypsis of insect larvea on bracken ferns

    Institute of Scientific and Technical Information of China (English)

    商辉; 严岳鸿

    2014-01-01

    蕨类植物和昆虫共同进化了三亿多年,但是两者的协同进化一直很少得到关注。对湖南省桑植县的凤尾蕨属植物上的昆虫幼虫进行调查,结果表明42棵4种凤尾蕨属植株上有夜蛾科幼虫89条,叶蜂科幼虫21条。叶蜂科幼虫通过形态和体色拟态凤尾蕨属植物的孢子囊群盖,取食凤尾蕨属植物的叶片;而夜蛾科幼虫隐藏在凤尾蕨属植物成熟的囊群盖中取食孢子,幼时乳白色,成熟时转变为淡黄色,有些会出现褐色斑点,同样与凤尾蕨属的孢子囊群盖具有拟态现象。进一步的调查还在凤尾蕨植物上发现猎食性的跳蛛,同时在其体表发现携带的孢子。首次在凤尾蕨属植物上发现拟态昆虫幼虫、特别是寄生性昆虫及其天敌跳蛛的发现,对研究蕨类植物、昆虫幼虫及其天敌之间存在的食物链关系和协同进化现象具有重要意义。%Ferns and insects live on the earth together more than 300 million years, but the interaction is rare known. A field surveys was hold in Sangzhi County of Hunan province about the insect larvae on Pteris spp. We found 89 Noctuidae larvae and 21 Tenthredinidae larvae on 42 bracken ferns belong to four species. The larvea of Tenthredinidae mimiced the indusium through appearance and color, and feeded on immature leaves. By contrast, the larvea of Noctuidae feeded on spores hiding under the indusium, whose color turns white to buff, with brown spot sometime, as another kind of soral crypsis. Meanwhile, a jump spider of prey was observed, which may be attracted by the larvea. The spider acts on the mature sporophyl, carrying several spores. These discoveries give us a good insight into the interaction and co-evolution among ferns, insect larvea and spider.

  11. Intoxicação experimental aguda por samambaia (Pteridium aquilinum em bovinos Experimental acute poisoning by bracken fern (Pteridium aquilinum in cattle

    Directory of Open Access Journals (Sweden)

    Bruno L. Anjos

    2009-09-01

    conflitantes, não permitindo concluir se a coagulação intravascular disseminada tem participação na patogênese das hemorragias nessa intoxicação. A citopatologia e histopatologia da medula óssea dos quatro bovinos intoxicados revelaram acentuada diminuição no número de células hematopoéticas das três linhagens medulares, caracterizando insuficiência medular por aplasia; conclui-se que apenas eventos da hemostasia primária devidos a trombocitopenia são responsáveis pelas hemorragias. Na hemocultura de três dos bovinos intoxicados houve crescimento de Klebsiella oxytoca, Staphylococcus hyicus e Staphylococcus aureus, indicando que a septicemia, facilitada pela neutropenia, pode ter participação na causa da morte de bovinos na intoxicação aguda pela ingestão de P. aquilinum. Aspectos adicionais de interesse na reprodução da intoxicação aguda por samambaia em bovinos deste relato incluem o desenvolvimento de hematúria na doença aguda e a apresentação da chamada forma laríngea da doença.This experiment was design to address the following points in relation to the acute poisoning by bracken fern (Pteridium aquilinum in cattle: 1 the severity of the thrombocytopenia in different stages of the intoxication and its relationship to possible deficits in the secondary hemostasis, 2 the relationship between neutropenia and the morphological signs of septicemia occasionally found at necropsy, and 3 the mechanism of anemia and its relationship with blood loss, medium life of erythrocytes and the progress of the disease. The fresh green upper parts of P. aquilinum were fed to four mixed breed calves with average age of 18 months and weights ranging from 190 to 215 kg. A calf of similar age and weight was kept together with the other four under the same conditions, except for the ingestion of P. aquilinum. The four fern-fed calves died with typical features of acute bracken fern poisoning after being fed with the plant for 53-58 days daily doses of 8.0, 8

  12. Dissipation of pterosin B in acid soils – Tracking the fate of the bracken fern carcinogen ptaquiloside

    DEFF Research Database (Denmark)

    Skourti-Stathaki, Erini; Clauson-Kaas, Frederik; Koefoed Brandt, Kristian

    2016-01-01

    -free areas. Soil samples were incubated with pterosin B at 3 and 8 μg g−1 for 10 days, whereas sterile (autoclaved) samples were incubated for 23 days. Pterosin B showed unexpected fast degradation in soils with full degradation in topsoils in 2–5 days. Pterosin B dissipation followed the sum of two...

  13. Intoxicação aguda por samambaia (Pteridium aquilinum em bovinos na Região Central do Rio Grande do Sul Acute poisoning by bracken fern (Pteridium aquilinum in cattle in central Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Bruno L. Anjos

    2008-10-01

    Full Text Available Foram revisados casos de intoxicação por samambaia (Pteridium aquilinum em bovinos de 10 pequenas propriedades rurais de sete municípios da Região Central do Rio Grande do Sul. O estudo abrangeu 6.256 necrospias de bovinos realizadas num período de 43 anos e incluiu 15 necropsias de bovinos que morreram em conseqüência da intoxicação aguda por samambaia. As taxas de morbidade e mortalidade foram 17,9% e a letalidade era virtualmente de 100%. Em 40% das propriedades a doença ocorreu em pequenos surtos afetando vários bovinos; em 60% das propriedades apenas um bovino era afetado. Os principais sinais clínicos incluíam febre (40-42ºC, apatia, salivação e hemorragias, principalmente pelas gengivas, pela cavidade nasal e pelo trato gastrintestinal. Múltiplas petéquias eram observadas nas mucosas e na pele. Ocasionalmente observou-se hematúria e sangue no leite. A doença era invariavelmente fatal após um curso clínico de dois dias. Alterações hematológicas consistiam de leucopenia por neutropenia, anemia normocítica normocrômica e trombocitopenia arregenerativa. Os achados de necropsia incluíam hemorragias de intensidade variável em vários órgãos e infartos no fígado. Tanto as hemorragias quanto os infartos foram confirmados histologicamente; agregados de bacilos e vasos trombosados foram observados em associação com os infartos. Aplasia da medula óssea era um achado consistente nos quatro casos em que esse órgão foi examinado.Cases of acute poisoning by bracken fern (Pteridium aquilinum in cattle from 10 small farms of seven municipalities of the Central Region of Rio Grande do Sul State, Brazil, were reviewed. The study encompassed 6,256 necropsies of cattle considering a 43-year period and included 15 necropsies of cattle dying from acute bracken poisoning. Morbidity and mortality were 17.9% and lethality was virtually 100%. In 40% of the farms the disease occurred in small outbreaks affecting several cattle

  14. Super-resolution image analysis as a means of monitoring bracken (Pteridium aquilinum) distributions

    Science.gov (United States)

    Holland, Jennie; Aplin, Paul

    2013-01-01

    The bracken (Pteridium aquilinum) fern is environmentally significant due to its great abundance and swift colonisation, and its perception as a problem plant in degrading agricultural or ecologically sensitive land. Various attempts have been made to map bracken using remote sensing, but these have proved relatively unsuccessful, often apparently constrained by the lack of spatial detail associated with medium spatial resolution satellite sensors such as the Landsat series. In this study, bracken was characterised using a combination of 30 m Landsat sensor imagery and 4 m IKONOS imagery. Different classification techniques were compared, including hard maximum likelihood classification and a super-resolution approach comprising soft classification and sub-pixel contouring. These techniques were applied to a range of image dates, including summer, winter and multitemporal images. Image analysis was supported by extensive field data collection, comprising both a land cover survey and stakeholder interviews. For the hard classified Landsat sensor imagery, the summer image proved least able to characterise bracken, due largely to the spectral similarity between (green) growing bracken and grasses and other vegetation. The winter images were more successful for identifying bracken due to the strong contrast between dead (brown/red) bracken and other vegetation. However, the multitemporal Landsat image was considerably more accurate than any of the single date images. The hard classified IKONOS image was more accurate overall than the Landsat sensor images for classifying land cover. Surprisingly, though, it was not comprehensively more accurate for mapping the bracken class. Notably, the producers accuracy of bracken was lower for the IKONOS image than the Landsat sensor images. This suggests image spatial resolution, although influential on the success of bracken characterisation, is not necessarily the sole or main determinant of classification accuracy. Also

  15. Сhanges in consumer properties of bracken using different storage methods

    Directory of Open Access Journals (Sweden)

    I. V. Shalisko

    2016-01-01

    Full Text Available The article compares the changes in consumer properties of bracken ordinary young shoots at different storage methods. Bracken is a source of vitamins, minerals, it is eaten in some countries -Japan, China, Korea, and also in Russia Shows some advantages in frozen storage. The structural and mechanical changes at themacro and micro levels. Compares elasticity raw samples at different storage methods. Data on the content of amino acids, fatty acids, vitamins, salt, water activity. From the obtained results revealed that the amino acid content in the composition of the frozen bracken decreased significantly as compared to fresh and salt fern (except aspartic acid, isoleucine, and leucine, whose number is close to their number in the salty fern. When storing the fern frozen there is a considerable amount of lipids. Also a significant presence of fat-tion of acids (as % of value, ±10% palmitic (24,86%, hexadecanoate (2,33%, stearic (1,06%, oleic (4,71%, linoleic (26,02%, α-linolenic (11,88%, γ-linolenic (3,13%, dihomo-γ-linolenic (2,28%, arahidonova (0,78%, arachidonic (14,83%, timonova (0,92%, Baganova (0,96%. There is the presence of essential fatty acids. Myristic, berestyeneva, palmitoleate, zonvakantie, andonova acids are present in smaller amount benefits. The results of determination of vitamins in the frozen samples showed that, despite significant losses in storage, they manage to keep the vitamins. It proposed the introduction of the freeze as an effective method of storage bracken. Storage method shoots bracken almost not been studied in frozen form, and it may be that innovation, which will expand the practical use of this type of native raw materials.

  16. Spatial Characteristics of Edible Wild Fern Harvesting in Mountainous Villages in Northeastern Japan Using GPS Tracks

    Directory of Open Access Journals (Sweden)

    Toshiya Matsuura

    2014-02-01

    Full Text Available Wild plants in forests provide valuable living resources for rural communities. The location where local people harvest various species is important to the wise use of forest ecosystem services. Using global positioning system (GPS tracking of harvesters’ activities as well as geographic information system (GIS and a generalized linear model (GLM, this study analyzed the spatial differences among harvesting sites of three popular edible ferns, i.e., ostrich fern (Matteuccia struthiopteris, bracken (Pteridium aquilinum, and royal fern (Osmunda japonica, in mountainous villages of Northeastern Japan. The explanatory variables used were vegetation classes, terrain features, and proximity to roadways. The GLM yielded clear differences in harvesting sites among species that were affected by both the species’ ecological characteristics and human behavior. Ostrich fern was harvested mainly in canopy openings along valley floors, whereas royal fern harvest sites were frequently located in snow avalanche scrublands. Bracken was mainly harvested in deforested areas or young conifer plantations. Whereas ostrich fern and bracken harvest sites were restricted by the accessibility from roadways, this was not the case for royal fern. Potential harvest sites of ferns were estimated with the highest value for bracken. Our results suggest that local harvesters seriously consider various natural and anthropogenic factors to maintain effective and sustainable harvesting.

  17. Fern Habitats and Rare Ferns in Oklahoma

    Directory of Open Access Journals (Sweden)

    Bruce A. Smith

    2008-12-01

    Full Text Available This paper features some of the more common fern habitats in Oklahoma and provides information on four rare Oklahoma ferns from two fern families: Aspleniaceae and Pteridaceae. Surprisingly, ferns can be found in a variety of habitats across Oklahoma.

  18. Knowledge-Based Estimation of Edible Fern Harvesting Sites in Mountainous Communities of Northeastern Japan

    Directory of Open Access Journals (Sweden)

    Toshiya Matsuura

    2013-12-01

    Full Text Available Once local expert knowledge regarding the harvesting of various non-timber forest products (NTFPs is lost, it is difficult to recover. We investigated whether the knowledge of expert forest harvesters can be used to determine the habitat distribution and harvesting sites of three popular edible wild ferns, i.e., ostrich fern (Matteuccia struthiopteris, bracken (Pteridium aquilinum, and royal fern (Osmunda japonica, in mountainous communities of western Fukushima, Japan. Using multi-criteria evaluation (MCE based on the analytic hierarchy process (AHP and geographic information system (GIS, we found that harvesters were easily able to recognize differences in the spatial characteristics of the habitat distribution of fern species due to both natural and anthropogenic factors. These factors were described by various GIS layers, such as vegetation and terrain features (e.g., gradient, aspect, and slope position derived from a 20-m digital elevation model (DEM. Harvesting sites were limited by their distance from a roadway, which differed among species. By comparison with the GPS records of actual harvesting sites, we estimated the potential harvesting sites of each fern species with reasonable accuracy, particularly for bracken. Our results show that the knowledge of expert forest harvesters can be quantified using MCE and GIS, which is useful for determining the spatial characteristics of NTFP harvesting and ensuring sustainable management practices.

  19. European medicinal and edible plants associated with subacute and chronic toxicity part I: Plants with carcinogenic, teratogenic and endocrine-disrupting effects.

    Science.gov (United States)

    Kristanc, Luka; Kreft, Samo

    2016-06-01

    In recent decades, the use of herbal medicines and food products has been widely embraced in many developed countries. These products are generally highly accepted by consumers who often believe that "natural" equals "safe". This is, however, an oversimplification because several botanicals have been found to contain toxic compounds in concentrations harmful to human health. Acutely toxic plants are in most cases already recognised as dangerous as a result of their traditional use, but plants with subacute and chronic toxicity are difficult or even impossible to detect by traditional use or by clinical research studies. In this review, we systematically address major issues including the carcinogenicity, teratogenicity and endocrine-disrupting effects associated with the use of herbal preparations with a strong focus on plant species that either grow natively or are cultivated in Europe. The basic information regarding the molecular mechanisms of the individual subtypes of plant-induced non-acute toxicity is given, which is followed by a discussion of the pathophysiological and clinical characteristics. We describe the genotoxic and carcinogenic effects of alkenylbenzenes, pyrrolizidine alkaloids and bracken fern ptaquiloside, the teratogenicity issues regarding anthraquinone glycosides and specific alkaloids, and discuss the human health concerns regarding the phytoestrogens and licorice consumption in detail. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Between two fern genomes.

    Science.gov (United States)

    Sessa, Emily B; Banks, Jo Ann; Barker, Michael S; Der, Joshua P; Duffy, Aaron M; Graham, Sean W; Hasebe, Mitsuyasu; Langdale, Jane; Li, Fay-Wei; Marchant, D Blaine; Pryer, Kathleen M; Rothfels, Carl J; Roux, Stanley J; Salmi, Mari L; Sigel, Erin M; Soltis, Douglas E; Soltis, Pamela S; Stevenson, Dennis W; Wolf, Paul G

    2014-01-01

    Ferns are the only major lineage of vascular plants not represented by a sequenced nuclear genome. This lack of genome sequence information significantly impedes our ability to understand and reconstruct genome evolution not only in ferns, but across all land plants. Azolla and Ceratopteris are ideal and complementary candidates to be the first ferns to have their nuclear genomes sequenced. They differ dramatically in genome size, life history, and habit, and thus represent the immense diversity of extant ferns. Together, this pair of genomes will facilitate myriad large-scale comparative analyses across ferns and all land plants. Here we review the unique biological characteristics of ferns and describe a number of outstanding questions in plant biology that will benefit from the addition of ferns to the set of taxa with sequenced nuclear genomes. We explain why the fern clade is pivotal for understanding genome evolution across land plants, and we provide a rationale for how knowledge of fern genomes will enable progress in research beyond the ferns themselves.

  1. Between Two Fern Genomes

    OpenAIRE

    Sessa, Emily B.; Banks, Jo; Michael S Barker; Der, Joshua P; Duffy, Aaron M; Graham, Sean W.; Hasebe, Mitsuyasu; Langdale, Jane; Li, Fay-Wei; Marchant, D; Kathleen M. Pryer; Rothfels, Carl J.; Roux, Stanley J.; Salmi, Mari L; Sigel, Erin M.

    2014-01-01

    Ferns are the only major lineage of vascular plants not represented by a sequenced nuclear genome. This lack of genome sequence information significantly impedes our ability to understand and reconstruct genome evolution not only in ferns, but across all land plants. Azolla and Ceratopteris are ideal and complementary candidates to be the first ferns to have their nuclear genomes sequenced. They differ dramatically in genome size, life history, and habit, and thus represent the immense divers...

  2. Effects of solutions to simulate acidic precipitation on fertilization of the Bracken fern (Pteridium aquilinum)

    Energy Technology Data Exchange (ETDEWEB)

    Evans, L.S.; Bozzone, D.M.

    1977-01-01

    Experiments were performed to determine the effects of chloride, nitrate, and sulfate in buffered solutions on sperm motility and fertilization in gametophytes of Pteridium aquilinum. Buffered solutions with various anions simulated exposures to acidic precipitation up to 3.5 hr. The presence of each anion decreased both sperm motility and fertilization.

  3. Ptaquiloside in irish bracken ferns and receiving waters, with implications for land managers

    DEFF Research Database (Denmark)

    O'Driscoll, Connie; Ramwell, Carmel; Harhen, Brendan

    2016-01-01

    Ptaquiloside, along with other natural phytotoxins, is receiving increased attention from scientists and land use managers. There is an urgent need to increase empirical evidence to understand the scale of phytotoxin mobilisation and potential to enter into the environment. In this study the risk...

  4. Amy Lum Fern

    Science.gov (United States)

    Rossi, Joe

    2007-01-01

    This article presents an interview with Amy Lum Fern, Hawai'i Department of Education teacher from 1933 to 1972. Amy Lum Fern was born in Honolulu in 1909. She received her early education at Central Grammar School and later attended McKinley High School. After graduating from McKinley in 1928, she entered the University of Hawai'i, where she…

  5. Cryopreservation of fern spores

    Science.gov (United States)

    Spore banks for ferns are analogous to seed banks for angiosperms and provide a promising ex situ conservation tool because large quantities of germplasm with high genetic variation can be conserved in a small space with low economic and technical costs. Ferns produce two types of spores with very ...

  6. Conservation of fern spores

    Science.gov (United States)

    Ferns are a diverse and important group of plants, but diversity of species and populations are at risk from increasing social pressures, loss of habitat and climate change. Ex situ conservation is a useful strategy to limit decline in genetic diversity and requires technologies to preserve fern ger...

  7. Relationship of the Gesell Developmental Exam and the Bracken Basic Concept Scale to Academic Achievement.

    Science.gov (United States)

    Sterner, Anne G.; McCallum, R. Steve

    1988-01-01

    Administered the Gesell Development Exam and the Bracken Basic Concept Scale (BBCS) to kindergarten graduates (N=80). Found the BBCS may be a better predictor of achievement from a current state of readiness. (Author/ABL)

  8. Flexible Envelope Request Notation (FERN)

    Science.gov (United States)

    Zoch, David R.; Lavallee, David; Weinstein, Stuart

    1991-01-01

    The following topics are presented in view graph form and include the following: scheduling application; the motivation for the Flexible Envelope Request Notation (FERN); characteristics of FERN; types of information needed in requests; where information is stored in requests; FERN structures; generic requests; resource availability for pooled resources; expressive notation; temporal constraints; time formats; changes to FERN; sample FERN requests; the temporal relationship between two steps; maximum activity length to limit step delays; alternative requests; the temporal relationship between two activities; and idle resource usage between steps.

  9. The omnipresent water fern

    NARCIS (Netherlands)

    Nierop, K.G.J.; Speelman, E.N.; de Leeuw, J.W.; Reichart, G.J.

    2011-01-01

    Several studies have reported the presence of large amounts of lignin in ubiquitously occurring species of the freshwater fern Azolla. Molecular analysis using flash pyrolysis and thermally assisted hydrolysis and methylation shows, however, that neither the leaves nor the roots of Azolla contain li

  10. The omnipresent water fern

    NARCIS (Netherlands)

    Nierop, K.G.J.; Speelman, E.N.; de Leeuw, J.W.; Reichart, G.J.

    2011-01-01

    Several studies have reported the presence of large amounts of lignin in ubiquitously occurring species of the freshwater fern Azolla. Molecular analysis using flash pyrolysis and thermally assisted hydrolysis and methylation shows, however, that neither the leaves nor the roots of Azolla contain

  11. Ptaquiloside from bracken in stream water at base flow and during storm events

    DEFF Research Database (Denmark)

    Clauson-Kaas, Frederik; Ramwell, Carmel; Hansen, Hans Chr. Bruun

    2016-01-01

    water soluble PTA has been shown to be leachable from bracken fronds, and present in the soil and water below bracken stands. This has raised concerns over whether the compound might pose a risk to drinking water sources. We investigated PTA concentrations in a small stream draining a bracken......-infested catchment at base flow and in response to storm events during a growth season, and included sampling of the bracken canopy throughfall. Streams in other bracken-dominated areas were also sampled at base flow for comparison, and a controlled pulse experiment was conducted in the field to study the in......-stream dynamics of PTA. Ptaquiloside concentrations in the stream never exceeded 61 ng L(-1) in the base flow samples, but peaked at 2.2 μg L(-1) during the studied storm events. The mass of PTA in the stream, per storm event, was 7.5-93 mg from this catchment. A clear temporal connection was observed between...

  12. Determination of ptaquiloside and pterosin B derived from bracken (Pteridium aquilinum) in cattle plasma, urine and milk.

    Science.gov (United States)

    Aranha, Paulo César Reis; Hansen, Hans Christian Bruun; Rasmussen, Lars Holm; Strobel, Bjarne W; Friis, Christian

    2014-03-01

    Ptaquiloside (PTA) is a toxin from bracken fern (Pteridium sp.) with genotoxic effects. Hydrolysis of PTA leads to the non-toxic and aromatised indanone, pterosin B (PTB). Here we present a sensitive, fast, simple and direct method, using SPE cartridges to clean and pre-concentrate PTA and PTB in plasma, urine and milk followed by LC-MS quantification. The average recovery of PTA in plasma, urine, and milk was 71, 88 and 77%, respectively, whereas recovery of PTB was 75, 82 and 63%. The method LOQ for PTA and PTB in plasma was 1.2 and 3.7ngmL(-1), 52 and 33ngmL(-1) for undiluted urine and 5.8 and 5.3ngmL(-1) for milk. The method is repeatable within and between days, with RSD values lower than 15% (PTA) and 20% (PTB). When PTA and PTB spiked samples were stored at -18°C for 14 days both compounds remained stable. In contrast, the PTA concentration was reduced by 15% when PTA spiked plasma was left for 5h at room temperature before SPE clean-up, whereas PTB remained stable. The method is the first to allow simultaneous quantification of PTA and PTB in biological fluids in a relevant concentration range. After intravenous administration of 0.092mg PTA per kgbw in a heifer, the plasma concentration was more than 300ngmL(-1) PTA and declined to 9.8ngmL(-1) after 6h, PTB was determined after 10min at 50ngmL(-1.)

  13. Ferns and fern allies of District Shopian, Kashmir Valley, India

    Directory of Open Access Journals (Sweden)

    SHAKOOR A. MIR

    2015-04-01

    Full Text Available Abstract. Mir SA, Mishra AK, Pala SA, Reshi ZA, Sharma MP. Ferns and fern allies of District Shopian, Kashmir Valley, India Biodiversitas 16: 27-43. Shopian, recently created hilly district of Kashmir valley, Jammu and Kashmir is surrounded by the lofty mountains of Pir-Panjal range. More than half area of district is occupied by different forests, subalpine, alpine and mountainous zones. Great altitudinal variation, adequate rainfall, high forest cover, large number of streams, springs and topographic variations render the district worthy for supporting rich fern flora. Therefore, the current study was aimed to undertake in-depth systematic survey of different habitats of Shopian for the collection of diversity of pteridophytes. Specimens were collected during 2010, 2011 and 2012 growing seasons from June to November. A total 81 species of ferns and fern allies belonging 27 genera and 11 families were reported. The dominant families of the region are Dryopteridaceae (25 species followed by Woodsiaceae (16 species, Aspleniaceae (13 species and Pteridaceae (12 species. Similarly, the dominant genera collected from here are Dryopteris (14 species, Asplenium (13, Polystichum (11 species and Athyrium (6 species. A list of the fern and fern allies, along with update nomenclature, their selected Synonym, diagnostic features, distributional and ecological notes have been provided here.

  14. Reliability of Bracken School Readiness Assessment, Third Edition Scores with Young Children in Mumbai, India

    Science.gov (United States)

    Shah, Mira B.; Schaefer, Barbara A.; Clark, Teresa P.

    2013-01-01

    To effectively provide early interventions to children, identifying those who are in need of these interventions is essential. In India, several problems hinder the process of early identification, including a lack of standardized measures for assessment. This study investigates the utility of the Bracken School Readiness Assessment, Third Edition…

  15. New species of Malaysian ferns

    NARCIS (Netherlands)

    Holttum, R.E.

    1962-01-01

    The present paper includes descriptions of several new species of ferns found among recent collections from various parts of Malaysia; also two new combinations of names of species which are of interest on account of their taxonomic history.

  16. SURVEY OF ORNAMENTAL FERNS, THEIR MORPHOLOGY AND ...

    African Journals Online (AJOL)

    ornamental ferns for environmental management and economic values. Ferns were collected from humid ... purposes, environmental protection, improvement and management in this region. ..... Journal of Current Research 2 (1):. 009-017.

  17. Synaptospory in the fern genus Pyrrosia (Polypodiaceae)

    NARCIS (Netherlands)

    Uffelen, van Gerda A.

    1985-01-01

    The correlation between sporoderm sculpture and life form of the sporophyte as postulated by Kramer (1977) is investigated for the fern genus Pyrrosia. This correlation is not found in Pyrrosia but may be present in other fern groups.

  18. Synaptospory in the fern genus Pyrrosia (Polypodiaceae)

    NARCIS (Netherlands)

    Uffelen, van Gerda A.

    1983-01-01

    The correlation between sporoderm sculpture and life form of the sporophyte as postulated by Kramer (1977) is investigated for the fern genus Pyrrosia. This correlation is not found in Pyrrosia but may be present in other fern groups.

  19. Conjunctival mucus ferning in hypovitaminosis A

    Directory of Open Access Journals (Sweden)

    Edward D

    1988-01-01

    Full Text Available The ocular ferning test was used to qualitatively assess mucus function in early stages of xerophthalmia. The results indicate that inspite of histological evidence of loss of goblet cells in the early stages, mucous function and production is sufficient to produce ferning. It is suggested that such derangements in mucous ferning may occur in more advanced stages of xerophthalmia.

  20. Ecological anatomy of ferns fronds

    Directory of Open Access Journals (Sweden)

    Nina M. Derzhavina

    2014-04-01

    Full Text Available Structural types of frond anatomy are distinguished on the basis of investigation of 30 species of homosporous ferns and with regard for literature: hydromorphic, hygromorphic, mesomorphic, subxeromorphic, and subsucculent (cryptic succulent. Following frond traits are of highest adaptive value: their area and thickness, type of mesophyll, dry weight of an area unit – specific superficial density, cellular volume, and number of cells per unit of frond area.

  1. Note on apomixis in ferns

    Directory of Open Access Journals (Sweden)

    J. P. Tilquin

    2014-02-01

    Full Text Available In 1964, two new types of apogamy were described in ferns. The sporangia contain at the starting-point 16 spore mother cells and at the endingpoint 32 diplospores. On the one hand, the meiosis is replaced by a mitosis, on the other hand, the first meiotic division aborts and the restituition nucleus divides mitotically. The author's observations imply that the second process is a variant of the first one.

  2. Further Experiments with Ferns in Culture: Regeneration.

    Science.gov (United States)

    Sheffield, Elizabeth; Attree, Stephen M.

    1983-01-01

    Ferns in culture provide versatile and easily manipulated material for a wide variety of experiments and observations. Information is provided that supplements earlier reports of the vast experimental potential of these cryptogams and outlines laboratory exercises which reveal the regenerative behavior of fern tissue. (JN)

  3. An Exploration into Fern Genome Space.

    Science.gov (United States)

    Wolf, Paul G; Sessa, Emily B; Marchant, Daniel Blaine; Li, Fay-Wei; Rothfels, Carl J; Sigel, Erin M; Gitzendanner, Matthew A; Visger, Clayton J; Banks, Jo Ann; Soltis, Douglas E; Soltis, Pamela S; Pryer, Kathleen M; Der, Joshua P

    2015-08-26

    Ferns are one of the few remaining major clades of land plants for which a complete genome sequence is lacking. Knowledge of genome space in ferns will enable broad-scale comparative analyses of land plant genes and genomes, provide insights into genome evolution across green plants, and shed light on genetic and genomic features that characterize ferns, such as their high chromosome numbers and large genome sizes. As part of an initial exploration into fern genome space, we used a whole genome shotgun sequencing approach to obtain low-density coverage (∼0.4X to 2X) for six fern species from the Polypodiales (Ceratopteris, Pteridium, Polypodium, Cystopteris), Cyatheales (Plagiogyria), and Gleicheniales (Dipteris). We explore these data to characterize the proportion of the nuclear genome represented by repetitive sequences (including DNA transposons, retrotransposons, ribosomal DNA, and simple repeats) and protein-coding genes, and to extract chloroplast and mitochondrial genome sequences. Such initial sweeps of fern genomes can provide information useful for selecting a promising candidate fern species for whole genome sequencing. We also describe variation of genomic traits across our sample and highlight some differences and similarities in repeat structure between ferns and seed plants.

  4. FERN Ethnomedicinal Plant Database: Exploring Fern Ethnomedicinal Plants Knowledge for Computational Drug Discovery.

    Science.gov (United States)

    Thakar, Sambhaji B; Ghorpade, Pradnya N; Kale, Manisha V; Sonawane, Kailas D

    2015-01-01

    Fern plants are known for their ethnomedicinal applications. Huge amount of fern medicinal plants information is scattered in the form of text. Hence, database development would be an appropriate endeavor to cope with the situation. So by looking at the importance of medicinally useful fern plants, we developed a web based database which contains information about several group of ferns, their medicinal uses, chemical constituents as well as protein/enzyme sequences isolated from different fern plants. Fern ethnomedicinal plant database is an all-embracing, content management web-based database system, used to retrieve collection of factual knowledge related to the ethnomedicinal fern species. Most of the protein/enzyme sequences have been extracted from NCBI Protein sequence database. The fern species, family name, identification, taxonomy ID from NCBI, geographical occurrence, trial for, plant parts used, ethnomedicinal importance, morphological characteristics, collected from various scientific literatures and journals available in the text form. NCBI's BLAST, InterPro, phylogeny, Clustal W web source has also been provided for the future comparative studies. So users can get information related to fern plants and their medicinal applications at one place. This Fern ethnomedicinal plant database includes information of 100 fern medicinal species. This web based database would be an advantageous to derive information specifically for computational drug discovery, botanists or botanical interested persons, pharmacologists, researchers, biochemists, plant biotechnologists, ayurvedic practitioners, doctors/pharmacists, traditional medicinal users, farmers, agricultural students and teachers from universities as well as colleges and finally fern plant lovers. This effort would be useful to provide essential knowledge for the users about the adventitious applications for drug discovery, applications, conservation of fern species around the world and finally to create

  5. Genome evolution of ferns: evidence for relative stasis of genome size across the fern phylogeny.

    Science.gov (United States)

    Clark, James; Hidalgo, Oriane; Pellicer, Jaume; Liu, Hongmei; Marquardt, Jeannine; Robert, Yannis; Christenhusz, Maarten; Zhang, Shouzhou; Gibby, Mary; Leitch, Ilia J; Schneider, Harald

    2016-05-01

    The genome evolution of ferns has been considered to be relatively static compared with angiosperms. In this study, we analyse genome size data and chromosome numbers in a phylogenetic framework to explore three hypotheses: the correlation of genome size and chromosome number, the origin of modern ferns from ancestors with high chromosome numbers, and the occurrence of several whole-genome duplications during the evolution of ferns. To achieve this, we generated new genome size data, increasing the percentage of fern species with genome sizes estimated to 2.8% of extant diversity, and ensuring a comprehensive phylogenetic coverage including at least three species from each fern order. Genome size was correlated with chromosome number across all ferns despite some substantial variation in both traits. We observed a trend towards conservation of the amount of DNA per chromosome, although Osmundaceae and Psilotaceae have substantially larger chromosomes. Reconstruction of the ancestral genome traits suggested that the earliest ferns were already characterized by possessing high chromosome numbers and that the earliest divergences in ferns were correlated with substantial karyological changes. Evidence for repeated whole-genome duplications was found across the phylogeny. Fern genomes tend to evolve slowly, albeit genome rearrangements occur in some clades. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  6. Fern and bryophyte endozoochory by slugs.

    Science.gov (United States)

    Boch, Steffen; Berlinger, Matthias; Fischer, Markus; Knop, Eva; Nentwig, Wolfgang; Türke, Manfred; Prati, Daniel

    2013-07-01

    Endozoochory plays a prominent role for the dispersal of seed plants, and dispersal vectors are well known. However, for taxa such as ferns and bryophytes, endozoochory has only been suggested anecdotally but never tested in controlled experiments. We fed fertile leaflets of three ferns and capsules of four bryophyte species to three slug species. We found that, overall, spores germinated from slug feces in 57.3% of all 89 fern and in 51.3% of all 117 bryophyte samples, showing that the spores survived gut passage of slugs. Moreover, the number of samples within which spores successfully germinated did not differ among plant species but varied strongly among slug species. This opens new ecological perspectives suggesting that fern and bryophyte endozoochory by gastropods is a so-far-overlooked mode of dispersal, which might increase local population sizes of these taxa by spore deposition on suitable substrates.

  7. Additions to the fern flora of Sulawesi

    NARCIS (Netherlands)

    Hovenkamp, P.H.; Joncheere, de G.J.

    1988-01-01

    A number of additions to the fern flora of Celebes are given here, including also the description of 15 new taxa in the Polypodiaceae, Cyatheaceae, Dennstaedtiaceae, Thelypteridaceae, Aspleniaceae, and Davalliaceae.

  8. Occurrence of the carcinogenic compound ptaquiloside in the soil environment

    DEFF Research Database (Denmark)

    Rasmussen, Lars Holm; Kroghsbo, Stine; Frisvad, Jens Christian

    2003-01-01

    -content in the standing biomass, which could be transferred to the soil by the end of the growing season, ranged between 10 and 260 mgm2, with nine sites having ptaquiloside loads over 100 mgm2. The carbon-content in the O-horizon, the precipitation, the amount of Bracken-litter, the turnover rate and the size of Bracken...

  9. Trends and concepts in fern classification

    Science.gov (United States)

    Christenhusz, Maarten J. M.; Chase, Mark W.

    2014-01-01

    Background and Aims Throughout the history of fern classification, familial and generic concepts have been highly labile. Many classifications and evolutionary schemes have been proposed during the last two centuries, reflecting different interpretations of the available evidence. Knowledge of fern structure and life histories has increased through time, providing more evidence on which to base ideas of possible relationships, and classification has changed accordingly. This paper reviews previous classifications of ferns and presents ideas on how to achieve a more stable consensus. Scope An historical overview is provided from the first to the most recent fern classifications, from which conclusions are drawn on past changes and future trends. The problematic concept of family in ferns is discussed, with a particular focus on how this has changed over time. The history of molecular studies and the most recent findings are also presented. Key Results Fern classification generally shows a trend from highly artificial, based on an interpretation of a few extrinsic characters, via natural classifications derived from a multitude of intrinsic characters, towards more evolutionary circumscriptions of groups that do not in general align well with the distribution of these previously used characters. It also shows a progression from a few broad family concepts to systems that recognized many more narrowly and highly controversially circumscribed families; currently, the number of families recognized is stabilizing somewhere between these extremes. Placement of many genera was uncertain until the arrival of molecular phylogenetics, which has rapidly been improving our understanding of fern relationships. As a collective category, the so-called ‘fern allies’ (e.g. Lycopodiales, Psilotaceae, Equisetaceae) were unsurprisingly found to be polyphyletic, and the term should be abandoned. Lycopodiaceae, Selaginellaceae and Isoëtaceae form a clade (the lycopods) that is

  10. Habitat Characteristics of Bracken-Covered Areas Intended for Afforestation in Ličko Sredogorje

    Directory of Open Access Journals (Sweden)

    Zvonko Seletković

    2013-12-01

    Full Text Available Background and Purpose: Forest cultures in continental part of Croatia are mainly based on bracken-covered areas and moors on deserted agriculture soils and pastures. Successful afforestation i.e. establishment of forest cultures depends among other things on the understanding of habitats and ecology of forest trees. The choice of best species of forest trees for afforestation needs to be based on the research in soil and climate characteristics of target habitats. The aims of this research were to show mesoclimatic characteristics of Ličko sredogorje and microclimatic and pedological characteristics of Ličko polje. Also, based on habitat characteristics and ecology of forest trees, the aim was to determine species of forest trees suitable for afforestation of bracken-covered areas. Materials and Methods: Climate, microclimate, pedological and plant nutrition researches were done at the area of Lika highlands. Climate analysis was done according to air temperatures, amount of precipitation, relative air humidity and other climate elements and appearances. Composite soil samples were taken from the depth of 0-30 cm in order to determine plant nutrition potential. Samples were prepared for further analysis in the laboratory. Results: The highest average annual air temperature of 9.6 °C was found at weather station Gračac and the lowest at Korenica station (8.1 °C. Average amount of precipitation for this region was around 1500 mm. Monthly rain factors were ranging from arid to perhumid. Considering thermal character of the climate, the area has moderately warm climate. Average volumetric soil humidity is 14.2 %. Soil has strong acid reaction, is very humus, good to richly supplied with total nitrogen, content of physiologically active phosphorus and potassium is low, and C/N ration normal. Conclusions: According to habitat characteristics in the area of Ličko sredogorje and ecological demands of forest tree species, forest cultures of Common

  11. A Mutant Hunt Using the C-Fern (Ceratopteris Richardii)

    Science.gov (United States)

    Calie, Patrick J.

    2005-01-01

    A modification of the popular C-Fern system, the tropical fern Ceratopteris richardii is developed in which students plate out a genetically mixed set of fern spores and then select for specific mutants. This exercise can provide students with an experience in plant mutant selection and can be used as a platform to expose students to a diverse…

  12. Epiphytism in ferns: diversity and history.

    Science.gov (United States)

    Dubuisson, Jean-Yves; Schneider, Harald; Hennequin, Sabine

    2009-01-01

    As for other vascular plants, numerous adaptive strategies have been selected in epiphytic ferns in order to survive in a constraining and desiccating environment and thus to prevent dehydration and/or to access to water and nutrients. Here we present some of the specializations that allow ferns to survive in this particular habitat. Some of the most spectacular epiphytic specializations are observed in the Polypodiaceae family, involving humus-collectors which entrap humus in specialized organs, and ant-plant mutualism strategies. We then address the question of epiphytism in an evolutionary context. There is little fossil evidence of vascular epiphytes. Inferring the evolution of epiphytism in extant ferns shows that diversification of major living epiphytic groups mostly occurred in the Tertiary. Finally, we focus on the Hymenophyllaceae family which provides an original example of hygrophilous epiphytic strategy that is unique in vascular plants.

  13. Beryllium: genotoxicity and carcinogenicity.

    Science.gov (United States)

    Gordon, Terry; Bowser, Darlene

    2003-12-10

    Beryllium (Be) has physical-chemical properties, including low density and high tensile strength, which make it useful in the manufacture of products ranging from space shuttles to golf clubs. Despite its utility, a number of standard setting agencies have determined that beryllium is a carcinogen. Only a limited number of studies, however, have addressed the underlying mechanisms of the carcinogenicity and mutagenicity of beryllium. Importantly, mutation and chromosomal aberration assays have yielded somewhat contradictory results for beryllium compounds and whereas bacterial tests were largely negative, mammalian test systems showed evidence of beryllium-induced mutations, chromosomal aberrations, and cell transformation. Although inter-laboratory differences may play a role in the variability observed in genotoxicity assays, it is more likely that the different chemical forms of beryllium have a significant effect on mutagenicity and carcinogenicity. Because workers are predominantly exposed to airborne particles which are generated during the machining of beryllium metal, ceramics, or alloys, testing of the mechanisms of the mutagenic and carcinogenic activity of beryllium should be performed with relevant chemical forms of beryllium.

  14. Fern rhizomes as fodder in Norway

    OpenAIRE

    Alm, Torbjørn

    2016-01-01

    Background Although ferns are often known under collective names in Norway, e.g. blom, a substantial number of vernacular names for individual fern species are known, in particular for useful or poisonous taxa. In the past, the rhizomes (Norwegian: moldfôr) of selected species were collected for fodder. Only scattered records of such use are available from southern Norway, and the tradition’s core area is found in the two North Norwegian counties of Nordland and Troms, in accordance with the ...

  15. Random grid fern for visual tracking

    Science.gov (United States)

    Cheng, Fei; Liu, Kai; Zhang, Jin; Li, YunSong

    2014-05-01

    Visual tracking is one of the significant research directions in computer vision. Although standard random ferns tracking method obtains a good performance for the random spatial arrangement of binary tests, the effect of the locality of image on ferns description ability are ignored and prevent them to describe the object more accurately and robustly. This paper proposes a novel spatial arrangement of binary tests to divide the bounding box into grids in order to keep more details of the image for visual tracking. Experimental results show that this method can improve tracking accuracy effectively.

  16. [Lectins of Dryopteris Adans fern species].

    Science.gov (United States)

    Basheka, O V; Stetsenko, N M; Pogorila, N F

    1999-01-01

    Lectin activity of three ferns species (Dryopteris bushiana Fom., D. laeta (Kom.) C. Chr, D. pseudomas (Wollaston) Holub et Pouzar) has been studied. We used hemagglutination reaction albumin and globulin fractions of fronds and rhizomes extracts with rat erythrocytes. The frond extract of D. pseudomas have shown higher activity as compared with other extracts. The lectin activity of D. laeta leaves was absent. The rhizomes of all three fern species could be characterized as high activity. Based on lectin activity the species were placed as follows order: D. buschiana > D. pseudomas > D. laeta. The dependence with lectin activity and elements (Mn, Fe, Cu, Ni, Zn, Pb, Rb, Sr) content were not found.

  17. Two new fern chloroplasts and decelerated evolution linked to the long generation time in tree ferns.

    Science.gov (United States)

    Zhong, Bojian; Fong, Richard; Collins, Lesley J; McLenachan, Patricia A; Penny, David

    2014-04-30

    We report the chloroplast genomes of a tree fern (Dicksonia squarrosa) and a "fern ally" (Tmesipteris elongata), and show that the phylogeny of early land plants is basically as expected, and the estimates of divergence time are largely unaffected after removing the fastest evolving sites. The tree fern shows the major reduction in the rate of evolution, and there has been a major slowdown in the rate of mutation in both families of tree ferns. We suggest that this is related to a generation time effect; if there is a long time period between generations, then this is probably incompatible with a high mutation rate because otherwise nearly every propagule would probably have several lethal mutations. This effect will be especially strong in organisms that have large numbers of cell divisions between generations. This shows the necessity of going beyond phylogeny and integrating its study with other properties of organisms.

  18. Food uses of ferns in China: a review

    Directory of Open Access Journals (Sweden)

    Yujing Liu

    2012-11-01

    Full Text Available Edible ferns are some of the most important wild vegetables in China. This paper reviews their food uses. The history of eating ferns in China may go back as far as 3000 years. An ethnobotanical inventory of edible ferns was created, with 52 species (including 4 varieties, which were traditionally used. The potential species number of edible ferns was estimated as 144 species (including 4 varieties. The cuisines, products and chemical components of ferns were also summarized. The most commonly eaten fern, Pteridium aquilinum var. latiusculum, was discussed in terms of its toxicity, massive productivity and development strategies. Suggestions and recommendations were proposed for the future development of edible ferns in China.

  19. The evolution of chloroplast genes and genomes in ferns.

    Science.gov (United States)

    Wolf, Paul G; Der, Joshua P; Duffy, Aaron M; Davidson, Jacob B; Grusz, Amanda L; Pryer, Kathleen M

    2011-07-01

    Most of the publicly available data on chloroplast (plastid) genes and genomes come from seed plants, with relatively little information from their sister group, the ferns. Here we describe several broad evolutionary patterns and processes in fern plastid genomes (plastomes), and we include some new plastome sequence data. We review what we know about the evolutionary history of plastome structure across the fern phylogeny and we compare plastome organization and patterns of evolution in ferns to those in seed plants. A large clade of ferns is characterized by a plastome that has been reorganized with respect to the ancestral gene order (a similar order that is ancestral in seed plants). We review the sequence of inversions that gave rise to this organization. We also explore global nucleotide substitution patterns in ferns versus those found in seed plants across plastid genes, and we review the high levels of RNA editing observed in fern plastomes.

  20. A new genus of Lindsaeoid ferns

    NARCIS (Netherlands)

    Kramer, K.U.

    1957-01-01

    In revising the New World representatives of the genus Lindsaea, the author came across a fern specimen from Borneo preserved in the Rijksherbarium, Leiden, that did not seem to fit into any described genus. It had been described as Schizoloma stortii v. A. v. R., but in the author’s opinion the gen

  1. Photosynthesis limitations in three fern species.

    Science.gov (United States)

    Gago, Jorge; Coopman, Rafael E; Cabrera, Hernán Marino; Hermida, Carmen; Molins, Arántzazu; Conesa, Miquel À; Galmés, Jeroni; Ribas-Carbó, Miquel; Flexas, Jaume

    2013-12-01

    Maximum photosynthesis rates in ferns are generally lower than those of seed plants, but little is known about the limiting factors, which are crucial to understand the evolution of photosynthesis in land plants. To address this issue, a gas exchange/chlorophyll fluorescence analysis was performed in three fern species spanning high phylogenetic range within Polypodiopsida (Osmunda regalis, Blechnum gibbum and Nephrolepis exaltata) to determine their maximum net photosynthesis (AN ), stomatal (gs ) and mesophyll (gm ) conductances to CO2 , and the maximum velocity of carboxylation (Vc,max ). The in vitro Rubisco specificity factor (SC /O ) was also determined. All three species had values for SC /O similar to those typical of seed plants, but values of AN , gs , gm and Vc,max were within the lowest range of those observed in seed plants. In addition, gs was unresponsive to light and CO2 , as already described in other fern species. On the contrary, gm varied with changes CO2 . A quantitative photosynthesis limitation analysis suggested that early land plants (ferns) presented not only stomatal limitations-which were less adjustable to the environment-but also restricted gm and Vc,max , resulting in limited maximum photosynthesis rates.

  2. How Fern Creek Is Beating Goliath

    Science.gov (United States)

    Donovan, Margaret; Galatowitsch, Patrick; Hefferin, Keri; Highland, Shanita

    2013-01-01

    The "David" is Fern Creek Elementary, a small urban school in Orlando, Florida, that serves an overwhelmingly disadvantaged student population. The "Goliaths" are the mountains of problems that many inner-city students face--poverty, homelessness, mobility, instability, limited parent involvement, and violent neighborhood…

  3. Techniques for carcinogenicity studies.

    Science.gov (United States)

    Weisburger, E K

    1981-09-01

    Short-term tests to detect genetic, chromosomal, or DNA damage are now required by regulatory agencies for any new compound proposed for commercial production. Furthermore, full-scale carcinogenicity tests may be required for certain compounds. In this circumstance, the compound-related factors including stability, purity, physical properties, and chemical structure and reactivity must be considered. Animal factors include species and strain of test animal, route of administration, age, sex, diet, and spontaneous tumor incidence. A team of qualified investigators with experience in various disciplines is required to conduct the studies properly. Quality control measures and adherence to the code of good laboratory practice are also necessary during all phases of the study. The investment in a carcinogenicity study therefore becomes fairly substantial in terms of both time and money.

  4. Food derived carcinogenic amnoimidazoazaarenes

    DEFF Research Database (Denmark)

    Frandsen, Henrik

    Carcinogenic aminoimidazoazaarenes are formed during cooking of meat and fish. Important factors for the formation of these compounds are meat type, cooking temperature and time. The compounds are genotoxic in bacterial and mammalian cells. In animal feeding studies the compounds tested so far we...... of the exocyclic amino group. Estimations of human cancer risk have indicated that ingestion of food containing aminoimidazoazaarenes are of importance....

  5. Cyanogenic polimorphysm in brackens, Pteridium arachnoideum and P. caudatum, from the northern Andes

    Directory of Open Access Journals (Sweden)

    Alberto de J. Oliveros-Bastidas

    2010-01-01

    Full Text Available Cyanogenesis in Pteridium caudatum and P. arachnoideum has been examined. Samples of the Andes of South America furnished from 0 to 4.63 mg of prunasin g-1 of frond dry weight (dw in P. caudatum and from 0 to 103 mg of g-1 dw in P. arachnoideum. In both fern species the continuous distribution of prunasin suggested cyanogenic polymorphism. The frequency of cyanogenic morphs was 84.7% for P. caudatum and 98.6% for P. arachnoideum. Cyanogenic activity was highest in the young crozier and waned rapidly with frond growth. The crozier head was found to yield HCN much more than the stipe.

  6. Isolation and characterisation of 13 pterosins and pterosides from bracken (Pteridium aquilinum (L.) Kuhn) rhizome.

    Science.gov (United States)

    Mohammad, Rizgar Hassan; Nur-E-Alam, Mohammad; Lahmann, Martina; Parveen, Ifat; Tizzard, Graham J; Coles, Simon J; Fowler, Mark; Drake, Alex F; Heyes, Derren; Thoss, Vera

    2016-08-01

    Systematic phytochemical investigations of the underground rhizome of Pteridium aquilinum (L.) Kuhn (Dennstaedtiaceae) afforded thirty-five pterosins and pterosides. By detailed analysis of one- and two-dimensional nuclear magnetic resonance spectroscopy, circular dichroism (CD) and high-resolution mass spectrometric data, thirteen previously undescribed pterosins and pterosides have been identified. Interestingly, for the first time 12-O-β-D-glucopyranoside substituted pterosins, rhedynosides C and D, and the sulfate-containing pterosin, rhedynosin H, alongside the two known compounds, histiopterosin A and (2S)-pteroside A2, were isolated from the rhizomes of subsp. aquilinum of bracken. In addition, six-membered cyclic ether pterosins and pterosides, rhedynosin A and rhedynoside A, are the first examples of this type of pterosin-sesquiterpenoid. Additionally, the three previously reported compounds (rhedynosin I, (2S)-2-hydroxymethylpterosin E and (2S)-12-hydroxypterosin A) were obtained for the first time from plants as opposed to mammalian metabolic products. Single crystal X-ray diffraction analysis was applied to the previously undescribed compounds (2R)-rhedynoside B, (2R)-pteroside B and (2S)-pteroside K, yielding the first crystal structures for pterosides, and three known pterosins, (2S)-pterosin A, trans-pterosin C and cis-pterosin C. Rhedynosin C is the only example of the cyclic lactone pterosins with a keto group at position C-14. Six selected pterosins ((2S)-pterosin A, (2R)-pterosin B and trans-pterosin C) and associated glycosides ((2S)-pteroside A, (2R)-pteroside B and pteroside Z) were assessed for their anti-diabetic activity using an intestinal glucose uptake assay; all were found to be inactive at 300 μM.

  7. The photosynthetic capacity in 35 ferns and fern allies: mesophyll CO2 diffusion as a key trait.

    Science.gov (United States)

    Tosens, Tiina; Nishida, Keisuke; Gago, Jorge; Coopman, Rafael Eduardo; Cabrera, Hernán Marino; Carriquí, Marc; Laanisto, Lauri; Morales, Loreto; Nadal, Miquel; Rojas, Roke; Talts, Eero; Tomas, Magdalena; Hanba, Yuko; Niinemets, Ülo; Flexas, Jaume

    2016-03-01

    Ferns and fern allies have low photosynthetic rates compared with seed plants. Their photosynthesis is thought to be limited principally by physical CO2 diffusion from the atmosphere to chloroplasts. The aim of this study was to understand the reasons for low photosynthesis in species of ferns and fern allies (Lycopodiopsida and Polypodiopsida). We performed a comprehensive assessment of the foliar gas-exchange and mesophyll structural traits involved in photosynthetic function for 35 species of ferns and fern allies. Additionally, the leaf economics spectrum (the interrelationships between photosynthetic capacity and leaf/frond traits such as leaf dry mass per unit area or nitrogen content) was tested. Low mesophyll conductance to CO2 was the main cause for low photosynthesis in ferns and fern allies, which, in turn, was associated with thick cell walls and reduced chloroplast distribution towards intercellular mesophyll air spaces. Generally, the leaf economics spectrum in ferns follows a trend similar to that in seed plants. Nevertheless, ferns and allies had less nitrogen per unit DW than seed plants (i.e. the same slope but a different intercept) and lower photosynthesis rates per leaf mass area and per unit of nitrogen.

  8. Fern Gametophytes in Culture--A Simple System for Studying Plant Development and Reproduction.

    Science.gov (United States)

    Dyer, A. F.

    1983-01-01

    Discusses fern life cycle and basic techniques for culturing fern gametophytes in the classroom. Also discusses investigations into the reproductive biology of ferns and into the early development of gametophytes. (JN)

  9. The fern sporangium: a unique catapult.

    OpenAIRE

    Noblin, X.; Rojas, N. O.; Westbrook, J; Llorens, C.; Argentina, M.; Dumais, J.

    2012-01-01

    International audience; Various plants and fungi have evolved ingenious devices to disperse their spores. One such mechanism is the cavitation-triggered catapult of fern sporangia. The spherical sporangia enclosing the spores are equipped with a row of 12 to 13 specialized cells, the annulus. When dehydrating, these cells induce a dramatic change of curvature in the sporangium, which is released abruptly after the cavitation of the annulus cells. The entire ejection process is reminiscent of ...

  10. Thirteen new records of ferns from Brazil.

    Science.gov (United States)

    Almeida, Thais Elias; Salino, Alexandre

    2015-01-01

    Thirteen fern species are reported for the first time for Brazil. Among the new records, eight are from Acre state (Cyatheasubincisa, Cyclodiumtrianae, Elaphoglossumstenophyllum, Hypoderrisbrauniana, Pleopeltisstolzei, Thelypterisarcana, Thelypteriscomosa, Thelypterisvaldepilosa), two are from Pará state (Polypodiumflagellare, Tectariaheracleifolia), one from Minas Gerais state (Alsophilasalvinii), one from Ceará state (Campyloneurumcostatum) and one from Bahia state (Thelypterisrolandii). Part of the species shows a disjunct occurrence or illustrates floristic relations between Brazilian and Andean Mountains or Central American Mountains.

  11. Towards Resolving the Complete Fern Tree of Life

    OpenAIRE

    Samuli Lehtonen

    2011-01-01

    In the past two decades, molecular systematic studies have revolutionized our understanding of the evolutionary history of ferns. The availability of large molecular data sets together with efficient computer algorithms, now enables us to reconstruct evolutionary histories with previously unseen completeness. Here, the most comprehensive fern phylogeny to date, representing over one-fifth of the extant global fern diversity, is inferred based on four plastid genes. Parsimony and maximum-likel...

  12. The fern sporangium: an ultrafast natural catapult

    Science.gov (United States)

    Noblin, Xavier; Argentina, Mederic; Westbrook, Jared; Llorens, Coraline; Rojas, Nicolas; Dumais, Jacques

    2012-02-01

    Plants have developed fascinating mechanisms to create ultra fast movements that often reach the upper limit allowed by physical laws. Inspiration for new technologies is one of the reasons for the strong interest for these mechanisms, along with the deep interest of understanding complex, natural systems. The fern sporangium is a capsule that contains the spores, it is surrounded by a row of cells called the annulus which acts as a beam. Due to the water evaporation from its cells, the annulus bends strongly and induces elastic energy storage during an opening phase. The tension in the cells breaks when cavitation bubbles appear in the cells, leading to a fast release of the elastic energy. The fern sporangium then acts as a catapult which ejects rapidly its spores by closing back to the initial closed shape. We have analyzed the slow opening motion and the fast catapulting mechanism. We found that the catapult motion involves two time scales, showing a very original behavior. In man-made catapults, the recoil motion needs to be arrested by a cross bar so that the projectile is released from the arm. We show here that the fern sporangium replaces the essential cross bar by an elegant poroelastic damping, leading to a completely autonomous, efficient device.

  13. Biochemical and evolutionary aspects of arthropod predation on ferns.

    Science.gov (United States)

    Balick, Michael J; Furth, David G; Cooper-Driver, Gillian

    1978-01-01

    The widely held assumption that very few arthropods feed on ferns was questioned following field observations of arthropod damage on ferns in the state of Veracruz, Mexico. The extent and type of damage was recorded and it was found that in a measured locality, ferns were no less attacked than the angiospermous flora. As chemistry and arthropod host relationships have been shown to be so closely intertwined, plants collected in the field were analysed for both condensed tannins and cyanogenic glycosides, compounds known to be effective deterrents in temperate climates. Although all ferns tested contained tannins these did not appear to inhibit predation. Cyanogenic glycosides were present in only 3% of the fern species analysed, and it is, therefore, unlikely that they play a significant role as defensive compounds in the ferns examined.A literature search revealed a large number of ferns cited as being arthropod hosts. Approximately 420 named species of arthropods have been recorded, the majority of which are from the orders Coleoptera, Hymenoptera, Lepidoptera, and Hemiptera. Both evolutionary primitive (sawflies) and advanced (moths) arthropods are reported to be present on ferns suggesting possible coevolution of arthropods and ferns both before and after the radiation of angiosperms.

  14. Distribution and dynamics of hayscented fern following stand harvest

    Science.gov (United States)

    Songlin Fei; Peter J. Gould; Melanie J. Kaeser; Kim C. Steiner

    2008-01-01

    The distribution and dynamics of hayscented fern were examined as part of a large-scale study of oak regeneration in Pennsylvania. The study included 69 stands covering 3,333 acres in two physiographic provinces. Hayscented fern was more widely distributed and occurred at higher densities in the Allegheny Plateau physiographic provinces versus the Ridge and Valley...

  15. Klukiopsis jurassica--A new Jurassic schizaeaceous fern from China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new Jurassic schizaeaceous fern Klukiopsis jurassica gen. et sp. nov. from Yima, Henan Province, China is described. The new fern is characterized by the abaxial sori arranged in two rows, apical and complete annulus and more than 800 smooth trilete spores in each sorus.

  16. Towards resolving the complete fern tree of life.

    Science.gov (United States)

    Lehtonen, Samuli

    2011-01-01

    In the past two decades, molecular systematic studies have revolutionized our understanding of the evolutionary history of ferns. The availability of large molecular data sets together with efficient computer algorithms, now enables us to reconstruct evolutionary histories with previously unseen completeness. Here, the most comprehensive fern phylogeny to date, representing over one-fifth of the extant global fern diversity, is inferred based on four plastid genes. Parsimony and maximum-likelihood analyses provided a mostly congruent results and in general supported the prevailing view on the higher-level fern systematics. At a deep phylogenetic level, the position of horsetails depended on the optimality criteria chosen, with horsetails positioned as the sister group either of Marattiopsida-Polypodiopsida clade or of the Polypodiopsida. The analyses demonstrate the power of using a 'supermatrix' approach to resolve large-scale phylogenies and reveal questionable taxonomies. These results provide a valuable background for future research on fern systematics, ecology, biogeography and other evolutionary studies.

  17. Thirteen new records of ferns from Brazil

    Directory of Open Access Journals (Sweden)

    Thais Almeida

    2015-02-01

    Full Text Available Thirteen fern species are reported for the first time for Brazil. Among the new records, eight are from Acre state (Cyathea subincisa, Cyclodium trianae, Elaphoglossum stenophyllum, Hypoderris brauniana, Pleopeltis stolzei, Thelypteris arcana, Thelypteris comosa, Thelypteris valdepilosa, two are from Pará state (Polypodium flagellare, Tectaria heracleifolia, one from Minas Gerais state (Alsophila salvinii, one from Ceará state (Campyloneurum costatum and one from Bahia state (Thelypteris rolandii. Part of the species shows a disjunct occurrence or illustrates floristic relations between Brazilian and Andean Mountains or Central American Mountains.

  18. Acrylonitrile: a suspected human carcinogen.

    Science.gov (United States)

    Koerselman, W; van der Graaf, M

    1984-01-01

    The literature on carcinogenicity of acrylonitrile (an important intermediate in the chemical industry) is reviewed. The three main conclusions are: (1) Acrylonitrile has genotoxic effects in various tests in microorganisms and in mammal cells. (2) Chronic exposure to acrylonitrile causes tumours in rats. (3) Results of epidemiological studies indicate that acrylonitrile may be a human carcinogen. From this it is clear that acrylonitrile is very probably carcinogenic to humans. Therefore the authors plead for a reduction of acrylonitrile standards to the lowest practicable limit.

  19. Carcinogen testing. Fact and fallacy.

    Science.gov (United States)

    Moore, J A

    1988-10-15

    In the absence of human information on the carcinogenicity of chemical substances, one must rely primarily on information from long-term animal testing. Although far from perfect, animal studies seem to be reasonable predictors of the human experience, both qualitatively and quantitatively. Short-term tests for genotoxicity may be helpful for establishing priorities for chemical testing, but they are not as strong indicators of potential carcinogenicity as had been previously thought. New directions in toxicologic research hold the promise for scientists being able to perform more reasoned assessments of carcinogenic risk.

  20. Chloroplast genome evolution in early diverged leptosporangiate ferns.

    Science.gov (United States)

    Kim, Hyoung Tae; Chung, Myong Gi; Kim, Ki-Joong

    2014-05-01

    In this study, the chloroplast (cp) genome sequences from three early diverged leptosporangiate ferns were completed and analyzed in order to understand the evolution of the genome of the fern lineages. The complete cp genome sequence of Osmunda cinnamomea (Osmundales) was 142,812 base pairs (bp). The cp genome structure was similar to that of eusporangiate ferns. The gene/intron losses that frequently occurred in the cp genome of leptosporangiate ferns were not found in the cp genome of O. cinnamomea. In addition, putative RNA editing sites in the cp genome were rare in O. cinnamomea, even though the sites were frequently predicted to be present in leptosporangiate ferns. The complete cp genome sequence of Diplopterygium glaucum (Gleicheniales) was 151,007 bp and has a 9.7 kb inversion between the trnL-CAA and trnVGCA genes when compared to O. cinnamomea. Several repeated sequences were detected around the inversion break points. The complete cp genome sequence of Lygodium japonicum (Schizaeales) was 157,142 bp and a deletion of the rpoC1 intron was detected. This intron loss was shared by all of the studied species of the genus Lygodium. The GC contents and the effective numbers of codons (ENCs) in ferns varied significantly when compared to seed plants. The ENC values of the early diverged leptosporangiate ferns showed intermediate levels between eusporangiate and core leptosporangiate ferns. However, our phylogenetic tree based on all of the cp gene sequences clearly indicated that the cp genome similarity between O. cinnamomea (Osmundales) and eusporangiate ferns are symplesiomorphies, rather than synapomorphies. Therefore, our data is in agreement with the view that Osmundales is a distinct early diverged lineage in the leptosporangiate ferns.

  1. A Catskill Flora and Economic Botany, I: Pteridophyta. The Ferns and Fern Allies. Bulletin No. 438, New York State Museum.

    Science.gov (United States)

    Brooks, Karl L.

    The information contained within this guide about flora of the ferns and fern allies of the Catskill Mountains of New York State covers medical and food uses of the plants, as well as the more typical floristic data of keys, drawings, and plant descriptions. (CS)

  2. Oxidative Stress in the Carcinogenicity of Chemical Carcinogens

    Energy Technology Data Exchange (ETDEWEB)

    Kakehashi, Anna; Wei, Min [Department of Pathology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-Ku, Osaka 545-8585 (Japan); Fukushima, Shoji [Japan Bioassay Research Center, Japan Industrial Safety and Health Association, 2445 Hirasawa, Hadano, Kanagawa 257-0015 (Japan); Wanibuchi, Hideki, E-mail: wani@med.osaka-cu.ac.jp [Department of Pathology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-Ku, Osaka 545-8585 (Japan)

    2013-10-28

    This review highlights several in vivo studies utilizing non-genotoxic and genotoxic chemical carcinogens, and the mechanisms of their high and low dose carcinogenicities with respect to formation of oxidative stress. Here, we survey the examples and discuss possible mechanisms of hormetic effects with cytochrome P{sub 450} inducers, such as phenobarbital, α-benzene hexachloride and 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane. Epigenetic processes differentially can be affected by agents that impinge on oxidative DNA damage, repair, apoptosis, cell proliferation, intracellular communication and cell signaling. Non-genotoxic carcinogens may target nuclear receptors and induce post-translational modifications at the protein level, thereby impacting on the stability or activity of key regulatory proteins, including oncoproteins and tumor suppressor proteins. We further discuss role of oxidative stress focusing on the low dose carcinogenicities of several genotoxic carcinogens such as a hepatocarcinogen contained in seared fish and meat, 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, arsenic and its metabolites, and the kidney carcinogen potassium bromate.

  3. Oxidative Stress in the Carcinogenicity of Chemical Carcinogens

    Directory of Open Access Journals (Sweden)

    Hideki Wanibuchi

    2013-10-01

    Full Text Available This review highlights several in vivo studies utilizing non-genotoxic and genotoxic chemical carcinogens, and the mechanisms of their high and low dose carcinogenicities with respect to formation of oxidative stress. Here, we survey the examples and discuss possible mechanisms of hormetic effects with cytochrome P450 inducers, such as phenobarbital, a-benzene hexachloride and 1,1-bis(p-chlorophenyl-2,2,2-trichloroethane. Epigenetic processes differentially can be affected by agents that impinge on oxidative DNA damage, repair, apoptosis, cell proliferation, intracellular communication and cell signaling. Non-genotoxic carcinogens may target nuclear receptors and induce post-translational modifications at the protein level, thereby impacting on the stability or activity of key regulatory proteins, including oncoproteins and tumor suppressor proteins. We further discuss role of oxidative stress focusing on the low dose carcinogenicities of several genotoxic carcinogens such as a hepatocarcinogen contained in seared fish and meat, 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, arsenic and its metabolites, and the kidney carcinogen potassium bromate.

  4. Absorption of foliar-applied arsenic by the arsenic hyperaccumulating fern (Pteris vittata L.)

    Energy Technology Data Exchange (ETDEWEB)

    Bondada, Bhaskar R.; Tu, Shuxin; Ma, Lena Q

    2004-10-01

    The fact that heavy metals can enter various domains of the plant system through foliar pathways spurred us to explore if the fronds of the Chinese brake fern (Pteris vittata L.), a hyperaccumulator of arsenic, a carcinogenic metalloid, was proficient in absorbing arsenic in the form of sprays. The specific objective of this study was to investigate the impact of frond age, form of arsenic, and time of application on the absorption of foliar-applied arsenic by the brake fern; also examined were the effects of foliar sprays on surface ultrastructure and arsenic speciation in the frond following absorption. Foliar sprays of different arsenic concentrations (0, 50, 100, 200, and 400 ppm) were applied to young and fertile fronds. A positive linear relationship existed between arsenic concentration and absorption; the arsenic concentration of fronds increased from 50 to 200 ppm. Time-course analysis with excised pinnae indicated an initial linear increase followed by a plateau at 48 h. The young fronds with immature sori absorbed more arsenic (3100 ppm) than the fertile mature fronds (890 ppm). In the frond, the arsenic absorption was greatest in the lamina of the pinnae followed by the sori and the rachis. Applying arsenic during night (20:00-22:00 h) or afternoon (12:00-14:00 h) resulted in greater absorption of arsenic than the application in the morning (08:00-10:00 h). The arsenic absorption was greater through abaxial surfaces than through adaxial surfaces. The brake fern absorbed more arsenic when it was applied in the form of arsenite. Regardless of the form of arsenic and the surface it was applied to, arsenic occurred as arsenite, the reduced and the most toxic form of arsenic, after having been absorbed by the fronds. Scanning electron microscopy revealed no surface morphological alterations following all arsenic sprays. The study unequivocally illustrated that the Chinese brake fern absorbed foliar-applied arsenic with great efficiency. Consequently, the

  5. Effects of temperature and desiccation on ex situ conservation of nongreen fern spores

    Science.gov (United States)

    Conservation of the genetic diversity of ferns is limited by the paucity of ex situ spore banks. Conflicting reports of fern spore response to low temperature and moisture impedes establishment of fern spore banks. There is little information available to evaluate longevity of fern spores under dif...

  6. [Fiber as a carcinogenic agent].

    Science.gov (United States)

    Pott, F

    1987-04-01

    According to the findings that long, thin, and durable fibres have a high carcinogenic potency after intrapleural and intraperitoneal administration, the elongated shape of a particle represents a carcinogenic agent; this physical phenomenon is a special cause of cancer. It induces a biological process which can lead to cancer by several as yet unknown steps. However, the properties of the material the fibres are made of determine the carcinogenic potency of a fibre in a secondary way although they do not seem to be responsible for the true carcinogenic agent. For example, these properties determine the degree of solubility and flexibility. The persistence of fibres in the tissue is a very important property with regard to their carcinogenic effect because the formation of a tumour takes many years or some decades. It can be assumed that a fibre has to remain by the bronchial or serosa tissue until the induction of tumour cells occurs. If this hypothesis is correct, there could be a "durability threshold value" for fibres whose length and diameter would otherwise indicate a high carcinogenic potency. There are indications that other fibre properties apart from length, diameter and durability are important for tumour induction, however, at present, they cannot be included in a definition of carcinogenic fibres. It is proposed to classify all natural and man-made mineral fibres with an aspect ratio of greater than 5:1 as carcinogenic when they are longer than 3 microns, thinner than 1 micron (or can split into such fine fibres) and when they can persist in the tissue for more than 3 years.

  7. Evolutionary Conservation of ABA Signaling for Stomatal Closure in Ferns.

    Science.gov (United States)

    Cai, Shengguan; Chen, Guang; Wang, Yuanyuan; Huang, Yuqing; Marchant, Blaine; Wang, Yizhou; Yang, Qian; Dai, Fei; Hills, Adrian; Franks, Peter J; Nevo, Eviatar; Soltis, Doug; Soltis, Pamela; Sessa, Emily; Wolf, Paul G; Xue, Dawei; Zhang, Guoping; Pogson, Barry J; Blatt, Mike R; Chen, Zhong-Hua

    2017-02-23

    ABA-driven stomatal regulation reportedly evolved after the divergence of ferns, during the early evolution of seed plants approximately 360 Mya. This hypothesis is based on the observation that the stomata of certain fern species are unresponsive to ABA, but exhibit passive hydraulic control. However, ABA-induced stomatal closure was detected in some mosses and lycophytes. Here, we observed that a number of ABA signaling and membrane transporter protein families diversified over the evolutionary history of land plants. The aquatic ferns Azolla filiculoides and Salvinia cucullata have representatives of 23 families of proteins orthologous to those of Arabidopsis thaliana and all other land plant species studied. Phylogenetic analysis of the key ABA signaling proteins indicates an evolutionarily conserved stomatal response to ABA. Moreover, comparative transcriptomic analysis has identified a suite of ABA responsive genes that differentially expressed in a terrestrial fern species, Polystichum proliferum. These genes encode proteins associated with ABA biosynthesis, transport, reception, transcription, signaling, and ion and sugar transport, which fit the general ABA signaling pathway constructed from Arabidopsis thaliana and Hordeum vulgare. The retention of these key ABA-responsive genes could have had a profound effect on the adaptation of ferns to dry conditions. Furthermore, stomatal assays have shown the primary evidence for ABA-induced closure of stomata in two terrestrial fern species P. proliferum and Nephrolepis exaltata. In summary, we report new molecular and physiological evidence for the presence of active stomatal control in ferns.

  8. First insights into fern matK phylogeny.

    Science.gov (United States)

    Kuo, Li-Yaung; Li, Fay-Wei; Chiou, Wen-Liang; Wang, Chun-Neng

    2011-06-01

    MatK, the only maturase gene in the land plant plastid genome, is a very popular phylogenetic marker that has been extensively applied in reconstructing angiosperm phylogeny. However, the use of matK in fern phylogeny is largely unknown, due to difficulties with amplification: ferns have lost the flanking trnK exons, typically the region used for designing stable priming sites. We developed primers that are either universal or lineage-specific that successfully amplify matK across all fern families. To evaluate whether matK is as powerful a phylogenetic marker in ferns as in angiosperms, we compared its sequence characteristics and phylogenetic performance to those of rbcL and atpA. Among these three genes, matK has the highest variability and substitution evenness, yet shows the least homoplasy. Most importantly, applying matK in fern phylogenetics better resolved relationships among families, especially within eupolypods I and II. Here we demonstrate the power of matK for fern phylogenetic reconstruction, as well as provide primers and extensive sequence data that will greatly facilitate future evolutionary studies of ferns.

  9. The evolution, morphology and development of fern leaves

    Directory of Open Access Journals (Sweden)

    Alejandra eVasco

    2013-09-01

    Full Text Available Leaves are lateral determinate structures formed in a predictable sequence (phyllotaxy on the flanks of an indeterminate shoot apical meristem. The origin and evolution of leaves in vascular plants has been widely debated. Being the main conspicuous organ of nearl all vascular plants and often easy to recognize as such, it seems surprising that leaves have had multiple origins. For decades, morphologists, anatomists, paleobotanists, and systematists have contributed data to this debate. More recently, molecular genetic studies have provided insight into leaf evolution and development mainly within angiosperms and, to a lesser extent, lycophytes. There has been recent interest in extending leaf evolutionary developmental studies to other species and lineages, particularly in lycophytes and ferns. Therefore, a review of fern leaf morphology, evolution and development is timely. Here we discuss the theories of leaf evolution in ferns, morphology and diversity of fern leaves, and experimental results of fern leaf development. We summarize what is known about the molecular genetics of fern leaf development and what future studies might tell us about the evolution of fern leaf development.

  10. The fern sporangium: a unique catapult.

    Science.gov (United States)

    Noblin, X; Rojas, N O; Westbrook, J; Llorens, C; Argentina, M; Dumais, J

    2012-03-16

    Various plants and fungi have evolved ingenious devices to disperse their spores. One such mechanism is the cavitation-triggered catapult of fern sporangia. The spherical sporangia enclosing the spores are equipped with a row of 12 to 13 specialized cells, the annulus. When dehydrating, these cells induce a dramatic change of curvature in the sporangium, which is released abruptly after the cavitation of the annulus cells. The entire ejection process is reminiscent of human-made catapults with one notable exception: The sporangia lack the crossbar that arrests the catapult arm in its returning motion. We show that much of the sophistication and efficiency of the ejection mechanism lies in the two very different time scales associated with the annulus closure.

  11. Some new external flavonoids from American ferns

    Energy Technology Data Exchange (ETDEWEB)

    Wollenweber, E.

    1979-01-01

    American gymnogrammoid ferns have been analysed for the flavonoid aglycones present in frond exudates. They are predominantly methylated chalcones, dihydrochalcones, flavones, and flavonols, occurring mostly as farinose deposit (''ceraceous indument''). This is the first report of external flavonoids on Pterozonium species; a chalcone has been identified. On Cheilanthes kaulfussii and Cheilanthes viscida traces of flavonoid aglycones are observed, dissolved in lipophilic exudate material. On Pellaea longimucronata a flavonol is found even on leaves which appear glaucous. 2',4',6'-Trihydroxychalcone is found for the second time in the plant kingdom on Adiantum sulphureum. Galangin-3,7-dimethylether is found as a new natural flavonol on Cheilanthes kaulfussii. In addition, samples of Pityrogramma chrysoconia and Pit. triangularis var. maxonii have been investigated. The results indicate chemotaxonomic implication of flavonoid patterns.

  12. Carcinogenicity of hair dye components.

    Science.gov (United States)

    Van Duuren, B L

    1980-03-01

    The available animal carcinogenicity data on hair dye components was reviewed. From this review it became clear that certain hair dye components, some of which are still in hair dye formulations now on the market, are animal carcinogens. The compounds of concern that are still in use are: 3-amino-4-methoxyaniline, 2-nitro-4-aminoaniline and 3-nitro-4-hydroxyaniline. Certain azo dyes formerly used, and related compounds still in use, contain the benzidine moiety. Two of these compounds, Direct Blue 6 and Direct Black 38, have been shown to be metabolized in animals to the human carcinogen benzidine. Furthermore, skin absorption studies carried out with radiolabeled hair dye components applied to animal or human skin have conclusively shown that these compounds are systemically absorbed and excreted. Known cocarcinogens such as catechol and pyrogallol, which enhance benzo(a)pyrene carcinogenicity on mouse skin, are used as hair dye components. It is not known whether such compounds will enhance the carcinogenicity of substituted aniline hair dye chemicals. The available epidemiologic data are not sufficient to link hair dye use with an increased incidence in human cancer.

  13. THE ANTIMICROBIAL ACTIVITY OF SOME EXTRACTS OF FERN GAMETOPHYTES

    Directory of Open Access Journals (Sweden)

    Ionica Deliu

    2013-12-01

    Full Text Available The nature freely offers us many resources for health and beauty. The ferns and their therapeutic properties are less exploit in Romania, except Lycopodium clavatum and Equisetum arvense. Some of the fern properties were demonstrated, like antioxidant, antimicrobial, antiviral, antihelmintic properties. Plants are reasonable alternative to synthetic drugs, avoid the side effect and high cost of synthetic drugs production. Also, the drug resistance bacteria can be controlled using plant derived remedies. In this study the antimicrobial effect of methanolic and ethanolic extracts from three fern species were tested. The extracts were gained from gametophytic stage of ferns obtained in vitro. The most obvious effect was observed for Asplenium trichomanes-ramosum extract. The total polyphenols and flavonoids content were established, too.

  14. Status Report, Phyllitis scolopendrium (L.) Newm. Var. Americana Fern

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Status report concerning theAmerican Hart's Tongue Fern in the US and Canada is reviwed concerning all known populations - including those presumed to be extirpated....

  15. Fern Biology in Mexico - (A Class Field Program)

    Science.gov (United States)

    Tryon, Rolla; And Others

    1973-01-01

    Organized field trips in the tropics proved to be an effective way to gather new information about ferns. The areas of study covered were: systematics and ecology, cytology and gametophyte structure, and morphogenesis and physiology. (PS)

  16. Using Water Clover to Demonstrate Sexual Reproduction in Ferns.

    Science.gov (United States)

    Settle, Wilbur J.

    1980-01-01

    Procedures are described for preparing spores from the fern, water clover, for an educational demonstration of germination and sexual reproduction. The demonstration is recommended for biology instructors who want to illustrate the alternation of phases in plants. (SA)

  17. THE ANTIMICROBIAL ACTIVITY OF SOME EXTRACTS OF FERN GAMETOPHYTES

    OpenAIRE

    Ionica Deliu; Carmen Bejan; Emilia Vişoiu; Liliana Cristina Soare

    2013-01-01

    The nature freely offers us many resources for health and beauty. The ferns and their therapeutic properties are less exploit in Romania, except Lycopodium clavatum and Equisetum arvense. Some of the fern properties were demonstrated, like antioxidant, antimicrobial, antiviral, antihelmintic properties. Plants are reasonable alternative to synthetic drugs, avoid the side effect and high cost of synthetic drugs production. Also, the drug resistance bacteria can be controlled using plant derive...

  18. Gene transfer from a parasitic flowering plant to a fern

    OpenAIRE

    Davis, Charles C.; Anderson, William R.; Wurdack, Kenneth J

    2005-01-01

    The rattlesnake fern (Botrychium virginianum (L.) Sw.) is obligately mycotrophic and widely distributed across the northern hemisphere. Three mitochondrial gene regions place this species with other ferns in Ophioglossaceae, while two regions place it as a member of the largely parasitic angiosperm order Santalales (sandalwoods and mistletoes). These discordant phylogenetic placements suggest that part of the genome in B. virginianum was acquired by horizontal gene transfer (HGT), perhaps fro...

  19. The evolution of chloroplast genome structure in ferns.

    Science.gov (United States)

    Wolf, Paul G; Roper, Jessie M; Duffy, Aaron M

    2010-09-01

    The plastid genome (plastome) is a rich source of phylogenetic and other comparative data in plants. Most land plants possess a plastome of similar structure. However, in a major group of plants, the ferns, a unique plastome structure has evolved. The gene order in ferns has been explained by a series of genomic inversions relative to the plastome organization of seed plants. Here, we examine for the first time the structure of the plastome across fern phylogeny. We used a PCR-based strategy to map and partially sequence plastomes. We found that a pair of partially overlapping inversions in the region of the inverted repeat occurred in the common ancestor of most ferns. However, the ancestral (seed plant) structure is still found in early diverging branches leading to the osmundoid and filmy fern lineages. We found that a second pair of overlapping inversions occurred on a branch leading to the core leptosporangiates. We also found that the unique placement of the gene matK in ferns (lacking a flanking intron) is not a result of a large-scale inversion, as previously thought. This is because the intron loss maps to an earlier point on the phylogeny than the nearby inversion. We speculate on why inversions may occur in pairs and what this may mean for the dynamics of plastome evolution.

  20. Early development of fern gametophytes in microgravity

    Science.gov (United States)

    Roux, Stanley J.; Chatterjee, Ani; Hillier, Sheila; Cannon, Tom

    2003-01-01

    Dormant spores of the fern Ceratopteris richardii were flown on Shuttle mission STS-93 to evaluate the effects of micro-g on their development and on their pattern of gene expression. Prior to flight the spores were sterilized and sown into one of two environments: (1) Microscope slides in a video-microscopy module; and (2) Petri dishes. All spores were then stored in darkness until use. Spore germination was initiated on orbit after exposure to light. For the spores on microscope slides, cell level changes were recorded through the clear spore coat of the spores by video microscopy. After their exposure to light, spores in petri dishes were frozen in orbit at four different time points during which on earth gravity fixes the polarity of their development. Spores were then stored frozen in Biological Research in Canister units until recovery on earth. The RNAs from these cells and from 1-g control cells were extracted and analyzed on earth after flight to assay changes in gene expression. Video microscopy results revealed that the germinated spores developed normally in microgravity, although the polarity of their development, which is guided by gravity on earth, was random in space. Differential Display-PCR analyses of RNA extracted from space-flown cells showed that there was about a 5% change in the pattern of gene expression between cells developing in micro-g compared to those developing on earth. c2002 Published by Elsevier Science Ltd on behalf of COSPAR.

  1. Early development of fern gametophytes in microgravity

    Science.gov (United States)

    Roux, Stanley J.; Chatterjee, Ani; Hillier, Sheila; Cannon, Tom

    Dormant spores of the fern Ceratopteris richardii were flown on Shuttle mission STS-93 to evaluate the effects of /micro-g on their development and on their pattern of gene expression. Prior to flight the spores were sterilized and sown into one of two environments: (1) Microscope slides in a video-microscopy module; and (2) Petri dishes. All spores were then stored in darkness until use. Spore germination was initiated on orbit after exposure to light. For the spores on microscope slides, cell level changes were recorded through the clear spore coat of the spores by video microscopy. After their exposure to light, spores in petri dishes were frozen in orbit at four different time points during which on earth gravity fixes the polarity of their development. Spores were then stored frozen in Biological Research in Canister units until recovery on earth. The RNAs from these cells and from /1-g control cells were extracted and analyzed on earth after flight to assay changes in gene expression. Video microscopy results revealed that the germinated spores developed normally in microgravity, although the polarity of their development, which is guided by gravity on earth, was random in space. Differential Display-PCR analyses of RNA extracted from space-flown cells showed that there was about a 5% change in the pattern of gene expression between cells developing in /micro-g compared to those developing on earth.

  2. Reconstructed tree fern Alethopteris zeilleri (Carboniferous, Medullosales)

    Energy Technology Data Exchange (ETDEWEB)

    Zodrow, Erwin L. [Department of Earth Sciences, University College of Cape Breton, Sydney, Nova, Scotia (Canada B1P 6L2)

    2007-01-02

    From a smaller open-pit area in the roof shale of the basal Cantabrian coal seam in Sydney Coalfield, Cape Breton Island, Nova Scotia, Canada, large amounts of the pteridosperm foliage Alethopteris zeilleri (Ragot) were found. This foliage is associated with abundant, naked medullosalean axes and dichotomies of varying sizes, up to 0.80-m long, cauline structures 0.90 m and 1.3 m long, detached ovules assigned to Pachytesta incrassata Brongniart, rare male-pollen organs of the type Dolerotheca Halle, rooted tree ferns in life position, and one specimen each of a juvenile medullosalean frond and root mantle. The fossils are compression/impression-preserved, and the foliage yielded thickly cutinized cuticles with unoriented cells (57-103 by 27-57 {mu}m) in intercostal fields. Ultimate rachises, and abaxial surfaces (excluding costal fields) show a mixture of simple and complexly-branched trichomes, and two different structural bases. These, together with fractal dimensionality of curvatures of anticlinal walls in intercostal fields, have taxonomic potential for alethopterids. The finds suggest reconstructing A. zeilleri (Ragot) as a tree, 5-7 m high, that bore both P. incrassata Brongniart and Dolerotheca-type fructifications. Its habitat was low-land coastal plains in the Pennsylvanian coal swamps of ancestral Sydney Coalfield. (author)

  3. Involvement of allelopathy in the formation of monospecific colonies of ferns.

    Science.gov (United States)

    Kato-Noguchi, Hisashi

    2015-05-01

    Some fern species often dominate plant communities by forming large monospecific colonies. However, the potential mechanism for this domination of the ferns remains obscure. Many plants secrete a wide range of compounds into the rhizosphere and change the chemical and physical properties of the rhizosphere soil. Through the secretion of compounds, such as allelopathic substances, plants inhibit the germination and growth of neighboring plants to compete more effectively for the resources. Ferns contain a variety of secondary metabolites and some of those compounds are released from the ferns into the rhizosphere soil, either as exudates from living ferns or by decomposition of fern residues in sufficient quantities to affect the germination and growth of neighboring plants as allelopathic substances. Therefore, allelopathic chemical interaction of the ferns with neighboring plants may play an important role in the formation of the monospecific colonies of the ferns.

  4. Towards resolving the complete fern tree of life.

    Directory of Open Access Journals (Sweden)

    Samuli Lehtonen

    Full Text Available In the past two decades, molecular systematic studies have revolutionized our understanding of the evolutionary history of ferns. The availability of large molecular data sets together with efficient computer algorithms, now enables us to reconstruct evolutionary histories with previously unseen completeness. Here, the most comprehensive fern phylogeny to date, representing over one-fifth of the extant global fern diversity, is inferred based on four plastid genes. Parsimony and maximum-likelihood analyses provided a mostly congruent results and in general supported the prevailing view on the higher-level fern systematics. At a deep phylogenetic level, the position of horsetails depended on the optimality criteria chosen, with horsetails positioned as the sister group either of Marattiopsida-Polypodiopsida clade or of the Polypodiopsida. The analyses demonstrate the power of using a 'supermatrix' approach to resolve large-scale phylogenies and reveal questionable taxonomies. These results provide a valuable background for future research on fern systematics, ecology, biogeography and other evolutionary studies.

  5. Nicotinamide metabolism in ferns: formation of nicotinic acid glucoside.

    Science.gov (United States)

    Ashihara, Hiroshi; Yin, Yuling; Watanabe, Shin

    2011-03-01

    The metabolic fate of [carbonyl-(14)C]nicotinamide was investigated in 9 fern species, Psilotum nudum, Angiopteris evecta, Lygodium japonicum, Acrostichum aureum, Asplenium antiquum, Diplazium subsinuatum, Thelypteris acuminate, Blechnum orientale and Crytomium fortune. All fern species produce a large quantity of nicotinic acid glucoside from [(14)C]nicotinamide, but trigonelline formation is very low. Increases in the release of (14)CO(2) with incubation time was accompanied by decreases in [carboxyl-(14)C]nicotinic acid glucoside. There was slight stimulation of nicotinic acid glucoside formation by 250 mM NaCl in mature leaves of the mangrove fern, Acrostichum aureum, but it is unlikely that this compound acts as a compatible solute. Nicotinamide and nicotinic acid salvage for pyridine nucleotide synthesis was detected in all fern species, although this activity was always less than nicotinic acid glucoside synthesis. Predominant formation of nicotinic acid glucoside is characteristic of nicotinic acid metabolism in ferns. This reaction appears to act as a detoxication mechanism, removing excess nicotinic acid.

  6. FTIR and py-GC-MS spectra of true-fern and seed-fern sphenopterids (Sydney Coalfield, Nova Scotia, Canada, Pennsylvanian)

    Science.gov (United States)

    Zodrow, E.L.; Mastalerz, Maria

    2002-01-01

    Sphenopterid specimens from the Late Pennsylvanian of Sydney Coalfield, Canada, are investigated by FTIR and py-GC-MS techniques as part of an on-going research project into the biochemistry and chemotaxonomy of Pennsylvanian-age pteridophylls. Included in the investigation are samples of the true-fern species Oligocarpia brongniartii and Zeilleria delicatula that are preserved as naturally macerated cuticles (NMC), and the seed-fern Eusphenopteris neuropteroides that is also preserved as a compression/impression. FTIR spectra of NMC seed-fern E. neuropteroides, and fern sphenopterid O. brongniartii are very similar, except that the latter does not have aromatic bands in the 700-900 cm-1 out-of-plane region, py-GC-MS show more aromatic compounds for the seed fern than for the two true-fern sphenopterids. Another difference between seed-fern and true-fern sphenopterids is a lower ratio of CH2 to CH3 in chemically treated specimens (CTC) for the seed fern. These observations suggest slightly higher aromaticity for the seed ferns, perhaps related to some chemotaxonomic differences. Comparison of FTIR and py-GC-MS characteristics of sphenopterids and other plant groups shows that these two techniques have potential to identifying chemotaxonomic signals from Carboniferous pteridophylls in general, although more data are needed to confirm this. ?? 2002 Elsevier Science B.V. All rights reserved.

  7. Gene transfer from a parasitic flowering plant to a fern.

    Science.gov (United States)

    Davis, Charles C; Anderson, William R; Wurdack, Kenneth J

    2005-11-07

    The rattlesnake fern (Botrychium virginianum (L.) Sw.) is obligately mycotrophic and widely distributed across the northern hemisphere. Three mitochondrial gene regions place this species with other ferns in Ophioglossaceae, while two regions place it as a member of the largely parasitic angiosperm order Santalales (sandalwoods and mistletoes). These discordant phylogenetic placements suggest that part of the genome in B. virginianum was acquired by horizontal gene transfer (HGT), perhaps from root-parasitic Loranthaceae. These transgenes are restricted to B. virginianum and occur across the range of the species. Molecular and life-history traits indicate that the transfer preceded the global expansion of B. virginianum, and that the latter may have happened very rapidly. This is the first report of HGT from an angiosperm to a fern, through either direct parasitism or the mediation of interconnecting fungal symbionts.

  8. Assessment of the Contribution of WorldView-2 Strategically ...

    African Journals Online (AJOL)

    Zinhle

    Positioned Bands in Bracken fern (Pteridium aquilinum (L.) Kuhn). Mapping. Zinhle Ngubane1, John Odindi1,Onisimo Mutanga1, Rob Slotow2 ..... Holland, J & Aplin, P 2013, 'Super-resolution image analysis as a means of monitoring bracken.

  9. 野生蕨菜人工栽培生态地域筛选研究%A Research for Ecoclistrict Selection of Wild Bracken Domescication

    Institute of Scientific and Technical Information of China (English)

    田明英; 许淑桂; 刘倩; 王直朋; 王洪章

    2001-01-01

    研究了野生蕨菜人工栽培的部分技术问题。通过试验,筛选出了比较适宜蕨菜栽培生长的自然生态环境地域—河滩疏林地;初步解决了孢子育苗的技术问题,找出了适宜蕨菜生长的最佳温、湿度、光强度及pH值等。试验结果证明,运用孢子育苗进行人工栽培蕨菜是切实可行的。%This article has done a research to partial technical problems of wild bracken d omestication. By experiments,at first,the more proper nataral ecoenvironment dis trict has been selected out,that is sparse woods flood land. And second, the t echnical problem of growing spore seedlings artificially has been tentatively so lved, and found out some optimal guidelines about temperature,humidity,light in t ensity, pH and so on. Which are proper for the growth of wild bracken. The resul t of experiment attests that it is feasible for applying spore breeding to artifi cial cultivation.

  10. Phosphorus speciation by {sup 31}P NMR spectroscopy in bracken (Pteridium aquilinum (L.) Kuhn) and bluebell (Hyacinthoides non-scripta (L.) Chouard ex Rothm.) dominated semi-natural upland soil

    Energy Technology Data Exchange (ETDEWEB)

    Ebuele, Victor O.; Santoro, Anna; Thoss, Vera, E-mail: v.thoss@bangor.ac.uk

    2016-10-01

    Access to P species is a driver for plant community composition based on nutrient acquisition. Here we investigated the distribution and accumulation of soil inorganic P (Pi) and organic P (Po) forms in a bracken and bluebell dominated upland soil for the period between bluebell above ground dominance until biomass is formed from half bluebells and half bracken. Chemical characterisation and {sup 31}P Nuclear Magnetic Resonance spectroscopy was used to determine the organic and inorganic P species. Total P concentration in soils was 0.87 g kg{sup −1}, while in plants (above- and below-ground parts) total P ranged between 0.84–4.0 g kg{sup −1} and 0.14–2.0 g kg{sup −1} for bluebell and bracken, respectively. The P speciation in the plant samples was reflected in the surrounding soil. The main forms of inorganic P detected in the NaOH-EDTA soil extracts were orthophosphate (20.0–31.5%), pyrophosphate (0.6–2.5%) and polyphosphate (0.4–7.0%). Phytate (myo-IP{sub 6}) was the most dominant organic P form (23.6–40.0%). Other major peaks were scyllo-IP{sub 6} and α- and β- glycerophosphate (glyP). In bluebells and bracken the main P form detected was orthophosphate ranging from (21.7–80.4%) and 68.5–81.1%, in above-ground and below-ground biomass, respectively. Other detected forms include α-glyP (4.5–14.4%) and β-glyP (0.9–7.7%) in bluebell, while in bracken they were detected only in stripe and blade in ranges of 2.5–5.5% and 4.4–9.6%, respectively. Pyrophosphate, polyphosphate, scyllo-IP{sub 6}, phosphonates, found in soil samples, were not detected in any plant parts. In particular, the high abundance of phytate in the soil and in bluebell bulbs, may be related to a mechanism through which bluebells create a recalcitrant phosphorus store which form a key part of their adaptation to nutrient poor conditions. - Highlights: • Organic P forms were the dominant P species detected in the bracken (Pteridium aquilinum) and bluebell

  11. Gene silencing in a polyploid homosporous fern: paleopolyploidy revisited.

    OpenAIRE

    Gastony, G J

    1991-01-01

    Because of their high chromosome numbers, homosporous vascular plants were considered paleopolyploids until recent enzyme electrophoretic studies rejected this hypothesis by showing that they express only diploid numbers of isozymes. In polyploid sporophytes of the homosporous fern pelleae rufa, however, progressive diminution of phosphoglucoisomerase activities encoded by one ancestral genome culminates in tetraploid plants exhibiting a completely diploidized electrophoretic phenotype for th...

  12. Ferns and lycophytes of Pernambuco State, Brazil: Metaxyaceae

    Directory of Open Access Journals (Sweden)

    Iva Carneiro Leão Barros

    2010-09-01

    Full Text Available The present paper elucidates part of the fern flora of Pernambuco State. Metaxyaceae is native to the state and is represented by a single species, Metaxya rostrata (Kunth C. Presl. Descriptions and illustrations, as well as geographical distribution and habitats, are presented.

  13. Why are there so few species of ferns?

    Science.gov (United States)

    Ranker, Tom A; Sundue, Michael A

    2015-07-01

    A recent study has documented a natural hybridization event between two fern lineages that last shared a common ancestor about 60 million years ago. This is one of the deepest hybridization events ever described and has important implications for plant speciation theory.

  14. Instructions for collecting tree ferns of the family Cyatheaceae

    NARCIS (Netherlands)

    Holttum, R.E.

    1957-01-01

    The next monographic study which will be undertaken for the series Pteridophyta of the Flora Malesiana will be devoted to the tree ferns of the Cyatheaceae. In connection with the large size of these plants and the desirability of having more and complete material at our disposal, the following note

  15. Comparative morphology of the gametophyte of some Thelypteroid ferns

    NARCIS (Netherlands)

    Sen, Tuhinsri

    1981-01-01

    A study of the development of the gametophytes of sixteen thelypteroid ferns reveals similarities and significant differences among them. Combinations of the diversified features of the prothalli appear to have a tremendous impact on identification and delimitation of the major taxa, and support the

  16. Checklist of the Ferns, Natural Falls State Park

    Directory of Open Access Journals (Sweden)

    Smith, Bruce A.

    2001-12-01

    Full Text Available Natural Falls State Park, formerly known as Dripping Springs is located in northeast Oklahoma. The park's natural beauty and flora have attracted visitors since 1907. In a 1988 visit to the Oklahoma State University Herbarium, I noticed that several herbarium sheets of ferns were collected from Dripping Springs. This was intriguing and made me want to visit the area. Due to my interest in floristics and taxonomy, Natural Falls State Park seemed the perfect place to create a checklist of ferns. Thus, the objective of this study was to create an inventory of the ferns of Dripping Springs using my collection and the collections and observations from earlier botanists. A systematic collection of the ferns of Dripping Springs was conducted on August 7, 1998, October 15, 1998, and October 20, 2001. Using standard taxonomic methods, each plant was identified to species and subsequently inventoried. In three days of collecting, 17species from 6 families and 12 genera were encountered. Since 1925 a total of 19 species from 6 families and 12 genera have been reported to occur.

  17. New observations and synthesis of paleogene heterosporous water ferns

    NARCIS (Netherlands)

    Collinson, M.E.; Smith, S.Y.; van Konijnenburg-van Cittert, J.H.A.; Batten, D.J.; Refidaff, C.; Barke, J.; Marone, F.

    Premise of research. Reproductive structures of modern genera of heterosporous water ferns (Marsileaceae and Salviniaceae) are widespread and abundant in plant mesofossil assemblages from the Paleogene. For Salviniaceae, whole fertile fossil plants give a good understanding of morphology. These

  18. The omnipresent water fern Azolla caroliniana does not contain lignin

    NARCIS (Netherlands)

    Nierop, K.G.J.; Speelman, E.N.; Leeuw, J.W. de; Reichart, G.-J.

    2011-01-01

    Several studies have reported the presence of large amounts of lignin in ubiquitously occurring species of the freshwater fern Azolla. Molecular analysis using flash pyrolysis and thermally assisted hydrolysis and methylation shows, however, that neither the leaves nor the roots of Azolla contain

  19. A 4000-species dataset provides new insight into the evolution of ferns.

    Science.gov (United States)

    Testo, Weston; Sundue, Michael

    2016-12-01

    Ferns are the second-most diverse lineage of vascular plants on Earth, yet the best-sampled time-calibrated phylogeny of the group to date includes fewer than 5% of global diversity and was published seven years ago. We present a time-calibrated phylogeny that includes nearly half of extant fern diversity. Our results are evaluated in the context of previous studies and the fossil record, and we develop new hypotheses about the radiation of leptosporangiate ferns. We used sequence data from six chloroplast regions for nearly 4000 species of ferns to generate the most comprehensive phylogeny of the group ever published. We calibrate the phylogeny with twenty-six fossils and use an array of phylogenetic methods to resolve phylogenetic relationships, estimate divergence times, and infer speciation, extinction, and net diversification rates. We infer a mid-late Silurian origin for ferns (including horsetails) and an early Carboniferous origin for leptosporangiate ferns. Most derived fern families appeared in the Cretaceous and persisted for millions of years before rapidly diversifying in the Cenozoic. We find no evidence of differential rates of diversification among terrestrial and epiphytic species. Our findings challenge previous hypotheses on the evolutionary history of ferns and present a new paradigm for their Cenozoic radiation. We estimate earlier divergences for most fern lineages than were reported in previous studies and provide evidence of extended persistence of major fern lineages prior to rapid diversification in the last fifty million years.

  20. Leaf evolution in early-diverging ferns: insights from a new fern-like plant from the Late Devonian of China.

    Science.gov (United States)

    Wang, De-Ming; Xu, Hong-He; Xue, Jin-Zhuang; Wang, Qi; Liu, Le

    2015-06-01

    With the exception of angiosperms, the main euphyllophyte lineages (i.e. ferns sensu lato, progymnosperms and gymnosperms) had evolved laminate leaves by the Late Devonian. The evolution of laminate leaves, however, remains unclear for early-diverging ferns, largely represented by fern-like plants. This study presents a novel fern-like taxon with pinnules, which provides new insights into the early evolution of laminate leaves in early-diverging ferns. Macrofossil specimens were collected from the Upper Devonian (Famennian) Wutong Formation of Anhui and Jiangsu Provinces, South China. A standard degagement technique was employed to uncover compressed plant portions within the rock matrix. A new fern-like taxon, SHOUGANGIA BELLA GEN ET SP NOV: , is described and represents an early-diverging fern with highly derived features. It has a partially creeping stem with adventitious roots only on one side, upright primary and secondary branches arranged in helices, tertiary branches borne alternately or (sub)oppositely, laminate and usually lobed leaves with divergent veins, and complex fertile organs terminating tertiary branches and possessing multiple divisions and numerous terminal sporangia. Shougangia bella provides unequivocal fossil evidence for laminate leaves in early-diverging ferns. It suggests that fern-like plants, along with other euphyllophyte lineages, had independently evolved megaphylls by the Late Devonian, possibly in response to a significant decline in atmospheric CO2 concentration. Among fern-like plants, planate ultimate appendages are homologous with laminate pinnules, and in the evolution of megaphylls, fertile organs tend to become complex. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. [Anatomy of six species of Dryopteris ferns (Dryopteridaceae) from Mexico].

    Science.gov (United States)

    Hernández, Victoria; Terrazas, Teresa; Angeles, Guillermo

    2006-12-01

    Rhizome and foliar anatomy of the Mexican Dryopteris Adans. species were studied and compared with other Dryopteridaceae and other fern families to identify anatomical features with diagnostic value. The anatomy of rhizome, stipe, and blade is similar in species of the Dryopteris patula complex. The cells with un-lignified, thickened wall, with cap or U-shape around the meristeles belong to the collenchyma, in contrast with other fern families. Dryopteris wallichiana (Spreng.) Hyl. is anatomically distinguished from the other studied species by having more layers of sclerenchyma and meristeles on the stipe, and by the lack of sclereid nests on the rhizome. Dryopteris rossii C. Chr. and D. maxonii Underw. & C. Chr. are characterized by the presence of crystals on the periphery of rhizome nests. D. maxonni and D. wallichiana lack blade glands.

  2. A Precious Fern Species Discovered in Jiulong, Sichuan

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Supported by the US National Science Foundation and the National Natural Science Foundation of China, a rare and endangered fern, Isoetes hypsophila, was discovered by a Sino-US research team headed by Prof. SUN Hang from the CAS Kunming Institute of Botany (KIB) and Dr. David E. Boufford from Harvard University in a recent trip to Jiulong, Sichuan, during its botanical survey in the Hengduan Mountains in south China. Scientists say the plant is found for the first time in the region.

  3. Variation of desiccation tolerance and longevity in fern spores.

    Science.gov (United States)

    Ballesteros, Daniel; Hill, Lisa M; Walters, Christina

    2017-04-01

    This work contributes to the understanding of plant cell responses to extreme water stress when it is applied at different intensity and duration. Fern spores are used to explore survival at relative humidity (RH)desiccation damage occurs in desiccation tolerant cells, and that it is expressed as a time-dependent response, otherwise known as aging. Copyright © 2017 Elsevier GmbH. All rights reserved.

  4. Morphology, Physiology, and Anatomy of Penny Fern (Drymoglossum phyloselloidesand Its Effect on Cocoa

    Directory of Open Access Journals (Sweden)

    Fitria Yuliasmara

    2013-08-01

    Full Text Available This study aims to determine the anatomy, physiology and morphology of penny fern (Drimoglosum phylloseloides and its effect on cocoa. Morphological observation of penny fern used microscope to observe the roots, stems, leaves and spores. Physiology of penny fern was observed based on number of stomata and stomatal conductance using stomata printing method, while the amount of chlorophyll based on spectrophotometric method and rate of transpiration used cobalt chloride paper. Penny fern anatomy on cross-sectional and longitudinal in roots, stems and leaves. Penny fern growth was observed based the length of tendrils once a week during rainy and dry season. While the effect of penny fern invasion was observed based on variable leaf area with gravimetric method, the cross-section of attacked cacao branch using microtom and microscope and chlorophyll content by chlorophyll meter. Results showed that penny fern is a epiphytic weed which was crassulaceae acid metabolism plants that have the ability to absorb carbon dioxide at night and carry out photosynthesis during the day with closed stomata. Penny ferns reproduce using spores. The growth rate of penny fern 2.18 cm/week during the dry season and while in rainy season 3.89 cm/week. Penny fern leaf contains 0.0212 mg/g chlorophyll. Penny fern stomata density was 18.33/mm 2 with a width of opening stomata at night 26.3 µm which caused a veryslow rate of transpiration of 0.69 mm 2 /seconds. The existence penny fern on cocoa decreased leaf area and chlorophyll content decreased crop productivity which was indicated by decreasing in number of flowers, number of small, medium fruit, and large pods. However it had no effect on the number of leaves on one side flush cocoa. Key words: Drimoglosum phylloseloides, weeds, decrease productivity, Theobroma cacao

  5. Asplenium bird’s nest ferns in rainforest canopies are climate-contingent refuges for frogs

    OpenAIRE

    Brett R Scheffers; Ben L. Phillips; Shoo, Luke P

    2014-01-01

    Epiphytes are important for canopy dwelling organisms because they provide a cool and moist microhabitat in the relatively hot and dry canopy. Here we examine whether epiphytic Asplenium ferns act as important habitats for arboreal frogs. We conducted extensive fern and habitat surveys for frogs in the Philippines, and complimented these surveys with roaming day and night canopy surveys to identify the full extent of habitat use across the vertical strata. We artificially dried ferns of vario...

  6. The physiological implications of primary xylem organization in two ferns.

    Science.gov (United States)

    Brodersen, Craig R; Roark, Lindsey C; Pittermann, Jarmila

    2012-11-01

    Xylem structure and function are well described in woody plants, but the implications of xylem organization in less-derived plants such as ferns are poorly understood. Here, two ferns with contrasting phenology and xylem organization were selected to investigate how xylem dysfunction affects hydraulic conductivity and stomatal conductance (g(s)). The drought-deciduous pioneer species, Pteridium aquilinum, exhibits fronds composed of 25 to 37 highly integrated vascular bundles with many connections, high g(s) and moderate cavitation resistance (P50 = -2.23 MPa). By contrast, the evergreen Woodwardia fimbriata exhibits sectored fronds with 3 to 5 vascular bundles and infrequent connections, low g(s) and high resistance to cavitation (P50 = -5.21 MPa). Xylem-specific conductivity was significantly higher in P. aqulinium in part due to its wide, efficient conduits that supply its rapidly transpiring pinnae. These trade-offs imply that the contrasting xylem organization of these ferns mirrors their divergent life history strategies. Greater hydraulic connectivity and g(s) promote rapid seasonal growth, but come with the risk of increased vulnerability to cavitation in P. aquilinum, while the conservative xylem organization of W. fimbriata leads to slower growth but greater drought tolerance and frond longevity.

  7. Limitation of distribution of two rare ferns in fragmented landscape

    Science.gov (United States)

    Tájek, Přemysl; Bucharová, Anna; Münzbergová, Zuzana

    2011-09-01

    Species distribution in the landscape is limited either by 1. diaspore production, dispersal and establishment abilities or 2. by availability of suitable habitats; 3. or by a combination of both factors. The relative importance of these factors is species-dependent and has mainly been studied for seed plants. We studied the importance of habitat and dispersal limitation for distribution of two rare fern species, Asplenium adulterinum and Asplenium cuneifolium, restricted to serpentine rocks, using analysis of their distribution on a regional scale (several kilometers). Within the model region, all 98 serpentine rocks were mapped. We used data on abiotic characteristics and on the presence of all vascular plant species on the rocks to predict which of the rocks were suitable for the two Asplenium species. Suitable habitats were positively defined mainly by the presence of appropriate microhabitats and the height of the highest rock, which represents the size of space with lowered concurrence. Other determinants of habitat suitability differed between species. Neither species occupied all suitable localities, indicating dispersal limitation. Locality isolation significantly affected one of the species but not the other. Overall, the results suggest that both fern species have suitable but unoccupied localities in the region and demonstrates that ferns, similar to seed plants, are limited by their dispersal ability in the landscape.

  8. Global phylogeny and biogeography of grammitid ferns (Polypodiaceae).

    Science.gov (United States)

    Sundue, Michael A; Parris, Barbara S; Ranker, Tom A; Smith, Alan R; Fujimoto, Erin L; Zamora-Crosby, Delia; Morden, Clifford W; Chiou, Wen-Liang; Chen, Cheng-Wei; Rouhan, Germinal; Hirai, Regina Y; Prado, Jefferson

    2014-12-01

    We examined the global historical biogeography of grammitid ferns (Polypodiaceae) within a phylogenetic context. We inferred phylogenetic relationships of 190 species representing 31 of the 33 currently recognized genera of grammitid ferns by analyzing DNA sequence variation of five plastid DNA regions. We estimated the ages of cladogenetic events on an inferred phylogeny using secondary fossil calibration points. Historical biogeographical patterns were inferred via ancestral area reconstruction. Our results supported four large-scale phylogenetic and biogeographic patterns: (1) a monophyletic grammitid clade that arose among Neotropical polypod ancestors about 31.4 Ma; (2) a paraphyletic assemblage of clades distributed in the Neotropics and the Afro-Malagasy region; (3) a large clade distributed throughout the Asia-Malesia-Pacific region that originated about 23.4 Ma; and, (4) an Australian or New Zealand origin of the circumaustral genus Notogrammitis. Most genera were supported as monophyletic except for Grammitis, Oreogrammitis, Radiogrammitis, and Zygophlebia. Grammitid ferns are a well-supported monophyletic group with two biogeographically distinct lineages: a primarily Neotropical grade exhibiting several independent successful colonizations to the Afro-Malagasy region and a primarily Paleotropical clade exhibiting multiple independent dispersals to remote Pacific islands and temperate, austral regions.

  9. Sorption equilibrium of mercury onto ground-up tree fern

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Y.-S. [Department of Chemical Engineering, I-Shou University, No. 1, Section 1, Hsueh-Cheng Road, Ta-Hsu Hsiang, Kaohsiung County 840, Taiwan (China)], E-mail: ysho@isu.edu.tw; Wang, C.-C. [Department of Chemical Engineering, I-Shou University, No. 1, Section 1, Hsueh-Cheng Road, Ta-Hsu Hsiang, Kaohsiung County 840, Taiwan (China)

    2008-08-15

    The sorption behavior of mercury at different temperatures onto ground-up tree fern was investigated. The experimental results were fitted to two two-parameter isotherms, the Freundlich and Langmuir isotherms, as well as to two three-parameter isotherms, the Redlich-Peterson and Sips isotherms to obtain the characteristic parameters of each model. A comparison of best-fitting was performed using the coefficient of determination and Chi-square test. Both the Langmuir and Redlich-Peterson isotherms were found to well represent the measured sorption data. According to the evaluation using the Langmuir equation, the saturated monolayer sorption capacity of mercury ions onto ground-up tree fern was 26.5 mg/g at 298 K. It was noted that an increase in temperature resulted in a higher mercury ion loading per unit weight of the tree fern. In addition, various thermodynamic parameters, such as {delta}G{sup o}, {delta}H{sup o}, and {delta}S{sup o}, were calculated and compared with the sorption of mercury by other sorbents.

  10. Ferns: the missing link in shoot evolution and development

    Directory of Open Access Journals (Sweden)

    Andrew Robert George Plackett

    2015-11-01

    Full Text Available Shoot development in land plants is a remarkably complex process that gives rise to an extreme diversity of forms. Our current understanding of shoot developmental mechanisms comes almost entirely from studies of angiosperms (flowering plants, the most recently diverged plant lineage. Shoot development in angiosperms is based around a layered multicellular apical meristem that produces lateral organs and/or secondary meristems from populations of founder cells at its periphery. In contrast, non-seed plant shoots develop from either single apical initials or from a small population of morphologically distinct apical cells. Although developmental and molecular information is becoming available for non-flowering plants, such as the model moss Physcomitrella patens, making valid comparisons between highly divergent lineages is extremely challenging. As sister group to the seed plants, the monilophytes (ferns and relatives represent an excellent phylogenetic midpoint of comparison for unlocking the evolution of shoot developmental mechanisms, and recent technical advances have finally made transgenic analysis possible in the emerging model fern Ceratopteris richardii. This review compares and contrasts our current understanding of shoot development in different land plant lineages with the aim of highlighting the potential role that the fern C. richardii could play in shedding light on the evolution of underlying genetic regulatory mechanisms.

  11. Structure-function constraints of tracheid-based xylem: a comparison of conifers and ferns.

    Science.gov (United States)

    Pittermann, Jarmila; Limm, Emily; Rico, Christopher; Christman, Mairgareth A

    2011-10-01

    The ferns comprise one of the most ancient tracheophytic plant lineages, and occupy habitats ranging from tundra to deserts and the equatorial tropics. Like their nearest relatives the conifers, modern ferns possess tracheid-based xylem but the structure-function relationships of fern xylem are poorly understood. Here, we sampled the fronds (megaphylls) of 16 species across the fern phylogeny, and examined the relationships among hydraulic transport, drought-induced cavitation resistance, the xylem anatomy of the stipe, and the gas-exchange response of the pinnae. For comparison, the results are presented alongside a similar suite of conifer data. Fern xylem is as resistant to cavitation as conifer xylem, but exhibits none of the hydraulic or structural trade-offs associated with resistance to cavitation. On a conduit diameter basis, fern xylem can exhibit greater hydraulic efficiency than conifer and angiosperm xylem. In ferns, wide and long tracheids compensate in part for the lack of secondary xylem and allow ferns to exhibit transport rates on a par with those of conifers. We suspect that it is the arrangement of the primary xylem, in addition to the intrinsic traits of the conduits themselves, that may help explain the broad range of cavitation resistance in ferns.

  12. Random ferns method implementation for the general-purpose machine learning

    CERN Document Server

    Kursa, Miron B

    2012-01-01

    In this paper I present an extended implementation of the Random ferns algorithm contained in the R package rFerns. It differs from the original by the ability of consuming categorical and numerical attributes instead of only binary ones. Also, instead of using simple attribute subspace ensemble it employs bagging and thus produce error approximation and variable importance measure modelled after Random forest algorithm. I also present benchmarks' results which show that although Random ferns' accuracy is mostly smaller than achieved by Random forest, its speed and good quality of importance measure it provides make rFerns a reasonable choice for a specific applications.

  13. Leaf photosynthetic rate of tropical ferns is evolutionarily linked to water transport capacity.

    Science.gov (United States)

    Zhang, Shi-Bao; Sun, Mei; Cao, Kun-Fang; Hu, Hong; Zhang, Jiao-Lin

    2014-01-01

    Ferns usually have relatively lower photosynthetic potential than angiosperms. However, it is unclear whether low photosynthetic potential of ferns is linked to leaf water supply. We hypothesized that there is an evolutionary association of leaf water transport capacity with photosynthesis and stomatal density in ferns. In the present study, a series of functional traits relating to leaf anatomy, hydraulics and physiology were assessed in 19 terrestrial and 11 epiphytic ferns in a common garden, and analyzed by a comparative phylogenetics method. Compared with epiphytic ferns, terrestrial ferns had higher vein density (Dvein), stomatal density (SD), stomatal conductance (gs), and photosynthetic capacity (Amax), but lower values for lower epidermal thickness (LET) and leaf thickness (LT). Across species, all traits varied significantly, but only stomatal length (SL) showed strong phylogenetic conservatism. Amax was positively correlated with Dvein and gs with and without phylogenetic corrections. SD correlated positively with Amax, Dvein and gs, with the correlation between SD and Dvein being significant after phylogenetic correction. Leaf water content showed significant correlations with LET, LT, and mesophyll thickness. Our results provide evidence that Amax of the studied ferns is linked to leaf water transport capacity, and there was an evolutionary association between water supply and demand in ferns. These findings add new insights into the evolutionary correlations among traits involving carbon and water economy in ferns.

  14. Mineral fibre persistence and carcinogenicity.

    Science.gov (United States)

    McDonald, J C

    1998-10-01

    Epidemiological research during the past 40 years has demonstrated with increasing clarity that amphibole asbestos fibres--crocidolite, amosite and tremolite--are more carcinogenic than chrysotile. A smaller number of well-controlled studies using lung burden analyses, while adding to the specificity of this conclusion, have shown that amphibole fibres also differ from chrysotile in being far more durable and biopersistent in lung tissue. Analyses of mesothelioma and lung cancer in a large cohort of Canadian chrysotile miners and millers have recently shown that the low-level presence of fibrous tremolite in these mines, rather than the chrysotile, may well be responsible. The high risk of lung cancer, but not of mesothelioma, in the chrysotile textile industry remains anomalous and cannot be explained in this way. These various findings are directly relevant to the choice of the experimental methods which should be used for screening man-made fibres for industrial use. Although it is clear that biopersistence is a major determinant of cancer risk in animals, and perhaps also in man, other factors affecting the biological activity of mineral fibres may also be important.

  15. Water properties in fern spores: sorption characteristics relating to water affinity, glassy states, and storage stability.

    Science.gov (United States)

    Ballesteros, Daniel; Walters, Christina

    2007-01-01

    Ex situ conservation of ferns may be accomplished by maintaining the viability of stored spores for many years. Storage conditions that maximize spore longevity can be inferred from an understanding of the behaviour of water within fern spores. Water sorption properties were measured in spores of five homosporeous species of ferns and compared with properties of pollen, seeds, and fern leaf tissue. Isotherms were constructed at 5, 25, and 45 degrees C and analysed using different physicochemical models in order to quantify chemical affinity and heat (enthalpy) of sorption of water in fern spores. Fern spores hydrate slowly but dry rapidly at ambient relative humidity. Low Brunauer-Emmet-Teller monolayer values, few water-binding sites according to the D'Arcy-Watt model, and limited solute-solvent compatibility according to the Flory-Huggins model suggest that fern spores have low affinity for water. Despite the low water affinity, fern spores demonstrate relatively high values of sorption enthalpy (DeltaH(sorp)). Parameters associated with binding sites and DeltaH(sorp) decrease with increasing temperature, suggesting temperature- and hydration-dependent changes in volume of spore macromolecules. Collectively, these data may relate to the degree to which cellular structures within fern spores are stabilized during drying and cooling. Water sorption properties within fern spores suggest that storage at subfreezing temperatures will give longevities comparable with those achieved with seeds. However, the window of optimum water contents for fern spores is very narrow and much lower than that measured in seeds, making precise manipulation of water content imperative for achieving maximum longevity.

  16. A progress report on the work toward propagation and reintroduction of the threatened plant American Hart's Tongue Fern (Phyllitis scolopendrium)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Report describes efforts to propogate the fern spores in the lab. Attempts to propagate the spores from the Am. Hart's Tongue Fern in the Lab is reviewed. Spores...

  17. Asplenium bird’s nest ferns in rainforest canopies are climate-contingent refuges for frogs

    Directory of Open Access Journals (Sweden)

    Brett R. Scheffers

    2014-12-01

    Full Text Available Epiphytes are important for canopy dwelling organisms because they provide a cool and moist microhabitat in the relatively hot and dry canopy. Here we examine whether epiphytic Asplenium ferns act as important habitats for arboreal frogs. We conducted extensive fern and habitat surveys for frogs in the Philippines, and complimented these surveys with roaming day and night canopy surveys to identify the full extent of habitat use across the vertical strata. We artificially dried ferns of various sizes to identify relationships between water and temperature buffering. Ferns are the preferred diurnal microhabitat and breeding habitat for arboreal frogs. A strong positive relationship exists between fern size and frog usage and abundance. Our drying experiments show that large ferns buffer maximum temperatures and reduce variability in temperatures, and buffering is directly linked to their hydration. Frogs are likely using large ferns for their moist, cool, environments for breeding and daytime retreat, which supports the buffered microhabitat hypothesis—these plants promote species coexistence through habitat creation and amelioration of physical stress. However, drying experiments suggest that this buffering is contingent on regular rainfall. Altered rainfall regimes could lead to the unexpected loss of the functional capacity of these important fern habitats.

  18. Ancestral stomatal control results in a canalization of fern and lycophyte adaptation to drought.

    Science.gov (United States)

    McAdam, Scott A M; Brodribb, Timothy J

    2013-04-01

    Little is known about how a predominantly passive hydraulic stomatal control in ferns and lycophytes might impact water use under stress. Ferns and lycophytes occupy a diverse array of habitats, from deserts to rainforest canopies, raising the question of whether stomatal behaviour is the same under all ecological strategies and imposes ecological or functional constraints on ferns and lycophytes. We examined the stomatal response of a diverse sample of fern and lycophyte species to both soil and atmospheric water stress, assessing the foliar level of the hormone abscisic acid (ABA) over drought and recovery and the critical leaf water potential (Ψl) at which photosynthesis in droughted leaves failed to recover. The stomata of all ferns and lycophytes showed very predictable responses to soil and atmospheric water deficit via Ψl, while stomatal closure was poorly correlated with changes in ABA. We found that all ferns closed stomata at very low levels of water stress and their survival afterwards was limited only by their capacitance and desiccation tolerance. Ferns and lycophytes have constrained stomatal responses to soil and atmospheric water deficit as a consequence of a predominantly passive stomatal regulation. This results in a monotypic strategy in ferns and lycophytes under water stress.

  19. Field Guide to Northeastern Ferns. New York State Museum Bulletin Number 444.

    Science.gov (United States)

    Ogden, Eugene C.

    This guide was developed for use by individuals with little or no botanical training who wish to identify native ferns of New York, New England, New Jersey, and Pennsylvania. A random access key, developed by the author, provides multiple pathways for identification of 60 species in 29 genera of ferns. (CS)

  20. The mucilage secreting hairs on the young fronds of some Leptosporangiate Ferns

    NARCIS (Netherlands)

    Hennipman, E.

    1968-01-01

    During a collecting trip to Thailand, as a member of the Thai-Dutch botanical expedition 1965/1966, I was struck by the excessive amount of mucilage sometimes present on the circinnate fronds of several leptosporangiate ferns. This was especially evident in representatives of the monotypic fern fami

  1. Klukiopsis jurassica——A new Jurassic schizaeaceous fern from China

    Institute of Scientific and Technical Information of China (English)

    邓胜徽[1; 王仕俊[2

    2000-01-01

    A new Jurassic schizaeaceous fern Klukiopsis jurassica gen. et sp. nov. from Yima, Henan Province, China is described. The new fern is characterized by the abaxial sori arranged in two rows, apical and complete annulus and more than 800 smooth trilete spores in each sorus.

  2. 75 FR 23151 - Noxious Weeds; Old World Climbing Fern and Maidenhair Creeper

    Science.gov (United States)

    2010-05-03

    ... Inspection Service 7 CFR Parts 360 and 361 Noxious Weeds; Old World Climbing Fern and Maidenhair Creeper... noxious weed regulations by adding Old World climbing fern (Lygodium microphyllum (Cavanilles) R. Brown) and maidenhair creeper (Lygodium flexuosum (Linnaeus) Swartz) to the list of terrestrial noxious weeds...

  3. In Vitro Conservation of Some Threatened and Economically Important Ferns Belonging to the Indian Subcontinent

    Directory of Open Access Journals (Sweden)

    Shastri P. Shukla

    2014-01-01

    Full Text Available This study was undertaken to identify methods of mass multiplication for five ornamental, economically important ferns (Nephrolepis biserrata (Sw. Schott., N. cordifolia cv. ‘‘duffii’’ (L. Presl., N. exaltata cv. bostoniensis (L. Schott., Pteris vittata L., and Cyclosorus dentatus Link., and three threatened ferns, namely, Cyathea spinulosa Wall. ex. Hook, Pityrogramma calomelanos (L. Link., and Microsorum punctatum (L. Schott., through in vitro techniques. Collections were made from different biodiversity zones of India including Northeast Himalayas, Kumaon Himalayas, and Western Ghat and successfully introduced and grown in a fern-house. Aseptic cultures were raised at the morphogenic level of callus, axillary shoot, multiple shoot, and rooted plants. An optimized medium is described for each fern species. Plantlets were also produced from spore culture of Cyathea spinulosa and successfully hardened under fern house conditions.

  4. Crowdfunding the Azolla fern genome project: a grassroots approach.

    Science.gov (United States)

    Li, Fay-Wei; Pryer, Kathleen M

    2014-01-01

    Much of science progresses within the tight boundaries of what is often seen as a "black box". Though familiar to funding agencies, researchers and the academic journals they publish in, it is an entity that outsiders rarely get to peek into. Crowdfunding is a novel means that allows the public to participate in, as well as to support and witness advancements in science. Here we describe our recent crowdfunding efforts to sequence the Azolla genome, a little fern with massive green potential. Crowdfunding is a worthy platform not only for obtaining seed money for exploratory research, but also for engaging directly with the general public as a rewarding form of outreach.

  5. A Gompertz regression model for fern spores germination

    Directory of Open Access Journals (Sweden)

    Gabriel y Galán, Jose María

    2015-06-01

    Full Text Available Germination is one of the most important biological processes for both seed and spore plants, also for fungi. At present, mathematical models of germination have been developed in fungi, bryophytes and several plant species. However, ferns are the only group whose germination has never been modelled. In this work we develop a regression model of the germination of fern spores. We have found that for Blechnum serrulatum, Blechnum yungense, Cheilanthes pilosa, Niphidium macbridei and Polypodium feuillei species the Gompertz growth model describe satisfactorily cumulative germination. An important result is that regression parameters are independent of fern species and the model is not affected by intraspecific variation. Our results show that the Gompertz curve represents a general germination model for all the non-green spore leptosporangiate ferns, including in the paper a discussion about the physiological and ecological meaning of the model.La germinación es uno de los procesos biológicos más relevantes tanto para las plantas con esporas, como para las plantas con semillas y los hongos. Hasta el momento, se han desarrollado modelos de germinación para hongos, briofitos y diversas especies de espermatófitos. Los helechos son el único grupo de plantas cuya germinación nunca ha sido modelizada. En este trabajo se desarrolla un modelo de regresión para explicar la germinación de las esporas de helechos. Observamos que para las especies Blechnum serrulatum, Blechnum yungense, Cheilanthes pilosa, Niphidium macbridei y Polypodium feuillei el modelo de crecimiento de Gompertz describe satisfactoriamente la germinación acumulativa. Un importante resultado es que los parámetros de la regresión son independientes de la especie y que el modelo no está afectado por variación intraespecífica. Por lo tanto, los resultados del trabajo muestran que la curva de Gompertz puede representar un modelo general para todos los helechos leptosporangiados

  6. Effect of synthetic detergents on germination of fern spores

    Energy Technology Data Exchange (ETDEWEB)

    Devi, Y.; Devi, S.

    1986-12-01

    Synthetic detergents constitute one of the most important water pollutants by contaminating the lakes and rivers through domestic and industrial use. Considerable information is now available for the adverse effects of detergents an aquatic fauna including fish, algae, and higher aquatic plants. Marked inhibition of germination in orchids and brinjals and of seedlings growth in raddish suggest that rapidly growing systems could be sensitive to detergent polluted water. The present study of the effect of linear alkyl benzene sulphonate on germination of the spores of a fern, Diplazium esculentum aims at the understanding of the effects of water pollution on pteridophytes and the development of spore germination assay for phytoxicity evaluation.

  7. Ultrasonic synthesis of fern-like ZnO nanoleaves and their enhanced photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Qing Lan [School of Mathematics and Physics, Changzhou University, Jiangsu 213164 (China); School of Electronics and Information, Nantong University, Jiangsu 226019 (China); Xiong, Rui [School of Physics and Technology, Wuhan University, Hubei 430072 (China); Zhai, Bao-gai [School of Mathematics and Physics, Changzhou University, Jiangsu 213164 (China); Huang, Yuan Ming, E-mail: dongshanisland@126.com [School of Mathematics and Physics, Changzhou University, Jiangsu 213164 (China)

    2015-01-01

    Graphical abstract: - Highlights: • Fern-like ZnO nanoleaves were synthesized by ultrasonicating Zn microcrystals in water. • A fern-like ZnO nanoleaf is a self-assembly of ZnO nanoplates along one ZnO nanorod. • Fern-like ZnO nanoleaves exhibit enhanced photocatalytic activity than ZnO nanocrystals. • The branched hierarchical structures are responsible for the enhanced photocatalytic activity. - Abstract: Two-dimensional fern-like ZnO nanoleaves were synthesized by ultrasonicating zinc microcrystals in water. The morphology, crystal structure, optical property and photocatalytic activity of the fern-like ZnO nanoleaves were characterized with scanning electron microscopy, X-ray diffraction, transmission electron microscopy, photoluminescence spectroscopy and ultraviolet–visible spectroscopy, respectively. It is found that one fern-like ZnO nanoleaf is composed of one ZnO nanorod as the central trunk and a number of ZnO nanoplates as the side branches in opposite pairs along the central ZnO nanorod. The central ZnO nanorod in the fern-like nanoleaves is about 1 μm long while the side-branching ZnO nanoplates are about 100 nm long and 20 nm wide. Further analysis has revealed that ZnO nanocrystals are the building blocks of the central ZnO nanorod and the side-branching ZnO nanoplates. Under identical conditions, fern-like ZnO nanoleaves exhibit higher photocatalytic activity in photodegrading methyl orange in aqueous solution than spherical ZnO nanocrystals. The first-order photocatalytic rate constant of the fern-like ZnO nanoleaves is about four times as large as that of the ZnO nanoparticles. The branched architecture of the hierarchical nanoleaves is suggested be responsible for the enhanced photocatalytic activity of the fern-like ZnO nanoleaves.

  8. Carcinogenic effects of benzene: Cesare Maltoni's contributions.

    Science.gov (United States)

    Mehlman, Myron A

    2002-12-01

    Cesare Maltoni's contributions to understanding, identifying, and characterizing widely used commercial chemicals in experimental animals are among the most important methods developed in the history of toxicology and serve to protect working men and women, the general population, and our environment from hazardous substances. Maltoni developed experimental methods that have reached the "platinum standard" for protection of public health. Benzene was among the 400 or more chemicals that Maltoni and his associates tested for carcinogenicity. In 1976, Maltoni reported that benzene is a potent experimental carcinogen. Maltoni's experiments clearly demonstrated that benzene is carcinogenic in Sprague-Dawley rats, Wistar rats, Swiss mice, and RF/J mice when administered by inhalation or ingestion. Benzene caused carcinomas of the Zymbal gland, oral cavity, nasal cavities; cancers of the skin, forestomach, mammary glands, and lungs; angiosarcomas and hepatomas of the liver; and hemolymphoreticular cancers. Thus, benzene was shown to be a multipotential carcinogen that produced cancers in several species of animals by various routes of administration. On November 2, 1977, Chemical Week reported that Maltoni provided a "bombshell" when he demonstrated the "first direct link" between benzene and cancer. In this paper, I shall summarize early experiments and human studies and reports; Maltoni's experimental contribution to understanding the carcinogenicity of benzene in humans and animals; earlier knowledge concerning benzene toxicity; and benzene standards and permissible exposure levels.

  9. Cell-mediated mutagenesis by chemical carcinogens

    Energy Technology Data Exchange (ETDEWEB)

    Huberman, E.; Langenbach, R.

    1978-01-01

    The cell-mediated mutation system, with the proper choice of metabolizing cells, can be used to detect the mutagenic activities of different classes of chemical carcinogens. When fibroblastic cells were used as the metabolizing cells, a correlation between the in vivo carcinogenic activity and the in vitro mutagenic activity of 11 aromatic polycyclic hydrocarbons was observed. When primary liver cells were used as the metabolizing cells, three known liver carcinogens were demonstrated to be mutagenic by the cell-mediated assay, while two non-carcinogenic analogues were not mutagenic. These results from the cell-mediated system suggest that the reactive intermediates of the carcinogens are stable enough to be transferred from the metabolizing cells to the V79 cells. The cell-mediated mutagenesis system is a simple in vitro assay which may simulate the in vivo situation. It was concluded that this approach could be extended to the co-cultivation of cells from other organs or tissues with mutable mammalian cells.

  10. Mutagenicity, carcinogenicity and teratogenicity of beryllium.

    Science.gov (United States)

    Léonard, A; Lauwerys, R

    1987-07-01

    The carcinogenicity of a number of beryllium compounds has been confirmed in experiments on laboratory animals and this metal has to be treated as a possible carcinogenic threat to man. These carcinogenic properties are associated with mutagenic activity as shown by the results of short-term tests performed in vitro with beryllium chloride and beryllium sulfate. These soluble beryllium compounds can produce some infidelity of in vitro synthesis, forward gene mutations in microorganisms and in mammalian cells. They are also able to induce cell transformation. In addition to the positive results obtained in several short-term assays beryllium compounds have been found to bind to nucleoproteins, to inhibit certain enzymes needed for DNA synthesis, to bind nucleic acids to cell membranes and to inhibit microtubule polymerization. The teratogenicity of beryllium salts is relatively unknown and needs additional investigation.

  11. [Leather azo dyes: mutagenic and carcinogenic risks].

    Science.gov (United States)

    Clonfero, E; Venier, P; Granella, M; Levis, A G

    1990-01-01

    The paper reviews the carcinogenicity and mutagenicity data on azo dyes used in the leather industry. Two water soluble benzidine-based dyes were classified as "probably carcinogenic to humans" by the International Agency for Research on Cancer (IARC). No other dyes have been evaluated by the IARC. Of the 48 azo dyes assayed in the Salmonella/microsome test, 20 gave positive results. Attention is drawn to the important role of the in vivo metabolism of azo compounds, which includes a preliminary reduction of the azo bonds and subsequent release of the aromatic amines of the dye. A useful assay (Prival test) for evaluating the mutagenic properties of azo dyes involves a reductive step that permits the release of any genotoxic agents present in the compounds. A list of leather azo dyes is furnished that are considered as potentially harmful due to the presence of a carcinogenic aromatic amine (benzidine, p-aminobenzene and derivatives) in their formulae.

  12. The ISS Carcinogens Data Bank (BDC).

    Science.gov (United States)

    Binetti, Roberto; Ceccarelli, Federica; Costamagna, Francesca Marina; D'Angiolini, Antonella; Fabri, Alessandra; Ferri, Maurizio; Riva, Giovanni; Roazzi, Paolo; Trucchi, Daniela; Marcello, Ida

    2008-01-01

    The Data Bank on Carcinogens (Banca Dati Cancerogeni, BDC) is a factual data bank, available on the Istituto Superiore di Sanità website, aimed at supporting the risk management decision making of central and local administrators. It can also represent a valuable tool for industry. The available information on carcinogenicity evaluations/classifications produced by European Union and by other institutions (IARC, USEPA, NTP, CCTN) is presented in a concise form accompanied by bibliographic references enabling the users to consult the original sources and, in some cases, to be directly connected to the relevant website. The classifications carried out by each organization in accordance with its own criteria assign the examined agents to specific qualitative categories and do not include quantitative assessment. BDC intends to provide an easy tool for experts, researchers and risk managers dealing with carcinogenic agents.

  13. In Silico Methods for Carcinogenicity Assessment.

    Science.gov (United States)

    Golbamaki, Azadi; Benfenati, Emilio

    2016-01-01

    Screening compounds for potential carcinogenicity is of major importance for prevention of environmentally induced cancers. A large sequence of alternative predictive models, ranging from short-term biological assays (e.g. mutagenicity tests) to theoretical models, have been attempted in this field. Theoretical approaches such as (Q)SAR are highly desirable for identifying carcinogens, since they actively promote the replacement, reduction, and refinement of animal tests. This chapter reports and describes some of the most noted (Q)SAR models based on the human expert knowledge and statistically approach, aiming at predicting the carcinogenicity of chemicals. Additionally, the performance of the selected models has been evaluated and the results are interpreted in details by applying these prediction models to some pharmaceutical molecules.

  14. Evolution of leaf form in marsileaceous ferns: evidence for heterochrony.

    Science.gov (United States)

    Pryer, Kathleen M; Hearn, David J

    2009-02-01

    Using an explicit phylogenetic framework, ontogenetic patterns of leaf form are compared among the three genera of marsileaceous ferns (Marsilea, Regnellidium, and Pilularia) with the outgroup Asplenium to address the hypothesis that heterochrony played a role in their evolution. We performed a Fourier analysis on a developmental sequence of leaves from individuals of these genera. Principal components analysis of the harmonic coefficients was used to characterize the ontogenetic trajectories of leaf form in a smaller dimensional space. Results of this study suggest that the "evolutionary juvenilization" observed in these leaf sequences is best described using a mixed model of heterochrony (accelerated growth rate and early termination at a simplified leaf form). The later stages of the ancestral, more complex, ontogenetic pattern were lost in Marsileaceae, giving rise to the simplified adult leaves of Marsilea, Regnellidium, and Pilularia. Life-history traits such as ephemeral and uncertain habitats, high reproductive rates, and accelerated maturation, which are typical for marsileaceous ferns, suggest that they may be "r strategists." The evidence for heterochrony presented here illustrates that it has resulted in profound ecological and morphological consequences for the entire life history of Marsileaceae.

  15. Development of the gametophyte of the fern Schizaea pusilla

    Science.gov (United States)

    Kiss, J. Z.; Swatzell, L. J.

    1996-01-01

    Schizaea pusilla is a pteridophyte with several unique developmental characteristics. In contrast to most other fern species, S. pusilla gametophytes remain filamentous throughout their development, and the gametophytes are associated with an endophytic fungus which appears to be mycorrhizal. In terms of tropistic responses, apical filament cells of young gametophytes are negatively phototropic compared with germ filaments of other ferns which exhibit positive phototropism. Cryofixation (propane jet freezing and high-pressure freezing) in conjunction with freeze substitution electron microscopy was used to study young gametophytes. The results demonstrate that apical filament cells have a distinctive structural polarity and that rhizoids also can be successfully frozen by these methods. The cytoskeleton and endomembrane system were particularly well preserved in cryofixed cells. In addition, Schizaea gametophytes were used as a test system to evaluate potential artifacts of propane jet freezing and high pressure freezing. There was little apparent difference in ultrastructure between cells cryofixed by either freezing method. These gametophytes will be useful in determining the effectiveness of cryofixation techniques and as a model system in tip growth studies.

  16. Detection of chlorophylls in spores of seven ferns.

    Science.gov (United States)

    Tseng, Mei-Hwei; Lin, Kuei-Huei; Huang, Yi-Jia; Chang, Ya-Lan; Huang, Sheng-Cih; Kuo, Li-Yaung; Huang, Yao-Moan

    2017-03-01

    Fern spores were traditionally classified into chlorophyllous (green) and nonchlorophyllous (nongreen) types based on the color visible to the naked eye. Recently, a third type, "cryptochlorophyllous spores", is recognized, and these spores are nongreen under white light but contain chlorophylls. Epifluorescence microscopy was previously used to detect chlorophylls in cryptochlorophyllous spores. In addition to epifluorescence microscopy, current study performed some other approaches, including spore-squash epifluorescence, absorption spectra, laser-induced fluorescence emission spectra, thin layer chromatography (TLC), and ultra-high performance liquid chromatography with ultraviolet and mass spectrometric detection (UHPLC-UV-MS) in order to detect chlorophylls of spores of seven ferns (Sphaeropteris lepifera, Ceratopteris thalictroides, Leptochilus wrightii, Leptochilus pothifolius, Lepidomicrosorum buergerianum, Osmunda banksiifolia, and Platycerium grande). Destructive methods, such as TLC and UHPLC-UV-MS, successfully detected chlorophylls inside the spores when their signals of red fluorescence under epifluorescence microscope were masked by spore wall. Although UHPLC-UV-MS analysis was the most sensitive and reliable for determining the chlorophylls of spores, spore-squash epifluorescence is not only reliable but also cost- and time-effective one among our study methods. In addition, we first confirmed that Lepidomicrosorium buergerianum, Leptochilus pothifolius, Leptochilus wrightii, and Platycerium grande, produce cryptochlorophyllous spores.

  17. A free-access online key to identify Amazonian ferns

    Directory of Open Access Journals (Sweden)

    Gabriela Zuquim

    2017-03-01

    Full Text Available There is urgent need for more data on species distributions in order to improve conservation planning. A crucial but challenging aspect of producing high-quality data is the correct identification of organisms. Traditional printed floras and dichotomous keys are difficult to use for someone not familiar with the technical jargon. In poorly known areas, such as Amazonia, they also become quickly outdated as new species are described or ranges extended. Recently, online tools have allowed developing dynamic, interactive, and accessible keys that make species identification possible for a broader public. In order to facilitate identifying plants collected in field inventories, we developed an internet-based free-access tool to identify Amazonian fern species. We focused on ferns, because they are easy to collect and their edaphic affinities are relatively well known, so they can be used as an indicator group for habitat mapping. Our key includes 302 terrestrial and aquatic entities mainly from lowland Amazonian forests. It is a free-access key, so the user can freely choose which morphological features to use and in which order to assess them. All taxa are richly illustrated, so specimens can be identified by a combination of character choices, visual comparison, and written descriptions. The identification tool was developed in Lucid 3.5 software and it is available at http://keyserver.lucidcentral.org:8080/sandbox/keys.jsp.

  18. Invariant Hough Random Ferns for Object Detection and Tracking

    Directory of Open Access Journals (Sweden)

    Yimin Lin

    2014-01-01

    Full Text Available This paper introduces an invariant Hough random ferns (IHRF incorporating rotation and scale invariance into the local feature description, random ferns classifier training, and Hough voting stages. It is especially suited for object detection under changes in object appearance and scale, partial occlusions, and pose variations. The efficacy of this approach is validated through experiments on a large set of challenging benchmark datasets, and the results demonstrate that the proposed method outperforms state-of-the-art conventional methods such as bounding-box-based and part-based methods. Additionally, we also propose an efficient clustering scheme based on the local patches’ appearance and their geometric relations that can provide pixel-accurate, top-down segmentations from IHRF back-projections. This refined segmentation can be used to improve the quality of online object tracking because it avoids the drifting problem. Thus, an online tracking framework based on IHRF, which is trained and updated in each frame to distinguish and segment the object from the background, is established. Finally, the experimental results on both object segmentation and long-term object tracking show that this method yields accurate and robust tracking performance in a variety of complex scenarios, especially in cases of severe occlusions and nonrigid deformations.

  19. Ecological and evolutionary consequences of desiccation tolerance in tropical fern gametophytes.

    Science.gov (United States)

    Watkins, James E; Mack, Michelle C; Sinclair, Thomas R; Mulkey, Stephen S

    2007-01-01

    Ferns have radiated into the same diverse environments as spermatophytes, and have done so with an independent gametophyte that is not protected by the parent plant. The degree and extent of desiccation tolerance (DT) in the gametophytes of tropical fern species was assessed to understand mechanisms that have allowed ferns to radiate into a diversity of habitats. Species from several functional groups were subjected to a series of desiccation events, including varying degrees of intensity and multiple desiccation cycles. Measurements of chlorophyll fluorescence were used to assess recovery ability and compared with species ecology and gametophyte morphology. It is shown that vegetative DT (rare in vascular plants) is widely exhibited in fern gametophytes and the degree of tolerance is linked to species habitat preference. It is proposed that gametophyte morphology influences water-holding capacity, a novel mechanism that may help to explain how ferns have radiated into drought-prone habitats. Fern gametophytes have often been portrayed as extreme mesophytes with little tolerance for desiccation. The discovery of DT in gametophytes holds potential for improving our understanding of both the controls on fern species distribution and their evolution. It also advances a new system with which to study the evolution of DT in vascular plants.

  20. Ultrasonic synthesis of fern-like ZnO nanoleaves and their enhanced photocatalytic activity

    Science.gov (United States)

    Ma, Qing Lan; Xiong, Rui; Zhai, Bao-gai; Huang, Yuan Ming

    2015-01-01

    Two-dimensional fern-like ZnO nanoleaves were synthesized by ultrasonicating zinc microcrystals in water. The morphology, crystal structure, optical property and photocatalytic activity of the fern-like ZnO nanoleaves were characterized with scanning electron microscopy, X-ray diffraction, transmission electron microscopy, photoluminescence spectroscopy and ultraviolet-visible spectroscopy, respectively. It is found that one fern-like ZnO nanoleaf is composed of one ZnO nanorod as the central trunk and a number of ZnO nanoplates as the side branches in opposite pairs along the central ZnO nanorod. The central ZnO nanorod in the fern-like nanoleaves is about 1 μm long while the side-branching ZnO nanoplates are about 100 nm long and 20 nm wide. Further analysis has revealed that ZnO nanocrystals are the building blocks of the central ZnO nanorod and the side-branching ZnO nanoplates. Under identical conditions, fern-like ZnO nanoleaves exhibit higher photocatalytic activity in photodegrading methyl orange in aqueous solution than spherical ZnO nanocrystals. The first-order photocatalytic rate constant of the fern-like ZnO nanoleaves is about four times as large as that of the ZnO nanoparticles. The branched architecture of the hierarchical nanoleaves is suggested be responsible for the enhanced photocatalytic activity of the fern-like ZnO nanoleaves.

  1. Physiological mechanisms drive differing foliar calcium content in ferns and angiosperms.

    Science.gov (United States)

    Funk, Jennifer L; Amatangelo, Kathryn L

    2013-09-01

    Recent evidence points to ferns containing significantly lower contents of foliar calcium and other cations than angiosperms. This is especially true of more ancient 'non-polypod' fern lineages, which predate the diversification of angiosperms. Calcium is an important plant nutrient, the lack of which can potentially slow plant growth and litter decomposition, and alter soil invertebrate communities. The physiological mechanisms limiting foliar calcium (Ca) content in ferns are unknown. While there is a lot we do not know about Ca uptake and transport in plants, three physiological processes are likely to be important. We measured transpiration rate, cation exchange capacity, and leaching loss to determine which process most strongly regulates foliar Ca content in a range of fern and co-occurring understory angiosperm species from a montane Hawaiian rainforest. We found higher instantaneous and lifetime (corrected for leaf lifespan) transpiration rates in angiosperms relative to ferns. Ferns preferentially incorporated Ca into leaves relative to strontium, which suggests that root or stem cation exchange capacity differs between ferns and angiosperms, potentially affecting calcium transport in plants. There were no differences in foliar Ca leaching loss between groups. Among the physiological mechanisms measured, foliar Ca was most strongly correlated with leaf-level transpiration rate and leaf lifespan. This suggests that inter-specific differences in a leaf's lifetime transpiration may play a significant role in determining plant nutrition.

  2. Horizontal transfer of an adaptive chimeric photoreceptor from bryophytes to ferns.

    Science.gov (United States)

    Li, Fay-Wei; Villarreal, Juan Carlos; Kelly, Steven; Rothfels, Carl J; Melkonian, Michael; Frangedakis, Eftychios; Ruhsam, Markus; Sigel, Erin M; Der, Joshua P; Pittermann, Jarmila; Burge, Dylan O; Pokorny, Lisa; Larsson, Anders; Chen, Tao; Weststrand, Stina; Thomas, Philip; Carpenter, Eric; Zhang, Yong; Tian, Zhijian; Chen, Li; Yan, Zhixiang; Zhu, Ying; Sun, Xiao; Wang, Jun; Stevenson, Dennis W; Crandall-Stotler, Barbara J; Shaw, A Jonathan; Deyholos, Michael K; Soltis, Douglas E; Graham, Sean W; Windham, Michael D; Langdale, Jane A; Wong, Gane Ka-Shu; Mathews, Sarah; Pryer, Kathleen M

    2014-05-06

    Ferns are well known for their shade-dwelling habits. Their ability to thrive under low-light conditions has been linked to the evolution of a novel chimeric photoreceptor--neochrome--that fuses red-sensing phytochrome and blue-sensing phototropin modules into a single gene, thereby optimizing phototropic responses. Despite being implicated in facilitating the diversification of modern ferns, the origin of neochrome has remained a mystery. We present evidence for neochrome in hornworts (a bryophyte lineage) and demonstrate that ferns acquired neochrome from hornworts via horizontal gene transfer (HGT). Fern neochromes are nested within hornwort neochromes in our large-scale phylogenetic reconstructions of phototropin and phytochrome gene families. Divergence date estimates further support the HGT hypothesis, with fern and hornwort neochromes diverging 179 Mya, long after the split between the two plant lineages (at least 400 Mya). By analyzing the draft genome of the hornwort Anthoceros punctatus, we also discovered a previously unidentified phototropin gene that likely represents the ancestral lineage of the neochrome phototropin module. Thus, a neochrome originating in hornworts was transferred horizontally to ferns, where it may have played a significant role in the diversification of modern ferns.

  3. Tree fern trunks facilitate seedling regeneration in a productive lowland temperate rain forest.

    Science.gov (United States)

    Gaxiola, Aurora; Burrows, Larry E; Coomes, David A

    2008-03-01

    Seedling regeneration on forest floors is often impaired by competition with established plants. In some lowland temperate rain forests, tree fern trunks provide safe sites on which tree species establish, and grow large enough to take root in the ground and persist. Here we explore the competitive and facilitative effects of two tree fern species, Cyathea smithii and Dicksonia squarrosa, on the epiphytic regeneration of tree species in nutrient-rich alluvial forests in New Zealand. The difficulties that seedlings have in establishing on vertical tree fern trunks were indicated by the following observations. First, seedling abundance was greatest on the oldest sections of tree fern trunks, near the base, suggesting that trunks gradually recruited more and more seedlings over time, but many sections of trunk were devoid of seedlings, indicating the difficulty of establishment on a vertical surface. Second, most seedlings were from small-seeded species, presumably because smaller seeds can easily lodge on tree fern trunks. Deer browsing damage was observed on 73% of epiphytic seedlings growing within 2 m of the ground, whereas few seedlings above that height were browsed. This suggests that tree ferns provide refugia from introduced deer, and may slow the decline in population size of deer-preferred species. We reasoned that tree ferns would compete with epiphytic seedlings for light, because below the tree fern canopy photosynthetically active radiation (PAR) was about 1% of above-canopy PAR. Frond removal almost tripled %PAR on the forest floor, leading to a significant increase in the height growth rate (HGR) of seedlings planted on the forest floor, but having no effects on the HGRs of epiphytic seedlings. Our study shows evidence of direct facilitative interactions by tree ferns during seedling establishment in plant communities associated with nutrient-rich soils.

  4. THE DIVERSITY OF EPIPHYTIC FERN ON THE OIL PALM TREE (Elaeis guineensis Jacq. IN PEKANBARU, RIAU

    Directory of Open Access Journals (Sweden)

    Nery Sofiyanti

    2015-02-01

    Full Text Available Oil palm (Elaeis guineensis is one  main commodity in Riau Province. Morphologically, the trunk of oil palm  has suitable environment for the growth of epiphytic fern, due to its broaden base of petiole that may accumulate organic and anorganic debrish. The objective of this study was to investigate the diversity of epiphytic fern on the oil palm tree. A total of 125 oil palm trees from seven  study sites in Pekanbaru, Riau were observed. The number of epiphytic ferns identified in this study was 16 species belongs to six families.

  5. Carcinogenic compounds in alcoholic beverages: an update.

    Science.gov (United States)

    Pflaum, Tabea; Hausler, Thomas; Baumung, Claudia; Ackermann, Svenja; Kuballa, Thomas; Rehm, Jürgen; Lachenmeier, Dirk W

    2016-10-01

    The consumption of alcoholic beverages has been classified as carcinogenic to humans by the International Agency for Research on Cancer (IARC) since 1988. More recently, in 2010, ethanol as the major constituent of alcoholic beverages and its metabolite acetaldehyde were also classified as carcinogenic to humans. Alcoholic beverages as multi-component mixtures may additionally contain further known or suspected human carcinogens as constituent or contaminant. This review will discuss the occurrence and toxicology of eighteen carcinogenic compounds (acetaldehyde, acrylamide, aflatoxins, arsenic, benzene, cadmium, ethanol, ethyl carbamate, formaldehyde, furan, glyphosate, lead, 3-MCPD, 4-methylimidazole, N-nitrosodimethylamine, pulegone, ochratoxin A, safrole) occurring in alcoholic beverages as identified based on monograph reviews by the IARC. For most of the compounds of alcoholic beverages, quantitative risk assessment provided evidence for only a very low risk (such as margins of exposure above 10,000). The highest risk was found for ethanol, which may reach exposures in ranges known to increase the cancer risk even at moderate drinking (margin of exposure around 1). Other constituents that could pose a risk to the drinker were inorganic lead, arsenic, acetaldehyde, cadmium and ethyl carbamate, for most of which mitigation by good manufacturing practices is possible. Nevertheless, due to the major effect of ethanol, the cancer burden due to alcohol consumption can only be reduced by reducing alcohol consumption in general or by lowering the alcoholic strength of beverages.

  6. 40 CFR 799.9420 - TSCA carcinogenicity.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 31 2010-07-01 2010-07-01 true TSCA carcinogenicity. 799.9420 Section 799.9420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES... their selection. (ii) Age/weight. (A) Testing shall be started with young healthy animals as soon...

  7. Carcinogens formed when Meat is Cooked

    Energy Technology Data Exchange (ETDEWEB)

    Felton, J S; Salmon, C P; Knize, M G

    2003-05-30

    Diet has been associated with varying cancer rates in human populations for many years, yet the causes of the observed variation in cancer patterns have not been adequately explained (Wynder et al. 1977). Along with the effect of diet on human cancer incidence is the strong evidence that mutations are the initiating events in the cancer process (Vogelstein et al. 1992). Foods, when heated, are a good source of genotoxic carcinogens that very likely are a cause for some of these events(Doll et al. 1981). These carcinogens fall into two chemical classes: heterocyclic aromatic amines (HAA) and polycyclic aromatic hydrocarbons (PAH). There is ample evidence that many of these compounds are complete carcinogens in rodents(El-Bayoumy et al. 1995; Ohgaki et al. 1991). Heterocyclic aromatic amines are among the most potent mutagenic substances ever tested in the Ames/Salmonella mutagenicity test (Wakabayashi et al. 1992). Both classes of carcinogen cause tumors in rodents at multiple sites, (El-Bayoumy et al. 1995; Ohgaki et al. 1991) many of which are common tumor sites in people on a Western diet. An HAA, PhIP (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine), and a PAH, B[a]P (benzo[a]pyrene), of comparable carcinogenic potency caused mammary gland tumors in a feeding study in female rats (El-Bayoumy et al. 1995). In addition, PhIP has recently been shown to cause carcinomas in the prostate of the male rat (Shirai et al. 1997). Complementing the rodent cancer studies are numerous human case-control and prospective studies suggesting a relationship between overheated beef, chicken, and lamb, and cancer of the colon, breast, prostate, and stomach (Sinha et al. 1999; Ward et al. 1997; Zheng et al. 1998).

  8. Water-clover ferns, Marsilea, in the Southeastern United States

    Science.gov (United States)

    Jacono, Colette C.; Johnson, David M.

    2006-01-01

    A surge in the collection of exotic Marsilea, M. mutica, M. minuta and M. hirsuta in the southeastern United States has prompted the need for updated identification aids. This study provides an annotated key to all water-clover ferns occurring in the region. It describes and illustrates recently documented exotic species and a previously misidentified western introduction. It details the rediscovery of M. ancylopoda, presumed extinct, and confirms its identification as the western species M. oligospora. Finally it clarifies the status and distribution of two additional western North American species introduced to the southeast, M. vestita and M. macropoda.

  9. 美国紧急修补Fern Ridge坝

    Institute of Scientific and Technical Information of China (English)

    郑国良; 范友军

    2005-01-01

    俄勒冈州正在从美国联邦政府寻求4200万美元的紧急资金以修补Fem Ridge坝。2004年12月,美国陆军工程师团(USACE)将大坝的库水位降低了13.5m。降低库水位是由于发现有越来越多的泥沙从大坝的渗流集水沟流出。一个由USACE召集的独立调查委员会得出结论说,因管涌和/或内部侵蚀的原因,63a坝龄的Fern Ridge坝正处于溃坝的活跃状态,水库水位高程应当限制在110m以下,

  10. Macedonio Fernández: la forma de la experiencia

    Directory of Open Access Journals (Sweden)

    Mónica Bueno

    2015-10-01

    Full Text Available Podemos supor que, Macedonio Fernández, escritor da vanguardia argentina, constrói uma noção de experiência que descreve de uma maneira singular a relação vida/literatura. Museo de la Novela de la Eterna, sua novela “boa” (assim ele a chamava, não só narra a tensão entre o real e o ficcional senão que é um procedimento básico de construção do não-real, do que ainda não é, no sentido blochiano, e o conhecimento da experiência de Macedonio parece funcionar nessa perspectiva utópica.

  11. Application of Random Ferns for non-planar object detection

    Science.gov (United States)

    Mastov, Alexey; Konovalenko, Ivan; Grigoryev, Anton

    2015-12-01

    The real time object detection task is considered as a part of a project devoted to development of autonomous ground robot. This problem has been successfully solved with Random Ferns algorithm, which belongs to keypoint-based method and uses fast machine learning algorithms for keypoint matching step. As objects in the real world are not always planar, in this article we describe experiments of applying this algorithm for non-planar objects. Also we introduce a method for fast detection of a special class of non-planar objects | those which can be decomposed into planar parts (e.g. faces of a box). This decomposition needs one detector for each side, which may significantly affect speed of detection. Proposed approach copes with it by omitting repeated steps for each detector and organizing special queue of detectors. It makes the algorithm three times faster than naive one.

  12. The fern cavitation catapult: mechanism and design principles.

    Science.gov (United States)

    Llorens, C; Argentina, M; Rojas, N; Westbrook, J; Dumais, J; Noblin, X

    2016-01-01

    Leptosporangiate ferns have evolved an ingenious cavitation catapult to disperse their spores. The mechanism relies almost entirely on the annulus, a row of 12-25 cells, which successively: (i) stores energy by evaporation of the cells' content, (ii) triggers the catapult by internal cavitation, and (iii) controls the time scales of energy release to ensure efficient spore ejection. The confluence of these three biomechanical functions within the confines of a single structure suggests a level of sophistication that goes beyond most man-made devices where specific structures or parts rarely serve more than one function. Here, we study in detail the three phases of spore ejection in the sporangia of the fern Polypodium aureum. For each of these phases, we have written the governing equations and measured the key parameters. For the opening of the sporangium, we show that the structural design of the annulus is particularly well suited to inducing bending deformations in response to osmotic volume changes. Moreover, the measured parameters for the osmoelastic design lead to a near-optimal speed of spore ejection (approx. 10 m s(-1)). Our analysis of the trigger mechanism by cavitation points to a critical cavitation pressure of approximately -100 ± 14 bar, a value that matches the most negative pressures recorded in the xylem of plants. Finally, using high-speed imaging, we elucidated the physics leading to the sharp separation of time scales (30 versus 5000 µs) in the closing dynamics. Our results highlight the importance of the precise tuning of the parameters without which the function of the leptosporangium as a catapult would be severely compromised.

  13. Phylogeny and historical biogeography of the lastreopsid ferns (Dryopteridaceae).

    Science.gov (United States)

    Labiak, Paulo H; Sundue, Michael; Rouhan, Germinal; Hanks, Judith G; Mickel, John T; Moran, Robbin C

    2014-07-01

    • Premise of the study: As currently circumscribed, Lastreopsis has about 45 species and occurs in Australia, southern Asia, Africa, Madagascar, and the neotropics. Previous molecular phylogenetic studies suggested that Lastreopsis is paraphyletic. Our study focuses on resolving relationships among the lastreopsid ferns (Lastreopsis, Megalastrum, and Rumohra), the evolution of morphological characters, and an understanding of the temporal and spatial patterns that have led to the current diversity and geographical distribution of its extant species.• Methods: Phylogenetic relationships were recovered under Bayesian, maximum likelihood, and maximum parsimony methods, using a data set of four plastid markers. Divergence time estimates were made using BEAST, and the biogeographic hypotheses were tested under the DEC model and the RASP/S-DIVA methods.• Key results: Lastreopsis was recovered as paraphyletic, and at least one of its clades should be recognized as a distinct genus, Parapolystichum. Coveniella poecilophlebia and Oenotrichia tripinnata were nested within Lastreopsis s.s., Megalastrum and Rumohra as sister to the Lastreopsis s.s., and the Lastreopsis amplissima clades. The initial diversification of the lastreopsids took place at about 56.55 Ma, from a neotropical ancestor.• Conclusions: Taxonomic recognition of Parapolystichum is warranted to preserve the monophyly of Lastreopsis. Diversification among the main clades of the lastreopsid ferns was influenced by climatic and geological changes in the southern hemisphere. The biogeographic history of the group is intimately related to the trans-Antarctic corridor between Australia and South America, with evidence for multiple lineage interchanges between Australia and South America during the Oligocene and the Eocene epochs.

  14. 77 FR 15798 - Notice of Intent To Repatriate Cultural Items: San Francisco State University, San Francisco, CA

    Science.gov (United States)

    2012-03-16

    .... History and Description of the Cultural Items At an unknown date, a basket (item 1-3-42/86) was donated to... bracken fern root. There are no records at the Treganza Museum concerning acquisition of this item. Based... of 44 cm and is made of deer grass, saw grass, redbud and bracken fern root. A tag attached to...

  15. Evaluation of the Inhalation Carcinogenicity of Ethylene Oxide (Final Report)

    Science.gov (United States)

    EPA has finalized its Evaluation of the Inhalation Carcinogenicity of Ethylene Oxide. This assessment addresses the potential carcinogenicity from long-term inhalation exposure to ethylene oxide. Now final, this assessment updates the carcinogenicity information in EPA’s 1985 Hea...

  16. Management plan for the Aleutian shield fern on Adak Island, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The endangered Aleutian shield fern, Polystichum aleuticum is known from only two locations, Atka and Adak islands in the Aleutian Islands, Alaska (Lipkin 1985),...

  17. New combinations of the fern genus Tectaria (Tectariaceae) for the Flora of China.

    OpenAIRE

    Christenhusz, Maarten

    2010-01-01

    For studies on the fern family Tectariaceae for the Flora of China, four species previously treated as Ctenitopsis need new combinations in Tectaria. The new combinations are proposed here and information on their types is provided.

  18. Mobile Acoustical Bat Monitoring Annual Summary Report CY 2014 and 2015 - Fern Cave National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These reports summarize bat calls collected along transects at Fern Cave NWR between 2014 and 2015. Calls were classified using Bat Call ID ([BCID] version 2.5a)...

  19. Mobile Acoustical Bat Monitoring Annual Summary Report CY 2012-2013 - Fern Cave National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes bat calls collected along transects at Fern Cave NWR in 2012 and 2013. Calls were classified using Bat Call ID ([BCID] version 2.5a) software...

  20. Mobile Acoustical Bat Monitoring Summary Report 2012 - Fern Cave National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes bat calls collected along transects at Fern Cave NWR in 2012. Calls were classified using EchoClass(v1.1) software, but classification of...

  1. Using a Microscale Approach to Rapidly Separate and Characterize Three Photosynthetic Pigment Species from Fern

    Science.gov (United States)

    Ayudhya, Theppawut Israsena Na; Posey, Frederick T.; Tyus, Jessica C.; Dingra, Nin N.

    2015-01-01

    A rapid separation of three photosynthetic pigments (chlorophyll "a" and "b" and xanthophyll) from fern ("Polystichum acrostichoides") is described using microscale solvent extraction and traditional thin layer chromatography that minimizes use of harmful chemicals and lengthy procedures. The experiment introduces…

  2. Stable detection of expanded target by the use of boosting random ferns

    Science.gov (United States)

    Deng, Li; Wang, Chunhong; Rao, Changhui

    2012-10-01

    This paper studies the problem of keypoints recognition of extended target which lacks of texture information, and introduces an approach of stable detection of these targets called boosting random ferns (BRF). As common descriptors in this circumstance do not work as well as usual cases, matching of keypoints is hence turned into classification task so as to make use of the trainable characteristic of classifier. The kernel of BRF is consisted of random ferns as the classifier and AdaBoost (Adaptive Boosting) as the frame so that accuracy of random ferns classifier can be boosted to a relatively high level. Experiments compare BRF with widely used SURF descriptor and single random ferns classifier. The result shows that BRF obtains higher recognition rate of keypoints. Besides, for image sequence, BRF provides stronger stability than SURF in target detection, which proves the efficiency of BRF aiming to extended target which lacks of texture information.

  3. TWO ALKYLATED FLAVONOID ISOLATED FROM THE STEM OF THE FERN Chingia sakayensis (Zeiller Holtt

    Directory of Open Access Journals (Sweden)

    Suyatno Suyatno

    2010-06-01

    Full Text Available Two known alkylated flavonoid namely matteucinol dan matteucinol-7-O-b-D-glucoside was isolated for the first time from the fern Chingia sakayensis (Zeiller Holtt's stem. Their structures were elucidated on the basis of spectroscopic evidence and by comparation with those reported data in literature.   Keywords: Fern, Chingia sakayensis, stem, alkylated flavonoid, matteucinol, matteucinol-7-O-b-D-glucoside

  4. Transcriptome-mining for single-copy nuclear markers in ferns.

    Directory of Open Access Journals (Sweden)

    Carl J Rothfels

    Full Text Available BACKGROUND: Molecular phylogenetic investigations have revolutionized our understanding of the evolutionary history of ferns-the second-most species-rich major group of vascular plants, and the sister clade to seed plants. The general absence of genomic resources available for this important group of plants, however, has resulted in the strong dependence of these studies on plastid data; nuclear or mitochondrial data have been rarely used. In this study, we utilize transcriptome data to design primers for nuclear markers for use in studies of fern evolutionary biology, and demonstrate the utility of these markers across the largest order of ferns, the Polypodiales. PRINCIPAL FINDINGS: We present 20 novel single-copy nuclear regions, across 10 distinct protein-coding genes: ApPEFP_C, cryptochrome 2, cryptochrome 4, DET1, gapCpSh, IBR3, pgiC, SQD1, TPLATE, and transducin. These loci, individually and in combination, show strong resolving power across the Polypodiales phylogeny, and are readily amplified and sequenced from our genomic DNA test set (from 15 diploid Polypodiales species. For each region, we also present transcriptome alignments of the focal locus and related paralogs-curated broadly across ferns-that will allow researchers to develop their own primer sets for fern taxa outside of the Polypodiales. Analyses of sequence data generated from our genomic DNA test set reveal strong effects of partitioning schemes on support levels and, to a much lesser extent, on topology. A model partitioned by codon position is strongly favored, and analyses of the combined data yield a Polypodiales phylogeny that is well-supported and consistent with earlier studies of this group. CONCLUSIONS: The 20 single-copy regions presented here more than triple the single-copy nuclear regions available for use in ferns. They provide a much-needed opportunity to assess plastid-derived hypotheses of relationships within the ferns, and increase our capacity to

  5. The microsoroid ferns: Inferring the relationships of a highly diverse lineage of Paleotropical epiphytic ferns (Polypodiaceae, Polypodiopsida).

    Science.gov (United States)

    Kreier, Hans-Peter; Zhang, Xian-Chun; Muth, Heiko; Schneider, Harald

    2008-09-01

    The relationships of the microsoroid ferns were studied using a DNA sequence-based phylogenetic approach. Nucleotide sequences for up to four chloroplast genome regions were assembled for 107 samples from 87 species. Microsoroids s.l. include six lineages of which two are species rich. The results indicate that several genera are not monophyletic (e.g. Microsorum), several controversial genera are confirmed to be monophyletic (e.g. Leptochilus), and some genera new to science should be recognized (M. membranaceum clade). Unique insights were gained into the biogeographic history of this highly diverse epiphytic vascular plant lineage that is widespread in continental Asia to Australasia. Evidence was found for splits into lineages diversifying in parallel in continental Asia and Malesia. No evidence was recovered for an African radiation because all African microsoroid species either also are found in Asia or have sister species in continental Asia. In contrast, evidence for independent radiations were discovered for the Australasian region.

  6. Stable transformation of ferns using spores as targets: Pteris vittata and Ceratopteris thalictroides.

    Science.gov (United States)

    Muthukumar, Balasubramaniam; Joyce, Blake L; Elless, Mark P; Stewart, C Neal

    2013-10-01

    Ferns (Pteridophyta) are very important members of the plant kingdom that lag behind other taxa with regards to our understanding of their genetics, genomics, and molecular biology. We report here, to our knowledge, the first instance of stable transformation of fern with recovery of transgenic sporophytes. Spores of the arsenic hyperaccumulating fern Pteris vittata and tetraploid 'C-fern Express' (Ceratopteris thalictroides) were stably transformed by Agrobacterium tumefaciens with constructs containing the P. vittata actin promoter driving a GUSPlus reporter gene. Reporter gene expression assays were performed on multiple tissues and growth stages of gametophytes and sporophytes. Southern-blot analysis confirmed stable transgene integration in recovered sporophytes and also confirmed that no plasmid from A. tumefaciens was present in the sporophyte tissues. We recovered seven independent transformants of P. vittata and four independent C. thalictroides transgenics. Inheritance analyses using β-glucuronidase (GUS) histochemical staining revealed that the GUS transgene was stably expressed in second generation C. thalictroides sporophytic tissues. In an independent experiment, the gusA gene that was driven by the 2× Cauliflower mosaic virus 35S promoter was bombarded into P. vittata spores using biolistics, in which putatively stable transgenic gametophytes were recovered. Transformation procedures required no tissue culture or selectable marker genes. However, we did attempt to use hygromycin selection, which was ineffective for recovering transgenic ferns. This simple stable transformation method should help facilitate functional genomics studies in ferns.

  7. On the widespread capacity for, and functional significance of, extreme inbreeding in ferns.

    Science.gov (United States)

    Sessa, Emily B; Testo, Weston L; Watkins, James E

    2016-08-01

    Homosporous vascular plants utilize three different mating systems, one of which, gametophytic selfing, is an extreme form of inbreeding only possible in homosporous groups. This mating system results in complete homozygosity in all progeny and has important evolutionary and ecological implications. Ferns are the largest group of homosporous land plants, and the significance of extreme inbreeding for fern evolution has been a subject of debate for decades. We cultured gametophytes in the laboratory and quantified the relative frequencies of sporophyte production from isolated and paired gametophytes, and examined associations between breeding systems and several ecological and evolutionary traits. The majority of fern species studied show a capacity for gametophytic selfing, producing sporophytes from both isolated and paired gametophytes. While we did not follow sporophytes to maturity to investigate potential detrimental effects of homozygosity at later developmental stages, our results suggest that gametophytic selfing may have greater significance for fern evolution and diversification than has previously been realized. We present evidence from the largest study of mating behavior in ferns to date that the capacity for extreme inbreeding is prevalent in this lineage, and we discuss its implications and relevance and make recommendations for future studies of fern mating systems.

  8. Mycorrhizae increase arsenic uptake by the hyperaccumulator Chinese brake fern (Pteris vittata L.).

    Science.gov (United States)

    Al Agely, Abid; Sylvia, David M; Ma, Lena Q

    2005-01-01

    Chinese brake fern (Pteris vittata L.) is a hyperaccumulator of arsenic (As) that grows naturally on soils in the southern United States. It is reasonable to expect that mycorrhizal symbiosis may be involved in As uptake by this fern. This is because arbuscular mycorrhizal (AM) fungi have a well-documented role in increasing plant phosphorus (P) uptake, P and As have similar chemical properties, and ferns are known to be colonized by AM fungi. We conducted a factorial greenhouse experiment with three levels of As (0, 50, and 100 mg kg(-1)) and P (0, 25, and 50 mg kg(-1)) and with and without Chinese brake fern colonized by a community of AM fungi from an As-contaminated site. We found that the AM fungi not only tolerated As amendment, but their presence increased frond dry mass at the highest As application rate. Furthermore, the AM fungi increased As uptake across a range of P levels, while P uptake was generally increased only when there was no As amendment. These data indicate that AM fungi have an important role in arsenic accumulation by Chinese brake fern. Therefore, to effectively phytoremediate As-contaminated soils, the mycorrhizal status of ferns needs to be taken into account.

  9. RADON AND CARCINOGENIC RISK IN MOSCOW

    Directory of Open Access Journals (Sweden)

    S. M. Golovanev

    2015-01-01

    Full Text Available Objective: comparative evaluation of carcinogenic risk inMoscowfrom radon in indoor and atmospheric pollutants.Materials and methods: the lung cancer incidence in Moscow; radiation-hygienic passport of the territory; .U.S. EPA estimated average age at all and radon induced deaths, years of life lost; Report of UNSCEAR 2006 and WHO handbook on indoor radon, 2009. Trend analysis of incidence; evaluation of the excess relative risk; assessment of ratio radon-induced population risk and published values оf total population carcinogenic risk from chemical carcinogens.Results: it is shown that the 304 cases of lung cancer per year (1. 85 10-3 on average from 2006 to 2011 (21280diseases for 70 years in addition to background level induced by radon; the differences in average trends of all lungcancer incidence in the districts can exceed 25%.Conclusion. The potential of risk reduction by measures of mitigation radon concentration exceeds 5 times the cost efficiency to reduce emissions from vehicles and can reduce cancer incidence, on average 236 cases per year; population risk 16520 cases over 70 years or save not less than 2832 person-years of life per year. The annual effect of reducing losses from not-survival of 12 years as a result of radon-induced lung cancer deaths exceeds 14160000 dollars. The evaluating of the carcinogenic risk from radon in accordance with the definition of population risk increases the predictive evaluation of the effectiveness of preventive measures more than twice.

  10. [Carcinogenic activity of the pesticide propoxur].

    Science.gov (United States)

    Pylev, L N; Vasil'eva, L A; Smirnova, O V; Khrustalev, S A; Trukhina, G M

    2010-01-01

    Wistar rats were fed propoxur in their diet at 0, 500, 3000, and 8000 ppm during throughout their life. The number of tumors was equal in the control and experimental groups. These were hemoblastoses and breast and uterine tumors. All tumors occurred spontaneously in the rats. A few experimental animals were found to have bladder epithelial hyperplasia that might be pretumorous; however, no bladder tumors were detected. It is concluded that the investigations revealed no carcinogenic activity of propoxur.

  11. Report on carcinogens monograph on 1-bromopropane.

    Science.gov (United States)

    2013-09-01

    The National Toxicology Program conducted a cancer evaluation on 1 bromopropane for possible listing in the Report on Carcinogens (RoC). The cancer evaluation is captured in the RoC monograph, which was peer reviewed in a public forum. The monograph consists of two components: (Part 1) the cancer evaluation, which reviews the relevant scientific information, assesses its quality, applies the RoC listing criteria to the scientific information, and provides the NTP recommendation for listing status for 1 bromopropane in the RoC, and (Part 2) the substance profile proposed for the RoC, containing the NTP's listing status recommendation, a summary of the scientific evidence considered key to reaching that decision, and data on properties, use, production, exposure, and Federal regulations and guidelines to reduce exposure to 1-bromopropane. This monograph provides an assessment of the available scientific information on 1 bromopropane, including human exposure and properties, disposition and toxicokinetics, cancer studies in experimental animals, and studies of mechanisms and other related effects, including relevant toxicological effects, genetic toxicology, and mechanisms of carcinogenicity. From this assessment, the NTP recommended that 1 bromopropane be listed as reasonably anticipated to be a human carcinogen in the RoC based on sufficient evidence from studies in experimental animals, which found inhalation exposure to 1-bromopropane caused skin tumors in male rats, large intestine tumors in female and male rats, and lung tumors in female mice. Also noted was that 1 bromopropane, either directly or via reactive metabolites, caused molecular alterations that typically are associated with carcinogenesis, including genotoxicity, oxidative stress, and glutathione depletion. These alterations, observed in mainly in vitro and toxicity studies in rodents, are relevant to possible mechanisms of human carcinogenicity and support the relevance of the cancer studies in

  12. Cobalt and antimony: genotoxicity and carcinogenicity.

    Science.gov (United States)

    De Boeck, Marlies; Kirsch-Volders, Micheline; Lison, Dominique

    2003-12-10

    The purpose of this review is to summarise the data concerning genotoxicity and carcinogenicity of Co and Sb. Both metals have multiple industrial and/or therapeutical applications, depending on the considered species. Cobalt is used for the production of alloys and hard metal (cemented carbide), diamond polishing, drying agents, pigments and catalysts. Occupational exposure to cobalt may result in adverse health effects in different organs or tissues. Antimony trioxide is primarily used as a flame retardant in rubber, plastics, pigments, adhesives, textiles, and paper. Antimony potassium tartrate has been used worldwide as an anti-shistosomal drug. Pentavalent antimony compounds have been used for the treatment of leishmaniasis. Co(II) ions are genotoxic in vitro and in vivo, and carcinogenic in rodents. Co metal is genotoxic in vitro. Hard metal dust, of which occupational exposure is linked to an increased lung cancer risk, is proven to be genotoxic in vitro and in vivo. Possibly, production of active oxygen species and/or DNA repair inhibition are mechanisms involved. Given the recently provided proof for in vitro and in vivo genotoxic potential of hard metal dust, the mechanistic evidence of elevated production of active oxygen species and the epidemiological data on increased cancer risk, it may be advisable to consider the possibility of a new evaluation by IARC. Both trivalent and pentavalent antimony compounds are generally negative in non-mammalian genotoxicity tests, while mammalian test systems usually give positive results for Sb(III) and negative results for Sb(V) compounds. Assessment of the in vivo potential of Sb2O3 to induce chromosome aberrations (CA) gave conflicting results. Animal carcinogenicity data were concluded sufficient for Sb2O3 by IARC. Human carcinogenicity data is difficult to evaluate given the frequent co-exposure to arsenic. Possible mechanisms of action, including potential to produce active oxygen species and to interfere with

  13. Genotoxicity and carcinogenicity risk of carbon nanotubes.

    Science.gov (United States)

    Toyokuni, Shinya

    2013-12-01

    Novel materials are often commercialized without a complete assessment of the risks they pose to human health because such assessments are costly and time-consuming; additionally, sometimes the methodology needed for such an assessment does not exist. Carbon nanotubes have the potential for widespread application in engineering, materials science and medicine. However, due to the needle-like shape and high durability of multiwalled carbon nanotubes (MWCNTs), concerns have been raised that they may induce asbestos-like pathogenicity when inhaled. Indeed, experiments in rodents supported this hypothesis. Notably, the genetic alterations in MWCNT-induced rat malignant mesothelioma were similar to those induced by asbestos. Single-walled CNTs (SWCNTs) cause mitotic disturbances in cultured cells, but thus far, there has been no report that SWCNTs are carcinogenic. This review summarizes the recent noteworthy publications on the genotoxicity and carcinogenicity of CNTs and explains the possible molecular mechanisms responsible for this carcinogenicity. The nanoscale size and needle-like rigid structure of CNTs appear to be associated with their pathogenicity in mammalian cells, where carbon atoms are major components in the backbone of many biomolecules. Publishing adverse events associated with novel materials is critically important for alerting people exposed to such materials. CNTs still have a bright future with superb economic and medical merits. However, appropriate regulation of the production, distribution and secondary manufacturing processes is required, at least to protect the workers.

  14. The evolving definition of carcinogenic human papillomavirus

    Directory of Open Access Journals (Sweden)

    Castle Philip E

    2009-05-01

    Full Text Available Abstract Thirteen human papillomavirus (HPV genotypes have been judged to be carcinogenic or probably carcinogenic, and the cause of virtually all cervical cancer worldwide. Other HPV genotypes could possibly be involved. Although the inclusion of possibly carcinogenic HPV genotypes may hurt test specificity, it may indirectly increase the reassurance following a negative HPV test (i.e. the negative predictive value of an HPV test for cervical precancer and cancer. The future of cervical cancer screening in low-resource setting, however, may include once-in-a-lifetime, low-cost and rapid HPV testing. However, the tradeoff of more false positives for greater reassurance may not be acceptable if the local infrastructure cannot manage the screen positives. Now is the time for the community of scientists, doctors, and public health advocates to use the data presented at the 100th International Agency for Research on Cancer monograph meeting to rationally decide the target HPV genotypes for the next generation of HPV tests for use in high-resource and low-resource settings. The implications of including possibly HPV genotypes on HPV test performance, also for guidance on the use of these tests for cervical cancer prevention programs, are discussed.

  15. Mutagenicity, carcinogenicity, and teratogenicity of acrylonitrile.

    Science.gov (United States)

    Léonard, A; Gerber, G B; Stecca, C; Rueff, J; Borba, H; Farmer, P B; Sram, R J; Czeizel, A E; Kalina, I

    1999-05-01

    Acrylonitrile (AN) is an important intermediary for the synthesis of a variety of organic products, such as artificial fibres, household articles and resins. Although acute effects are the primary concern for an exposure to AN, potential genotoxic, carcinogenic and teratogenic risks of AN have to be taken seriously in view of the large number of workers employed in such industries and the world-wide population using products containing and possibly liberating AN. An understanding of the effect of acrylonitrile must be based on a characterization of its metabolism as well as of the resulting products and their genotoxic properties. Tests for mutagenicity in bacteria have in general been positive, those in plants and on unscheduled DNA synthesis doubtful, and those on chromosome aberrations in vivo negative. Wherever positive results had been obtained, metabolic activation of AN appeared to be a prerequisite. The extent to which such mutagenic effects are significant in man depends, however, also on the conditions of exposure. It appears from the limited data that the ultimate mutagenic factor(s), such as 2-cyanoethylene oxide, may have little opportunity to act under conditions where people are exposed because it is formed only in small amounts and is rapidly degraded. The carcinogenic action of AN has been evaluated by various agencies and ranged from 'reasonably be anticipated to be a human carcinogen' to 'cannot be excluded', the most recent evaluation being 'possibly carcinogenic to humans'. Animal data that confirm the carcinogenic potential of AN have certain limitations with respect to the choice of species, type of tumors and length of follow up. Epidemiological studies which sometimes, but not always, yielded positive results, encounter the usual difficulties of confounding factors in chemical industries. Exposure of workers to AN should continue to be carefully monitored, but AN would not have to be considered a cancer risk to the population provided

  16. Terrestrial Invertebrate Arsenic Accumulation Associated With an Arsenic Hyperaccumulating Fern, Pteris vittata (Polypodiales: Pteridaceae).

    Science.gov (United States)

    Jaffe, B D; Ketterer, M E; Hofstetter, R W

    2016-10-01

    Arsenic (As) can play an important role in the contamination of soils, waters, and air. The toxicity of As to most organisms is well established, but little is known about the interactions between environmental As and terrestrial invertebrates and the fate of As through trophic levels. Pteris vittata L. (Polypodiales: Pteridaceae), a fern that hyperaccumulates arsenic, serves as a potential mechanism to facilitate interactions between environmental arsenic and other biota. We compared invertebrate arsenic concentrations (hereafter as [As]) and bioaccumulation factors associated with soil and fern [As] to elucidate relationships between invertebrate and environmental As exposure. We collected invertebrates in pitfall traps from field sites associated with P. vittata, and identified them to order for whole body arsenic analysis and subsequently family for classification into functional feeding groups. We found that overall [As] in invertebrates increased with soil [As], but not with fern [As]. The absence of a relationship between fern [As] and invertebrate [As] may indicate invertebrates are avoiding the fern. Individual taxonomic groups significantly differed in whole body [As], and individual taxa also varied in their relationship between whole body [As] relative to soil and fern [As]. Overall invertebrate abundance decreased as invertebrate [As] load increased but varied across taxa. One particular herbivore, Callopistria floridensis (Florida fern caterpillar), associated with relatively low environmental As exposure contained over 4,000 mg kg(-1) As. Our results show that As bioaccumulates into higher trophic levels and invertebrate body [As] covary with exposure to naturally occurring environmental [As] associated with P. vittata. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. Phylogenetic Relationships of the Fern Cyrtomium falcatum (Dryopteridaceae) from Dokdo Island Based on Chloroplast Genome Sequencing.

    Science.gov (United States)

    Raman, Gurusamy; Choi, Kyoung Su; Park, SeonJoo

    2016-12-02

    Cyrtomium falcatum is a popular ornamental fern cultivated worldwide. Native to the Korean Peninsula, Japan, and Dokdo Island in the Sea of Japan, it is the only fern present on Dokdo Island. We isolated and characterized the chloroplast (cp) genome of C. falcatum, and compared it with those of closely related species. The genes trnV-GAC and trnV-GAU were found to be present within the cp genome of C. falcatum, whereas trnP-GGG and rpl21 were lacking. Moreover, cp genomes of Cyrtomium devexiscapulae and Adiantum capillus-veneris lack trnP-GGG and rpl21, suggesting these are not conserved among angiosperm cp genomes. The deletion of trnR-UCG, trnR-CCG, and trnSeC in the cp genomes of C. falcatum and other eupolypod ferns indicates these genes are restricted to tree ferns, non-core leptosporangiates, and basal ferns. The C. falcatum cp genome also encoded ndhF and rps7, with GUG start codons that were only conserved in polypod ferns, and it shares two significant inversions with other ferns, including a minor inversion of the trnD-GUC region and an approximate 3 kb inversion of the trnG-trnT region. Phylogenetic analyses showed that Equisetum was found to be a sister clade to Psilotales-Ophioglossales with a 100% bootstrap (BS) value. The sister relationship between Pteridaceae and eupolypods was also strongly supported by a 100% BS, but Bayesian molecular clock analyses suggested that C. falcatum diversified in the mid-Paleogene period (45.15 ± 4.93 million years ago) and might have moved from Eurasia to Dokdo Island.

  18. Survival and growth of epiphytic ferns depend on resource sharing

    Directory of Open Access Journals (Sweden)

    Hua-Zheng eLu

    2016-03-01

    Full Text Available Locally available resources can be shared within clonal plant systems through physiological integration, thus enhancing their survival and growth. Most epiphytes exhibit clonal growth habit, but few studies have tested effects of physiological integration (resource sharing on survival and growth of epiphytes and whether such effects vary with species. We conducted two experiments, one on individuals (single ramets and another on groups (several ramets within a plot, with severed and intact rhizome treatments (without and with physiological integration on two dominant epiphytic ferns (Polypodiodes subamoena and Lepisorus scolopendrium in a subtropical montane moist forest in Southwest China. Rhizome severing (preventing integration significantly reduced ramet survival in the individual experiment and number of surviving ramets in the group experiment, and it also decreased biomass of both species in both experiments. However, the magnitude of such integration effects did not vary significantly between the two species. We conclude that resource sharing may be a general strategy for clonal epiphytes to adapt to forest canopies where resources are limited and heterogeneously distributed in space and time.

  19. Herschel und die Zukunft der Fern-Infrarot-Astronomie

    Science.gov (United States)

    Linz, Hendrik

    2015-06-01

    Schon lange ist die beobachtende Astronomie den engen Grenzen des optisch Sichbaren entwachsen und hat fast alle Bereiche des elektromagnetischen Spektrums für sich dienstbar gemacht. Im sogenannten nahen und mittleren Infrarot (Wellenlängen zwischen 1-30 μm) sowie im Millimeter- und Radio-Regime (Wellenlängen zwischen 1 mm und 10 m) ist die Erdatmosphäre relativ gut durchlässig für elektromagnetische Signale oder hat zumindest eine Vielzahl von spektral begrenzten Transmissionsfenstern, die astronomische Beobachtungen zumindest von höheren Bergen aus möglich machen. Allerdings ist das sogenannte Ferne Infrarot (FIR, 30-300 μm Wellenlänge) von der Erde aus fast völlig unzugänglich für astronomische Beobachtungen. Selbst für die besten Beobachtungsplätze der Erde bleibt die atmosphärische Transmission durch die immense Wasserdampf- Absorption auf ein absolutes Minimum beschränkt. Jedoch erlaubt uns das FIR Zugang zu Informationen, die sehr nützlich sind für die astrophysikalische Forschung und komplementär zu anderen Wellenlängen-Bereichen.

  20. On the infinite fern of Galois representations of unitary type

    CERN Document Server

    Chenevier, Gaetan

    2009-01-01

    Let E be a CM number field, F its maximal totally real subfield, c the generator of Gal(E/F), p an odd prime totally split in E, and S a finite set of places of E containing the places above p. Let r : G_{E,S} --> GL_3(F_p^bar) be a modular, absolutely irreducible, Galois representation of type U(3), i.e. such that r^* = r^c, and let X(r) be the rigid analytic generic fiber of its universal G_{E,S}-deformation of type U(3). We show that each irreducible component of the Zariski-closure of the modular points in X(r) has dimension at least 6[F:Q]. We study an analogue of the infinite fern of Gouvea-Mazur in this context and deal with the Hilbert modular case as well. As important steps, we prove that any first order deformation of a generic enough crystalline representation of Gal(Q_p^bar/Q_p) (of any dimension) is a linear combination of trianguline deformations, and that unitary eigenvarieties (of any rank) are etale over the weight space at the non-critical classical points. As another application, we obtain...

  1. Essential Oil Constituents and Antioxidant Activity of Asplenium Ferns.

    Science.gov (United States)

    Hammami, Saoussen; Snène, Ali; El Mokni, Ridha; Faidi, Khaled; Falconieri, Danilo; Dhaouadi, Hatem; Piras, Alessandra; Mighri, Zine; Porcedda, Silvia

    2016-09-01

    Two fern species Asplenium adiantum-nigrum L. and Asplenium trichomanes L. collected from the Kroumiria region (Northwest of Tunisia) were individually submitted to hydrodistillation in a Clevenger type apparatus. Volatile organic compounds were identified by GC-MS and GC-FID. Thus, 35 compounds were identified in A. adiantum-nigrum essential oil accounting for 77.5% of the whole constituents dominated by palmitic acid (34.5%); however, only 29 volatiles were identified in A. trichomanes showing a high amount of phytol, an odorous diterpene alcohol, representing 14.4% of the total oil contents. The total phenolic content and the antioxidant effects of crude extracts from both pteridophytes were determined using Folin-Ciocalteu and 2,2'-diphenyl-1-picrylhydrazyl free radical-scavenging assays, respectively. A. adiantum-nigrum ethyl acetate extract is shown to be lower in total phenolic contents (49.3 mg gallic acid equivalent/g) than similar extract from A. trichomanes (55.4 mg GAE/g).

  2. Survival and Growth of Epiphytic Ferns Depend on Resource Sharing.

    Science.gov (United States)

    Lu, Hua-Zheng; Song, Liang; Liu, Wen-Yao; Xu, Xing-Liang; Hu, Yue-Hua; Shi, Xian-Meng; Li, Su; Ma, Wen-Zhang; Chang, Yan-Fen; Fan, Ze-Xin; Lu, Shu-Gang; Wu, Yi; Yu, Fei-Hai

    2016-01-01

    Locally available resources can be shared within clonal plant systems through physiological integration, thus enhancing their survival and growth. Most epiphytes exhibit clonal growth habit, but few studies have tested effects of physiological integration (resource sharing) on survival and growth of epiphytes and whether such effects vary with species. We conducted two experiments, one on individuals (single ramets) and another on groups (several ramets within a plot), with severed and intact rhizome treatments (without and with physiological integration) on two dominant epiphytic ferns (Polypodiodes subamoena and Lepisorus scolopendrium) in a subtropical montane moist forest in Southwest China. Rhizome severing (preventing integration) significantly reduced ramet survival in the individual experiment and number of surviving ramets in the group experiment, and it also decreased biomass of both species in both experiments. However, the magnitude of such integration effects did not vary significantly between the two species. We conclude that resource sharing may be a general strategy for clonal epiphytes to adapt to forest canopies where resources are limited and heterogeneously distributed in space and time.

  3. Effects of nickel on the fern Regnellidium diphyllum Lindm. (Marsileaceae

    Directory of Open Access Journals (Sweden)

    MA. Kieling-Rubio

    Full Text Available The heterosporous fern Regnellidium diphyllum occurs in southern Brazil and some adjoining localities in Uruguay and Argentina. Currently it is on the list of threatened species in the state of Rio Grande do Sul. Anthropic alterations such as the conversion of wetlands into agricultural areas or water and soil contamination by pollutants may compromise the establishment and survival of this species. Nickel (Ni is an essential nutrient for plants but increasing levels of this metal due to pollution can cause deleterious effects especially in aquatic macrophytes. Megaspore germination tests were performed using Meyer's solution, at concentrations of 0 (control, 0.05, 0.5, 1, 5, 10, 20, 30, 50 and 100 mg L-1 of Ni. The initial development of apomictic sporophytes was studied using solutions containing 0 (control to 4.8 mg L-1 of Ni. A significant negative relation was observed between the different Ni concentrations and the megaspore germination/sporophyte formation rates. Primary roots, primary leaves and secondary leaves were significantly shorter at 3.2 and 4.8 mg L-1 of Ni, when compared with the treatment without this metal. At 4.8 mg L-1, leaves also presented chlorosis and necrosis. The introduction of pollutants with Ni in the natural habitat of Regnellidium diphyllum may inhibit the establishment of plants in the initial stage of development, a problem to be considered in relation to the conservation of this species.

  4. Arsenic in the rhizosphere soil solution of ferns.

    Science.gov (United States)

    Wei, Chaoyang; Zheng, Huan; Yu, Jiangping

    2012-12-01

    The aim of this study was to explore the evidence of arsenic hyperaccumulation in plant rhizosphere solutions. Six common fern plants were selected and grown in three types of substrate: arsenic (As) -tailings, As-spiked soil, and soil-As-tailing composites. A rhizobox was designed with an in-situ collection of soil solutions to analyze changes in the As concentration and valence as well as the pH, dissolved organic carbon (DOC) and total nitrogen (TN). Arsenite composed less than 20% of the total As, and As depletion was consistent with N depletion in the rhizosphere solutions of the various treatments. The As concentrations in the rhizosphere and non-rhizosphere solutions in the presence of plants were lower than in the respective controls without plants, except for in the As-spiked soils. The DOC concentrations were invariably higher in the rhizosphere versus non-rhizosphere solutions from the various plants; however, no significant increase in the DOC content was observed in Pteris vittata, in which only a slight decrease in pH appeared in the rhizosphere compared to non-rhizosphere solutions. The results showed that As reduction by plant roots was limited, acidification-induced solubilization was not the mechanism for As hyperaccumulation.

  5. Report on carcinogens monograph on cumene.

    Science.gov (United States)

    2013-09-01

    The National Toxicology Program conducted a cancer evaluation on cumene for possible listing in the Report on Carcinogens (RoC). The cancer evaluation is captured in the RoC monograph, which was peer reviewed in a public forum. The monograph consists of two components: (Part 1) the cancer evaluation, which reviews the relevant scientific information, assesses its quality, applies the RoC listing criteria to the scientific information, and provides the NTP recommendation for listing status for cumene in the RoC, and (Part 2) the substance profile proposed for the RoC, containing the NTP's listing status recommendation, a summary of the scientific evidence considered key to reaching that decision, and data on properties, use, production, exposure, and Federal regulations and guidelines to reduce exposure to cumene. This monograph provides an assessment of the available scientific information on cumene, including human exposure and properties, disposition and toxicokinetics, cancer studies in experimental animals, and studies of mechanisms and other related effects, including relevant toxicological effects, genetic toxicology, and mechanisms of carcinogenicity. From this assessment, the NTP recommended that cumene be listed as reasonably anticipated to be a human carcinogen in the RoC based on sufficient evidence from studies in experimental animals, which found that cumene exposure caused lung tumors in male and female mice and liver tumors in female mice. Several proposed mechanisms of carcinogenesis support the relevance to humans of the lung and liver tumors observed in experimental animals. Specifically, there is evidence that humans and experimental animals metabolize cumene through similar metabolic pathways. In addition, mutations of the K-ras oncogene and p53 tumor-suppressor gene observed in cumene-induced lung tumors in mice, along with altered expression of many other genes, resemble molecular alterations found in human lung and other cancers.

  6. Fern-associated arbuscular mycorrhizal fungi are represented by multiple Glomus spp.: do environmental factors influence partner identity?

    Science.gov (United States)

    West, Brittany; Brandt, Jessica; Holstien, Kay; Hill, April; Hill, Malcolm

    2009-06-01

    Symbioses involving arbuscular mycorrhizal fungi (AMF) are among the most important ecological associations for many plant species. The diversity of AMF associated with ferns, however, remains poorly studied. Using recently designed Glomus-specific primers, we surveyed the AMF community associated with ferns from deciduous, broad-leaved second-growth forest habitats at the eastern edge of the piedmont region of central Virginia, USA. Results indicate that this molecular approach may be a useful tool for detecting AMF in ferns compared to traditional techniques based on morphology. Over 30 potential fungal ribotypes were identified from eight fern species using denaturing gradient gel electrophoresis. Fungal ribotypes were found to differ widely in terms of (1) the number of fern partners with which they interact and (2) their relative frequency within each fern. Sequence analysis of fungal isolates from three species of fern indicated that the primers were generally highly specific for Glomus species but some non-target DNA was also amplified. Cloned polymerase chain reaction (PCR) products from Polystichum acrostichoides and Osmunda regalis revealed several phylogenetically distinct Glomus species. A single Glomus species was identified in the cloned PCR products from Botrychium virginianum. These findings challenge the hypothesis that the extent or degree of fern-fungal symbiosis is somehow tied to root complexity. Environmental factors appear to influence the suite of AMF that form partnerships with ferns. Some species of fern from similar habitats associated with dissimilar fungal partners (e.g., P. acrostichoides and Athyrium filix-femina var. asplenioides), whereas others harbored uniform fungal communities (e.g., Asplenium platyneuron). The significance of these data in terms of ecological and evolutionary dynamics of the AMF-fern symbiosis is discussed.

  7. Restoring Native Forest Understory: The Influence of Ferns and Light in a Hawaiian Experiment

    Directory of Open Access Journals (Sweden)

    Robert Shallenberger

    2013-03-01

    Full Text Available Ecological restoration is an increasingly important component of sustainable land management. We explore potential facilitative relationships for enhancing the cost-effectiveness of restoring native forest understory, focusing on two factors: (1 overstory shade and (2 possible facilitation by a fern (Dryopteris wallichiana, one of few native colonists of pasture in our montane Hawaiˈi study system. We planted 720 understory tree seedlings and over 4000 seeds of six species under six planting treatments: a full factorial combination of low, medium and high light, situating plantings in either the presence or absence of a mature fern. After three years, 75% of outplanted seedlings survived. Seedling survivorship was significantly higher in the presence of a fern (79% vs. 71% without a fern and in medium and low light conditions (81% vs. 64% in high light. Relative height was highest at low to medium light levels. After 2.2 years, 2.8% of the planted seeds germinated. We observed no significant differences in seed germination relative to light level or fern presence. Analyzing several approaches, we found nursery germination of seeds followed by outplanting ca. 20% less costly than direct seeding in the field. This study opens new questions about facilitation mechanisms that have the potential to increase the extent and effectiveness of restoration efforts.

  8. Edge effects on fern community in an Atlantic Forest remnant of Rio Formoso, PE, Brazil.

    Science.gov (United States)

    Silva, I A A; Pereira, A F N; Barros, I C L

    2011-05-01

    We have investigated how edge effects influence the fern community of Jaguarão Forest (08º 35' 49" S and 35º 15' 39" W), located in the district of Rio Formoso, Pernambuco, Brazil. A comparative analysis was made of the interior and edge of the fragment of forest, regarding the richness, abundance and diversity of ferns in the two areas. Six plots of 10 × 20 m were chosen, three in each area. A total of 381 ferns were recorded, which were distributed among 25 species, 17 genera and 12 families. The two areas (edge and interior) were found to differ, with distinct relative air humidities and temperatures (p = 0.00254 and p = 0.00019, respectively). The interior showed higher diversity (t = 7.251 and p = 0.018) and richness (t = 6.379 and p = 0.023) than the edge area, but the same abundance (t = 1.728; p = 0.226) as the edge. Regarding the composition of the flora, it was clear that the interior is a habitat completely distinct from the edge with regard to the fern community, given that only one species, Adiantum petiolatum Desv., was common to both environments. It was concluded that the edge effect causes a decrease in richness and abundance of the fern species found in Jaguarão Forest, where the more sensitive species are being replaced by species that are tolerant to the disturbance caused by the creation of an edge.

  9. Chemical constituents analysis and antidiabetic activity validation of four fern species from Taiwan.

    Science.gov (United States)

    Chen, Chen-Yu; Chiu, Fu-Yu; Lin, Yenshou; Huang, Wei-Jan; Hsieh, Po-Shiuan; Hsu, Feng-Lin

    2015-01-22

    Pterosins are abundant in ferns, and pterosin A was considered a novel activator of adenosine monophosphate-activated protein kinase, which is crucial for regulating blood glucose homeostasis. However, the distribution of pterosins in different species of ferns from various places in Taiwan is currently unclear. To address this question, the distribution of pterosins, glucose-uptake efficiency, and protective effects of pterosin A on β-cells were examined. Our results showed that three novel compounds, 13-chloro-spelosin 3-O-β-d-glucopyranoside (1), (3R)-Pterosin D 3-O-β-d-(3'-p-coumaroyl)-glucopyranoside (2), and (2R,3R)-Pterosin L 3-O-β-d-(3'-p-coumaroyl)-glucopyranoside (3), were isolated for the first time from four fern species (Ceratopteris thalictroides, Hypolepis punctata, Nephrolepis multiflora, and Pteridium revolutum) along with 27 known compounds. We also examined the distribution of these pterosin compounds in the mentioned fern species (except N. multiflora). Although all pterosin analogs exhibited the same effects in glucose uptake assays, pterosin A prevented cell death and reduced reactive oxygen species (ROS) production. This paper is the first report to provide new insights into the distribution of pterosins in ferns from Taiwan. The potential anti-diabetic activity of these novel phytocompounds warrants further functional studies.

  10. Soral Crypsis: Protective Mimicry of a Coccid on an Indian Fern

    Institute of Scientific and Technical Information of China (English)

    Biplab Patra; Subir Bera; R. James Hickey

    2008-01-01

    Herbivory with crypsis is not well documented in ferns. The present record of cryptic coloration of coccid Saissetia filicum Boisduval (Homoptera: Coccidae) to the sori of a fern species Asplenium nidus L. (Aspleniaceae) is unique. Predatory beetles (Jauravia sp., Coleoptera: Coccinellidae) that feed on the coccids, are suggested to be selective pressure for the development of the present homopteran soral crypsis. A higher rate of effective predation is noticed in the vegetative leaves than the fertile leaves. Aggressive ants were found harvesting honeydew secretions from the coccids and defending the trophobionts as well as the host fern from their natural enemies. In addition, a possible three-way mutualistic relationship among the coccids, its host fern and the tending ant is suggested. Differential numbers of coccids on vegetative and fertile leaves is correlated with their phenol content and degree of predation by beetles. Such coloration mimicry by the coccids may enable them to obtain the necessary blend of sorus of the host fern needed to evade beetle detection and attack.

  11. Comparison of rat olfactory mucosal responses to carcinogenic and non-carcinogenic chloracetanilides

    Science.gov (United States)

    Genter, M.B.; Warner, B.M.; Medvedovic, M.; Sartor, M.A.

    2009-01-01

    Alachlor and butachlor are chloracetanilide herbicides that induce olfactory tumors in rats, whereas propachlor does not. The mechanism by which alachlor induces tumors is distinct from many other nasal carcinogens, in that alachlor induces a gradual de-differentiation of the olfactory mucosa (OM) to a more respiratory-like epithelium, in contrast to other agents that induce cytotoxicity, followed by an aberrant regenerative response. We studied biochemical and genomic effects of these compounds to identify processes that occur in common between alachlor- and butachlor-treated rats. Because we have previously shown that matrix metalloproteinase-2 (MMP2) is activated in OM by alachlor, in the present studies we evaluated both MMP2 activation and changes in OM gene expression in response to carcinogenic and non-carcinogenic chloracetanilide treatments. All three chloracetanilides activated MMP2, and > 300 genes were significantly up- or downregulated between control and alachlor-treated rats. The most significantly regulated gene was vomeromodulin, which was dramatically upregulated by alachlor and butachlor treatment (>60-fold), but not by propachlor treatment. Except for similar gene responses in alachlor- and butachlor-treated rats, we did not identify clear-cut differences that would predict OM carcinogenicity in this study. PMID:19425180

  12. Occurrence, uses, and carcinogenicity of arylamines.

    Science.gov (United States)

    Chung, King-Thom

    2015-01-01

    Arylamines are chemically synthesized and contained in oxidants, epoxy polymers, explosives, fungicides, pesticides, colorants, polyurethanes, and used in rubber, pharmacology, cosmetics, and other chemical industries. Many arylamines are ubiquitously present in cigarette smoke, cooking fume hoods, foods, automobile exhaust, industrial sites, etc. Some arylamines can be generated through azo reduction by intestinal, skin, and environmental microorganisms from azo dyes that are widely used. Arylamines can also be generated by reduction of the nitro-group containing polyhydrated hydrocarbons including muntions. Some arylamines are released by burning nitrogen containing organic materials at high temperatures. Some medical drugs are also arylamines. Furthermore, many arylamines are essential constituents of normal metabolism or the result of abnormal metabolism or dietary sources. Some arylamines are mutagenic, carcinogenic or the cause of other kinds of maladies. Some arylamine are considered the major etiological agents of bladder tumors in humans and animals but may also induce other types of cancers in various organs. The organ, tissue, and species specificity of the arylamine-inducing carcinogenesis may be determined by their availability, distribution, and the presence of metabolic activation/detoxicification enzymes of each organ or tissue of different species. The ubiquitous arylamines, therefore, pose serious hazards to human health and environment. This article will address the occurrence, uses, carcinogenicity, and other arylamines-induced diseases.

  13. Carcinogenicity/tumour promotion by NDL PCB

    Energy Technology Data Exchange (ETDEWEB)

    Schrenk, D. [Kaiserslautern Univ. (Germany). Food Chemistry and Environmental Toxicology

    2004-09-15

    Polychlorinated biphenyls (PCBs) belong to the group of persistent environmental pollutants exhibiting neurotoxic, teratogenic and tumour-promoting effects in experimental animal models. PCB congeners can be divided into 'dioxinlike' and 'non-dioxinlike' congeners on the basis of their ability to act as aryl hydrocarbon receptor (AhR) agonists. Like the most toxic dioxin congener 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) 'dioxinlike' PCBs bind to the AhR and show characteristic effects on the expression of AhR-regulated genes including the induction of cytochrome P450 (CYP) 1A1. On the other hand, 'non-dioxinlike' PCB congeners have a lower or no binding affinity to the AhR, but exhibit a 'phenobarbital-type' induction of CYP 2B1/2 activity. A carcinogenic potential of PCBs has been demonstrated with technical mixtures such as Aroclors or Clophens. In these studies the liver and the thyroid gland were found to be the principal target organs of PCB-mediated carcinogenesis in rodents. No studies have been published, however, on the carcinogenicity of individual congeners. In two-stage initiation-promotion protocols in rats, both technical mixtures and individual 'dioxinlike' and 'non-dioxinlike' congeners were reported to act as liver tumour promoters.

  14. Evaluation of the potential carcinogenicity of chlorambucil. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1988-06-01

    Chlorambucil is a probable human carcinogen, classified as weight-of-evidence Group B1 under the EPA Guidelines for Carcinogen Risk Assessment. Evidence on potential carcinogenicity from animal studies is Sufficient, and the evidence from human studies is Limited. Data available are inadequate for calculating a potency factor (F) and no quantitative inferences can be made according to the CAG's methodology for evaluating potential carcinogens. Chlorambucil is, therefore, assigned to the median potency factor range and placed in potency group 2. Combining the weight-of-evidence group and the potency group, chlorambucil is assigned a MEDIUM hazard ranking.

  15. Tobacco carcinogens, their biomarkers and tobacco-induced cancer.

    Science.gov (United States)

    Hecht, Stephen S

    2003-10-01

    The devastating link between tobacco products and human cancers results from a powerful alliance of two factors - nicotine and carcinogens. Without either one of these, tobacco would be just another commodity, instead of being the single greatest cause of death due to preventable cancer. Nicotine is addictive and toxic, but it is not carcinogenic. This addiction, however, causes people to use tobacco products continually, and these products contain many carcinogens. What are the mechanisms by which this deadly combination leads to 30% of cancer-related deaths in developed countries, and how can carcinogen biomarkers help to reveal these mechanisms?

  16. Arsenic bioavailability in the soil amended with leaves of arsenic hyperaccumulator, Chinese brake fern (Pteris vittata L.)

    NARCIS (Netherlands)

    Du, X.; Cui, Y.S.; Weng, L.P.; Cao, Q.; Yang Zhu, Yang

    2008-01-01

    An incubation experiment was carried out to better understand the fate of As during the decomposition of As-rich Chinese brake fern (Pteris vittata L.) leaves and to assess As bioavailability in soil. Dried fern leaves with an As concentration of 1,150 +/- 14 microg/g were amended with unpolluted so

  17. Plastome sequences of Lygodium japonicum and Marsilea crenata reveal the genome organization transformation from basal ferns to core leptosporangiates.

    Science.gov (United States)

    Gao, Lei; Wang, Bo; Wang, Zhi-Wei; Zhou, Yuan; Su, Ying-Juan; Wang, Ting

    2013-01-01

    Previous studies have shown that core leptosporangiates, the most species-rich group of extant ferns (monilophytes), have a distinct plastid genome (plastome) organization pattern from basal fern lineages. However, the details of genome structure transformation from ancestral ferns to core leptosporangiates remain unclear because of limited plastome data available. Here, we have determined the complete chloroplast genome sequences of Lygodium japonicum (Lygodiaceae), a member of schizaeoid ferns (Schizaeales), and Marsilea crenata (Marsileaceae), a representative of heterosporous ferns (Salviniales). The two species represent the sister and the basal lineages of core leptosporangiates, respectively, for which the plastome sequences are currently unavailable. Comparative genomic analysis of all sequenced fern plastomes reveals that the gene order of L. japonicum plastome occupies an intermediate position between that of basal ferns and core leptosporangiates. The two exons of the fern ndhB gene have a unique pattern of intragenic copy number variances. Specifically, the substitution rate heterogeneity between the two exons is congruent with their copy number changes, confirming the constraint role that inverted repeats may play on the substitution rate of chloroplast gene sequences.

  18. 76 FR 45649 - Notice of Final Federal Agency Actions on I-5: Fern Valley Interchange Project: Jackson County, OR

    Science.gov (United States)

    2011-07-29

    ... Federal Highway Administration Notice of Final Federal Agency Actions on I-5: Fern Valley Interchange... the meaning of 23 U.S.C. 139(l)(1). The actions relate to a proposed highway project, I-5: Fern Valley... Administration, 530 Center Street, NE., Suite 420, Salem, Oregon 97301, Telephone: (503) 316-2559. The I-5:...

  19. Arsenic bioavailability in the soil amended with leaves of arsenic hyperaccumulator, Chinese brake fern (Pteris vittata L.)

    NARCIS (Netherlands)

    Du, X.; Cui, Y.S.; Weng, L.P.; Cao, Q.; Yang Zhu, Yang

    2008-01-01

    An incubation experiment was carried out to better understand the fate of As during the decomposition of As-rich Chinese brake fern (Pteris vittata L.) leaves and to assess As bioavailability in soil. Dried fern leaves with an As concentration of 1,150 +/- 14 microg/g were amended with unpolluted

  20. Use of rbcL and trnL-F as a two-locus DNA barcode for identification of NW-European ferns: an ecological perspective

    NARCIS (Netherlands)

    Groot, de G.A.; During, H.J.; Maas, J.W.; Schneider, H.; Erkens, R.H.J.

    2011-01-01

    Although consensus has now been reached on a general two-locus DNA barcode for land plants, the selected combination of markers (rbcL + matK) is not applicable for ferns at the moment. Yet especially for ferns, DNA barcoding is potentially of great value since fern gametophytes—while playing an esse

  1. Evidence for radiations of cheilanthoid ferns in the Greater Cape Floristic Region

    DEFF Research Database (Denmark)

    Eiserhardt, Wolf L.; Rohwer, Jens G.; Russell, Stephen J.;

    2011-01-01

    adapted cheilanthoid ferns. To test this hypothesis with special emphasis on the alternative hypothesis of frequent colonization, the phylogenetic relations, divergence times, and ancestral areas of the cheilanthoid ferns of the GCFR and adjacent regions are investigated. The dataset includes 22...... cheilanthoid fern species occurring in the GCFR. With two exceptions, all GCFR-endemics are part of two clades that diversified in the Afro-Madagascan region. The GCFR-endemics are further concentrated in three high-endemism subclades that did not originate simultaneously, but within the timeframe...... of angiosperm Cape Clades diversification. According to ancestral area reconstructions the ancestors of the two larger Afro-Madagascan clades were likely GCFR-endemic, and a substantial part of the diversification history of these clades took place in the GCFR. The high diversity of cheilanthoids in the GCFR...

  2. Volatile organic compounds in the strongly fragrant fern genus Melpomene (Polypodiaceae).

    Science.gov (United States)

    Kessler, M; Connor, E; Lehnert, M

    2015-03-01

    Volatile organic compounds (VOCs) are common among plants, both as attractants for pollinators and as defence against herbivores. While much studied among flowering plants, the prevalence and function of VOCs among ferns is little known. Using headspace sorption and gas chromatography, we analysed the VOCs of dried specimens of six species of grammitid fern (Polypodiaceae), including two species of the genus Melpomene, which is characterised by a distinctive sweet smell. We identified 38 VOCs, including 22 not previously recorded among ferns. The two species of Melpomene had distinct VOC cocktails, including 12 substances not found in the other four studied genera, mainly involving fatty acid derivatives (FADs) and aromatics. We propose that these VOCs have, at least in part, a function in herbivore defence, but note that the VOC bouquet of Melpomene is distinct from that typically found in angiosperms.

  3. Identifying potential habitat for the endangered Aleutian shield fern using topographical characteristics

    Science.gov (United States)

    Duarte, Adam; Wolcott, Daniel M.; Chow, T. Edwin

    2012-01-01

    The Aleutian shield fern Polystichum aleuticum is endemic to the Aleutian archipelago of Alaska and is listed as endangered pursuant to the U.S. Endangered Species Act. Despite numerous efforts to discover new populations of this species, only four known populations are documented to date, and information is needed to prioritize locations for future surveys. Therefore, we incorporated topographical habitat characteristics (elevation, slope, aspect, distance from coastline, and anthropogenic footprint) found at known Aleutian shield fern locations into a Geographical Information System (GIS) model to create a habitat suitability map for the entirety of the Andreaonof Islands. A total of 18 islands contained 489.26 km2 of highly suitable and moderately suitable habitat when weighting each factor equally. This study reports a habitat suitability map for the endangered Aleutian shield fern using topographical characteristics, which can be used to assist current and future recovery efforts for the species.

  4. Effect of linear alkyl benzene sulfonate on germination of spores of the aquatic fern Ceratopteris thalictroides

    Energy Technology Data Exchange (ETDEWEB)

    Singh, J.; Devi, S. (National Botanical Research Institute, Lucknow (India))

    1989-07-01

    Validity of fern spore germination bioassays for the effects of environmental pollution was established by many researchers. Some workers studied the phytotoxicity of linear alkyl benzene sulfonate (LAS) on the spores of Diplazium esculentum and observed that LAS levels above 0.001% are toxic to fern spores. Water pollution due to synthetic detergents has been increasing continuously during the last few years due to their extensive use in domestic life, agriculture and industry. These detergents are among the most common pollutants responsible for water pollution. In view of this fact, the phytotoxicity of LAS on germination of an aquatic fern Ceratopteris thalictroides spores was studied. However, in these studies, only germination pattern was taken as index and no observations were made on the developmental stages.

  5. An Early Cretaceous root-climbing epiphyte (Lindsaeaceae) and its significance for calibrating the diversification of polypodiaceous ferns.

    Science.gov (United States)

    Schneider, H; Kenrick, P

    2001-05-01

    The discovery of fossilised roots of a lindsaeoid fern within the trunk of the extinct tree fern Tempskya provides new fossil evidence for Lindsaeaceae in the Mesozic, as well as the first direct evidence of an ecological association between Tempskya and root-climbing epiphytes. Data were collected from permineralised Tempskya trunks from the Aspen Shale (Early Cretaceous, Albian), Wyoming (USA). The roots of the lindsaeoid fossil are clearly distinguishable from those of Tempskya and other living ferns based on a suite of distinctive anatomical features, which are described in detail. The foliage is unknown. The new fossil is interpreted as a root climber, and comparisons are made with similar living species in Lindsaea subgenus Odontoloma (Lindsaeaceae). The documentation of Lindsaeaceae in the Early Cretaceous adds to a small but growing body of data on the diversification of polypodiaceous ferns during this important period. These recent discoveries point to a much earlier (Early Cretaceous) crown group radiation of polypodiaceous ferns than previously suspected.

  6. FERN – a Java framework for stochastic simulation and evaluation of reaction networks

    Directory of Open Access Journals (Sweden)

    Zimmer Ralf

    2008-08-01

    Full Text Available Abstract Background Stochastic simulation can be used to illustrate the development of biological systems over time and the stochastic nature of these processes. Currently available programs for stochastic simulation, however, are limited in that they either a do not provide the most efficient simulation algorithms and are difficult to extend, b cannot be easily integrated into other applications or c do not allow to monitor and intervene during the simulation process in an easy and intuitive way. Thus, in order to use stochastic simulation in innovative high-level modeling and analysis approaches more flexible tools are necessary. Results In this article, we present FERN (Framework for Evaluation of Reaction Networks, a Java framework for the efficient simulation of chemical reaction networks. FERN is subdivided into three layers for network representation, simulation and visualization of the simulation results each of which can be easily extended. It provides efficient and accurate state-of-the-art stochastic simulation algorithms for well-mixed chemical systems and a powerful observer system, which makes it possible to track and control the simulation progress on every level. To illustrate how FERN can be easily integrated into other systems biology applications, plugins to Cytoscape and CellDesigner are included. These plugins make it possible to run simulations and to observe the simulation progress in a reaction network in real-time from within the Cytoscape or CellDesigner environment. Conclusion FERN addresses shortcomings of currently available stochastic simulation programs in several ways. First, it provides a broad range of efficient and accurate algorithms both for exact and approximate stochastic simulation and a simple interface for extending to new algorithms. FERN's implementations are considerably faster than the C implementations of gillespie2 or the Java implementations of ISBJava. Second, it can be used in a straightforward

  7. Not only in the temperate zone: independent gametophytes of two vittarioid ferns (Pteridaceae, Polypodiales) in East Asian subtropics.

    Science.gov (United States)

    Kuo, Li-Yaung; Chen, Cheng-Wei; Shinohara, Wataru; Ebihara, Atsushi; Kudoh, Hiroshi; Sato, Hirotoshi; Huang, Yao-Moan; Chiou, Wen-Liang

    2017-03-01

    Independent gametophyte ferns are unique among vascular plants because they are sporophyteless and reproduce asexually to maintain their populations in the gametophyte generation. Such ferns had been primarily discovered in temperate zone, and usually hypothesized with (sub)tropical origins and subsequent extinction of sporophyte due to climate change during glaciations. Presumably, independent fern gametophytes are unlikely to be distributed in tropics and subtropics because of relatively stable climates which are less affected by glaciations. Nonetheless, the current study presents cases of two independent gametophyte fern species in subtropic East Asia. In this study, we applied plastid DNA sequences (trnL-L-F and matK + ndhF + chlL datasets) and comprehensive sampling (~80%) of congeneric species for molecular identification and divergence time estimation of these independent fern gametophytes. The two independent gametophyte ferns were found belonging to genus Haplopteris (vittarioids, Pteridaceae) and no genetic identical sporophyte species in East Asia. For one species, divergence times between its populations imply recent oversea dispersal(s) by spores occurred during Pleistocene. By examining their ex situ and in situ fertility, prezygotic sterility was found in these two Haplopteris, in which gametangia were not or very seldom observed, and this prezygotic sterility might attribute to their lacks of functional sporophytes. Our field observation and survey on their habitats suggest microhabitat conditions might attribute to this prezygotic sterility. These findings point to consideration of whether recent climate change during the Pleistocene glaciation resulted in ecophysiological maladaptation of non-temperate independent gametophyte ferns. In addition, we provided a new definition to classify fern gametophyte independences at the population level. We expect that continued investigations into tropical and subtropical fern gametophyte floras will

  8. Preliminary investigations on fossil diversity variation of Mesozoic Marattialean ferns in China

    Institute of Scientific and Technical Information of China (English)

    Zikun JIANG; Yongdong WANG; and Ning TIAN

    2008-01-01

    The Marattiales is one of the oldest lineages of vascular plants with extensive fossil records dated back to the Carboniferous. Understanding the fossil diversity variation and distribution pattern is helpful for exploring the evolutionary history of this fern group. In this work, the preliminary analysis of diversity change and distribution of the Mesozoic Marattialean fossil records in China are reported covering the Triassic and Jurassic periods based on available published data. In addition, a brief discussion is made regarding to the potential causes for these variation and distribution of this fern group.

  9. Determination of heavy metals in soil and different parts of Diplazium esculentum (medicinal fern)

    Science.gov (United States)

    Jasim, Hind S.; Idris, Mushrifah; Abdullah, Aminah; Kadhum, A. A. H.

    2014-09-01

    Diplazium esculentum is a widely used medicinal fern in Malaysia and other regions worldwide. Heavy metals in plants should be determined because prolonged human intake of toxic trace elements, even at low doses, results in organ malfunction and causes chronic toxicity. Hence, substantial information should be obtained from plants that grow on soils containing high concentrations of heavy metals. This study aimed to determine the physicochemical characteristics of soil and heavy metal concentrations (Pb, Cr, Mn, Cu, and Zn) in different parts of D. esculentum and soil, which were collected from the fern garden of Universiti Kebangsaan Malaysia. Results showed that heavy metals were highly accumulated in D. esculentum roots.

  10. CLINICAL APPLICATION AND EVALUATION OF SALIVA FERNING TEST IN SJGREN S SYNDROME

    Institute of Scientific and Technical Information of China (English)

    丁玲; 唐燕

    2000-01-01

    ffeStnn6 Objectif L' dtude admit pour but d' aPPrdcier to wileur du test de foug4rimtion (Ferning Test ) adns ie diagnostic de xdrostwnie chez ies malaies atteints du Syndrew de Sjbgren (ss). methaes ho dchantillons dewtnd de alivefraiche out did Obtenus chez 78 malades avec ie diagnostic de SS etabli scion ies critsres de ~munautd Eurowinne et chez 80tdmoins dins. ie dchantillons out ate ~mind sons microscope ordinaire. In cristallimtion etait classifide en 4 type scion iePhenondne de fougdrimtion (ferning...

  11. A new species of fern of the genus Pteris (Filicales: Pteridaceae) endemic to Costa Rica.

    OpenAIRE

    Rojas Alvarado, Alexander Fco.; Palacios Ríos, Mónica

    2014-01-01

    Abstract: A new species of fern of the genus Pteris (Filicales: Pteridaceae) endemic to Costa Rica. The new fern species Pteris herrerae A. Rojas & M. Palacios, endemic to Costa Rica, is described. It differs from P. decurrens C. Presl in basal segments reduced to 1/5-1/2 of the next segment (vs. 2/3-3/4), basal pinnae not bifurcated (vs. bifurcated), pinnae apex mucronate (vs. acuminate) and segment apex undulate (vs. dentate). It differs from Pteris consanguinea in the elliptic pinnae (vs. ...

  12. Kinetics of ptaquiloside hydrolysis in aqueous solution

    DEFF Research Database (Denmark)

    Ayala-Luis, Karina B.; Bildsøe Hansen, Pernille; Rasmussen, Lars Holm;

    2006-01-01

    Ptaquiloside (PTA) is a well-known toxin produced by the bracken fern (Pteridium aquilinum (L.) Kuhn). It is proposed that PTA from bracken stands can leach through soil and sediments into drinking-water reservoirs, thus representing a concern for human health. To predict the persistence of the t......Ptaquiloside (PTA) is a well-known toxin produced by the bracken fern (Pteridium aquilinum (L.) Kuhn). It is proposed that PTA from bracken stands can leach through soil and sediments into drinking-water reservoirs, thus representing a concern for human health. To predict the persistence...

  13. Biomonitoring human exposure to environmental carcinogenic chemicals

    DEFF Research Database (Denmark)

    Farmer, P.B.; Sepai, O.; Lawrence, R.

    1996-01-01

    aberrations and sister chromatid exchanges) and mutation frequency was estimated at a number of loci including the hprt gene and genes involving in cancer development. Blood and urine samples from individuals exposed to urban pollution were collected. Populations exposed through occupational or medical......A coordinated study was carried out on the development, evaluation and application of biomonitoring procedures for populations exposed to environmental genotoxic pollutants. The procedures used involved both direct measurement of DNA or protein damage (adducts) and assessment of second biological...... for detecting carcinogen-induced damage to DNA and proteins, and subsequent biological effects. These methods were validated with the occupational exposures, which showed evidence of DNA and/or protein and/or chromosome damage in workers in a coke oven plant, garage workers exposed to diesel exhaust and workers...

  14. Method for converting asbestos to non-carcinogenic compounds

    Science.gov (United States)

    Selby, Thomas W.

    1996-01-01

    Hazardous and carcinogenic asbestos waste characterized by a crystalline fibrous structure is transformed into non-carcinogenic, relatively nonhazardous, and non-crystalline solid compounds and gaseous compounds which have commercial utilization. The asbestos waste is so transformed by the complete fluorination of the crystalline fibrous silicate mineral defining the asbestos.

  15. Workshop on problem areas associated with developing carcinogen guidelines

    Energy Technology Data Exchange (ETDEWEB)

    1984-06-01

    A workshop was conducted to discuss problem areas associated with developing carcinogen guidelines. Session topics included (1) definition of a carcinogen for regulatory purposes; (2) potency; (3) risk assessment; (4) uncertainties; (5) de minimis quantity; and (6) legal and regulatory issues. Separate abstracts have been prepared for individual papers. (ACR)

  16. Emissions and air exposure of carcinogens and co-carcinogens in four Nordic countries

    DEFF Research Database (Denmark)

    Fauser, Patrik; Plejdrup, Marlene Schmidt; Ketzel, Matthias;

    . A list of carcinogenic andco-carcinogenic pollutants (particles, heavy metals and organic compounds) emittedfrom energy production, industrial activities, road transport, navigation, agriculture, residential heating and product use was compiled. Pollutant emissions levels for 2010and trends for 1990......This project (KoL 12-08) was performed for the Climate and Air Quality Group (KlimaogLuftgruppen, KoL), Nordic Council of Ministers by atmospheric emission, exposureand epidemiology experts from Denmark, Finland, Norway and Sweden. Emission inventory methods and exposure models were presented...... to 2010 were compiled and discussed, and modelled andmeasured atmospheric concentrations for 2010 were compiled on regional, urbanand local scales. Nordic maps of emissions and air concentrations of PM2.5, PM10, NOx,NMVOC, benzene, BaP, dioxin, cadmium and nickel were compiled for allaggregated main...

  17. Carcinogenic risk of copper gluconate evaluated by a rat medium-term liver carcinogenicity bioassay protocol

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Masayoshi; Usuda, Koji; Hayashi, Seigo; Ogawa, Izumi; Furukawa, Satoshi [Nissan Chemical Industries Limited, Toxicology and Environmental Science Department, Biological Research Laboratories, Saitama (Japan); Igarashi, Maki [Tokyo University of Agriculture, Laboratory of Protection of Body Function, Department of Food and Nutritional Science, Graduate School of Agriculture, Tokyo (Japan); Nakae, Dai [Tokyo University of Agriculture, Laboratory of Protection of Body Function, Department of Food and Nutritional Science, Graduate School of Agriculture, Tokyo (Japan); Tokyo Metropolitan Institute of Public Health, Tokyo (Japan)

    2008-08-15

    Carcinogenic risk and molecular mechanisms underlying the liver tumor-promoting activity of copper gluconate, an additive of functional foods, were investigated using a rat medium-term liver carcinogenicity bioassay protocol (Ito test) and a 2-week short-term administration experiment. In the medium-term liver bioassay, Fischer 344 male rats were given a single i.p. injection of N-nitrosodiethylamine at a dose of 200 mg/kg b.w. as a carcinogenic initiator. Starting 2 weeks thereafter, rats received 0, 10, 300 or 6,000 ppm of copper gluconate in diet for 6 weeks. All rats underwent 2/3 partial hepatectomy at the end of week 3, and all surviving rats were killed at the end of week 8. In the short-term experiment, rats were given 0, 10, 300 or 6,000 ppm of copper gluconate for 2 weeks. Numbers of glutathione S-transferase placental form (GST-P) positive lesions, single GST-P-positive hepatocytes and 8-oxoguanine-positive hepatocytes, and levels of cell proliferation and apoptosis in the liver were significantly increased by 6,000 ppm of copper gluconate in the medium-term liver bioassay. Furthermore, hepatic mRNA expression of genes relating to the metal metabolism, inflammation and apoptosis were elevated by 6,000 ppm of copper gluconate both in the medium-term liver bioassay and the short-term experiments. These results indicate that copper gluconate possesses carcinogenic risk toward the liver at the high dose level, and that oxidative stress and inflammatory and pro-apoptotic signaling statuses may participate in its underlying mechanisms. (orig.)

  18. FURTHER NOTES ON THE FERN-GENUS HETEROGONIUM PRESL

    Directory of Open Access Journals (Sweden)

    R. E. HOLTTUM

    2015-11-01

    Full Text Available In the "Sarawak Museum Journal," volume V (1949, pages 156-166,I gave a revised account of the genus Heterogonium Presl, based on specimens in the Singapore herbarium. Dr M. A. Donk wrote subsequently pointing out that specimens at Bogor (Buitenzorg add materially to the information contained in that paper. The present paper gives the result of a study of the Bogor specimens. I am glad to express my gratitude to Dr Donk for calling my attention to species which I had overlooked when searching literature on Malaysian ferns for indications of affinity to Heterogonium. The Bogor material includes the type specimens of Acrostichum teysmannianum Bak., Phegopteris schizoloma v. A. v. R. Dryopteris sagenoides forma contracta v. A. v. R., Polybotrya nieuwenhuisii Racib. and Polybotrya nieuwenhuisii var. brooksii v. A. v. R., also many sheets of H. giganteum, and material of H. sagenoides from a wider geographic range than I had previously seen. Summarizing the results of the present paper, I have united H.nieuwenhuisii and H. stenosemioides of my former paper, and have also united H. saxicola with H. giganteum. Further, I now recognize a second exindusiate species allied to H. sagenoides; but the variation in pubescence among exindusiate specimens, as within the species H. sagenoides proper, is very considerable, and I find it very difficult to draw specific limits. It is likely that there are local races, but much more field work in many localities is necessary before one can speak with certainty about this or define their status taxonomically. One interesting fact is that no exindusiate specimens of this alliance have been found in the Malay Peninsula, whereas Peninsular collections of indusiate H. sagenoides aremore abundant than from any other area. It is especially the variation in pubescence among specimens of H. sagenoides, and the lack of clear-cut varieties or subspecies within the Malay Peninsula, that deters me from distinguishing more

  19. Diffusional limitations explain the lower photosynthetic capacity of ferns as compared with angiosperms in a common garden study.

    Science.gov (United States)

    Carriquí, M; Cabrera, H M; Conesa, M À; Coopman, R E; Douthe, C; Gago, J; Gallé, A; Galmés, J; Ribas-Carbo, M; Tomás, M; Flexas, J

    2015-03-01

    Ferns are thought to have lower photosynthetic rates than angiosperms and they lack fine stomatal regulation. However, no study has directly compared photosynthesis in plants of both groups grown under optimal conditions in a common environment. We present a common garden comparison of seven angiosperms and seven ferns paired by habitat preference, with the aims of (1) confirming that ferns do have lower photosynthesis capacity than angiosperms and quantifying these differences; (2) determining the importance of diffusional versus biochemical limitations; and (3) analysing the potential implication of leaf anatomical traits in setting the photosynthesis capacity in both groups. On average, the photosynthetic rate of ferns was about half that of angiosperms, and they exhibited lower stomatal and mesophyll conductance to CO2 (gm ), maximum velocity of carboxylation and electron transport rate. A quantitative limitation analysis revealed that stomatal and mesophyll conductances were co-responsible for the lower photosynthesis of ferns as compared with angiosperms. However, gm alone was the most constraining factor for photosynthesis in ferns. Consistently, leaf anatomy showed important differences between angiosperms and ferns, especially in cell wall thickness and the surface of chloroplasts exposed to intercellular air spaces.

  20. Effects of Flavonoids Extracted from Sweet Fern and Bitter Fern on DPPH Elimination%食用甜蕨及苦蕨黄酮类化合物对DPPH自由基的清除效果

    Institute of Scientific and Technical Information of China (English)

    方玉梅; 谭萍; 王毅红; 张春生

    2012-01-01

    为了弄清食用甜蕨和苦蕨黄酮提取物的抗氧化特性,以VE为对照,采用分光光度法等方法,研究了食用甜蕨和苦蕨黄酮类化合物对DPPH自由基清除率的影响.结果表明;在510nm下,甜蕨和苦蕨黄酮提取液的含量分别为843.59μg/g和614.15μg/g;甜蕨和苦蕨黄酮提取物对DPPH均有较好的清除效果,苦蕨与甜蕨黄酮提取物浓度为12.283μg/mL时,对DPPH的清除率分别为87,13%和50.21%,苦蕨黄酮提取液的抗氧化能力显著高于甜蕨,但二者的抗氧化能力均显著高于VE.%In order to ascertain the antioxidant properties of flavonoids extracted from sweet fern and bitter fern, the elimination rate on DPPH radical was studied taking VE as the control using spectrophotometric and other methods. The results showed that at 510 nm, the content of flavonoids extract of sweet fern and bitter fern was 843. 59 μg/g and 614. 15 μg/g respectively. The extraction of the flavonoids from sweet fern and bitter fern on DPPH elimination had The better effect. The flavonoids extracted from the sweet fern and bitter fern on DPPH elimination rate was 50. 21% and 87. 13% separately when the flavonoids concentration was 12. 283 μg/mL. The antioxidant capacity of the bitter fern flavonoids was significantly higher than that of the sweet fern flavonoids, but the antioxidant capacity of the sweet fern and bitter fern were significantly higher than VE.

  1. Seed ferns survived the end-Cretaceous mass extinction in Tasmania.

    Science.gov (United States)

    McLoughlin, Stephen; Carpenter, Raymond J; Jordan, Gregory J; Hill, Robert S

    2008-04-01

    Seed ferns, dominant elements of the vegetation in many parts of the world from the Triassic to Cretaceous, were considered to have disappeared at the end of the Cretaceous together with several other groups that had occupied key positions in terrestrial and marine ecosystems such as dinosaurs, plesiosaurs, and ammonoids. Seed-fern demise is generally correlated with competition from diversifying flowering plants through the Cretaceous and the global environmental crisis related to the Chicxulub impact event in the paleotropics at the end of the period. New fossils from Tasmania show that one seed-fern lineage survived into the Cenozoic by at least 13 million years. These fossils are described here as a new species, Komlopteris cenozoicus. Komlopteris is a genus of seed ferns attributed to Corystospermaceae and until now was not known from sediments younger than the Early Cretaceous. Discovery of this "Lazarus taxon," together with the presence of a range of other relictual fossil and extant organisms in Tasmania, other southern Gondwanan provinces, and some regions of northern North America and Asia, underscores high-latitude regions as biodiversity refugia during global environmental crises and highlights their importance as sources of postextinction radiations.

  2. The Lindsaeoid ferns of the Old World V. The smaller Pacific islands

    NARCIS (Netherlands)

    Kramer, K.U.

    1970-01-01

    The present paper is the third regional revision of the Old World Lindsaeoid ferns. The second (the fourth in the entire series on the Old World Lindsaeoids) will be published as vol. II, 1 part 3 of Flora Malesiana; it is awaiting publication as the present paper goes to the press. Species fully de

  3. A review of the fern genus Hypolepis (Dennstardtiaceae) in the Malesian and Pacific regions

    NARCIS (Netherlands)

    Brownsey, P.J.

    1987-01-01

    Fourteen species and one subspecies of the fern genus Hypolepis Bernh. are recognised in the Malesian and Pacific regions, excluding Australia and New Zealand. Three species, H. hawaiiensis, H. malesiana and H. scabristipes, and one subspecies, H. elegans subsp. carolinensis, are described for the f

  4. Cyathea nilgirensis Holttum (Cyatheaceae: Pteridophyta: a threatened tree fern from central Western Ghats, India

    Directory of Open Access Journals (Sweden)

    S.N. Dudani

    2014-01-01

    Full Text Available While studying some of the exclusive and threatened swamps overgrown with wild nutmeg trees (Myristica swamps, in the Kathalekan forest of Uttara Kannada in central Western Ghats, Cyathea nilgirensis Holttum, a southern Indian endemic tree fern was seen growing in the deep shade of the swampy forest. This is a new report of its distribution anywhere from north of Western Ghats.

  5. Reconciling extreme branch length differences: decoupling time and rate through the evolutionary history of filmy ferns.

    Science.gov (United States)

    Schuettpelz, Eric; Pryer, Kathleen M

    2006-06-01

    The rate of molecular evolution is not constant across the Tree of Life. Characterizing rate discrepancies and evaluating the relative roles of time and rate along branches through the past are both critical to a full understanding of evolutionary history. In this study, we explore the interactions of time and rate in filmy ferns (Hymenophyllaceae), a lineage with extreme branch length differences between the two major clades. We test for the presence of significant rate discrepancies within and between these clades, and we separate time and rate across the filmy fern phylogeny to simultaneously yield an evolutionary time scale of filmy fern diversification and reconstructions of ancestral rates of molecular evolution. Our results indicate that the branch length disparity observed between the major lineages of filmy ferns is indeed due to a significant difference in molecular evolutionary rate. The estimation of divergence times reveals that the timing of crown group diversification was not concurrent for the two lineages, and the reconstruction of ancestral rates of molecular evolution points to a substantial rate deceleration in one of the clades. Further analysis suggests that this may be due to a genome-wide deceleration in the rate of nucleotide substitution.

  6. Rhizosphere and non-rhizosphere mycoflora of two ferns from Panhala Fort, Kolhapur, Maharashtra, India

    Directory of Open Access Journals (Sweden)

    P. R. Hande

    2016-03-01

    Full Text Available Hypodematium crenatum (Forssk. Kuhn and Anogramma leptophylla (L. Link are threatened fern species from Western Ghats.  The present paper endorses the preliminary study on mycoflora associated with these ferns.  Eighteen fungal species have been isolated from rhizosphere and non-rhizosphere soils of selected ferns.  More diversity of fungi was observed in non-rhizosphere as compared to rhizosphere soils of both the ferns.  Aspergillus was found to be the most dominant genus among the population followed by Penicillium.  Higher percentage of fungal species is shown by H. crenatum, i.e., 44.5% in non-rhizosphere and 27.77% in rhizosphere; while a lower percentage of fungal species was found in A. leptophylla, i.e., 38.88% in non-rhizosphere and 16.66% in rhizosphere.  Number of colony forming units per gram soil was more in non-rhizosphere of A. leptophylla while it was less in non-rhizosphere of H. crenatum.  Inhibitory rhizosphere effect was exerted by A. leptophylla while H. crenatum has stimulatory effect on soil fungi. 

  7. Qasimia gen. nov., an early Marattia-like fern from the Permian of Saudi Arabia

    NARCIS (Netherlands)

    Hill, C.R.; Wagner, R.H.; El-Khayal, A. A.

    1985-01-01

    The marattialean fern Qasimia schyfsmae (Lemoigne) gen. et comb. nov. is described from the Late Permian plant bed at Unayzah in central Saudi Arabia. Although no organic matter is preserved, impregnation of the compressions by iron minerals at an early stage of diagenesis has partly mineralised the

  8. Burmese amber fossils bridge the gap in the Cretaceous record of polypod ferns

    OpenAIRE

    Schmidt, AR; Heinrichs, J.; Schneider, Harald

    2016-01-01

    publisher: Elsevier articletitle: Burmese amber fossils bridge the gap in the Cretaceous record of polypod ferns journaltitle: Perspectives in Plant Ecology, Evolution and Systematics articlelink: http://dx.doi.org/10.1016/j.ppees.2016.01.003 content_type: article copyright: Copyright © 2016 Elsevier GmbH. All rights reserved.

  9. Notes on the scholarly trajectory of Mª. Dolores Fernández-Posse

    Directory of Open Access Journals (Sweden)

    Gilman, Antonio

    2007-12-01

    Full Text Available The scholarly trajectory of Mª Dolores Fernández- Posse involved an ongoing process of critical observation, reflection, and change that is quite rare in Archaeology. Her change from normativism to a historically informed functionalism is representative of the general evolution of Spanish archaeological studies over the course of the past thirty years. What is unusual about Fernández-Posse -and attests to her straightforward and unassuming intelligence- is that she herself changed her mind and voiced that change with clarity and humor.

    La trayectoria científica de Mª Dolores Fernández-Posse se caracterizó por un proceso continuo de observación crítica, reflexión y cambio, algo poco común en Arqueología. Su cambio del normativismo a un funcionalismo de orientación histórica es representativo de la evolución de los estudios arqueológicos en España a lo largo de los últimos treinta años. Lo realmente inusual de Fernández-Posse -y lo que atestigua su directa pero no pretenciosa inteligencia- es que ella misma cambió de ideas y publicitó ese cambio con claridad y humor.

  10. A review of the fern genus Hypolepis (Dennstardtiaceae) in the Malesian and Pacific regions

    NARCIS (Netherlands)

    Brownsey, P.J.

    1987-01-01

    Fourteen species and one subspecies of the fern genus Hypolepis Bernh. are recognised in the Malesian and Pacific regions, excluding Australia and New Zealand. Three species, H. hawaiiensis, H. malesiana and H. scabristipes, and one subspecies, H. elegans subsp. carolinensis, are described for the f

  11. A Cognitive Reading Guide: Equalizing Instruction for "Where the Red Fern Grows."

    Science.gov (United States)

    Giannuzzi, Michelle L.; Hudson, Floyd

    1998-01-01

    Provides a cognitive reading guide for the first four chapters of the novel, "Where the Red Fern Grows" (Rawls, 1961), that incorporates teacher-directed whole-class instruction with a student reading guide to equalize instruction for various levels of learners. Ideas for whole-class instruction are contained within the lesson plans. (CR)

  12. Ever since Klekowski: testing a set of radical hypotheses revives the genetics of ferns and lycophytes.

    Science.gov (United States)

    Haufler, Christopher H

    2014-12-01

    There have been three periods of significant discovery in the exploration of fern and lycophyte genetics. First, during the 1930s, Andersson-Kottö conducted crossing studies on ferns. The publication of Manton's magnum opus on fern chromosomes in 1950 stimulated the second. The third emerged from Klekowski's 1973 American Journal of Botany publication that posed hypotheses linking breeding system dynamics and polyploid genetic architecture. Although Klekowski's assertions (predominant inbreeding and active polyploid genomes) were not supported, his hypotheses served as the impetus for improving our knowledge of the evolutionary mechanisms of ferns and lycophytes. It is now understood that (1) homosporous vascular plants are genetically diploid at high chromosome numbers and (2) both heterosporous and homosporous plants store and release genetic variation through a similar range of breeding systems. However, the seeming paradox of diploid genetic expression in homosporous vascular plants with high chromosome numbers remains unresolved. Ongoing and future research should include (1) more studies of gametophyte biology to elucidate the range and frequency of different breeding systems; (2) genomic analyses and new research on the mechanisms controlling bivalent formation to help discover how and why homosporous plant chromosomes appear so structurally stable; (3) considering whether the frequency of allopolyploidy in lineages can help explain why some are highly polyploid; and (4) chromosome painting studies to identify the dynamics of chromosome behavior in homosporous vascular plants. These open questions and continuing investigations demonstrate the longstanding impact of Klekowski's stimulating contribution.

  13. Alsophila weidenbrueckii (Cyatheaceae), a new scaly tree fern from Papua New Guinea

    NARCIS (Netherlands)

    Lehnert, M.

    2016-01-01

    The scaly tree fern Alsophila weidenbrueckii is described and illustrated as new to science. It occurs in the Bismarck range in north-eastern New Guinea at 1200–2100 m in evergreen wet mountain forest. The species reaches maturity at a comparatively old age and large size and regenerates only in int

  14. Interannual variation and host affiliations of endophytic fungi associated with ferns at La Selva, Costa Rica.

    Science.gov (United States)

    Del Olmo-Ruiz, Mariana; Arnold, A Elizabeth

    2014-01-01

    Ferns are an ancient and diverse lineage of vascular plants that differ morphologically, chemically and in growth habits from the angiosperms with which they co-occur. We used a culture-based approach coupled with phylogenetic analyses to characterize the incidence, diversity and composition of fungal endophyte assemblages in ferns, with a focus on healthy aboveground tissues of seven species of eupolypods at La Selva, Costa Rica. Endophytes were isolated from every individual plant and were similarly abundant and diverse in frond blades and stalks, in different vegetation types, in epiphytic vs. terrestrial species, and between sampling years. However, abundance, diversity and community structure differed significantly among fern species, and composition differed markedly between sampling years. Phylogenetic classification using separate and combined datasets revealed that as for many Neotropical angiosperms, the majority (95%) of endophyte taxa were Ascomycota, with particular dominance by Sordariomycetes, Eurotiomycetes and Dothideomycetes. However, our data suggest higher phylogenetic richness and stronger host affinities in fern associated endophytes relative to those studied in angiosperms thus far.

  15. The invention of WUS-like stem cell-promoting functions in plants predates leptosporangiate ferns.

    Science.gov (United States)

    Nardmann, Judith; Werr, Wolfgang

    2012-01-01

    The growth of land plants depends on stem cell-containing meristems which show major differences in their architecture from basal to higher plant species. In Arabidopsis, the stem cell niches in the shoot and root meristems are promoted by WUSCHEL (WUS) and WOX5, respectively. Both genes are members of a non-ancestral clade of the WUS-related homeobox (WOX) gene family, which is absent in extant bryophytes and lycophytes. Our analyses of five fern species suggest that a single WUS orthologue was present in the last common ancestor (LCA) of leptosporangiate ferns and seed plants. In the extant fern Ceratopteris richardii, the WUS pro-orthologue marks the pluripotent cell fate of immediate descendants of the root apical initial, so-called merophytes, which undergo a series of stereotypic cell divisions and give rise to all cell types of the root except the root cap. The invention of a WUS-like function within the WOX gene family in an ancestor of leptosporangiate ferns and seed plants and its amplification and sub-functionalisation to different stem cell niches might relate to the success of seed plants, especially angiosperms.

  16. Effect of temperature on green spore longevity for the ferns Equisetum ramosissimum and Osmunda regalis

    Science.gov (United States)

    Some fern species produce chlorophyllic or green spores. Green spores lose viability quickly compared to nongreen spores, and so need specialized treatment for long term conservation in germplasm banks. Dry storage at different temperatures (25 ºC, 4 ºC, -25 ºC, -80 ºC and -196 ºC) was studied in ...

  17. Effects of arsenic on nitrogen metabolism in arsenic hyperaccumulator and non-hyperaccumulator ferns

    Science.gov (United States)

    This study investigated the effects of arsenic on the in vitro activities of the enzymes (nitrate reductase and nitrite reductase) involved in nitrate metabolism in the roots, rhizomes, and fronds of two four-month old fern plants, Pteris vittata, an arsenic-hyperaccumulator, and Pteris ensiformis, ...

  18. Report of work on ferns carried out at Bogor 1957-1958

    NARCIS (Netherlands)

    Holttum, R.E.

    1959-01-01

    I spent the period from Oct. 8, 1957, to March 27, 1958, at Bogor, Indonesia. During that period I worked regularly in the Herbarium Bogoriense. The main part of my work consisted of a complete rearrangement of the fern herbarium, which consists of some 20,000- 30,000 specimens.

  19. Real-Time RGB-D Camera Relocalization via Randomized Ferns for Keyframe Encoding.

    Science.gov (United States)

    Glocker, Ben; Shotton, Jamie; Criminisi, Antonio; Izadi, Shahram

    2015-05-01

    Recovery from tracking failure is essential in any simultaneous localization and tracking system. In this context, we explore an efficient keyframe-based relocalization method based on frame encoding using randomized ferns. The method enables automatic discovery of keyframes through online harvesting in tracking mode, and fast retrieval of pose candidates in the case when tracking is lost. Frame encoding is achieved by applying simple binary feature tests which are stored in the nodes of an ensemble of randomized ferns. The concatenation of small block codes generated by each fern yields a global compact representation of camera frames. Based on those representations we define the frame dissimilarity as the block-wise hamming distance (BlockHD). Dissimilarities between an incoming query frame and a large set of keyframes can be efficiently evaluated by simply traversing the nodes of the ferns and counting image co-occurrences in corresponding code tables. In tracking mode, those dissimilarities decide whether a frame/pose pair is considered as a novel keyframe. For tracking recovery, poses of the most similar keyframes are retrieved and used for reinitialization of the tracking algorithm. The integration of our relocalization method into a hand-held KinectFusion system allows seamless continuation of mapping even when tracking is frequently lost.

  20. Coeval Eocene blooms of the freshwater fern Azolla in and around Arctic and Nordic seas

    NARCIS (Netherlands)

    Barke, J.; Burgh, A.H.P. van der; Konijnenburg-van Cittert, J.H.A. van; Collinson, M.E.; Pearce, M.A.; Bujak, J.; Heilman-Clausen, C.; Lotter, A.F.; Speelman, E.N.; Kempen, M.M.L. van; Reichart, G.-J.; Brinkhuis, H.

    2012-01-01

    For a short time interval (c. 1.2 Myr) during the early middle Eocene (~ 49 Myr), the central Arctic Ocean was episodically densely covered by the freshwater fern Azolla, implying sustained freshening of surface waters. Coeval Azolla fossils in neighboring Nordic seas were thought to have been

  1. A review of the fern genus Hypolepis (Dennstardtiaceae) in the Malesian and Pacific regions

    NARCIS (Netherlands)

    Brownsey, P.J.

    1987-01-01

    Fourteen species and one subspecies of the fern genus Hypolepis Bernh. are recognised in the Malesian and Pacific regions, excluding Australia and New Zealand. Three species, H. hawaiiensis, H. malesiana and H. scabristipes, and one subspecies, H. elegans subsp. carolinensis, are described for the

  2. A fern AINTEGUMENTA gene mirrors BABY BOOM in promoting apogamy in Ceratopteris richardii.

    Science.gov (United States)

    Bui, Linh T; Pandzic, Dzevida; Youngstrom, Christopher E; Wallace, Simon; Irish, Erin E; Szövényi, Péter; Cheng, Chi-Lien

    2017-04-01

    Asexual reproduction is widespread in land plants, including ferns where 10% of all species are obligate asexuals. In these ferns, apogamous sporophytes are generated directly from gametophytes, bypassing fertilization. In the model fern Ceratopteris richardii, a sexual species, apogamy can be induced by culture on high sugar media. BABY BOOM (BBM) genes in angiosperms are known to promote somatic embryogenesis, which like apogamy produce sporophytes without fertilization. Here, a Brassica napus BBM (BnBBM) was used to investigate genetic similarity between apogamy in ferns and somatic embryogenesis in angiosperms. A C. richardii transcriptome was constructed from which one AINTEGUMENTA-LIKE unigene, CrANT, was identified. Whole mount in situ hybridization showed that CrANT is expressed in sperm and fertilized eggs. Phylogenetic analysis grouped CrANT with other non-seed-plant ANT genes to the euANT clade but in a branch separate from BBM genes. Overexpression of CrANT or BnBBM promotes apogamy in C. richardii without sugar supplement. CrANT knockdown gametophytes responded weakly to sugar for apogamy promotion. Theses results suggest some genetic conservation between apogamy and somatic embryogenesis and that such asexual reproduction may be ancient. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  3. Phytochemical studies on five medicinal ferns collected from Southern Western Ghats, Tamilnadu

    Institute of Scientific and Technical Information of China (English)

    A John De Britto; D Herin Sheeba Gracelin; P Benjamin Jeya Rathna Kumar

    2012-01-01

    Objective: To analyze the phytochemical constituents of five medicinal ferns Pteris biaurita (P. biaurita) L., Lygodium flexiuosam (L. flexiuosam) (L.) Sw., Hemionitis arifolia (H. arifolia) (Burm. f.) T. Moore, Actinopteris radiate (A. radiata) (J. Koenig ex Sw.) Link and Adiantum latifolium (A. latifolium) Lam. Methods: The shade dried and powdered fronds (50 g) were extracted successively with 250 mL of petroleum ether, benzene, chloroform, methanol and distilled water using a Soxhlet extractor for 8 h at a temperature of 50-60℃ (not exceeding the boiling point of the solvent). Phytochemical analysis of the extracts was carried out according to the standard procedures. Results: Among the twenty five tested extracts, twenty extracts showed the presence of flavonoids. Phenolic compounds are present in methanol extracts of all the ferns. Five extracts showed the presence of triterpinoids and catechins. Ten extracts showed the occurrence of sugars and reducing sugars. Fifteen extracts showed the presence of alkaloids. Tannins and saponins are present in eight extracts. Steroids occurred in all the twenty five extracts. Only three extracts showed the presence of anthroquinones and amino acids. Conclusions: From this investigation, it can be concluded that the selected five medicinal ferns contain more bioactive principles. These potential ferns could be used as bio control agnets.

  4. Community structure of ferns in riparian forest: evaluation in anthropization gradient

    Directory of Open Access Journals (Sweden)

    Ivanete Teresinha Mallmann

    2016-03-01

    Full Text Available Riparian forests are essential to the maintenance of biodiversity and foster the development of ferns that are indicators of environmental quality. However, these forests have been degraded due mainly to high population density, pattern of urban settlement and agricultural expansion in rural areas. This study evaluated the environmental quality of riparian vegetation of the Cadeia River in Southern Brazil, using phytosociological parameters of the understory’s fern community and a Rapid Assessment Protocol of Habitat Quality (RAPQH. One hundred and twenty plots of 25 m2 were equally distributed among three fragments (FI, FII, FIII. All species of herbaceous ferns were inventoried in each sample unit. We calculated parameters of density, frequency, relative dominance and importance value (IV of species for the analysis of community structure. The lowest species richness was recorded at FIII (seven species. The floristic composition is more heterogeneous and richness is higher in FI, where the parcels had greater plant cover and RAPQH scores. The RAPQH score decreased with increasing degree of urbanization in the surrounding matrix and FI and FII were classified as “natural,” while FIII was classified as “impacted.” Considering the four species with the highest IV in the three fragments (totaling 69.11% of IV in the FI, 78.36% and 91.06% in FII and FIII respectively, it can be affirmed that the fern community structure is degraded with increasing anthropization.

  5. The Lindsaeoid ferns of the Old World V. The smaller Pacific islands

    NARCIS (Netherlands)

    Kramer, K.U.

    1970-01-01

    The present paper is the third regional revision of the Old World Lindsaeoid ferns. The second (the fourth in the entire series on the Old World Lindsaeoids) will be published as vol. II, 1 part 3 of Flora Malesiana; it is awaiting publication as the present paper goes to the press. Species fully

  6. SEM Studies on Vessels in Ferns. XV. Selected Rosette Epiphytes (Aspleniaceae, Elaphoglossaceae, Vittariaceae).

    Science.gov (United States)

    Schneider; Carlquist

    1999-09-01

    Tracheary elements from macerations of roots and rhizomes of Asplenium nidus, Elaphoglossum hirtum, and Vittaria lineata were studied by means of SEM. All of these have perforation plates in tracheary elements of both roots and rhizomes. The perforation plates in roots and rhizomes show greatest development of perforations (perforations a little wider than pits of tracheary elements) in E. hirtum roots and rhizomes and least in V. lineata roots and in rhizomes of A. nidus (porose pit membranes in many perforations). The secondary wall framework of perforation plates is little different from that of pitted wall areas in these three species. These rosette epiphytes have a lower degree of specialization of perforation plates that might accommodate rapid flow related to moisture availability fluctuations in comparison to perforation plates in vessels of rhizomatous epiphytic ferns. Generalizations are not warranted at this point, however. Rows of cushion-like structures occur adjacent to angles of the tracheary elements of E. hirtum. This is the first report of these in leptosporangiate ferns; they are known thus far only in a eusporangiate fern, Danaea elliptica (Marattiaceae). Raised frames of wall material around perforations are newly reported for tracheary elements of ferns in E. hirtum.

  7. An estimation of the carcinogenic risk associated with the intake of multiple relevant carcinogens found in meat and charcuterie products.

    Science.gov (United States)

    Hernández, Ángel Rodríguez; Boada, Luis D; Almeida-González, Maira; Mendoza, Zenaida; Ruiz-Suárez, Norberto; Valeron, Pilar F; Camacho, María; Zumbado, Manuel; Henríquez-Hernández, Luis A; Luzardo, Octavio P

    2015-05-01

    Numerous epidemiological studies have demonstrated a link between excessive meat consumption and the incidence of various cancers, especially colorectal cancer, and it has been suggested that environmental carcinogens present in meat might be related to the increased risk of cancer associated with this food. However, there are no studies evaluating the carcinogenic potential of meat in relation to its content of carcinogens. Our purpose was to emphasize the relevance of environmental carcinogens existing in meat as a determinant of the association between cancer and meat consumption. Because within Europe, Spain shows high consumption of meat and charcuterie, we performed this study focusing on Spanish population. Based on the preferences of consumers we acquired 100 samples of meat and charcuterie that reflect the variety available in the European market. We quantified in these samples the concentration of 33 chemicals with calculated carcinogenic potential (PAHs, organochlorine pesticides, and dioxin-like PCBs). The carcinogenic risk of these contaminants was assessed for each food using a risk ratio based on the current consumption of meat and charcuterie and the maximum tolerable intake of these foods depending on the level of contamination by the carcinogens they contain. Our results indicate that the current consumption of beef, pork, lamb, chicken, and "chorizo", represents a relevant carcinogenic risk for consumers (carcinogenic risk quotient between 1.33 and 13.98). In order to reduce carcinogenic risk, the study population should halve the monthly consumption of these foods, and also not to surpass the number of 5 servings of beef/pork/chicken (considered together). Copyright © 2015 Elsevier B.V. All rights reserved.

  8. rbcL and matK earn two thumbs up as the core DNA barcode for ferns.

    Directory of Open Access Journals (Sweden)

    Fay-Wei Li

    Full Text Available BACKGROUND: DNA barcoding will revolutionize our understanding of fern ecology, most especially because the accurate identification of the independent but cryptic gametophyte phase of the fern's life history--an endeavor previously impossible--will finally be feasible. In this study, we assess the discriminatory power of the core plant DNA barcode (rbcL and matK, as well as alternatively proposed fern barcodes (trnH-psbA and trnL-F, across all major fern lineages. We also present plastid barcode data for two genera in the hyperdiverse polypod clade--Deparia (Woodsiaceae and the Cheilanthes marginata group (currently being segregated as a new genus of Pteridaceae--to further evaluate the resolving power of these loci. PRINCIPAL FINDINGS: Our results clearly demonstrate the value of matK data, previously unavailable in ferns because of difficulties in amplification due to a major rearrangement of the plastid genome. With its high sequence variation, matK complements rbcL to provide a two-locus barcode with strong resolving power. With sequence variation comparable to matK, trnL-F appears to be a suitable alternative barcode region in ferns, and perhaps should be added to the core barcode region if universal primer development for matK fails. In contrast, trnH-psbA shows dramatically reduced sequence variation for the majority of ferns. This is likely due to the translocation of this segment of the plastid genome into the inverted repeat regions, which are known to have a highly constrained substitution rate. CONCLUSIONS: Our study provides the first endorsement of the two-locus barcode (rbcL+matK in ferns, and favors trnL-F over trnH-psbA as a potential back-up locus. Future work should focus on gathering more fern matK sequence data to facilitate universal primer development.

  9. Exploring the utility of three nuclear regions to reconstruct reticulate evolution in the fern genus Asplenium

    Institute of Scientific and Technical Information of China (English)

    Harald SCHNEIDER; Adriana NAVARRO-GOMEZ; Stephen J.RUSSELL; Stephen ANSELL; Michal GRUNDMANN; Johannes VOGEL

    2013-01-01

    Three nuclear regions nuclear ribosomal internal transcribed spacer (nrITS) and intron regions of two nuclear low-copy genes-gapCp,and pgiC,in combination with one chloroplast genome region were employed to explore patterns of reticulate evolution in the fern genus Asplenium.This is the one of the first studies using DNA sequences of multiple nuclear markers in ferns.All three nuclear markers amplified well with PCR and several copies were recovered by cloning PCR products.All three nuclear regions showed congruent results by recovering the neo-allotetraploid Asplenium adulterinum as the hybrid of diploid A.trichomanes and diploid A.viride.Conflicting results were obtained for several nodes.First,gapCp did not discriminate between A.aethiopicum and A.praegracile whereas the other markers recovered these two taxa as distinct.Conflicts among gene-trees were found in respect to A.monanthes,chloroplast and pgiC suggested a sister relationship ofA.monanthes and A.trichomanes but gapCp and nrITS nested A.monanthes within A.normale.Our results confirm:(i) the usefulness of several nuclear regions,in particular gapCp and pgiC,to unravel reticulate evolution in ferns and species differentiation and (ii) highlights the need to employ more than one nuclear region to obtain reliable hypotheses on reticulate events versus incomplete lineage sorting.Especially,if one assumes that the reticulation event might have occurred in the more distant past.Considering the expected high frequency of reticulate evolution in ferns,the establishment of robust and informative nuclear genomic markers is critical to achieve further progress in our efforts to elucidate fern evolution.

  10. Evidence for a Cenozoic radiation of ferns in an angiosperm-dominated canopy.

    Science.gov (United States)

    Schuettpelz, Eric; Pryer, Kathleen M

    2009-07-07

    In today's angiosperm-dominated terrestrial ecosystems, leptosporangiate ferns are truly exceptional--accounting for 80% of the approximately 11,000 nonflowering vascular plant species. Recent studies have shown that this remarkable diversity is mostly the result of a major leptosporangiate radiation beginning in the Cretaceous, following the rise of angiosperms. This pattern is suggestive of an ecological opportunistic response, with the proliferation of flowering plants across the landscape resulting in the formation of many new niches--both on forest floors and within forest canopies--into which leptosporangiate ferns could diversify. At present, one-third of leptosporangiate species grow as epiphytes in the canopies of angiosperm-dominated tropical rain forests. However, we know too little about the evolutionary history of epiphytic ferns to assess whether or not their diversification was in fact linked to the establishment of these forests, as would be predicted by the ecological opportunistic response hypothesis. Here we provide new insight into leptosporangiate diversification and the evolution of epiphytism by integrating a 400-taxon molecular dataset with an expanded set of fossil age constraints. We find evidence for a burst of fern diversification in the Cenozoic, apparently driven by the evolution of epiphytism. Whether this explosive radiation was triggered simply by the establishment of modern angiosperm-dominated tropical rain forest canopies, or spurred on by some other large-scale extrinsic factor (e.g., climate change) remains to be determined. In either case, it is clear that in both the Cretaceous and Cenozoic, leptosporangiate ferns were adept at exploiting newly created niches in angiosperm-dominated ecosystems.

  11. Fern spore longevity in saline water: can sea bottom sediments maintain a viable spore bank?

    Science.gov (United States)

    de Groot, G Arjen; During, Heinjo

    2013-01-01

    Freshwater and marine sediments often harbor reservoirs of plant diaspores, from which germination and establishment may occur whenever the sediment falls dry. Therewith, they form valuable records of historical inter- and intraspecific diversity, and are increasingly exploited to facilitate diversity establishment in new or restored nature areas. Yet, while ferns may constitute a considerable part of a vegetation's diversity and sediments are known to contain fern spores, little is known about their longevity, which may suffer from inundation and--in sea bottoms--salt stress. We tested the potential of ferns to establish from a sea or lake bottom, using experimental studies on spore survival and gametophyte formation, as well as a spore bank analysis on sediments from a former Dutch inland sea. Our experimental results revealed clear differences among species. For Asplenium scolopendrium and Gymnocarpium dryopteris, spore germination was not affected by inundated storage alone, but decreased with rising salt concentrations. In contrast, for Asplenium trichomanes subsp. quadrivalens germination decreased following inundation, but not in response to salt. Germination rates decreased with time of storage in saline water. Smaller and less viable gametophytes were produced when saline storage lasted for a year. Effects on germination and gametophyte development clearly differed among genotypes of A. scolopendrium. Spore bank analyses detected no viable spores in marine sediment layers. Only two very small gametophytes (identified as Thelypteris palustris via DNA barcoding) emerged from freshwater sediments. Both died before maturation. We conclude that marine, and likely even freshwater sediments, will generally be of little value for long-term storage of fern diversity. The development of any fern vegetation on a former sea floor will depend heavily on the deposition of spores onto the drained land by natural or artificial means of dispersal.

  12. The fern-spore abundance anomaly at the Cretaceous-Tertiary boundary: A regional bioevent in western North America

    Science.gov (United States)

    Fleming, R. F.; Nichols, D. J.

    At most localities where the palynological Cretaceous-Tertiary (K-T) boundary has been located in continuous deposition sequences in nonmarine rocks, an anomalous abundance of fern spores occurs immediately above the boundary. The fern-spore anomaly is characterized by unusually high relative abundance of fern spores and dominance by only one of a few species at each locality; it is independent of lithology. Its presence at the K-T boundary at localities from New Mexico to Saskatchewan is evidence of a regional bioevent in earliest Tertiary time: the overwhelming dominance of the continental flora by pioneer species following catastrophic destruction of existing plant communities by the terminal Cretaceous event.

  13. Towards incorporating epigenetic mechanisms into carcinogen identification and evaluation.

    Science.gov (United States)

    Herceg, Zdenko; Lambert, Marie-Pierre; van Veldhoven, Karin; Demetriou, Christiana; Vineis, Paolo; Smith, Martyn T; Straif, Kurt; Wild, Christopher P

    2013-09-01

    Remarkable progress in the field of epigenetics has turned academic, medical and public attention to the potential applications of these new advances in medicine and various fields of biomedical research. The result is a broader appreciation of epigenetic phenomena in the a etiology of common human diseases, most notably cancer. These advances also represent an exciting opportunity to incorporate epigenetics and epigenomics into carcinogen identification and safety assessment. Current epigenetic studies, including major international sequencing projects, are expected to generate information for establishing the 'normal' epigenome of tissues and cell types as well as the physiological variability of the epigenome against which carcinogen exposure can be assessed. Recently, epigenetic events have emerged as key mechanisms in cancer development, and while our search of the Monograph Volume 100 revealed that epigenetics have played a modest role in evaluating human carcinogens by the International Agency for Research on Cancer (IARC) Monographs so far, epigenetic data might play a pivotal role in the future. Here, we review (i) the current status of incorporation of epigenetics in carcinogen evaluation in the IARC Monographs Programme, (ii) potential modes of action for epigenetic carcinogens, (iii) current in vivo and in vitro technologies to detect epigenetic carcinogens, (iv) genomic regions and epigenetic modifications and their biological consequences and (v) critical technological and biological issues in assessment of epigenetic carcinogens. We also discuss the issues related to opportunities and challenges in the application of epigenetic testing in carcinogen identification and evaluation. Although the application of epigenetic assays in carcinogen evaluation is still in its infancy, important data are being generated and valuable scientific resources are being established that should catalyse future applications of epigenetic testing.

  14. Relationship between Structures and Carcinogenicities of Heterocyclic Amines

    Institute of Scientific and Technical Information of China (English)

    JU Xue-hai; DAI Qian-huan; CHEN Sha; WANG Wen-jun

    2004-01-01

    Semi-empirical molecular orbital calculations were performed on heterocyclic aromatic amines(HCAs). The relationship between the structures and the carcinogenicities can be rationally elucidated by the models based on the metabolism of HCAs and the Di-region theory. The degree of easiness for the formation of Di-region electrophilic centers determines the carcinogenic activity. There is a good linear relationship between the observed carcinogenicities and the PM3 calculated parameters, with r=0.973 and F=29.8>(F*0.*01).

  15. Dehydropyrrolizidine Alkaloid Toxicity, Cytotoxicity, and Carcinogenicity

    Directory of Open Access Journals (Sweden)

    Bryan L. Stegelmeier

    2016-11-01

    Full Text Available Dehydropyrrolizidine alkaloid (DHPA-producing plants have a worldwide distribution amongst flowering plants and commonly cause poisoning of livestock, wildlife, and humans. Previous work has produced considerable understanding of DHPA metabolism, toxicity, species susceptibility, conditions, and routes of exposure, and pathogenesis of acute poisoning. Intoxication is generally caused by contaminated grains, feed, flour, and breads that result in acute, high-dose, short-duration poisoning. Acute poisoning produces hepatic necrosis that is usually confirmed histologically, epidemiologically, and chemically. Less is known about chronic poisoning that may result when plant populations are sporadic, used as tisanes or herbal preparations, or when DHPAs contaminate milk, honey, pollen, or other animal-derived products. Such subclinical exposures may contribute to the development of chronic disease in humans or may be cumulative and probably slowly progress until liver failure. Recent work using rodent models suggest increased neoplastic incidence even with very low DHPA doses of short durations. These concerns have moved some governments to prohibit or limit human exposure to DHPAs. The purpose of this review is to summarize some recent DHPA research, including in vitro and in vivo DHPA toxicity and carcinogenicity reports, and the implications of these findings with respect to diagnosis and prognosis for human and animal health.

  16. Dehydropyrrolizidine Alkaloid Toxicity, Cytotoxicity, and Carcinogenicity

    Science.gov (United States)

    Stegelmeier, Bryan L.; Colegate, Steven M.; Brown, Ammon W.

    2016-01-01

    Dehydropyrrolizidine alkaloid (DHPA)-producing plants have a worldwide distribution amongst flowering plants and commonly cause poisoning of livestock, wildlife, and humans. Previous work has produced considerable understanding of DHPA metabolism, toxicity, species susceptibility, conditions, and routes of exposure, and pathogenesis of acute poisoning. Intoxication is generally caused by contaminated grains, feed, flour, and breads that result in acute, high-dose, short-duration poisoning. Acute poisoning produces hepatic necrosis that is usually confirmed histologically, epidemiologically, and chemically. Less is known about chronic poisoning that may result when plant populations are sporadic, used as tisanes or herbal preparations, or when DHPAs contaminate milk, honey, pollen, or other animal-derived products. Such subclinical exposures may contribute to the development of chronic disease in humans or may be cumulative and probably slowly progress until liver failure. Recent work using rodent models suggest increased neoplastic incidence even with very low DHPA doses of short durations. These concerns have moved some governments to prohibit or limit human exposure to DHPAs. The purpose of this review is to summarize some recent DHPA research, including in vitro and in vivo DHPA toxicity and carcinogenicity reports, and the implications of these findings with respect to diagnosis and prognosis for human and animal health. PMID:27916846

  17. Toxicity and Carcinogenicity of Dichlorodiphenyltrichloroethane (DDT)

    Science.gov (United States)

    Harada, Takanori; Takeda, Makio; Kojima, Sayuri; Tomiyama, Naruto

    2016-01-01

    Dichlorodiphenyltrichloroethane (DDT) is still used in certain areas of tropics and subtropics to control malaria and other insect-transmitted diseases. DDT and its metabolites have been extensively studied for their toxicity and carcinogenicity in animals and humans and shown to have an endocrine disrupting potential affecting reproductive system although the effects may vary among animal species in correlation with exposure levels. Epidemiologic studies revealed either positive or negative associations between exposure to DDT and tumor development, but there has been no clear evidence that DDT causes cancer in humans. In experimental animals, tumor induction by DDT has been shown in the liver, lung, and adrenals. The mechanisms of hepatic tumor development by DDT have been studied in rats and mice. DDT is known as a non-genotoxic hepatocarcinogen and has been shown to induce microsomal enzymes through activation of constitutive androstane receptor (CAR) and to inhibit gap junctional intercellular communication (GJIC) in the rodent liver. The results from our previously conducted 4-week and 2-year feeding studies of p,p′-DDT in F344 rats indicate that DDT may induce hepatocellular eosinophilic foci as a result of oxidative DNA damage and leads them to hepatic neoplasia in combination with its mitogenic activity and inhibitory effect on GJIC. Oxidative stress could be a key factor in hepatocarcinogenesis by DDT. PMID:26977256

  18. Tobacco carcinogen NNK-induced lung cancer animal models and associated carcinogenic mechanisms.

    Science.gov (United States)

    Ge, Guang-Zhe; Xu, Tian-Rui; Chen, Ceshi

    2015-07-01

    Tobacco usage is a major risk factor in the development, progression, and outcomes for lung cancer. Of the carcinogens associated with lung cancer, tobacco-specific nitrosamines 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is among the most potent ones. The oncogenic mechanisms of NNK are not entirely understood, hindering the development of effective strategies for preventing and treating smoking-associated lung cancers. Here, we introduce the NNK-induced lung cancer animal models in different species and its potential mechanisms. Finally, we summarize several chemopreventive agents developed from these animal models.

  19. Different leaf cost-benefit strategies of ferns distributed in contrasting light habitats of sub-tropical forests

    National Research Council Canada - National Science Library

    Zhu, Shi-Dan; Li, Rong-Hua; Song, Juan; He, Peng-Cheng; Liu, Hui; Berninger, Frank; Ye, Qing

    2016-01-01

    ...) have a different leaf cost-benefit strategy compared with ferns that occur in natural forests (FNF), with a quicker return on carbon investment in disturbed habitats compared with old-growth forests...

  20. Environmental carcinogens and mutational pathways in atherosclerosis.

    Science.gov (United States)

    Pulliero, A; Godschalk, R; Andreassi, M G; Curfs, D; Van Schooten, F J; Izzotti, A

    2015-05-01

    Atherosclerosis is associated with DNA damage in both circulating and vessel-wall cells and DNA adducts derived from exposure to environmental mutagens are abundant in atherosclerotic vessels. Environmental chemical carcinogens identified as risk factor for atherosclerosis include polycyclic aromatic hydrocarbons (benzo(a)pyrene, dimethylbenz(a)anthracene, beta-naphthoflavone, pyrene, 3-methylcolanthrene), arsenic, cadmium, 1,3-butadiene, cigarette smoke. Accordingly, polymorphisms of genes encoding for phase I/II metabolic reaction and DNA repair are risk factor for cardiovascular diseases, although their role is negligible as compared to other risk factors. The pathogenic relevance of mutation-related molecular damage in atherosclerosis has been demonstrated in experimental animal models involving the exposure to chemical mutagens. The relevance of mutation-related events in worsening atherosclerosis prognosis has been demonstrated in human clinical studies mainly as referred to mitochondrial DNA damage. Atherosclerosis is characterized by the occurrence of high level of oxidative damage in blood vessel resulting from both endogenous and exogenous sources. Mitochondrial damage is a main endogenous source of oxidative stress whose accumulation causes activation of intrinsic apoptosis through BIRC2 inhibition and cell loss contributing to plaque development and instability. Environmental physical mutagens, including ionizing radiation, are a risk factor for atherosclerosis even at the low exposure dose occurring in case of occupational exposure or the high exposure doses occurring during radiotherapy. Conversely, the role of exciting UV radiation in atherosclerosis is still uncertain. This review summarizes the experimental and clinical evidence supporting the pathogenic role of mutation-related pathway in atherosclerosis examining the underlying molecular mechanisms.

  1. Ferns are less dependent on passive dilution by cell expansion to coordinate leaf vein and stomatal spacing than angiosperms.

    Science.gov (United States)

    Carins Murphy, Madeline R; Jordan, Gregory J; Brodribb, Timothy J

    2017-01-01

    Producing leaves with closely spaced veins is a key innovation linked to high rates of photosynthesis in angiosperms. A close geometric link between veins and stomata in angiosperms ensures that investment in enhanced venous water transport provides the strongest net carbon return to the plant. This link is underpinned by "passive dilution" via expansion of surrounding cells. However, it is not known whether this 'passive dilution' mechanism is present in plant lineages other than angiosperms and is another key feature of the angiosperms' evolutionary success. Consequently, we sought to determine whether the 'passive dilution' mechanism is; (i) exclusive to the angiosperms, (ii) a conserved mechanism that evolved in the common ancestor of ferns and angiosperms, or (iii) has evolved continuously over time. To do this we first we assessed the plasticity of vein and stomatal density and epidermal cell size in ferns in response to light environment. We then compared the relationships between these traits found among ferns with modelled relationships that assume vein and stomatal density respond passively to epidermal cell expansion, and with those previously observed in angiosperms. Vein density, stomatal density and epidermal cell size were linked in ferns with remarkably similar relationships to those observed in angiosperms, except that fern leaves had fewer veins per stomata. However, plasticity was limited in ferns and stomatal spacing was dependent on active stomatal differentiation as well as passive cell expansion. Thus, ferns (like angiosperms) appear to coordinate vein and stomatal density with epidermal cell expansion to some extent to maintain a constant ratio between veins and stomata in the leaf. The different general relationships between vein density and stomatal density in ferns and angiosperms suggests the groups have different optimum balances between the production of vein tissue dedicated to water supply and stomatal tissue for gas exchange.

  2. Historical reconstruction of climatic and elevation preferences and the evolution of cloud forest-adapted tree ferns in Mesoamerica

    OpenAIRE

    Sosa, Victoria; Ornelas, Juan Francisco; Ramírez-Barahona, Santiago; Gándara, Etelvina

    2016-01-01

    Background Cloud forests, characterized by a persistent, frequent or seasonal low-level cloud cover and fragmented distribution, are one of the most threatened habitats, especially in the Neotropics. Tree ferns are among the most conspicuous elements in these forests, and ferns are restricted to regions in which minimum temperatures rarely drop below freezing and rainfall is high and evenly distributed around the year. Current phylogeographic data suggest that some of the cloud forest-adapted...

  3. Asphalt fume dermal carcinogenicity potential: I. dermal carcinogenicity evaluation of asphalt (bitumen) fume condensates.

    Science.gov (United States)

    Clark, Charles R; Burnett, Donald M; Parker, Craig M; Arp, Earl W; Swanson, Mark S; Minsavage, Gary D; Kriech, Anthony J; Osborn, Linda V; Freeman, James J; Barter, Robert A; Newton, Paul E; Beazley, Shelley L; Stewart, Christopher W

    2011-10-01

    Asphalt (bitumen) fume condensates collected from the headspace above paving and Type III built up roofing asphalt (BURA) tanks were evaluated in two-year dermal carcinogenicity assays in male C3H/HeNCrl mice. A third sample was generated from the BURA using a NIOSH laboratory generation method. Similar to earlier NIOSH studies, the BURA fume condensates were applied dermally in mineral oil twice per week; the paving sample was applied 7 days/week for a total weekly dose of 50 mg/wk in both studies. A single benign papilloma was observed in a group of 80 mice exposed to paving fume condensate at the end of the two-year study and only mild skin irritation was observed. The lab generated BURA fume condensate resulted in statistically significant (P<0.0001) increases in squamous cell carcinomas (35 animals or 55% of animals at risk). The field-matched BURA condensate showed a weaker but significant (P=0.0063) increase (8 carcinomas or 13% of animals) and a longer average latency (90 weeks vs. 76 for the lab fume). Significant irritation was observed in both BURA condensates. It is concluded that the paving fume condensate was not carcinogenic under the test conditions and that the field-matched BURA fume condensate produced a weak tumor response compared to the lab generated sample.

  4. Carcinogenicity and co-carcinogenicity studies on propoxur in mouse skin.

    Science.gov (United States)

    Shukla, Y; Baqar, S M; Mehrotra, N K

    1998-12-01

    Propoxur (2-isopropoxyphenyl methylcarbamate) is a widely used broad spectrum carbamate insecticide mainly used to control household pests. Propoxur exposure is reported to inhibit cholinesterase activity in rodents. Apart from other toxic effects, propoxur was found to possess tumorigenic activity in rats after oral administration. Propoxur does not produce tumours in mice or hamsters, or bladder hyperplasia in dogs and monkeys following oral feeding. In this set of investigations the complete carcinogenic, tumour initiating and promoting potential of propoxur was evaluated in male and female Swiss albino mice, since no information was available following dermal exposure of propoxur. The animals were exposed to propoxur through topical painting on the interscapular region at a dose of 100 mg/kg body weight. The results revealed that propoxur has tumour promoting potential on mouse skin following a two-stage initiation-promotion protocol, but it failed to induce the tumour(s) at a significant level, when tested for tumour initiating and complete carcinogenic property.

  5. Human exposure to dioxins through the diet in Catalonia, Spain: carcinogenic and non-carcinogenic risk.

    Science.gov (United States)

    Llobet, Juan M; Domingo, Jose L; Bocio, Ana; Casas, Conrad; Teixidó, Angel; Müller, Lutz

    2003-03-01

    The main objectives of this study were to estimate the dietary intake of dioxins by the population of Catalonia, Spain, to determine which food groups showed the greatest contribution to this intake, and to assess the health risks potentially associated with the dietary dioxin intake. From June to August 2000, food samples were randomly acquired in seven cities of Catalonia. Dioxin concentrations were determined in 108 samples belonging to the following groups: vegetables, fruits, pulses, cereals, fish and shellfish, meats and meat products, eggs, milk and dairy products, and oils and fats. Estimates of average daily food consumption were obtained from recent studies. Total dietary intake of dioxins for the general population of Catalonia was estimated to be 95.4 pg WHO-TEQ/day (78.4 pg I-TEQ/day), with fish and shellfish (31%), diary products (25%), cereals (14%) and meat (13%) showing the greatest percentages of contribution to dioxin intake. The contribution of all the rest of food groups to the total dietary intake was under 20%. The non-carcinogenic risk index of dioxin intake through the diet was in the range 0.34-1.36, while the carcinogenic risk level was 1,360 excess cancer over a lifetime of 70 years. Our results corroborate the decreasing tendency in dietary intake of dioxins found in recent studies (2000-2001) from various countries.

  6. Does the term carcinogen send the wrong message?

    Science.gov (United States)

    Flamm, W G; Hughes, D

    1997-08-19

    The term carcinogen has been used by scientists and health regulatory officials for decades. During the last 20 years there have been attempts to redefine the term to make it more rigorous. But, as predicted two decades ago by a benchmark-setting subcommittee of the National Cancer Advisory Board, advances in scientific understanding have brought about dramatic changes in the way we are able to view the term carcinogen. These changes, their scientific bases and their effect on defining the term carcinogen are described. An alternative to the use of the term carcinogen is suggested by the recently proposed US Environmental Agency's guidelines for cancer risk assessment which appear to be in accord with current scientific understanding and the importance of considering the factors affecting the term carcinogen. The guidelines set forth four questions, the answers to which could, in our judgment, replace the need to define or use the term carcinogen which, in light of new scientific knowledge, has become more misleading than useful.

  7. Trichloroethylene: Mechanistic, Epidemiologic and Other Supporting Evidence of Carcinogenic Hazard

    Science.gov (United States)

    Rusyn, Ivan; Chiu, Weihsueh A.; Lash, Lawrence H.; Kromhout, Hans; Hansen, Johnni; Guyton, Kathryn Z.

    2013-01-01

    The chlorinated solvent trichloroethylene (TCE) is a ubiquitous environmental pollutant. The carcinogenic hazard of TCE was the subject of a 2012 evaluation by a Working Group of the International Agency for Research on Cancer (IARC). Information on exposures, relevant data from epidemiologic studies, bioassays in experimental animals, and toxicity and mechanism of action studies was used to conclude that TCE is carcinogenic to humans (Group 1). This article summarizes the key evidence forming the scientific bases for the IARC classification. Exposure to TCE from environmental sources (including from hazardous waste sites and contaminated water) is common throughout the world. While workplace use of TCE has been declining, occupational exposures remain of concern, especially in developing countries. Strongest human evidence is from studies of occupational TCE exposure and kidney cancer. Positive, although less consistent, associations were reported for liver cancer and non-Hodgkin's lymphoma. TCE is carcinogenic at multiple sites in multiple species and strains of experimental animals. The mechanistic evidence includes extensive data on the toxicokinetics and genotoxicity of TCE and its metabolites. Together, available evidence provided a cohesive database supporting the human cancer hazard of TCE, particularly in the kidney. For other target sites of carcinogenicity, mechanistic and other data were found to be more limited. Important sources of susceptibility to TCE toxicity and carcinogenicity were also reviewed by the Working Group. In all, consideration of the multiple evidence streams presented herein informed the IARC conclusions regarding the carcinogenicity of TCE. PMID:23973663

  8. Trichloroethylene: Mechanistic, epidemiologic and other supporting evidence of carcinogenic hazard.

    Science.gov (United States)

    Rusyn, Ivan; Chiu, Weihsueh A; Lash, Lawrence H; Kromhout, Hans; Hansen, Johnni; Guyton, Kathryn Z

    2014-01-01

    The chlorinated solvent trichloroethylene (TCE) is a ubiquitous environmental pollutant. The carcinogenic hazard of TCE was the subject of a 2012 evaluation by a Working Group of the International Agency for Research on Cancer (IARC). Information on exposures, relevant data from epidemiologic studies, bioassays in experimental animals, and toxicity and mechanism of action studies was used to conclude that TCE is carcinogenic to humans (Group 1). This article summarizes the key evidence forming the scientific bases for the IARC classification. Exposure to TCE from environmental sources (including hazardous waste sites and contaminated water) is common throughout the world. While workplace use of TCE has been declining, occupational exposures remain of concern, especially in developing countries. The strongest human evidence is from studies of occupational TCE exposure and kidney cancer. Positive, although less consistent, associations were reported for liver cancer and non-Hodgkin lymphoma. TCE is carcinogenic at multiple sites in multiple species and strains of experimental animals. The mechanistic evidence includes extensive data on the toxicokinetics and genotoxicity of TCE and its metabolites. Together, available evidence provided a cohesive database supporting the human cancer hazard of TCE, particularly in the kidney. For other target sites of carcinogenicity, mechanistic and other data were found to be more limited. Important sources of susceptibility to TCE toxicity and carcinogenicity were also reviewed by the Working Group. In all, consideration of the multiple evidence streams presented herein informed the IARC conclusions regarding the carcinogenicity of TCE.

  9. Best practices for clinical pathology testing in carcinogenicity studies.

    Science.gov (United States)

    Young, Jamie K; Hall, Robert L; O'Brien, Peter; Strauss, Volker; Vahle, John L

    2011-02-01

    The Society of Toxicologic Pathology (STP) and American Society for Veterinary Clinical Pathology (ASCVP) convened a Clinical Pathology in Carcinogenicity Studies Working Group to recommend best practices for inclusion of clinical pathology testing in carcinogenicity studies. Regulatory guidance documents and literature were reviewed, and veterinary pathologists from North America, Japan, and Europe were surveyed regarding current practices, perceived value, and recommendations for clinical pathology testing in carcinogenicity studies. For two-year rodent carcinogenicity studies, the Working Group recommends that clinical pathology testing be limited to collection of blood smears at scheduled and unscheduled sacrifices to be examined only if indicated to aid in the diagnosis of possible hematopoietic neoplasia following histopathologic evaluation. Additional clinical pathology testing is most appropriately used to address specific issues from prior toxicity studies or known test article-related class effects. Inadequate data were available to make a recommendation concerning clinical pathology testing for alternative six-month carcinogenicity assays using genetically modified mice, although the Working Group suggests that it may be appropriate to use the same approach as for two-year carcinogenicity studies since the study goal is the same.

  10. Glycoside Hydrolase (GH) 45 and 5 Candidate Cellulases in Aphelenchoides besseyi Isolated from Bird’s-Nest Fern

    Science.gov (United States)

    Tsay, Tung-Tsuan; Tsai, Isheng J.; Chen, Peichen J.

    2016-01-01

    Five Aphelenchoides besseyi isolates collected from bird’s-nest ferns or rice possess different parasitic capacities in bird’s-nest fern. Two different glycoside hydrolase (GH) 45 genes were identified in the fern isolates, and only one was found in the rice isolates. A Abe GH5-1 gene containing an SCP-like family domain was found only in the fern isolates. Abe GH5-1 gene has five introns suggesting a eukaryotic origin. A maximum likelihood phylogeny revealed that Abe GH5-1 is part of the nematode monophyletic group that can be clearly distinguished from those of other eukaryotic and bacterial GH5 sequences with high bootstrap support values. The fern A. besseyi isolates were the first parasitic plant nematode found to possess both GH5 and GH45 genes. Surveying the genome of the five A. besseyi isolates by Southern blotting using an 834 bp probe targeting the GH5 domain suggests the presence of at least two copies in the fern-origin isolates but none in the rice-origin isolates. The in situ hybridization shows that the Abe GH5-1 gene is expressed in the nematode ovary and testis. Our study provides insights into the diversity of GH in isolates of plant parasitic nematodes of different host origins. PMID:27391812

  11. No evidence of general CO2 insensitivity in ferns: one stomatal control mechanism for all land plants?

    Science.gov (United States)

    Franks, Peter J; Britton-Harper, Zoe J

    2016-08-01

    Stomatal regulation of plant carbon uptake and water loss under changing environmental conditions was a crucial evolutionary step in the colonization of land by plants. There are currently two conflicting models describing the nature of stomatal regulation across terrestrial vascular plants: the first is characterized by a fundamental mechanistic similarity across all lineages, and the second is characterized by the evolution of major differences in angiosperms compared with more ancient lineages. Specifically, the second model posits that stomata of ferns lack a response to elevated atmospheric CO2 concentration (ca ) and therefore cannot regulate leaf intercellular CO2 concentration (ci ). We compared stomatal sensitivity to changes in ca in three distantly related fern species and a representative angiosperm species. Fern and angiosperm stomata responded strongly and similarly to changes in ca . As a result, ci /ca was maintained within narrow limits during ca changes. Our results challenge the model in which stomata of ferns generally lack a response to elevated ca and that angiosperms evolved new dynamic mechanisms for regulating leaf gas exchange that differ fundamentally from ferns. Instead, the results are consistent with a universal stomatal control mechanism that is fundamentally conserved across ferns and angiosperms, and therefore likely all vascular plant divisions.

  12. Two azole fungicides (carcinogenic triadimefon and non-carcinogenic myclobutanil) exhibit different hepatic cytochrome P450 activities in medaka fish

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chun-Hung [Department of Agricultural Chemistry, National Taiwan University, Taipei, Taiwan (China); Chou, Pei-Hsin [Department of Environmental Engineering, National Cheng-Kung University, Tainan, Taiwan (China); Chen, Pei-Jen, E-mail: chenpj@ntu.edu.tw [Department of Agricultural Chemistry, National Taiwan University, Taipei, Taiwan (China)

    2014-07-30

    Highlights: • We assess ecotoxicological impact of azole fungicides in the aquatic environment. • Carcinogenic and non-carcinogenic azoles show different CYP activities in medaka. • We compare azole-induced CYP expression and carcinogenesis between fish and rodents. • Liver CYP-enzyme induction is a key event in conazole-induced tumorigenesis. • We suggest toxicity evaluation methods for azole fungicides using medaka fish. - Abstract: Conazoles are a class of imidazole- or triazole-containing drugs commonly used as fungicides in agriculture and medicine. The broad application of azole drugs has led to the contamination of surface aquifers receiving the effluent of municipal or hospital wastewater or agricultural runoff. Several triazoles are rodent carcinogens; azole pollution is a concern to environmental safety and human health. However, the carcinogenic mechanisms associated with cytochrome P450 enzymes (CYPs) of conazoles remain unclear. We exposed adult medaka fish (Oryzias latipes) to continuous aqueous solutions of carcinogenic triadimefon and non-carcinogenic myclobutanil for 7 to 20 days at sub-lethal or environmentally relevant concentrations and assessed hepatic CYP activity and gene expression associated with CYP-mediated toxicity. Both triadimefon and myclobutanil induced hepatic CYP3A activity, but only triadimefon enhanced CYP1A activity. The gene expression of cyp3a38, cyp3a40, pregnane x receptor (pxr), cyp26b, retinoid acid receptor γ1 (rarγ1) and p53 was higher with triadimefon than myclobutanil. As well, yeast-based reporter gene assay revealed that 4 tested conazoles were weak agonists of aryl hydrocarbon receptor (AhR). We reveal differential CYP gene expression with carcinogenic and non-carcinogenic conazoles in a lower vertebrate, medaka fish. Liver CYP-enzyme induction may be a key event in conazole-induced tumorigenesis. This information is essential to evaluate the potential threat of conazoles to human health and fish

  13. Two azole fungicides (carcinogenic triadimefon and non-carcinogenic myclobutanil) exhibit different hepatic cytochrome P450 activities in medaka fish.

    Science.gov (United States)

    Lin, Chun-Hung; Chou, Pei-Hsin; Chen, Pei-Jen

    2014-07-30

    Conazoles are a class of imidazole- or triazole-containing drugs commonly used as fungicides in agriculture and medicine. The broad application of azole drugs has led to the contamination of surface aquifers receiving the effluent of municipal or hospital wastewater or agricultural runoff. Several triazoles are rodent carcinogens; azole pollution is a concern to environmental safety and human health. However, the carcinogenic mechanisms associated with cytochrome P450 enzymes (CYPs) of conazoles remain unclear. We exposed adult medaka fish (Oryzias latipes) to continuous aqueous solutions of carcinogenic triadimefon and non-carcinogenic myclobutanil for 7 to 20 days at sub-lethal or environmentally relevant concentrations and assessed hepatic CYP activity and gene expression associated with CYP-mediated toxicity. Both triadimefon and myclobutanil induced hepatic CYP3A activity, but only triadimefon enhanced CYP1A activity. The gene expression of cyp3a38, cyp3a40, pregnane x receptor (pxr), cyp26b, retinoid acid receptor γ1 (rarγ1) and p53 was higher with triadimefon than myclobutanil. As well, yeast-based reporter gene assay revealed that 4 tested conazoles were weak agonists of aryl hydrocarbon receptor (AhR). We reveal differential CYP gene expression with carcinogenic and non-carcinogenic conazoles in a lower vertebrate, medaka fish. Liver CYP-enzyme induction may be a key event in conazole-induced tumorigenesis. This information is essential to evaluate the potential threat of conazoles to human health and fish populations in the aquatic environment.

  14. Invariant Hough random ferns for RGB-D-based object detection

    Science.gov (United States)

    Lou, Xiaoping; Dong, Mingli; Wang, Jun; Sun, Peng; Lin, Yimin

    2016-09-01

    This paper studies the challenging problem of object detection using rich image and depth features. An invariant Hough random ferns framework for RGB-D images is proposed here, which primarily consists of a rotation-invariant RGB-D local binary feature, random ferns classifier training, Hough mapping and voting, searches for the maxima, and back projection. In comparison with traditional three-dimensional local feature extraction techniques, this method is effective in reducing the amount of computation required for feature extraction and matching. Moreover, the detection results showed that the proposed method is robust against rotation and scale variations, changes in illumination, and part-occlusions. The authors believe that this method will facilitate the use of perception in fields such as robotics.

  15. Antheridiogen determines sex in ferns via a spatiotemporally split gibberellin synthesis pathway.

    Science.gov (United States)

    Tanaka, Junmu; Yano, Kenji; Aya, Koichiro; Hirano, Ko; Takehara, Sayaka; Koketsu, Eriko; Ordonio, Reynante Lacsamana; Park, Seung-Hyun; Nakajima, Masatoshi; Ueguchi-Tanaka, Miyako; Matsuoka, Makoto

    2014-10-24

    Some ferns possess the ability to control their sex ratio to maintain genetic variation in their colony with the aid of antheridiogen pheromones, antheridium (male organ)-inducing compounds that are related to gibberellin. We determined that ferns have evolved an antheridiogen-mediated communication system to produce males by modifying the gibberellin biosynthetic pathway, which is split between two individuals of different developmental stages in the colony. Antheridiogen acts as a bridge between them because it is more readily taken up by prothalli than bioactive gibberellin. The pathway initiates in early-maturing prothalli (gametophytes) within a colony, which produce antheridiogens and secrete them into the environment. After the secreted antheridiogen is absorbed by neighboring late-maturing prothalli, it is modified in to bioactive gibberellin to trigger male organ formation.

  16. Solubility and accumulation of metals in Chinese brake fern, vetiver and rostrate sesbania using chelating agents.

    Science.gov (United States)

    Lou, L Q; Ye, Z H; Wong, M H

    2007-01-01

    Greenhouse experiments were conducted to study the effects of chelating agents on the growth and metal accumulation of Chinese brake fern (Pteris vittata L.), vetiver (Vetiveria zizanioides L.), and rostrate sesbania (Sesbania rostrata L.) in soil contaminated with arsenic (As), Cu, Pb, and Zn. Among the five chelating agents used [ethylenediaminetriacetic acid (EDTA), hydroxyethylenediaminetriacetic acid (HEDTA), nitrilotriacetic acid (NTA), oxalic acid (OA), and phytic acid (PA)], OA was the best to mobilize As, EDTA to mobilize Cu and Pb, and HEDTA to mobilize Zn from soil, respectively. The biomass of vetiver was the highest, followed by rostrate sesbania. All chelating agents inhibited the growth of Chinese brake fern and rostrate sesbania, but HEDTA significantly increased the aboveground biomass of vetiver. Dry weights of both Chinese brake fern and rostrate sesbania decreased with increasing EDTA concentrations amended in the soil, especially in treatments with high EDTA concentrations. EDTA and HEDTA enhanced Cu, Zn, and Pb, but lowered As accumulation in all three plant species, except for As in vetiver, while OA significantly enhanced As accumulation in the aboveground part of vetiver. Concentrations of Cu, Zn, and Pb in the aboveground parts of plants increased significantly with the increase of EDTA concentrations and treatment time. In addition to As, Chinese brake fern also accumulated the highest Cu, Pb, and Zn in its aboveground parts among the three plant species grown in metal-contaminated soil with EDTA/HEDTA treatments. This species, therefore, can be used to simultaneously clean up As, Cu, Pb, and Zn from contaminated soils with the aid of EDTA or HEDTA.

  17. RESEARCHES CONCERNING THE IN VITRO DIFFERENTIATION OF THE FERN PHEGOPTERIS CONNECTILIS (MICHX.) WATT

    OpenAIRE

    Liliana Cristina SOARE; Emilia VISOIU; ANDREI, M.

    2007-01-01

    Phegopteris connectilis is an apogamous species, endangered in certain regions. The ex situ conservation, through the in vitro production of the gametophyte, as well as the embryos and the plants, followed by their cryo-stocking, is necessary for ensuring the survival of the endangered species, while at pace with international methodology. The differentiation of the gametophyte is characteristic of the leptosporangiate ferns, passing through the following stages: prothallic filament, prothall...

  18. First megafossil evidence of Cyatheaceous tree fern from the Indian Cenozoic

    Indian Academy of Sciences (India)

    Subir Bera; Sudha Gupta; Mahasin Ali Khan; Aniruddha De; Radhanath Mukhopadhyay

    2014-08-01

    A part of the compressed tree fern axis with leaf and adventitious root scars in unusual arrangement from Plio–Pleistocene sediments of Arunachal Pradesh, India is described as Cyathea siwalika sp. nov. This record suggests that Cyathea was an important component of tropical evergreen forest in the area during the Plio–Pleistocene and this group subsequently declined in importance within the local vegetation.

  19. DPPH FREE RADICAL SCAVENGER ACTIVITY OF FLAVONOID FROM THE LEAVES OF FERN Chingia sakayensis (Zeiller Holtt

    Directory of Open Access Journals (Sweden)

    Suyatno Suyatno

    2010-06-01

    Full Text Available A flavonoid compound in flavonol type namely kaemferol was isolated from the ethyl acetate fraction of the methanol extract of the fern Chingia sakayensis (Zeiller Holtt's leaves. The DPPH free radical scavenger activity of kaemferol was stronger than buthyl hyroxy toluene (BHT but it was weaker than ascorbic acid (vitamin C and -tocopherol (vitamin E.   Keywords: Chingia sakayensis, kaemferol, DPPH free radical scavenger activity

  20. Desiccation tolerance mechanism in resurrection fern-ally Selaginella tamariscina revealed by physiological and proteomic analysis.

    Science.gov (United States)

    Wang, Xiaonan; Chen, Sixue; Zhang, Heng; Shi, Lei; Cao, Fenglin; Guo, Lihai; Xie, Yongming; Wang, Tai; Yan, Xiufeng; Dai, Shaojun

    2010-12-03

    Drought is one of the most severe limitations to plant growth and productivity. Resurrection plants have evolved a unique capability to tolerate desiccation in vegetative tissues. Fern-ally Selaginella tamariscina (Beauv.) is one of the most primitive vascular resurrection plants, which can survive a desiccated state and recover when water becomes available. To better understand the mechanism of desiccation tolerance, we have applied physiological and proteomic analysis. Samples of S. tamariscina were water-deprived for up to seven days followed by 12 h of rewatering. Our results showed that endogenous abscisic acid (ABA) increased to regulate dehydration-responsive genes/proteins and physiological processes. In the course of dehydration, the contents of osmolytes represented by soluble sugars and proline were increased to maintain cell structure integrity. The activities of four antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and glutathione reductase (GR)) also increased. In contrast, both the rate of photosynthesis and the chlorophyll content decreased, and plasma membrane integrity was lost. We identified 138 desiccation-responsive two-dimensional electrophoresis (2-DE) spots, representing 103 unique proteins. Hierarchical clustering analysis revealed that 83% of the proteins were down-regulated upon dehydration. They were mainly involved in photosynthesis, carbohydrate and energy metabolism, stress and defense, protein metabolism, signaling, membrane/transport, cell structure, and cell division. The dynamic expression changes of the desiccation-responsive proteins provide strong evidence that cell structure modification, photosynthesis reduction, antioxidant system activation, and protein post-transcriptional/translational modifications are essential to the poikilochlorophyllous fern-ally S. tamariscina in response to dehydration. In addition, our comparative analysis of dehydration-responsive proteins in vegetative tissues

  1. First megafossil evidence of Cyatheaceous tree fern from the Indian Cenozoic

    Science.gov (United States)

    Bera, Subir; Gupta, Sudha; Khan, Mahasin Ali; De, Aniruddha; Mukhopadhyay, Radhanath

    2014-08-01

    A part of the compressed tree fern axis with leaf and adventitious root scars in unusual arrangement from Plio-Pleistocene sediments of Arunachal Pradesh, India is described as Cyathea siwalika sp. nov. This record suggests that Cyathea was an important component of tropical evergreen forest in the area during the Plio-Pleistocene and this group subsequently declined in importance within the local vegetation.

  2. A new population of Aleutian shield fern (Polystichum aleuticum C. Christens.) on Adak Island, Alaska

    Science.gov (United States)

    Talbot, Sandra L.; Talbot, Stephen S.

    2002-01-01

    We report and describe a new population of the endangered Aleutian shield fern (Polystichum aleuticum C. Christens.) discovered on Mount Reed, Adak Island, Alaska. The new population is located at a lower elevation than the other known populations, placing the species' known elevational range between 338 m and 525 m. The discovery of this population is significant because it increases the total number of known populations and individuals for the species.

  3. Gene flow among populations of two rare co-occurring fern species differing in ploidy level.

    Science.gov (United States)

    Bucharová, Anna; Münzbergová, Zuzana

    2012-01-01

    Differences in ploidy levels among different fern species have a vast influence on their mating system, their colonization ability and on the gene flow among populations. Differences in the colonization abilities of species with different ploidy levels are well known: tetraploids, in contrast to diploids, are able to undergo intra-gametophytic selfing. Because fertilization is a post-dispersal process in ferns, selfing results in better colonization abilities in tetraploids because of single spore colonization. Considerably less is known about the gene flow among populations of different ploidy levels. The present study examines two rare fern species that differ in ploidy. While it has already been confirmed that tetraploid species are better at colonizing, the present study focuses on the gene flow among existing populations. We analyzed the genetic structure of a set of populations in a 10×10 km study region using isoenzymes. Genetic variation in tetraploid species is distributed mainly among populations; the genetic distance between populations is correlated with the geographical distance, and larger populations host more genetic diversity than smaller populations. In the diploid species, most variability is partitioned within populations; the genetic distance is not related to geographic distance, and the genetic diversity of populations is not related to the population size. This suggests that in tetraploid species, which undergo selfing, gene flow is limited. In contrast, in the diploid species, which experience outcrossing, gene flow is extensive and the whole system behaves as one large population. Our results suggest that in ferns, the ability to colonize new habitats and the gene flow among existing populations are affected by the mating system.

  4. New Fern Materials from Guizhou%贵州蕨类植物新资料

    Institute of Scientific and Technical Information of China (English)

    潘炉台; 赵俊华; 王培善

    2011-01-01

    Tectaria yunnanensis (Bak.) Ching, a new recorded fern species in Guizhou and a new variety,Pteris deltodon Bak. var. monstrosa P. S. Wang et J. H. Zhao collected by the authors are now delivered as follows.%报道了贵州一新记录蕨类植物种--云南三叉蕨和一新变种--畸形岩凤尾蕨.

  5. Horsetails are the sister group to all other monilophytes and Marattiales are sister to leptosporangiate ferns.

    Science.gov (United States)

    Knie, Nils; Fischer, Simon; Grewe, Felix; Polsakiewicz, Monika; Knoop, Volker

    2015-09-01

    The "Monilophyte" clade comprising ferns, horsetails and whisk ferns receives unequivocal support from molecular data as the sister clade to seed plants. However, the branching order of its earliest emerging lineages, the Equisetales (horsetails), the Marattiales, the Ophioglossales/Psilotales and the large group of leptosporangiate ferns has remained dubious. We investigated the mitochondrial nad2 and rpl2 genes as two new, intron-containing loci for a wide sampling of taxa. We found that both group II introns - nad2i542g2 and rpl2i846g2 - are universally present among monilophytes. Both introns have orthologues in seed plants where nad2i542g2 has evolved into a trans-arrangement. In contrast and despite substantial size extensions to more than 5kb in Psilotum, nad2i542g2 remains cis-arranged in the monilophytes. For phylogenetic analyses, we filled taxonomic gaps in previously investigated mitochondrial (atp1, nad5) and chloroplast (atpA, atpB, matK, rbcL, rps4) loci and created a 9-gene matrix that also included the new mitochondrial nad2 and rpl2 loci. We extended the taxon sampling with two taxa each for all land plant outgroups (liverworts, mosses, hornworts, lycophytes and seed plants) to minimize the risk of phylogenetic artefacts. We ultimately obtained a well-supported molecular phylogeny placing Marattiales as sister to leptosporangiate ferns and horsetails as sister to all remaining monilophytes. In addition, an indel in an exon of the here introduced rpl2 locus independently supports the placement of horsetails. We conclude that under dense taxon sampling, phylogenetic information from a prudent choice of loci is currently superior to character-rich phylogenomic approaches at low taxon sampling. As here shown the selective choice of loci and taxa enabled us to resolve the long-enigmatic diversifications of the earliest monilophyte lineages.

  6. Juan Caramuel y la probable arquitectura. Jorge Fernández-Santos

    OpenAIRE

    Gil Saura, Yolanda

    2016-01-01

    Reseña del libro de Jorge Fernández-Santos Ortiz-Iribas, Juan Caramuel y la probable arquitectura. Centro de Estudios Europa Hispánica, Madrid, 2014, 592 págs., 114 ilustraciones en color. Analiza la aportación del libro en relación a la historiografía de la arquitectura barroca española.

  7. Distribution, habitat preferences and population sizes of two threatened tree ferns, Cyathea cunninghamii and Cyathea x marcescens, in south-eastern Australia

    OpenAIRE

    Peacock, Ross J.; Downing, Alison; Brownsey, Patrick; Cameron, David

    2013-01-01

    The distribution, population sizes and habitat preferences of the rare tree ferns Cyathea cunninghamii Hook.f. (Slender Tree Fern) and F1 hybrid Cyathea x marcescens N.A.Wakef. (Skirted Tree Fern) in south-eastern Australia are described, together with the extension of the known distribution range of Cyathea cunninghamii from eastern Victoria into south-eastern New South Wales. Floristic and ecological data, encompassing most of the known habitat types, vegetation associations and population ...

  8. The Enrichment and Transfer of Heavy Metals for Two Ferns in Pb-Zn Tailing

    Directory of Open Access Journals (Sweden)

    Mai Jiajie

    2017-01-01

    Full Text Available The enrichment and transfer of 8 heavy metals of Equisetum ramosissimum and Pteris vittata growing naturally close to edge of the sewage pool in Bencun Pb-Zn Tailing, Eastern Guangdong were investigated. The results indicated that the pollution of Cd, Pb, Hg, Zn was very severe in this tailing, followed by Cu and Mn. The potential ecological risk of heavy metals was assessed to be very strong based on soil background values of Guangdong Province and at high risk according to criteria of the second grade State Soil Environmental Quality Standard, and Cd, Hg, Pb were the main factors leading to potential ecological risk. The content of 8 heavy metals in the two ferns did not reach critical content of hyperaccumulator, so neither of them was typical hyperaccumulator, but both had a certain tolerance to these heavy metal pollution. Underground parts of Pteris vittata had an enrichment coefficient above 1 and that of Equisetum ramosissimum had a value near 1, therefore the two ferns could be utilized as potential enrichment plants. The two ferns have strong adaptability to the tailing habitat and can be used as pioneers in ecological restoration of Pb-Zn tailings.

  9. The accumulation and subcellular distribution of arsenic and antimony in four fern plants.

    Science.gov (United States)

    Feng, R; Wang, X; Wei, C; Tu, S

    2015-01-01

    In the present study, Pteris cretica 'Albo-Lineata' (PC), Pteris fauriei (PF), Humata tyermanii Moore (HT), and Pteris ensiformis Burm (PE), were selected to explore additional plant materials for the phytoremediation of As and Sb co-contamination. To some extent, the addition of As and Sb enhanced the growth of HT, PE, and PF. Conversely, the addition of As and Sb negatively affected the growth of PC and was accompanied with the accumulation of high levels of As and Sb in the roots. The highest concentration of Sb was recorded as 6405 mg kg(-1) in the roots of PC, and that for As was 337 mg kg(-1) in the rhizome of PF. To some degree, As and Sb stimulated the uptake of each other in these ferns. Arsenic was mainly stored in the cytoplasmic supernatant (CS) fraction, followed by the cell wall (CW) fraction. In contrast, Sb was mainly found in the CW fraction and, to a lesser extent, in the CS fraction, suggesting that the cell wall and cytosol play different roles in As and Sb accumulation by fern plants. This study demonstrated that these fern plants show a good application potential in the phytoremediation of As and Sb co-contaminated environments.

  10. Mycorrhizal fungi modify element distribution in gametophytes and sporophytes of a fern Pellaeaviridis from metaliferous soils.

    Science.gov (United States)

    Turnau, Katarzyna; Przybyłowicz, Wojciech J; Ryszka, Przemysław; Orłowska, Elżbieta; Anielska, Teresa; Mesjasz-Przybyłowicz, Jolanta

    2013-08-01

    In the present study, the element distribution within mycothallic and nonmycothallic gametophytes and the early stages of sporophyte development of Pellaea viridis (Pteridaceae) were investigated. Gametophytes of this fern were collected from soil samples originating in the ultramafic area of the Agnes Mine near Barberton, South Africa. The gametophytes were grown on both the original soil and on a plant growth substratum obtained from the local botanical garden. Gametophytes and young sporophytes grown on substratum inoculated with Glomus tenue or non-inoculated were freeze-dried, and the distribution of elements was studied using micro-PIXE. The GeoPIXE II software package was used for quantitative elemental mapping complemented by data extracted from arbitrarily selected micro-areas. The obtained results suggest that although the fern itself avoids the uptake of large amounts of heavy metals, increased levels of Ni, Cr, Fe, Co and Ti were found in the part of the gametophyte that hosted the fungal endophyte. This finding suggests that the fungus might be active in the immobilisation of certain potentially toxic metals that are taken up from the soil by the plant, although other mechanisms cannot be excluded. For the first time, precise, quantitative measurements of the concentration of individual elements in the fern gametophytes and young sporophytes were obtained, along with their distribution within the plant parts.

  11. Fern and lycophyte guard cells do not respond to endogenous abscisic acid.

    Science.gov (United States)

    McAdam, Scott A M; Brodribb, Timothy J

    2012-04-01

    Stomatal guard cells regulate plant photosynthesis and transpiration. Central to the control of seed plant stomatal movement is the phytohormone abscisic acid (ABA); however, differences in the sensitivity of guard cells to this ubiquitous chemical have been reported across land plant lineages. Using a phylogenetic approach to investigate guard cell control, we examined the diversity of stomatal responses to endogenous ABA and leaf water potential during water stress. We show that although all species respond similarly to leaf water deficit in terms of enhanced levels of ABA and closed stomata, the function of fern and lycophyte stomata diverged strongly from seed plant species upon rehydration. When instantaneously rehydrated from a water-stressed state, fern and lycophyte stomata rapidly reopened to predrought levels despite the high levels of endogenous ABA in the leaf. In seed plants under the same conditions, high levels of ABA in the leaf prevented rapid reopening of stomata. We conclude that endogenous ABA synthesized by ferns and lycophytes plays little role in the regulation of transpiration, with stomata passively responsive to leaf water potential. These results support a gradualistic model of stomatal control evolution, offering opportunities for molecular and guard cell biochemical studies to gain further insights into stomatal control.

  12. Cytological features of oogenesis and their evolutionary significance in the fern Osmunda japonica.

    Science.gov (United States)

    Cao, Jian-Guo; Dai, Xiao-Fei; Wang, Quan-Xi

    2012-03-01

    The development of the egg and canal cells in the fern Osmunda japonica Thunb. was studied during oogenesis by transmission electron microscopy. The mature egg possesses no fertilization pore and no typical egg envelope. In addition, an extra wall formed around the canal cells during oogenesis and apparently blocked protoplasmic connections between the egg and the canal cells. The periodic acid Schiff (PAS) reaction revealed that the extra wall was most likely composed of polysaccharides. Maturation of the egg was accompanied by the formation of a separation cavity above the egg and by some changes in the morphology of the nucleus and cytoplasmic organelles. The chromatin of the nucleus becomes condensed and the upper surface of the nucleus becomes closely associated with the plasmalemma. Amyloplasts in the egg cytoplasm were numerous and conspicuous, with most in close proximity to the nucleus. Finally, the cytoplasm on one side of the egg became vesiculated and the overlying plasmalemma was easily disrupted. These cytological features of the egg and the canal cells during oogenesis in O. japonica are markedly different from those of the leptosporangiate ferns and suggest a significant evolutionary divergence in reproductive cellular features between Osmundaceae and leptosporangiate ferns.

  13. High-efficiency stable transformation of the model fern species Ceratopteris richardii via microparticle bombardment.

    Science.gov (United States)

    Plackett, Andrew R G; Huang, Liandong; Sanders, Heather L; Langdale, Jane A

    2014-05-01

    Ferns represent the most closely related extant lineage to seed plants. The aquatic fern Ceratopteris richardii has been subject to research for a considerable period of time, but analyses of the genetic programs underpinning developmental processes have been hampered by a large genome size, a lack of available mutants, and an inability to create stable transgenic lines. In this paper, we report a protocol for efficient stable genetic transformation of C. richardii and a closely related species Ceratopteris thalictroides using microparticle bombardment. Indeterminate callus was generated and maintained from the sporophytes of both species using cytokinin treatment. In proof-of-principle experiments, a 35S::β-glucuronidase (GUS) expression cassette was introduced into callus cells via tungsten microparticles, and stable transformants were selected via a linked hygromycin B resistance marker. The presence of the transgene in regenerated plants and in subsequent generations was validated using DNA-blot analysis, reverse transcription-polymerase chain reaction, and GUS staining. GUS staining patterns in most vegetative tissues corresponded with constitutive gene expression. The protocol described in this paper yields transformation efficiencies far greater than those previously published and represents a significant step toward the establishment of a tractable fern genetic model.

  14. The distribution of TPX2 in dividing leaf cells of the fern Asplenium nidus.

    Science.gov (United States)

    Panteris, E; Adamakis, I-D S; Chanoumidou, K

    2013-01-01

    Plant cell division requires the dynamic organisation of several microtubule arrays. The mechanisms of regulation of the above arrays are under rigorous research. Among several factors that are involved in plant microtubule dynamics, the Targeting Protein for Xklp2 (TPX2) has been found to play a role in spindle organisation, in combination with Aurora kinases, in dividing cells of angiosperms. Microtubule organisation in dividing cells of ferns exhibits certain peculiarities. Accordingly, the presence and distribution of a TPX2 homologue might be helpful in understanding the patterns and regulatory mechanisms of microtubule arrays in this plant group. In this study, a putative TPX2 homologue was identified using Western blotting in the fern Asplenium nidus. It was found, using immunostaining and CLSM, that it is co-localised with perinuclear preprophase microtubules and the prophase spindle, and follows the microtubule pattern during metaphase/anaphase and telophase. During cytokinesis, while in angiosperms TPX2 is degraded, in A. nidus the TPX2 signal persists, co-localising with the phragmoplast. In early post-cytokinetic cells, a TPX2 signal is present on the nuclear surface facing the daughter cell wall and, thereafter it is co-localised with the fern-specific microtubule aggregation that lines the new wall, which is possibly involved in cortical microtubule assembly.

  15. A phytotoxic active substance in the decomposing litter of the fern Gleichenia japonica.

    Science.gov (United States)

    Kato-Noguchi, Hisashi; Saito, Yoshihumi; Ohno, Osamu; Suenaga, Kiyotake

    2015-03-15

    The fern Gleichenia japonica often dominates plant communities by forming large monospecific stands throughout the temperate to tropical Asia. The objective of this study was the investigation of allelopathic property and substances of the decomposing litter of the fern to evaluate the possible involvement of its allelopathy in the domination. An aqueous methanol extract of G. japonica litter inhibited the growth of garden cress (Lepidium sativum), lettuce (Lactuca sativa), barnyard grass (Echinochloa crus-galli), and ryegrass (Lolium multiflorum). This result suggests that G. japonica litter contains growth inhibitory substances. The extract was purified by chromatography while monitoring the inhibitory activity, and a growth inhibitory substance was isolated. The chemical structure of the substance was determined by spectral data to be a novel compound, 13-O-β-fucopyranosyl-3β-hydroxymanool. This compound inhibited root and shoot growth of garden cress and barnyard grass at concentrations ranging from 89.7 to 271 μM for 50% inhibition. In addition, the compound had potent growth inhibitory activity with the soil taken from near the colony. The concentration of the compound in soil under a pure colony of G. japonica was 790 μM, suggesting that the compound may contribute to the establishment of monocultural stands by this fern.

  16. Not dead yet: the seasonal water relations of two perennial ferns during California's exceptional drought.

    Science.gov (United States)

    Baer, Alex; Wheeler, James K; Pittermann, Jarmila

    2016-04-01

    The understory of the redwood forests of California's coast harbors perennial ferns, including Polystichum munitum and Dryopteris arguta. Unusual for ferns, these species are adapted to the characteristic Mediterranean-type dry season, but the mechanisms of tolerance have not been studied. The water relations of P. munitum and D. arguta were surveyed for over a year, including measures of water potential (Ψ), stomatal conductance (gs) and frond stipe hydraulic conductivity (K). A dehydration and re-watering experiment on potted P. munitum plants corroborated the field data. The seasonal Ψ varied from 0 to below -3 MPa in both species, with gs and K generally tracking Ψ; the loss of K rarely exceeded 80%. Quantile regression analysis showed that, at the 0.1 quantile, 50% of K was lost at -2.58 and -3.84 MPa in P. munitum and D. arguta, respectively. The hydraulic recovery of re-watered plants was attributed to capillarity. The seasonal water relations of P. munitum and D. arguta are variable, but consistent with laboratory-based estimates of drought tolerance. Hydraulic and Ψ recovery following rain allows perennial ferns to survive severe drought, but prolonged water deficit, coupled with insect damage, may hamper frond survival. The legacy effects of drought on reproductive capacity and community dynamics are unknown.

  17. Absorption of Hazardous Pollutants by a Medicinal Fern Blechnum orientale L.

    Directory of Open Access Journals (Sweden)

    Xiao-min Zhu

    2013-01-01

    Full Text Available A Chinese medicinal fern Blechnum orientale (Linn was separately collected from polluted and unpolluted sites to determine whether it could accumulate hazardous pollutants or not. Metal concentrations (Cu, Zn, Mn, Pb, Cd, Cr, As, and Hg both in the fronds and roots and polycyclic aromatic hydrocarbons (PAHs in the fronds of this fern were quantified. At both sites, roots of B. orientale had significantly higher heavy metals than the fronds. Concentrations of Pb, As, Hg, Cd, and Cu in the fronds at the polluted site were more than 2, 6, 7, 14, 5, and 13 times of those at the unpolluted site. Translocation factor and bioaccumulation factor implied that B. orientale did not have a good ability to transport heavy metals from the roots to the fronds. Total PAHs in the fronds at the polluted site were significantly higher than those at the unpolluted site, indicating the physiological PAHs absorption by B. orientale growing at polluted sites. Uptake of pollutants via stomata might be the main reason causing the significant accumulation of hazardous pollutants in the fronds of B. orientale. Large-scale systematical survey and intensive monitoring on pollutants in this medicinal fern should be necessarily strengthened.

  18. Capsaicin in hot chili pepper: carcinogen, co-carcinogen or anticarcinogen?

    Science.gov (United States)

    Surh, Y J; Lee, S S

    1996-03-01

    Capsaicin (trans-8-methyl-N-vanillyl-6-nonenamide) is a major pungent ingredient of the Capsicum fruits such as hot green and red peppers. Besides its use as a food additive in various spicy cuisines, capsaicin is currently utilized for therapeutic purposes to treat various peripheral painful conditions such as rheumatoid arthritis and diabetic neuropathy. Considering consumption of capsaicin as a food additive and its current medicinal application in humans, correct evaluation and precise assessment of any harmful effects of this compound are essential from the public health standpoint. Numerous investigations have been conducted to determine the potential mutagenic and carcinogenic activity of capsaicin and chili pepper, but results are discordant. This review briefly examines findings in the literature of studies testing mutagenicity and tumorigenicity of capsaicin and presents a possible mechanistic basis for the dual effects exerted by the compound.

  19. Comparative toxicity and carcinogenicity of soluble and insoluble cobalt compounds.

    Science.gov (United States)

    Behl, Mamta; Stout, Matthew D; Herbert, Ronald A; Dill, Jeffrey A; Baker, Gregory L; Hayden, Barry K; Roycroft, Joseph H; Bucher, John R; Hooth, Michelle J

    2015-07-03

    Occupational exposure to cobalt is of widespread concern due to its use in a variety of industrial processes and the occurrence of occupational disease. Due to the lack of toxicity and carcinogenicity data following exposure to cobalt, and questions regarding bioavailability following exposure to different forms of cobalt, the NTP conducted two chronic inhalation exposure studies in rats and mice, one on soluble cobalt sulfate heptahydrate, and a more recent study on insoluble cobalt metal. Herein, we compare and contrast the toxicity profiles following whole-body inhalation exposures to these two forms of cobalt. In general, both forms were genotoxic in the Salmonella T98 strain in the absence of effects on micronuclei. The major sites of toxicity and carcinogenicity in both chronic inhalation studies were the respiratory tract in rats and mice, and the adrenal gland in rats. In addition, there were distinct sites of toxicity and carcinogenicity noted following exposure to cobalt metal. In rats, carcinogenicity was observed in the blood, and pancreas, and toxicity was observed in the testes of rats and mice. Taken together, these findings suggest that both forms of cobalt, soluble and insoluble, appear to be multi-site rodent carcinogens following inhalation exposure. Published by Elsevier Ireland Ltd.

  20. Phylogenetic Relationships of the Fern Cyrtomium falcatum (Dryopteridaceae) from Dokdo Island, Sea of East Japan, Based on Chloroplast Genome Sequencing.

    Science.gov (United States)

    Raman, Gurusamy; Choi, Kyoung Su; Park, SeonJoo

    2016-12-02

    Cyrtomium falcatum is a popular ornamental fern cultivated worldwide. Native to the Korean Peninsula, Japan, and Dokdo Island in the Sea of Japan, it is the only fern present on Dokdo Island. We isolated and characterized the chloroplast (cp) genome of C. falcatum, and compared it with those of closely related species. The genes trnV-GAC and trnV-GAU were found to be present within the cp genome of C. falcatum, whereas trnP-GGG and rpl21 were lacking. Moreover, cp genomes of Cyrtomium devexiscapulae and Adiantum capillus-veneris lack trnP-GGG and rpl21, suggesting these are not conserved among angiosperm cp genomes. The deletion of trnR-UCG, trnR-CCG, and trnSeC in the cp genomes of C. falcatum and other eupolypod ferns indicates these genes are restricted to tree ferns, non-core leptosporangiates, and basal ferns. The C. falcatum cp genome also encoded ndhF and rps7, with GUG start codons that were only conserved in polypod ferns, and it shares two significant inversions with other ferns, including a minor inversion of the trnD-GUC region and an approximate 3 kb inversion of the trnG-trnT region. Phylogenetic analyses showed that Equisetum was found to be a sister clade to Psilotales-Ophioglossales with a 100% bootstrap (BS) value. The sister relationship between Pteridaceae and eupolypods was also strongly supported by a 100% BS, but Bayesian molecular clock analyses suggested that C. falcatum diversified in the mid-Paleogene period (45.15 ± 4.93 million years ago) and might have moved from Eurasia to Dokdo Island.

  1. Studies in vitro to discern the structural requirements for carcinogenicity in analogues of the carcinogen 4-dimethylaminoazobenzene (butter yellow).

    Science.gov (United States)

    Ashby, J; Styles, J A; Paton, D

    1980-01-01

    4-Dimethylaminoazobenzene (butter yellow, DAB), is the parent member of a large family of 'azo-carcinogens'. Experiments have been conducted in vitro to determine the key structural requirements for carcinogenic activity in this chemical class, and it is suggested, based on the activity observed for 4-cyano-N,N-dimethylaniline, that the 4-phenylazo group of DAB is not an essential structural feature per se. The N-oxide derivative of DAB has been evaluated in vitro and the positive response observed related to its metabolic activation. It is concluded that cyclic amines, such as pyrrolidine, can replace the N-dimethyl group of DAB with a retention of biological activity. The confusion that exists in the literature concerning the chemical identity and carcinogenic status of 2-dimethylaminobenzo[c]cinnoline has been investigated, and it is concluded that it is a potential animal carcinogen. This observation also indicates that the phenylazo group of DAB can be incorporated within an aromatic ring system with a retention of biological activity. As observed earlier with a mixture of azobenzene and DAB, azobenzene also potentiates the cell transforming properties of the above cinnoline derivative in vitro. Two charts are presented. The first attempts to integrate DAB within a much larger family of carcinogens, and the second illustrates the usefulness of structure-activity studies in general.

  2. Evolution of the rpoB-psbZ region in fern plastid genomes: notable structural rearrangements and highly variable intergenic spacers

    Directory of Open Access Journals (Sweden)

    Su Ying-Juan

    2011-04-01

    Full Text Available Abstract Background The rpoB-psbZ (BZ region of some fern plastid genomes (plastomes has been noted to go through considerable genomic changes. Unraveling its evolutionary dynamics across all fern lineages will lead to clarify the fundamental process shaping fern plastome structure and organization. Results A total of 24 fern BZ sequences were investigated with taxon sampling covering all the extant fern orders. We found that: (i a tree fern Plagiogyria japonica contained a novel gene order that can be generated from either the ancestral Angiopteris type or the derived Adiantum type via a single inversion; (ii the trnY-trnE intergenic spacer (IGS of the filmy fern Vandenboschia radicans was expanded 3-fold due to the tandem 27-bp repeats which showed strong sequence similarity with the anticodon domain of trnY; (iii the trnY-trnE IGSs of two horsetail ferns Equisetum ramosissimum and E. arvense underwent an unprecedented 5-kb long expansion, more than a quarter of which was consisted of a single type of direct repeats also relevant to the trnY anticodon domain; and (iv ycf66 has independently lost at least four times in ferns. Conclusions Our results provided fresh insights into the evolutionary process of fern BZ regions. The intermediate BZ gene order was not detected, supporting that the Adiantum type was generated by two inversions occurring in pairs. The occurrence of Vandenboschia 27-bp repeats represents the first evidence of partial tRNA gene duplication in fern plastomes. Repeats potentially forming a stem-loop structure play major roles in the expansion of the trnY-trnE IGS.

  3. Glycophenotypic alterations induced by Pteridium aquilinum in mice gastric mucosa: synergistic effect with Helicobacter pylori infection.

    Directory of Open Access Journals (Sweden)

    Joana Gomes

    Full Text Available The bracken fern Pteridium aquilinum is a plant known to be carcinogenic to animals. Epidemiological studies have shown an association between bracken fern exposure and gastric cancer development in humans. The biological effects of exposure to this plant within the gastric carcinogenesis process are not fully understood. In the present work, effects in the gastric mucosa of mice treated with Pteridium aquilinum were evaluated, as well as molecular mechanisms underlying the synergistic role with Helicobacter pylori infection. Our results showed that exposure to Pteridium aquilinum induces histomorphological modifications including increased expression of acidic glycoconjugates in the gastric mucosa. The transcriptome analysis of gastric mucosa showed that upon exposure to Pteridium aquilinum several glycosyltransferase genes were differently expressed, including Galntl4, C1galt1 and St3gal2, that are mainly involved in the biosynthesis of simple mucin-type carbohydrate antigens. Concomitant treatment with Pteridium aquilinum and infection with Helicobacter pylori also resulted in differently expressed glycosyltransferase genes underlying the biosynthesis of terminal sialylated Lewis antigens, including Sialyl-Lewis(x. These results disclose the molecular basis for the altered pattern of glycan structures observed in the mice gastric mucosa. The gene transcription alterations and the induced glycophenotypic changes observed in the gastric mucosa contribute for the understanding of the molecular mechanisms underlying the role of Pteridium aquilinum in the gastric carcinogenesis process.

  4. Cannabis and tobacco smoke are not equally carcinogenic

    Directory of Open Access Journals (Sweden)

    Melamede Robert

    2005-10-01

    Full Text Available Abstract More people are using the cannabis plant as modern basic and clinical science reaffirms and extends its medicinal uses. Concomitantly, concern and opposition to smoked medicine has occurred, in part due to the known carcinogenic consequences of smoking tobacco. Are these reactions justified? While chemically very similar, there are fundamental differences in the pharmacological properties between cannabis and tobacco smoke. Cannabis smoke contains cannabinoids whereas tobacco smoke contains nicotine. Available scientific data, that examines the carcinogenic properties of inhaling smoke and its biological consequences, suggests reasons why tobacco smoke, but not cannabis smoke, may result in lung cancer.

  5. A call to expand regulation to all carcinogenic fibrous minerals

    Science.gov (United States)

    Baumann, F.; Steele, I.; Ambrosi, J.; Carbone, M.

    2013-05-01

    The regulatory term "asbestos" groups only the six fibrous minerals that were commercially used among approximately 400. The carcinogenicity of these six regulated minerals has been largely demonstrated and is related to fiber structure, fiber length/diameter ratio, and bio-persistence. From a public perception, the generic term "asbestos" refers to the fibrous minerals that cause asbestosis, mesothelioma and other cancers. However, other non-regulated fibrous minerals are potentially as dangerous as the regulatory asbestos because they share similar physical and chemical properties, epidemiological studies have demonstrated their relationship with asbestos-related diseases, and both in vitro and in vivo experiments have established the toxicity of these minerals. For example, the non-regulated asbestiform winchite and richterite minerals that contaminated the vermiculite mined from Libby, Montana, (USA) were associated with mesothelioma, lung cancer and asbestosis observed among the area's residents and miners. Many other examples of non-regulated carcinogenic fibrous minerals include, but are not limited to, antigorite, arfvedsonite, balangeroite, carlosturanite, erionite, fluoro-edenite, hornblende, mordenite, palygorskite, and sepiolite. To propose a regulatory definition that would provide protection from all carcinogenic fibers, we have conducted an interdisciplinary literature review to compare the characteristics of "asbestos" and of non-regulated mineral fibers that relate to carcinogenicity. We specifically studied two non-regulated fibrous minerals that are associated with asbestos-related diseases: the serpentine antigorite and the zeolite erionite. Both examples underscore the problem of regulation based on commercial, rather than scientific principles: 1) the occurrence of fibrous antigorite in materials used to pave roads has been correlated with high mesothelioma rates in New Caledonia. Antigorite was also the cause of asbestosis in Poland, and in

  6. Different slopes of a mountain can determine the structure of ferns and lycophytes communities in a tropical forest of Brazil

    Directory of Open Access Journals (Sweden)

    FELIPE C. NETTESHEIM

    2014-03-01

    Full Text Available A community of Ferns and Lycophytes was investigated by comparing the occurrence of species on different slopes of a paleoisland in Southeastern Brazil. Our goal was to evaluate the hypothesis that slopes with different geographic orientations determine a differentiation of Atlantic Forest ferns and lycophytes community. We recorded these plants at slopes turned towards the continent and at slopes turned towards the open sea. Analysis consisted of a preliminary assessment on fern beta diversity, a Non Metric Multidimensional Scaling (NMDS and a Student t-test to confirm if sites sampling units ordination was different at each axis. We further used the Pearson coefficient to relate fern species to the differentiation pattern and again Student's t-test to determine if richness, plant cover and abundance varied between the two sites. There was a relatively low number of shared species between the two sites and ferns and lycophytes community variation was confirmed. Some species were detected as indicators of the community variation but we were unable to detect richness, plant cover or abundance differences. Despite the evidence of this variation between the slopes, further works are needed to evaluate which processes are contributing to determine this pattern.

  7. Different slopes of a mountain can determine the structure of ferns and lycophytes communities in a tropical forest of Brazil.

    Science.gov (United States)

    Nettesheim, Felipe C; Damasceno, Elaine R; Sylvestre, Lana S

    2014-03-01

    A community of Ferns and Lycophytes was investigated by comparing the occurrence of species on different slopes of a paleoisland in Southeastern Brazil. Our goal was to evaluate the hypothesis that slopes with different geographic orientations determine a differentiation of Atlantic Forest ferns and lycophytes community. We recorded these plants at slopes turned towards the continent and at slopes turned towards the open sea. Analysis consisted of a preliminary assessment on fern beta diversity, a Non Metric Multidimensional Scaling (NMDS) and a Student t-test to confirm if sites sampling units ordination was different at each axis. We further used the Pearson coefficient to relate fern species to the differentiation pattern and again Student's t-test to determine if richness, plant cover and abundance varied between the two sites. There was a relatively low number of shared species between the two sites and ferns and lycophytes community variation was confirmed. Some species were detected as indicators of the community variation but we were unable to detect richness, plant cover or abundance differences. Despite the evidence of this variation between the slopes, further works are needed to evaluate which processes are contributing to determine this pattern.

  8. Prevalence of genotoxic chemicals among animal and human carcinogens evaluated in the IARC Monograph Series.

    Science.gov (United States)

    Bartsch, H; Malaveille, C

    1989-06-01

    To determine whether genotoxic and non-genotoxic carcinogens contribute similarly to the cancer burden in humans, an analysis was performed on agents that were evaluated in Supplements 6 and 7 to the IARC Monographs for their carcinogenic effects in humans and animals and for the activity in short-term genotoxicity tests. The prevalence of genotoxic carcinogens on four groups of agents, consisting of established human carcinogens (group 1, n = 30), probable human carcinogens (group 2A, n = 37), possible human carcinogens (group 2B, n = 113) and on agents with limited evidence of carcinogenicity in animals (a subset of group 3, n = 149) was determined. A high prevalence in the order of 80 to 90% of genotoxic carcinogens was found in each of the groups 1, 2A and 2B, which were also shown to be multi-species/multi-tissues carcinogens. The distribution of carcinogenic potency in rodents did not reveal any specific characteristic of the human carcinogens in group 1 that would differentiate them from agents in groups 2A, 2B and 3. The results of this analysis indicate that (a) an agent with unknown carcinogenic potential showing sufficient evidence of activity in in vitro/in vivo genotoxicity assays (involving as endpoints DNA damage and chromosomal/mutational damage) may represent a hazard to humans; and b) an agent showing lack of activity in this spectrum of genotoxicity assays should undergo evaluation for carcinogenicity by rodent bioassay, in view of the present lack of validated short-term tests for non-genotoxic carcinogens. Overall, this analysis implies that genotoxic carcinogens add more to the cancer burden in man than non-genotoxic carcinogens. Thus, identification of such genotoxic carcinogens and subsequent lowering of exposure will remain the main goal for primary cancer prevention in man.

  9. Trichloroethylene: Mechanistic, epidemiologic and other supporting evidence of carcinogenic hazard

    NARCIS (Netherlands)

    Rusyn, Ivan; Chiu, Weihsueh A.; Lash, Lawrence H.; Kromhout, Hans; Hansen, Johnni; Guyton, Kathryn Z.

    2014-01-01

    The chlorinated solvent trichloroethylene (TCE) is a ubiquitous environmental pollutant. The carcinogenic hazard of TCE was the subject of a 2012 evaluation by a Working Group of the International Agency for Research on Cancer (IARC). Information on exposures, relevant data from epidemiologic

  10. Flavonoids and alkenylbenzenes: mechanisms of mutagenic action and carcinogenic risk

    NARCIS (Netherlands)

    Rietjens, I.M.C.M.; Boersma, M.G.; Woude, van der H.; Jeurissen, S.M.F.; Schutte, M.E.; Alink, G.M.

    2005-01-01

    The present review focuses on the mechanisms of mutagenic action and the carcinogenic risk of two categories of botanical ingredients, namely the flavonoids with quercetin as an important bioactive representative, and the alkenylbenzenes, namely safrole, methyleugenol and estragole. For quercetin a

  11. An Interdisciplinary and Alternative Approach to Assess Carcinogenicity of Chlorobenzenes.

    Science.gov (United States)

    2007-11-02

    carcinogenic activity of 1,4-di-, 1,2,4,5-tetra-, penta-, and hexa - chlorobenzenes in the Ito’s "Medium-Term Bioassay System" using partially...GST-P positive foci and related morphometric analyses, gene expressions of CYP1 A2, c-fos, c-jun, GSH/GSSG ratio, tissue porphyrin levels, DNA damage

  12. Carcinogenic metal compounds: recent insight into molecular and cellular mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Beyersmann, Detmar [University of Bremen (Germany). Biochemistry, Department of Biology and Chemistry; Hartwig, Andrea [Technical University of Berlin (Germany). Institute of Food Technology and Food Chemistry

    2008-08-15

    Mechanisms of carcinogenicity are discussed for metals and their compounds, classified as carcinogenic to humans or considered to be carcinogenic to humans: arsenic, antimony, beryllium, cadmium, chromium, cobalt, lead, nickel and vanadium. Physicochemical properties govern uptake, intracellular distribution and binding of metal compounds. Interactions with proteins (e.g., with zinc finger structures) appear to be more relevant for metal carcinogenicity than binding to DNA. In general, metal genotoxicity is caused by indirect mechanisms. In spite of diverse physicochemical properties of metal compounds, three predominant mechanisms emerge: (1) interference with cellular redox regulation and induction of oxidative stress, which may cause oxidative DNA damage or trigger signaling cascades leading to stimulation of cell growth; (2) inhibition of major DNA repair systems resulting in genomic instability and accumulation of critical mutations; (3) deregulation of cell proliferation by induction of signaling pathways or inactivation of growth controls such as tumor suppressor genes. In addition, specific metal compounds exhibit unique mechanisms such as interruption of cell-cell adhesion by cadmium, direct DNA binding of trivalent chromium, and interaction of vanadate with phosphate binding sites of protein phosphatases. (orig.)

  13. Binding of chemical carcinogens to macromolecules in cultured human colon

    DEFF Research Database (Denmark)

    1977-01-01

    Metabolic activation of different chemical classes of carcinogens was studied in cultured human colon epithelia. Human colon epithelia were maintained in explant culture up to 4 days. Binding of benzo(a)pyrene, dimethylnitrosamine, and 1,2- dimethylhydrazine was found in both cell DNA and protein....... 1,2-Dimethylhydrazine methylated DNA at both N·7 and 0-6 positions of guanin....

  14. 18. Adduct detection in human monitoring for carcinogen exposure

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Determination of the covalently bound products (adducts) of carcinogens with DNA or proteins may be used for the monitoring of exposure to these compounds. Protein adducts are generally stable and are not enzymatically repaired, and the use of these for cxposure monitoring is normally carried out with globin or albumin, because

  15. Chronic toxicity and carcinogenicity study of erythritol in rats

    NARCIS (Netherlands)

    Lina, B.A.R.; Bos-Kuijpers, M.H.M.; Til, H.P.; Bär, A.

    1996-01-01

    The potential toxicity and carcinogenicity of erythritol, a low-calorie sugar substitute, were examined in Wistar Crl:(WI) WU BR rats. Groups of 50 rats of each sex consumed diets with 0, 2, 5, or 10% erythritol, or 10% mannitol, for a period of 104-107 weeks. To each of these main groups, two

  16. Trichloroethylene: Mechanistic, epidemiologic and other supporting evidence of carcinogenic hazard

    NARCIS (Netherlands)

    Rusyn, Ivan; Chiu, Weihsueh A.; Lash, Lawrence H.; Kromhout, Hans|info:eu-repo/dai/nl/074385224; Hansen, Johnni; Guyton, Kathryn Z.

    2014-01-01

    The chlorinated solvent trichloroethylene (TCE) is a ubiquitous environmental pollutant. The carcinogenic hazard of TCE was the subject of a 2012 evaluation by a Working Group of the International Agency for Research on Cancer (IARC). Information on exposures, relevant data from epidemiologic studie

  17. IARC Monographs: 40 Years of Evaluating Carcinogenic Hazards to Humans

    NARCIS (Netherlands)

    Pearce, Neil E; Blair, Aaron; Vineis, Paolo; Ahrens, Wolfgang; Andersen, Aage; Anto, Josep M; Armstrong, Bruce K; Baccarelli, Andrea A; Beland, Frederick A; Berrington, Amy; Bertazzi, Pier A; Birnbaum, Linda S; Brownson, Ross C; Bucher, John R; Cantor, Kenneth P; Cardis, Elisabeth; Cherrie, John W; Christiani, David C; Cocco, Pierluigi; Coggon, David; Comba, Pietro; Demers, Paul A; Dement, John M; Douwes, Jeroen; Eisen, Ellen A; Engel, Lawrence S; Fenske, Richard A; Fleming, Lora E; Fletcher, Tony; Fontham, Elizabeth; Forastiere, Francesco; Frentzel-Beyme, Rainer; Fritschi, Lin; Gerin, Michel; Goldberg, Marcel; Grandjean, Philippe; Grimsrud, Tom K; Gustavsson, Per; Haines, Andy; Hartge, Patricia; Hansen, Johnni; Hauptmann, Michael; Heederik, Dick; Hemminki, Kari; Hemon, Denis; Hertz-Picciotto, Irva; Hoppin, Jane A; Huff, James; Jarvholm, Bengt; Kang, Daehee; Karagas, Margaret R; Kjaerheim, Kristina; Kjuus, Helge; Kogevinas, Manolis; Kriebel, David; Kristensen, Petter; Kromhout, Hans; Laden, Francine; Lebailly, Pierre; LeMasters, Grace; Lubin, Jay H; Lynch, Charles F; Lynge, Elsebeth; 't Mannetje, Andrea; McMichael, Anthony J; McLaughlin, John R; Marrett, Loraine; Martuzzi, Marco; Merchant, James A; Merler, Enzo; Merletti, Franco; Miller, Anthony; Mirer, Franklin E; Monson, Richard; Nordby, Karl-Kristian; Olshan, Andrew F; Parent, Marie-Elise; Perera, Frederica P; Perry, Melissa J; Pesatori, Angela C; Pirastu, Roberta; Porta, Miquel; Pukkala, Eero; Rice, Carol; Richardson, David B; Ritter, Leonard; Ritz, Beate; Ronckers, Cecile M; Rushton, Lesley; Rusiecki, Jennifer A; Rusyn, Ivan; Samet, Jonathan M; Sandler, Dale P; de Sanjose, Silvia; Schernhammer, Eva; Seniori Constantini, Adele; Seixas, Noah; Shy, Carl; Siemiatycki, Jack; Silvermann, Debra T; Simonato, Lorenzo; Smith, Allan H; Smith, Martyn T; Spinelli, John J; Spitz, Margaret R; Stallones, Lorann; Stayner, Leslie T; Steenland, Kyle; Stenzel, Mark; Stewart, Bernard W; Stewart, Patricia A; Symanski, Elaine; Terracini, Benedetto; Tolbert, Paige E; Vainio, Harri; Vena, John; Vermeulen, Roel; Victora, Cesar G; Ward, Elizabeth M; Weinberg, Clarice R; Weisenburger, Dennis; Wesseling, Catharina; Weiderpass, Elisabete; Zahm, Shelia H

    2015-01-01

    BACKGROUND: Recently the International Agency for Research on Cancer (IARC) Programme for the Evaluation of Carcinogenic Risks to Humans has been criticized for several of its evaluations, and also the approach used to perform these evaluations. Some critics have claimed that IARC Working Groups' fa

  18. Non—Genotoxic Carcinogens.Approaches to Their Rish Assessment

    Institute of Scientific and Technical Information of China (English)

    J.A.CASTRO; M.I.DiazGomez; 等

    1993-01-01

    Epidemiological studies support the idea that most human cancers are related to chemicals present in the human environment.In turn,chemicals are believed to cause cancer via either genotoxic or non-genotoxic mechanisms.There were described in literature several simple rapid and inexpensive short term ests to reasonably predict the genotoxic nature of chemicals but in contrast,there is no reliable test or battery of tests available to predict the carcinogenicity of non-genotoxic compounds and this poses a major problem to their rish assessment.In addition,there are conflictive opinions about rish assessment needs for both classes of carcinogens.Some workers elieve that for non-genotoxic carcinogens,thresholds for exposure can be drawn while others do not.In this review,the reasons behind both of these opinions and the present hypotheses about the mechanism of action of non-genotoxic carcinogens are described and analyzed in relation to future needs.

  19. IARC Monographs: 40 Years of Evaluating Carcinogenic Hazards to Humans

    NARCIS (Netherlands)

    Pearce, Neil E; Blair, Aaron; Vineis, Paolo; Ahrens, Wolfgang; Andersen, Aage; Anto, Josep M; Armstrong, Bruce K; Baccarelli, Andrea A; Beland, Frederick A; Berrington, Amy; Bertazzi, Pier A; Birnbaum, Linda S; Brownson, Ross C; Bucher, John R; Cantor, Kenneth P; Cardis, Elisabeth; Cherrie, John W; Christiani, David C; Cocco, Pierluigi; Coggon, David; Comba, Pietro; Demers, Paul A; Dement, John M; Douwes, Jeroen; Eisen, Ellen A; Engel, Lawrence S; Fenske, Richard A; Fleming, Lora E; Fletcher, Tony; Fontham, Elizabeth; Forastiere, Francesco; Frentzel-Beyme, Rainer; Fritschi, Lin; Gerin, Michel; Goldberg, Marcel; Grandjean, Philippe; Grimsrud, Tom K; Gustavsson, Per; Haines, Andy; Hartge, Patricia; Hansen, Johnni; Hauptmann, Michael; Heederik, Dick; Hemminki, Kari; Hemon, Denis; Hertz-Picciotto, Irva; Hoppin, Jane A; Huff, James; Jarvholm, Bengt; Kang, Daehee; Karagas, Margaret R; Kjaerheim, Kristina; Kjuus, Helge; Kogevinas, Manolis; Kriebel, David; Kristensen, Petter; Kromhout, Hans; Laden, Francine; Lebailly, Pierre; LeMasters, Grace; Lubin, Jay H; Lynch, Charles F; Lynge, Elsebeth; 't Mannetje, Andrea; McMichael, Anthony J; McLaughlin, John R; Marrett, Loraine; Martuzzi, Marco; Merchant, James A; Merler, Enzo; Merletti, Franco; Miller, Anthony; Mirer, Franklin E; Monson, Richard; Nordby, Karl-Kristian; Olshan, Andrew F; Parent, Marie-Elise; Perera, Frederica P; Perry, Melissa J; Pesatori, Angela C; Pirastu, Roberta; Porta, Miquel; Pukkala, Eero; Rice, Carol; Richardson, David B; Ritter, Leonard; Ritz, Beate; Ronckers, Cecile M; Rushton, Lesley; Rusiecki, Jennifer A; Rusyn, Ivan; Samet, Jonathan M; Sandler, Dale P; de Sanjose, Silvia; Schernhammer, Eva; Seniori Constantini, Adele; Seixas, Noah; Shy, Carl; Siemiatycki, Jack; Silvermann, Debra T; Simonato, Lorenzo; Smith, Allan H; Smith, Martyn T; Spinelli, John J; Spitz, Margaret R; Stallones, Lorann; Stayner, Leslie T; Steenland, Kyle; Stenzel, Mark; Stewart, Bernard W; Stewart, Patricia A; Symanski, Elaine; Terracini, Benedetto; Tolbert, Paige E; Vainio, Harri; Vena, John; Vermeulen, Roel; Victora, Cesar G; Ward, Elizabeth M; Weinberg, Clarice R; Weisenburger, Dennis; Wesseling, Catharina; Weiderpass, Elisabete; Zahm, Shelia H

    2015-01-01

    BACKGROUND: Recently the International Agency for Research on Cancer (IARC) Programme for the Evaluation of Carcinogenic Risks to Humans has been criticized for several of its evaluations, and also the approach used to perform these evaluations. Some critics have claimed that IARC Working Groups' fa

  20. IARC Monographs: 40 Years of Evaluating Carcinogenic Hazards to Humans

    NARCIS (Netherlands)

    Pearce, Neil E; Blair, Aaron; Vineis, Paolo; Ahrens, Wolfgang; Andersen, Aage; Anto, Josep M; Armstrong, Bruce K; Baccarelli, Andrea A; Beland, Frederick A; Berrington, Amy; Bertazzi, Pier A; Birnbaum, Linda S; Brownson, Ross C; Bucher, John R; Cantor, Kenneth P; Cardis, Elisabeth; Cherrie, John W; Christiani, David C; Cocco, Pierluigi; Coggon, David; Comba, Pietro; Demers, Paul A; Dement, John M; Douwes, Jeroen; Eisen, Ellen A; Engel, Lawrence S; Fenske, Richard A; Fleming, Lora E; Fletcher, Tony; Fontham, Elizabeth; Forastiere, Francesco; Frentzel-Beyme, Rainer; Fritschi, Lin; Gerin, Michel; Goldberg, Marcel; Grandjean, Philippe; Grimsrud, Tom K; Gustavsson, Per; Haines, Andy; Hartge, Patricia; Hansen, Johnni; Hauptmann, Michael; Heederik, Dick|info:eu-repo/dai/nl/072910542; Hemminki, Kari; Hemon, Denis; Hertz-Picciotto, Irva; Hoppin, Jane A; Huff, James; Jarvholm, Bengt; Kang, Daehee; Karagas, Margaret R; Kjaerheim, Kristina; Kjuus, Helge; Kogevinas, Manolis; Kriebel, David; Kristensen, Petter; Kromhout, Hans|info:eu-repo/dai/nl/074385224; Laden, Francine; Lebailly, Pierre; LeMasters, Grace; Lubin, Jay H; Lynch, Charles F; Lynge, Elsebeth; 't Mannetje, Andrea; McMichael, Anthony J; McLaughlin, John R; Marrett, Loraine; Martuzzi, Marco; Merchant, James A; Merler, Enzo; Merletti, Franco; Miller, Anthony; Mirer, Franklin E; Monson, Richard; Nordby, Karl-Kristian; Olshan, Andrew F; Parent, Marie-Elise; Perera, Frederica P; Perry, Melissa J; Pesatori, Angela C; Pirastu, Roberta; Porta, Miquel; Pukkala, Eero; Rice, Carol; Richardson, David B; Ritter, Leonard; Ritz, Beate; Ronckers, Cecile M; Rushton, Lesley; Rusiecki, Jennifer A; Rusyn, Ivan; Samet, Jonathan M; Sandler, Dale P; de Sanjose, Silvia; Schernhammer, Eva; Seniori Constantini, Adele; Seixas, Noah; Shy, Carl; Siemiatycki, Jack; Silvermann, Debra T; Simonato, Lorenzo; Smith, Allan H; Smith, Martyn T; Spinelli, John J; Spitz, Margaret R; Stallones, Lorann; Stayner, Leslie T; Steenland, Kyle; Stenzel, Mark; Stewart, Bernard W; Stewart, Patricia A; Symanski, Elaine; Terracini, Benedetto; Tolbert, Paige E; Vainio, Harri; Vena, John; Vermeulen, Roel|info:eu-repo/dai/nl/216532620; Victora, Cesar G; Ward, Elizabeth M; Weinberg, Clarice R; Weisenburger, Dennis; Wesseling, Catharina; Weiderpass, Elisabete; Zahm, Shelia H

    2015-01-01

    BACKGROUND: Recently the International Agency for Research on Cancer (IARC) Programme for the Evaluation of Carcinogenic Risks to Humans has been criticized for several of its evaluations, and also the approach used to perform these evaluations. Some critics have claimed that IARC Working Groups'

  1. Trichloroethylene: Mechanistic, epidemiologic and other supporting evidence of carcinogenic hazard

    NARCIS (Netherlands)

    Rusyn, Ivan; Chiu, Weihsueh A.; Lash, Lawrence H.; Kromhout, Hans; Hansen, Johnni; Guyton, Kathryn Z.

    2014-01-01

    The chlorinated solvent trichloroethylene (TCE) is a ubiquitous environmental pollutant. The carcinogenic hazard of TCE was the subject of a 2012 evaluation by a Working Group of the International Agency for Research on Cancer (IARC). Information on exposures, relevant data from epidemiologic studie

  2. Cell-mediated mutagenesis and cell transformation by chemical carcinogens

    Energy Technology Data Exchange (ETDEWEB)

    Huberman, E.; Langenbach, R.

    1977-01-01

    Results are reported from studies that showed that mutagenesis of mammalian cells can be achieved by carcinogenic polycyclic hydrocarbons, nitrosamines, and aflatoxins when tested in the presence of fibroblasts and hepatocytes which are able to metabolize these carcinogens. Further, we have found that there is a relationship between the degree of mutant induction and the degree of carcinogenicity of the different chemicals tested. By simultaneously measuring the frequency of cell transformation and the frequency of mutation at one locus (ouabain resistance) in the same cell system, it was possible to estimate the genetic target site for cell transformation. The results indicated that the target site for transformation is approximately 20 times larger than that determined for ouabain resistance. The results suggest that cell transformation may be due to a mutational event and the mutation can occur in one out of a small number of the same or different genes, and that the cell-mediated mutagenesis approach may be a valuable means of detecting tissue-specific carcinogens.

  3. CARCINOGENIC EFFECTS OF LOW DOSES OF IONIZING RADIATION

    Science.gov (United States)

    Carcinogenic Effects of Low Doses of Ionizing RadiationR Julian Preston, Environmental Carcinogenesis Division, NHEERL, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711The form of the dose-response curve for radiation-induced cancers, particu...

  4. Population genetic variation in the tree fern Alsophila spinulosa (Cyatheaceae: effects of reproductive strategy.

    Directory of Open Access Journals (Sweden)

    Ting Wang

    Full Text Available BACKGROUND: Essentially all ferns can perform both sexual and asexual reproduction. Their populations represent suitable study objects to test the population genetic effects of different reproductive systems. Using the diploid homosporous fern Alsophila spinulosa as an example species, the main purpose of this study was to assess the relative impact of sexual and asexual reproduction on the level and structure of population genetic variation. METHODOLOGY/PRINCIPAL FINDINGS: Inter-simple sequence repeats analysis was conducted on 140 individuals collected from seven populations (HSG, LCH, BPC, MPG, GX, LD, and ZHG in China. Seventy-four polymorphic bands discriminated a total of 127 multilocus genotypes. Character compatibility analysis revealed that 50.0 to 70.0% of the genotypes had to be deleted in order to obtain a tree-like structure in the data set from populations HSG, LCH, MPG, BPC, GX, and LD; and there was a gradual decrease of conflict in the data set when genotypes with the highest incompatibility counts were successively deleted. In contrast, in population ZHG, only 33.3% of genotypes had to be removed to achieve complete compatibility in the data set, which showed a sharp decline in incompatibility upon the deletion of those genotypes. All populations examined possessed similar levels of genetic variation. Population ZHG was not found to be more differentiated than the other populations. CONCLUSIONS/SIGNIFICANCE: Sexual recombination is the predominant source of genetic variation in most of the examined populations of A. spinulosa. However, somatic mutation contributes most to the genetic variation in population ZHG. This change of the primary mode of reproduction does not cause a significant difference in the population genetic composition. Character compatibility analysis represents an effective approach to separate the role of sexual and asexual components in shaping the genetic pattern of fern populations.

  5. Marine Biodiversity in Juan Fernández and Desventuradas Islands, Chile: Global Endemism Hotspots.

    Science.gov (United States)

    Friedlander, Alan M; Ballesteros, Enric; Caselle, Jennifer E; Gaymer, Carlos F; Palma, Alvaro T; Petit, Ignacio; Varas, Eduardo; Muñoz Wilson, Alex; Sala, Enric

    2016-01-01

    The Juan Fernández and Desventuradas islands are among the few oceanic islands belonging to Chile. They possess a unique mix of tropical, subtropical, and temperate marine species, and although close to continental South America, elements of the biota have greater affinities with the central and south Pacific owing to the Humboldt Current, which creates a strong biogeographic barrier between these islands and the continent. The Juan Fernández Archipelago has ~700 people, with the major industry being the fishery for the endemic lobster, Jasus frontalis. The Desventuradas Islands are uninhabited except for a small Chilean military garrison on San Félix Island. We compared the marine biodiversity of these islands across multiple taxonomic groups. At San Ambrosio Island (SA), in Desventuradas, the laminarian kelp (Eisenia cokeri), which is limited to Desventuradas in Chile, accounted for >50% of the benthic cover at wave exposed areas, while more sheltered sites were dominated by sea urchin barrens. The benthos at Robinson Crusoe Island (RC), in the Juan Fernández Archipelago, comprised a diverse mix of macroalgae and invertebrates, a number of which are endemic to the region. The biomass of commercially targeted fishes was >2 times higher in remote sites around RC compared to sheltered locations closest to port, and overall biomass was 35% higher around SA compared to RC, likely reflecting fishing effects around RC. The number of endemic fish species was extremely high at both islands, with 87.5% of the species surveyed at RC and 72% at SA consisting of regional endemics. Remarkably, endemics accounted for 99% of the numerical abundance of fishes surveyed at RC and 96% at SA, which is the highest assemblage-level endemism known for any individual marine ecosystem on earth. Our results highlight the uniqueness and global significance of these biodiversity hotspots exposed to very different fishing pressures.

  6. De novo transcriptome assembly of a fern, Lygodium japonicum, and a web resource database, Ljtrans DB.

    Science.gov (United States)

    Aya, Koichiro; Kobayashi, Masaaki; Tanaka, Junmu; Ohyanagi, Hajime; Suzuki, Takayuki; Yano, Kenji; Takano, Tomoyuki; Yano, Kentaro; Matsuoka, Makoto

    2015-01-01

    During plant evolution, ferns originally evolved as a major vascular plant with a distinctive life cycle in which the haploid and diploid generations are completely separated. However, the low level of genetic resources has limited studies of their physiological events, as well as hindering research on the evolutionary history of land plants. In this study, to identify a comprehensive catalog of transcripts and characterize their expression traits in the fern Lygodium japonicum, nine different RNA samples isolated from prothalli, trophophylls, rhizomes and sporophylls were sequenced using Roche 454 GS-FLX and Illumina HiSeq sequencers. The hybrid assembly of the high-quality 454 GS-FLX and Illumina HiSeq reads generated a set of 37,830 isoforms with an average length of 1,444 bp. Using four open reading frame (ORF) predictors, 38,142 representative ORFs were identified from a total of 37,830 transcript isoforms and 95 contigs, which were annotated by searching against several public databases. Furthermore, an orthoMCL analysis using the protein sequences of L. japonicum and five model plants revealed various sets of lineage-specific genes, including those detected among land plant lineages and those detected in only L. japonicum. We have also examined the expression patterns of all contigs/isoforms, along with the life cycle of L. japonicum, and identified the tissue-specific transcripts using statistical expression analyses. Finally, we developed a public web resource, the L. japonicum transcriptome database at http://bioinf.mind.meiji.ac.jp/kanikusa/, which provides important opportunities to accelerate molecular research in ferns.

  7. Fern-synthesized silver nanocrystals: Towards a new class of mosquito oviposition deterrents?

    Science.gov (United States)

    Rajaganesh, Rajapandian; Murugan, Kadarkarai; Panneerselvam, Chellasamy; Jayashanthini, Sudalaimani; Aziz, Al Thbiani; Roni, Mathath; Suresh, Udaiyan; Trivedi, Subrata; Rehman, Hasibur; Higuchi, Akon; Nicoletti, Marcello; Benelli, Giovanni

    2016-12-01

    Mosquitoes act as vectors of devastating pathogens and parasites, representing a key threat for millions of humans and animals worldwide. Eco-friendly control tools are urgently required. We proposed a novel method of fern-mediated biosynthesis of silver nanoparticles (AgNP) using Dicranopteris linearis, acting as a reducing and capping agent. AgNP were characterized by UV-vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), zeta potential and particle size analysis. In mosquitocidal assays, the LC50 of D. linearis extract against Aedes aegypti ranged from 165.213 (larva I) to 255.055ppm (pupa). LC50 of D. linearis-synthesized AgNP ranged from 18.905 (larva I) to 29.328ppm (pupa). In the field, the application of D. linearis extract and AgNP (10×LC50) led to 100% larval reduction after 72h. Smoke toxicity experiments conducted against A. aegypti adults showed that D. linearis leaf-, stem- and root-based coils evoked mortality rates comparable to the permethrin-based positive control (58%, 47%, 34%, and 48% respectively). In ovicidal experiments, egg hatchability was reduced by 100% after treatment with 25ppm of AgNP and 300ppm of D. linearis extract. Interestingly, oviposition deterrent assays highlighted that 100ppm of fern extract reduced oviposition rates of more than 65%, while 10ppm of fern-fabricated AgNP reduced oviposition rates of more than 70% in A. aegypti (OAI were -0.52 and -0.55, respectively). Overall, our results highlighted that D. linearis-synthesized AgNP could be useful candidates to develop nano-formulated oviposition deterrents effective against dengue vectors.

  8. Antibody-based screening of cell wall matrix glycans in ferns reveals taxon, tissue and cell-type specific distribution patterns

    DEFF Research Database (Denmark)

    Leroux, Olivier; Sørensen, Iben; Marcus, Susan E.;

    2015-01-01

    plants, ferns have been largely neglected in cell wall comparative studies. Results: To explore fern cell wall diversity sets of monoclonal antibodies directed to matrix glycans of angiosperm cell walls have been used in glycan microarray and in situ analyses with 76 fern species and four species...... across the ferns and specifically associated with phloem cell walls and similarly the LM11 xylan epitope was associated with xylem cell walls. The LM5 galactan and LM6 arabinan epitopes, linked to pectic supramolecules in angiosperms, were associated with vascular structures with only limited detection...... in ground tissues. Mannan epitopes were found to be associated with the development of mechanical tissues. We provided the first evidence for the presence of MLG in leptosporangiate ferns. Conclusions: The data sets indicate that cell wall diversity in land plants is multifaceted and that matrix glycan...

  9. The physiological resilience of fern sporophytes and gametophytes: advances in water relations offer new insights into an old lineage

    Directory of Open Access Journals (Sweden)

    Jarmila ePittermann

    2013-08-01

    Full Text Available Ferns are some of the oldest vascular plants in existence and they are the second most diverse lineage of tracheophytes next to angiosperms. Recent efforts to understand fern success have fo-cused on the physiological capacity and stress tolerance of both the sporophyte and the gameto-phyte generations. In this review, we examine these insights through the lens of plant water rela-tions, focusing primarily on the form and function of xylem tissue in the sporophyte, as well as the tolerance to and recovery from drought and desiccation stress in both stages of the fern life cycle. The absence of secondary xylem in ferns is compensated by selection for efficient primary xylem composed of large, closely arranged tracheids with permeable pit membranes. Protection from drought-induced hydraulic failure appears to arise from a combination of pit membrane traits and the arrangement of vascular bundles. Features such as tracheid-based xylem and vari-ously sized megaphylls are shared between ferns and more derived lineages, and offer an oppor-tunity to compare convergent and divergent hydraulic strategies critical to the success of xylem-bearing plants. Fern gametophytes show a high degree of desiccation tolerance but new evidence shows that morphological attributes in the gametophytes may facilitate water retention, though little work has addressed the ecological significance of this variation. We conclude with an emergent hypothesis that selection acted on the physiology of both the sporophyte and gameto-phyte generations in a synchronous manner that is consistent with selection for drought tolerance in the epiphytic niche, and the increasingly diverse habitats of the mid to late Cenozoic.

  10. Historical reconstruction of climatic and elevation preferences and the evolution of cloud forest-adapted tree ferns in Mesoamerica.

    Science.gov (United States)

    Sosa, Victoria; Ornelas, Juan Francisco; Ramírez-Barahona, Santiago; Gándara, Etelvina

    2016-01-01

    Cloud forests, characterized by a persistent, frequent or seasonal low-level cloud cover and fragmented distribution, are one of the most threatened habitats, especially in the Neotropics. Tree ferns are among the most conspicuous elements in these forests, and ferns are restricted to regions in which minimum temperatures rarely drop below freezing and rainfall is high and evenly distributed around the year. Current phylogeographic data suggest that some of the cloud forest-adapted species remained in situ or expanded to the lowlands during glacial cycles and contracted allopatrically during the interglacials. Although the observed genetic signals of population size changes of cloud forest-adapted species including tree ferns correspond to predicted changes by Pleistocene climate change dynamics, the observed patterns of intraspecific lineage divergence showed temporal incongruence. Here we combined phylogenetic analyses, ancestral area reconstruction, and divergence time estimates with climatic and altitudinal data (environmental space) for phenotypic traits of tree fern species to make inferences about evolutionary processes in deep time. We used phylogenetic Bayesian inference and geographic and altitudinal distribution of tree ferns to investigate ancestral area and elevation and environmental preferences of Mesoamerican tree ferns. The phylogeny was then used to estimate divergence times and ask whether the ancestral area and elevation and environmental shifts were linked to climatic events and historical climatic preferences. Bayesian trees retrieved Cyathea, Alsophyla, Gymnosphaera and Sphaeropteris in monophyletic clades. Splits for species in these genera found in Mesoamerican cloud forests are recent, from the Neogene to the Quaternary, Australia was identified as the ancestral area for the clades of these genera, except for Gymnosphaera that was Mesoamerica. Climate tolerance was not divergent from hypothesized ancestors for the most significant

  11. Development of microsatellite markers in the tetraploid fern Ceratopteris thalictroides (Parkeriaceae) using RAD tag sequencing.

    Science.gov (United States)

    Yang, X Y; Long, Z C; Gichira, A W; Guo, Y H; Wang, Q F; Chen, J M

    2016-02-19

    To understand the genetic variability of the tetraploid fern Ceratopteris thalictroides (Parkeriaceae), we described 30 polymorphic microsatellite markers obtained using the restriction site-associated DNA (RAD) tag sequencing technique. A total of 26 individuals were genotyped for each marker. The number of alleles per locus ranged from 4 to 10, and the expected heterozygosity and the Shannon-Wiener index ranged from 0.264 to 0.852 and 0.676 to 2.032, respectively. Because these 30 microsatellite markers exhibit high degrees of genetic variation, they will be useful tools for studying the adaptive genetic variation and sustainable conservation of C. thalictroides.

  12. Effect of habitat preference on frond life span in three Cyathea tree ferns

    Science.gov (United States)

    Chiu, Tzu Yun; Wang, Hsiang Hua; Lun Kuo, Yao; Kume, Tomonori

    2013-04-01

    It has been reported that plants living in various geographical areas had different physiological forms, as factors of microenvironment have strong impacts on physiological characters. However, the physiological characters of fronds have been scarcely reported in ferns. In this study, we investigated physiological differences in response to the habitat preference in the three tree ferns in northeast Taiwan, Cyathea lepifera, C. spinulosa, and C. podophylla, prefer to open site, edge of forest, and interior forest, respectively. The canopy openness above the individuals of C. lepifera, C. spinulosa and C. podophylla were 29.2 ± 14.10 , 7.0 ± 3.07 and 5.0 ± 2.24 %, respectively. Among three species, C. podophylla had the longest frond life span (13.0 ± 4.12 months) than the two others (C. lepifera (6.8 ± 1.29 months) and C. spinulosa (7.3 ±1.35 months). Our result supported the general patterns that shade intolerant species have a shorter leaf life span than shade tolerant species. The maximum net CO2 assimilation of C. lepifera, C. spinulosa and C. podophylla were 11.46 ± 1.34, 8.27 ± 0.69, and 6.34 ± 0.54 μmol CO2 m-2 s-1, respectively. As well, C. lepifera had the highest photosynthetic light saturation point (LSP), while C. podophylla had the lowest LSP among these three tree ferns. These suggested that C. lepifera could be more efficient for capturing and utilizing light resources under the larger canopy openness condition than the other two species. We also found that frond C : N ratio were positively correlated with frond life span among species. C. podophylla, with the longest frond life span, had the highest frond C : N ratio (22.17 ± 1.95), which was followed by C. spinulosa (18.58 ± 1.37) and C. lepifera (18.68 ± 2.63) with shorter frond life span. The results were consistent to the theory that the fronds and leaves of shade intolerant species have high photosynthetic abilities with low C : N ratio. Key words: Canopy openness, frond life span

  13. Fossilized nuclei and chromosomes reveal 180 million years of genomic stasis in royal ferns.

    Science.gov (United States)

    Bomfleur, Benjamin; McLoughlin, Stephen; Vajda, Vivi

    2014-03-21

    Rapidly permineralized fossils can provide exceptional insights into the evolution of life over geological time. Here, we present an exquisitely preserved, calcified stem of a royal fern (Osmundaceae) from Early Jurassic lahar deposits of Sweden in which authigenic mineral precipitation from hydrothermal brines occurred so rapidly that it preserved cytoplasm, cytosol granules, nuclei, and even chromosomes in various stages of cell division. Morphometric parameters of interphase nuclei match those of extant Osmundaceae, indicating that the genome size of these reputed "living fossils" has remained unchanged over at least 180 million years-a paramount example of evolutionary stasis.

  14. Conocer el Nuevo Mundo: referencialidad en las ilustraciones de Fernández de Oviedo

    OpenAIRE

    Teglia, Vanina M.

    2014-01-01

    Las ilustraciones realizadas por el cronista oficial de Indias Gonzalo Fernández de Oviedo para sus apartados sobre la flora americana son las primeras de este tipo aparecidas mundialmente en una edición impresa. Entre los paradigmas del saber libresco medieval y el de la creciente valoración del testimonio de vista, el Veedor del Oro en el Nuevo Mundo, escritor y dibujante, recurre a las herramientas del lenguaje visual para, por un lado, ofrecer pruebas fehacientes de la naturaleza que esta...

  15. León Fernández Bonilla y la historiografía costarricense.

    OpenAIRE

    Quesada Camacho, Juan Rafael

    2011-01-01

    Se ha afirmado, con gran justicia que León Fernández Bonilla fue el fundador del Archivo Nacional, “granero” del historiador”, según la hermosa metáfora de Lucien Febvre. En efecto, don León, como se ha acostumbrado llamarlo, ocupó un lugar de primer orden en el origen de los estudios históricos en Costa Rica. ¿En qué contexto se dio su contribución a la historiografía costarricense?

  16. Genetic and Molecular Dissection of Arsenic Hyperaccumulation in the fern Pteris vittata.

    Energy Technology Data Exchange (ETDEWEB)

    Jo Ann Banks; David Salt

    2008-04-04

    Pteris vittata is a fern that is extraordinary in its ability to tolerate hyperaccumulate high levels of arsenic (As). The goals of the proposed research, to identify the genes that are necessary for As hyperaccumulation in P. vittata using molecular and genetic approaches and to understand the physiology of arsenic uptake and distribution in the living plant, were accomplished during the funding period. The genes that have been identified may ultimately enable the engineering or selection of other plants capable of As hyperaccumulation. This is important for the phytoremediation of arsenic-contaminated soils in areas where P. vittata cannot grow.

  17. Allelopathy is involved in the formation of pure colonies of the fern Gleichenia japonica.

    Science.gov (United States)

    Kato-Noguchi, Hisashi; Saito, Yoshihumi; Ohno, Osamu; Suenaga, Kiyotake

    2013-04-15

    The fern Gleichenia japonica is one of the most widely distributed fern and occurs throughout East to South Asia. The species often dominates plant communities by forming large monospecific colonies. However, the potential mechanism for this domination has not yet been described. The objective of this study was to test the hypothesis that allelochemicals are involved in the formation of G. japonica colonies. An aqueous methanol extract of G. japonica inhibited the growth of seedlings of garden cress (Lepidium sativum), lettuce (Lactuca sativa), ryegrass (Lolium multiflorum) and timothy (Phleum pratense). Increasing extract concentration increased the inhibition. These results suggest that G. japonica contain allelopathic substances. The extract was then purified by several chromatographies with monitoring the inhibitory activity and two growth inhibitory substances causing the allelopathic effect were isolated. The chemical structures of the two substances were determined by spectral data to be a novel compound 3-O-β-allopyranosyl-13-O-β-fucopyranosyl-3β-hydroxymanool (1) and 18-O-α-l-rhamnopyranosyl-(1→2)-β-d-glucopyranosyl-13-epitorreferol (2). These compounds inhibited the shoot and root growth of garden cress, lettuce, alfalfa (Medicago sativa), timothy, ryegrass and barnyardgrass (Echinochloa crus-galli) at concentrations greater than 0.1-1.0mM. The concentrations required for 50% growth inhibition of root and shoot growth of these test plants ranged from 0.72 to 3.49mM and 0.79 to 3.51mM for compounds 1 and 2, respectively. Concentration of compounds 1 and 2 in soil under the pure colony of G. japonica was 4.9 and 5.7mM, respectively, indicating concentrations over those required for 50% growth inhibition are potentially available under monocultural stands of these ferns. Therefore, these compounds may contribute to the allelopathic effects caused by presence of G. japonica and may thus contribute to the establishment of monocultural stands by this

  18. [A new species of fern of the genus Pteris (Filicales: Pteridaceae) endemic to Costa Rica].

    Science.gov (United States)

    Rojas Alvarado, Alexander Fco; Palacios Ríos, Mónica

    2006-09-01

    The new fern species Pteris herrerae A. Rojas & M. Palacios, endemic to Costa Rica, is described. It differs from P. decurrens C. Presl in basal segments reduced to 1/5-1/2 of the next segment (vs. 2/3-3/4), basal pinnae not bifurcated (vs. bifurcated), pinnae apex mucronate (vs. acuminate) and segment apex undulate (vs. dentate). It differs from Pteris consanguinea in the elliptic pinnae (vs. oblong), two segments reduced on the base (vs. lack), segments entire to undulate (vs. dentate), basal pinnae without basiscopic lobes (vs. with basiscopic lobes) and segment apex entire to undulate (vs. dentate).

  19. Lactoperoxidase-catalyzed activation of carcinogenic aromatic and heterocyclic amines.

    Science.gov (United States)

    Gorlewska-Roberts, Katarzyna M; Teitel, Candee H; Lay, Jackson O; Roberts, Dean W; Kadlubar, Fred F

    2004-12-01

    Lactoperoxidase, an enzyme secreted from the human mammary gland, plays a host defensive role through antimicrobial activity. It has been implicated in mutagenic and carcinogenic activation in the human mammary gland. The potential role of heterocyclic and aromatic amines in the etiology of breast cancer led us to examination of the lactoperoxidase-catalyzed activation of the most commonly studied arylamine carcinogens: 2-amino-1-methyl-6-phenylimidazo[4,5-b]-pyridine (PhIP), benzidine, 4-aminobiphenyl (ABP), 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx). In vitro activation was performed with lactoperoxidase (partially purified from bovine milk or human milk) in the presence of hydrogen peroxide and calf thymus DNA. Products formed during enzymatic activation were monitored by HPLC with ultraviolet and radiometric detection. Two of these products were characterized as hydrazo and azo derivatives by means of mass spectrometry. The DNA binding level of 3H- and 14C-radiolabeled amines after peroxidase-catalyzed activation was dependent on the hydrogen peroxide concentration, and the highest levels of carcinogen binding to DNA were observed at 100 microM H2O2. Carcinogen activation and the level of binding to DNA were in the order of benzidine > ABP > IQ > MeIQx > PhIP. One of the ABP adducts was identified, and the level at which it is formed was estimated to be six adducts/10(5) nucleotides. The susceptibility of aromatic and heterocyclic amines for lactoperoxidase-catalyzed activation and the binding levels of activated products to DNA suggest a potential role of lactoperoxidase-catalyzed activation of carcinogens in the etiology of breast cancer.

  20. Carcinogen derived biomarkers: applications in studies of human exposure to secondhand tobacco smoke

    OpenAIRE

    Hecht, S

    2004-01-01

    Objective: To review the literature on carcinogen derived biomarkers of exposure to secondhand tobacco smoke (SHS). These biomarkers are specifically related to known carcinogens in tobacco smoke and include urinary metabolites, DNA adducts, and blood protein adducts.

  1. Mensuration of sialic acid seric level in nelore cattle exposed and nonexposed to bracken fern (Pteridium aquilinum / Aferição da concentração sérica de ácido siálico em novilhas da raça nelore expostas e não expostas à samambaia (Pteridium aquilinum

    Directory of Open Access Journals (Sweden)

    Wilmar Sachetin Marçal

    2008-08-01

    Full Text Available The Pteridium aquilinum is one toxic plant present in several countries of the world. The chronic ingestion causes diseases to livestock with negative economics repercussion. In Paraná state the Pteridium aquilinum is present in 105 out 399 municipal districts existents. The high occurrence of the plant in many areas of the Paraná state and the wrong utilization of these areas for cattle breed increase the importance of research that look for means that epidemic control of intoxication. Because that research institutions in the Paraná state have looking for means to advance in diagnosis methods, especially to cattle suffering from Bovine Enzootic Hematuria. The biomarkers have been used in the diagnosis and postoperative follow-up of tumor in the human beings in a routinely bases for years. Researches about this subject were crescent in the medicine of companion animals, however still incipient about cattle. Specifically in the Bovine Enzootic Hematuria were verified that mucin, a substance present in the mucus from the mucosal surface of bladder, is produced by tumoral cells in reasonable accounts. Previous reports verified one relationship between the excessive mucus protein production by the bladder with hemangioma and high plasmatic concentration of the sialic acid. This suggests that sialic acid is associated with inflammatory response of the tumoral growth, and might be used such as tumoral biomarker.A Pteridium aquilinum é uma planta tóxica, disseminada em vários paises do mundo, cuja ingestão continua resulta em doenças com impacto negativo à pecuária bovina. No Paraná, esta presente em 105 dos 399 municípios do Estado. Por essa razão tem-se buscado por meios de controle epidemiológico da intoxicação, já que em algumas localidades do Paraná a planta está disseminada em muitas áreas utilizadas para cria e recria de bovinos. Assim sendo, as instituições de pesquisa do Estado têm buscado meios de diagnóstico precoce, sobretudo da forma clinica Hematúria Enzoótica dos Bovinos. Biomarcadores têm sido utilizados na rotina médica, há anos, para o diagnóstico e controle pós-operatório de pacientes com neoplasias. O numero de publicações nesta linha na medicina de animais de companhia tem sido crescente, porém, o tema ainda é pouco estudado como parte da abordagem diagnóstica de bovinos de corte. No caso específico da Hematúria Enzoótica dos Bovinos, estudos prévios comprovaram que a mucina, substancia presente no muco vesical, é produzida em quantidades consideráveis na superfície das células tumorais. Estudos prévios apontaram uma relação entre a produção excessiva de mucoproteína em animais com hemangioma de bexiga e a concentração plasmática do ácido siálico, comprovando que o ácido siálico é uma substancia associada ao processo inflamatório do desenvolvimento tumoral, o que sugere a possibilidade de seu uso como biomarcador tumoral.

  2. 2016 Award for Distinguished Contributions to the International Advancement of Psychology: Héctor Fernández-Álvarez.

    Science.gov (United States)

    2016-11-01

    The Award for Distinguished Contributions to the International Advancement of Psychology is given to individuals who have made sustained and enduring contributions to international cooperation and the advancement of knowledge in psychology. The 2016 award winner is Héctor Fernández-Álvarez, who "has woven a sophisticated network of international cooperation in psychotherapy research, training, and service provision throughout Latin America, Europe, and the United States." He was selected for his outstanding, innovative contributions to psychotherapy integration, clinical supervision, and the personal style of the therapist. Dr. Fernández-Álvarez's award citation, biography, and a selected bibliography are presented here. (PsycINFO Database Record

  3. Evaluation of carcinogenic potential of the herbicide glyphosate, drawing on tumor incidence data from fourteen chronic/carcinogenicity rodent studies.

    Science.gov (United States)

    Greim, Helmut; Saltmiras, David; Mostert, Volker; Strupp, Christian

    2015-03-01

    Abstract Glyphosate, an herbicidal derivative of the amino acid glycine, was introduced to agriculture in the 1970s. Glyphosate targets and blocks a plant metabolic pathway not found in animals, the shikimate pathway, required for the synthesis of aromatic amino acids in plants. After almost forty years of commercial use, and multiple regulatory approvals including toxicology evaluations, literature reviews, and numerous human health risk assessments, the clear and consistent conclusions are that glyphosate is of low toxicological concern, and no concerns exist with respect to glyphosate use and cancer in humans. This manuscript discusses the basis for these conclusions. Most toxicological studies informing regulatory evaluations are of commercial interest and are proprietary in nature. Given the widespread attention to this molecule, the authors gained access to carcinogenicity data submitted to regulatory agencies and present overviews of each study, followed by a weight of evidence evaluation of tumor incidence data. Fourteen carcinogenicity studies (nine rat and five mouse) are evaluated for their individual reliability, and select neoplasms are identified for further evaluation across the data base. The original tumor incidence data from study reports are presented in the online data supplement. There was no evidence of a carcinogenic effect related to glyphosate treatment. The lack of a plausible mechanism, along with published epidemiology studies, which fail to demonstrate clear, statistically significant, unbiased and non-confounded associations between glyphosate and cancer of any single etiology, and a compelling weight of evidence, support the conclusion that glyphosate does not present concern with respect to carcinogenic potential in humans.

  4. An analysis of the Gene-Tox Carcinogen Data Base.

    Science.gov (United States)

    Nesnow, S; Bergman, H

    1988-01-01

    The Gene-Tox Carcinogen Data Base is an evaluated source of cancer data on 506 chemicals selected in part for their previous assessment in genetic toxicology bioassays. This data base has been analyzed for the distribution of these chemicals into chemical classes. The major chemical classes (6% or greater of the total data base) are: acyl-, alkyl-, and aryl-halides; alcohols and phenols; aliphatic and aromatic amines, amides, and sulfonamides; benzene-ring-containing chemicals; organo-lead, -mercury, -phosphorous compounds, metals and derivatives, phosphoric acid esters, and phosphoramides; and polycyclic aromatic hydrocarbons. Cancer studies representing a subset of the Gene-Tox Carcinogen Data Base, 199 chemicals which were rated as Sufficient Positive/Negative or Limited Positive/Negative, were examined for distribution of those studies by animal species, gender, route of chemical administration, duration of study, major tumor sites, and major tumor types. These analyses revealed that the Gene-Tox Carcinogen Data Base contains a large number of lifetime studies involving the rat and mouse treated by oral routes of administration. The major organs that were targets were: liver, lung, skin, forestomach, bladder, and mammary gland, while the major tumor types were: carcinoma, sarcoma, papilloma, and adenoma. Chemicals in the data base have been assessed for species-specific carcinogenic effects, and these results indicate that for mice and rats there is a high correspondence (85%). This number is higher than that (71%) reported by Tennant et al. (1986) based on the recent results of 72 chronic cancer bioassays performed by the National Toxicology Program. This difference is probably based on the nature of the chemicals selected for inclusion in both data bases. Although the absolute value of this correspondence is unknown, it would seem to be within this range. When chemicals in the Gene-Tox Carcinogen Data Base were examined for their previous evaluation in 73

  5. El blocao (y el bloqueo de José Díaz Fernández

    Directory of Open Access Journals (Sweden)

    Luis Fernando Bueno Morillas

    2015-06-01

    Full Text Available El blocao (1928 fue la primera novela de José Díaz Fernández. Supuso un éxito editorial insólito hasta entonces porque reunía tres características novedosas: una actitud crítica ante la guerra de Marruecos, una integración de las novedades vanguardistas en la que su autor llamó literatura de avanzada y un posicionamiento del intelectual al lado de las reivindicaciones del pueblo. Sin embargo, aunque publicó otra novela un año después (La Venus mecánica, un libro teórico en el que definía la literatura que él propugnaba y practicaba (El nuevo romanticismo y algunas narraciones breves, Díaz Fernández se bloqueó y dejó la literatura narrativa que tan buenas expectativas levantó. Analizaremos las posibles causas de ese bloqueo.

  6. Polyphyly of the fern family Tectariaceae sensu Ching: Insights from cpDNA sequence data

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Tectariaceae are a pantropical fern family of about 20 genera, among which 8 are distributed in China. The morphological distinctiveness of the family is widely recognized, yet relatively little systematic research has been conducted on members of Tectariaceae. Phylogenetic analyses of chloroplast DNA sequence data (rbcL and atpB) from 15 species representing all 8 genera in China were carried out under parsimony criteria and Bayesian inference. The phylogenetic reconstructions indicated that the fern family Tectariaceae as traditionally circumscribed are polyphyletic. Ctenitis, Dryopsis, Lastreopsis clustered with and should be included within the newly-defined Dryopteridaceae, and Pleocnemia is also tentatively assigned to it. A narrowly monophyletic Tectariaceae is identified, which includes Ctenitopsis, Hemigramma, Pteridrys, Quercifilix, and Tectaria. In the single rbcL analysis, Arthropteris clustered with the above-mentioned monophyletic Tectariaceae. Although further investigations are still needed to identify infrafamilial relationships within the monophyletic Tectariaceae and to redefine several problematic genera, we propose a working concept here that better reflects the inferred evolutionary history of this group.

  7. Molecular Phylogeny of the Cliff Ferns (Woodsiaceae: Polypodiales) with a Proposed Infrageneric Classification.

    Science.gov (United States)

    Shao, Yizhen; Wei, Ran; Zhang, Xianchun; Xiang, Qiaoping

    2015-01-01

    The cliff fern family Woodsiaceae has experienced frequent taxonomic changes at the familial and generic ranks since its establishment. The bulk of its species were placed in Woodsia, while Cheilanthopsis, Hymenocystis, Physematium, and Protowoodsia are segregates recognized by some authors. Phylogenetic relationships among the genera of Woodsiaceae remain unclear because of the extreme morphological diversity and inadequate taxon sampling in phylogenetic studies to date. In this study, we carry out comprehensive phylogenetic analyses of Woodsiaceae using molecular evidence from four chloroplast DNA markers (atpA, matK, rbcL and trnL-F) and covering over half the currently recognized species. Our results show three main clades in Woodsiaceae corresponding to Physematium (clade I), Cheilanthopsis-Protowoodsia (clade II) and Woodsia s.s. (clade III). In the interest of preserving monophyly and taxonomic stability, a broadly defined Woodsia including the other segregates is proposed, which is characterized by the distinctive indument and inferior indusia. Therefore, we present a new subgeneric classification of the redefined Woodsia based on phylogenetic and ancestral state reconstructions to better reflect the morphological variation, geographic distribution pattern, and evolutionary history of the genus. Our analyses of the cytological character evolution support multiple aneuploidy events that have resulted in the reduction of chromosome base number from 41 to 33, 37, 38, 39 and 40 during the evolutionary history of the cliff ferns.

  8. Molecular Phylogeny of the Cliff Ferns (Woodsiaceae: Polypodiales with a Proposed Infrageneric Classification.

    Directory of Open Access Journals (Sweden)

    Yizhen Shao

    Full Text Available The cliff fern family Woodsiaceae has experienced frequent taxonomic changes at the familial and generic ranks since its establishment. The bulk of its species were placed in Woodsia, while Cheilanthopsis, Hymenocystis, Physematium, and Protowoodsia are segregates recognized by some authors. Phylogenetic relationships among the genera of Woodsiaceae remain unclear because of the extreme morphological diversity and inadequate taxon sampling in phylogenetic studies to date. In this study, we carry out comprehensive phylogenetic analyses of Woodsiaceae using molecular evidence from four chloroplast DNA markers (atpA, matK, rbcL and trnL-F and covering over half the currently recognized species. Our results show three main clades in Woodsiaceae corresponding to Physematium (clade I, Cheilanthopsis-Protowoodsia (clade II and Woodsia s.s. (clade III. In the interest of preserving monophyly and taxonomic stability, a broadly defined Woodsia including the other segregates is proposed, which is characterized by the distinctive indument and inferior indusia. Therefore, we present a new subgeneric classification of the redefined Woodsia based on phylogenetic and ancestral state reconstructions to better reflect the morphological variation, geographic distribution pattern, and evolutionary history of the genus. Our analyses of the cytological character evolution support multiple aneuploidy events that have resulted in the reduction of chromosome base number from 41 to 33, 37, 38, 39 and 40 during the evolutionary history of the cliff ferns.

  9. Polyphyly of the fern family Tectariaceae sensu Ching: insights from cpDNA sequence data.

    Science.gov (United States)

    Liu, HongMei; Zhang, XianChun; Chen, ZhiDuan; Dong, ShiYong; Qiu, YinLong

    2007-12-01

    Tectariaceae are a pantropical fern family of about 20 genera, among which 8 are distributed in China. The morphological distinctiveness of the family is widely recognized, yet relatively little systematic research has been conducted on members of Tectariaceae. Phylogenetic analyses of chloroplast DNA sequence data (rbcL and atpB) from 15 species representing all 8 genera in China were carried out under parsimony criteria and Bayesian inference. The phylogenetic reconstructions indicated that the fern family Tectariaceae as traditionally circumscribed are polyphyletic. Ctenitis, Dryopsis, Lastreopsis clustered with and should be included within the newly-defined Dryopteridaceae, and Pleocnemia is also tentatively assigned to it. A narrowly monophyletic Tectariaceae is identified, which includes Ctenitopsis, Hemigramma, Pteridrys, Quercifilix, and Tectaria. In the single rbcL analysis, Arthropteris clustered with the above-mentioned monophyletic Tectariaceae. Although further investigations are still needed to identify infrafamilial relationships within the monophyletic Tectariaceae and to redefine several problematic genera, we propose a working concept here that better reflects the inferred evolutionary history of this group.

  10. Fertile structures with in situ spores of a dipterid fern from the Triassic in southern China.

    Science.gov (United States)

    Wang, Yongdong; Li, Liqin; Guignard, Gaëtan; Dilcher, David L; Xie, Xiaoping; Tian, Ning; Zhou, Ning; Wang, Yan

    2015-05-01

    Clathropteris was a typical dipterid fern with well documented fossil record and was widely dispersed during the Mesozoic; however, our knowledge of fertile structures including in situ spores for this genus is still very limited. Here we report well-preserved compression specimens of Clathropteris obovata Oishi from the Late Triassic of Guangyuan, Sichuan Province, China. The specimens show round to oval and exindusiate sori, vertical to oblique annuli in sporangia, and in situ trilete spores with verrucate and baculate sculptures, which are comparable to dispersed spore genera of Converrucosisporites and Conbaculatisporites. Comparisons of relevant fossil taxa suggest that specimens of C. obovata from Triassic of China provide for the first time in Asia the detailed fertile structures with in situ spore characters of dipterid fossil Clathropteris. Unlike living Dipteris, Mesozoic fossils of Dipteridaceae show a high diversity and a range of complex morphology of in situ spores, thus are significant for the evolutionary links between Dipteridaceae and other related fern clade, including Gleicheniaceae and Matoniaceae of the Gleicheniales.

  11. Intramolecular co-action of two independent photosensory modules in the fern phytochrome 3.

    Science.gov (United States)

    Kanegae, Takeshi

    2015-01-01

    Fern phytochrome3/neochrome1 (phy3/neo1) is a chimeric photoreceptor composed of a phytochrome-chromophore binding domain and an almost full-length phototropin. phy3 thus contains two different light-sensing modules; a red/far-red light receptor phytochrome and a blue light receptor phototropin. phy3 induces both red light- and blue light-dependent phototropism in phototropin-deficient Arabidopsis thaliana (phot1 phot2) seedlings. The red-light response is dependent on the phytochrome module of phy3, and the blue-light response is dependent on the phototropin module. We recently showed that both the phototropin-sensing module and the phytochrome-sensing module mediate the blue light-dependent phototropic response. Particularly under low-light conditions, these two light-sensing modules cooperate to induce the blue light-dependent phototropic response. This intramolecular co-action of two independent light-sensing modules in phy3 enhances light sensitivity, and perhaps allowed ferns to adapt to the low-light canopy conditions present in angiosperm forests.

  12. Nutrient values and bioactivities of the extracts from three fern species in China: a comparative assessment.

    Science.gov (United States)

    Qi, Guoyuan; Yang, Liuqing; Xiao, Chunxia; Shi, Jing; Mi, Yashi; Liu, Xuebo

    2015-09-01

    Pteridium aquilinum, Osmunda cinnamomea Linn, and Athyrium multidentatum (Doll.) Ching are three fern species widely consumed as potherbs and traditional medicinal herbs in China. Nevertheless, no detailed comparative assessments of their nutrient values and bioactivities have been reported. In this paper, we examined the nutrient content of these ferns and the bioactivities of their extracts with a comparative method. The results indicated that they were nutrient dense for proteins, carbohydrates, fat and minerals. Compared with Pteridium aquilinum and Osmunda cinnamomea Linn, the extract from Athyrium multidentatum (Doll.) Ching was found to possess the strongest antioxidant activity, protective effects on biomolecules, cellular antioxidant activity, and antiproliferative effects owing to its highest total phenolic (476.52 ± 11.26 mg GAE per g extract) and total flavonoid (924.81 ± 4.25 mg RNE per g extract) contents. Further, Athyrium multidentatum (Doll.) Ching can lead to caspase-3 activation, poly ADP-ribose polymerase cleavage, mitochondrial membrane potential (MMP) reduction and inhibition of wound-healing in a dose-dependent manner in HepG2 cells. These results demonstrate the remarkable potential of Pteridium aquilinum, Osmunda cinnamomea Linn, and Athyrium multidentatum (Doll.) Ching as valuable sources of nutrients and natural antioxidants, and among which Athyrium multidentatum (Doll.) Ching has potential anticancer properties.

  13. Influence of gravity and light on the developmental polarity of Ceratopteris richardii fern spores

    Science.gov (United States)

    Edwards, E. S.; Roux, S. J.

    1998-01-01

    The polarity of germinating single-celled spores of the fern Ceratopteris richardii Brogn. is influenced by gravity during a time period prior to the first cellular division designated a "polarity-determination window". After this window closes, control of polarity is seen in the downward (with respect to gravity) migration of the nucleus along the proximal face of the spore and the subsequent downward growth of the primary rhizoid. When spores are germinated on a clinostat the direction of nuclear migration and subsequent primary rhizoid growth is random. However, in each case the direction of nuclear migration predicts the direction of rhizoid elongation. Although it is the most obvious movement, the downward migration is not the first movement of the nucleus. During the polarity-determination window, the nucleus moves randomly within a region centered behind the trilete marking. While the polarity of many fern spores has been reported to be controlled by light, spores of C. richardii are the first documented to have their polarity influenced by gravity. Directional white light also affects the polarity of these spores, but this influence is slight and is secondary to that of gravity.

  14. Ultrastructure of the Mature Egg and Fertilization in the Fern Ceratopteris thafictroides

    Institute of Scientific and Technical Information of China (English)

    Jian-Guo Cao; Nai-Ying Yang; Quan-Xi Wang

    2009-01-01

    The ultrastructure of the mature egg and fertilization in the fern Ceratopteris thalictroides (L.) Brongn. were observed by transmission electron microscopy. The results revealed that the mature egg possesses an obvious egg membrane at the periphery of the egg. Furthermore, a fertilization pore was identified in the upper egg membrane of the mature egg. The structure of the pore is described for the first time. The fertilization experiment indicated that spermatozoids crowd into the cavity above the egg through the neck canal of the archegonium; however, only one of these can penetrate into the egg through the fertilization pore. Immediately on penetration of the spermatozoid, the egg begins to shrink. The volume of the fertilized egg decreases to almost one-half that of the unfertilized egg. As a result, the protoplasm of the fertilized egg becomes dense and opaque, which may lead to a situation where the organelles of both the egg and the fertilizing spermatozoid become indistinguishable. Simultaneously, abundant vesicles containing concentric membranes or opaque materials appear near the fertilization pore in the cytoplasm of the fertilized egg. These vesicles are considered to act as a barrier that prevents polyspermy. The present study provides a new insight into the ultrastructure of the mature egg and the cytological mechanism of fertilization in ferns.

  15. Human Detection Using Random Color Similarity Feature and Random Ferns Classifier.

    Science.gov (United States)

    Zhang, Miaohui; Xin, Ming

    2016-01-01

    We explore a novel approach for human detection based on random color similarity feature (RCS) and random ferns classifier which is also known as semi-naive Bayesian classifier. In contrast to other existing features employed by human detection, color-based features are rarely used in vision-based human detection because of large intra-class variations. In this paper, we propose a novel color-based feature, RCS feature, which is yielded by simple color similarity computation between image cells randomly picked in still images, and can effectively characterize human appearances. In addition, a histogram of oriented gradient based local binary feature (HOG-LBF) is also introduced to enrich the human descriptor set. Furthermore, random ferns classifier is used in the proposed approach because of its faster speed in training and testing than traditional classifiers such as Support Vector Machine (SVM) classifier, without a loss in performance. Finally, the proposed method is conducted in public datasets and achieves competitive detection results.

  16. Leaf micromorphology of four medicinal ferns species in Tasik Chini, Pahang

    Science.gov (United States)

    Nurnida, M. K.; Noraini, T.; Ruzi, A. R.; Idris, S.

    2015-09-01

    A leaf micromorphology study was conducted on four selected medicinal ferns species in Tasik Chini, Pahang. The four chosen species were Adiantum latifolium Lam., Lygodium flexuosum (L.) Sw., Lygodium microphyllum (Cav.) R. Br. and Tectaria singaporeana (Wall.) Ching. The objective of this study is to identify the leaf micromorphological characteristics that can be used as supportive scientific data especially in authentification of medicinal ferns species. The procedures involved such as dehydration, critical point drying, gold coated and examination under scanning electron microscope. Results in this study have shown some similarities and variations in the leaf micromorphological characteristics such as presence of cuticular striation, type of epicuticular waxes, structural feature of stomata and also in the presence or absence and type of trichomes. Four types of epicuticular waxes and only one type of trichome were observed, that were specific for some species. As a conclusion, the results of this study definitely proven that leaf micromorphology can be used for species authentification and might useful as preliminary scientific data for future references and further study.

  17. Modelling phytoremediation by the hyperaccumulating fern, Pteris vittata, of soils historically contaminated with arsenic

    Energy Technology Data Exchange (ETDEWEB)

    Shelmerdine, Paula A.; Black, Colin R. [School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD (United Kingdom); McGrath, Steve P. [Rothamsted Research, Harpenden, Herts AL5 2JQ (United Kingdom); Young, Scott D., E-mail: scott.young@nottingham.ac.u [School of Biosciences, Biology Building, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom)

    2009-05-15

    Pteris vittata plants were grown on twenty-one UK soils contaminated with arsenic (As) from a wide range of natural and anthropogenic sources. Arsenic concentration was measured in fern fronds, soil and soil pore water collected with Rhizon samplers. Isotopically exchangeable soil arsenate was determined by equilibration with {sup 73}As{sup V}. Removal of As from the 21 soils by three sequential crops of P. vittata ranged between 0.1 and 13% of total soil As. Ferns grown on a soil subjected to long-term sewage sludge application showed reduced uptake of As because of high available phosphate concentrations. A combined solubility-uptake model was parameterised to enable prediction of phytoremediation success from estimates of soil As, 'As-lability' and soil pH. The model was used to demonstrate the remediation potential of P. vittata under different soil conditions and with contrasting assumptions regarding re-supply of the labile As pool from unavailable forms. - This paper presents a predictive model for phytoremediation of soils, historically contaminated with arsenic, by the hyperaccumulator P. vittata.

  18. Arsenic-induced morphogenic response in roots of arsenic hyperaccumulator fern Pteris vittata.

    Science.gov (United States)

    Forino, Laura Maria Costantina; Ruffini Castiglione, Monica; Bartoli, Giacomo; Balestri, Mirko; Andreucci, Andrea; Tagliasacchi, Anna Maria

    2012-10-15

    On the assumption that arsenic induces stress morphogenetic responses involved in As tolerance and hyperaccumulation in the Pteris vittata fern, we analyzed the root system of young sporophytes grown in 250, 334, and 500 μM As for five days and for 14 days. Anatomical and histological analyses were performed in plants grown for five days to evaluate the number, position, length and differentiation pattern of root hairs. AgNOR staining, employed to study nucleolus behavior in root apices, showed that arsenic influences nucleolar activity (evaluated by nucleolus size, number and absorbance) in the root meristem. In plants treated with 250 and 334 μM As an acropetal shift of root hair development and an increase in hair length and density were observed, linked to an ectopic pattern of differentiation. The opposite trend was recorded in plants treated with 500 μM As. It is worth noting the presence of living border-like cells, not yet observed in ferns, and their increase following As treatments. Analysis and vitality of border-like cells were surveyed after 14 days of treatments. In conclusion As treatments elicited a stress-induced morphogenic response which, by modifying the differentiation pattern, number and length of root hairs, modulating nucleolar activity and interacting with the rhizosphere by inducing border-like cell production, may adjust the rate of root uptake and its metabolic activity.

  19. Effect of soil pH on as hyperaccumulation capacity in fern species, Pityrogramma calomelanos.

    Science.gov (United States)

    Anh, B T Kim; Kim, D D; Kuschk, P; Tua, T V; Hue, N T; Minh, N N

    2013-03-01

    Arsenic uptake by hyperaccumulator plant species depends on many different environmental factors. Soil pH is one of the most important factors due to its combined effect on both chemical and biological processes. In greenhouse experiment, the effect of pH (within the pH range 3.6 - 8.9) on As uptake as well as biomass of Pityrogramma calomelanos was evaluated. The plants were grown in mining soil containing 645.6 mg As kg(-1) for 14 weeks. Within this time, the plant biomass growth was 3.78 - 8.64 g d. wt. per plant and the removal amounted 6.3-18.4 mg As per plant. Translocation factor (ratio of As in fronds to roots) of the fern was 3.6 - 9.7, indicating its potential in phytoremediation of As contaminated soil. Influence of pH on As bioavailability was visible as the available As concentration was higher in acidic soil compared to alkaline soil. Furthermore, it was found that As accumulation by Pityrogramma calomelanos was optimum in the soil of pH 3.6. Nevertheless, the results of this study demonstrate that remediation of As-contaminated mining soils, by this fern, can be improved by changing the soil pH from 4.6 to 6.8.

  20. Ceratopteris richardii (C-fern: A model for investigating adaptive modification of vascular plant cell walls

    Directory of Open Access Journals (Sweden)

    Olivier eLeroux

    2013-09-01

    Full Text Available Plant cell walls are essential for most aspects of plant growth, development, and survival, including cell division, expansive cell growth, cell-cell communication, biomechanical properties, and stress responses. Therefore, characterising cell wall diversity contributes to our overall understanding of plant evolution and development. Recent biochemical analyses, concomitantly with whole genome sequencing of plants located at pivotal points in plant phylogeny, have helped distinguish between homologous characters and those which might be more derived. Most plant lineages now have at least one fully sequenced representative and although genome sequences for fern species are in progress they not yet available this group. Ferns offer key advantages for the study of developmental processes leading to vascularisation and complex organs as well as the specific differences between diploid sporophyte tissues and haploid gametophyte tissues and the interplay between them. Ceratopteris richardii has been well investigated building a body of knowledge which combined with the genomic and biochemical information available for other plants will progress our understanding of wall diversity and its impact on evolution and development.

  1. Arbuscular mycorrhizae increase the arsenic translocation factor in the As hyperaccumulating fern Pteris vittata L.

    Science.gov (United States)

    Trotta, A; Falaschi, P; Cornara, L; Minganti, V; Fusconi, A; Drava, G; Berta, G

    2006-09-01

    Phytoremediation techniques are receiving more attention as decontaminating strategies. Phytoextraction makes use of plants to transfer contaminants from soil to the aboveground biomass. This research is devoted to study the effects of arbuscular mycorrhizae (AM) on growth and As hyperaccumulation in the Chinese brake fern Pteris vittata. We grew for 45 days P. vittata sporophytes, infected or not infected with the AM fungi Glomus mosseae or Gigaspora margarita, in a hydroponic system on quartz sand. As-treated plants were weekly fed with 25 ppm As. The As treatment produced a dramatic increase of As concentration in pinnae and a much lower increase in roots of both mycorrhizal and control plants. Mycorrhization increased pinnae dry weight (DW) (G. margarita = G. mosseae) and leaf area (G. margarita > G. mosseae), strongly reduced root As concentration (G. mosseae > G. margarita), and increased the As translocation factor (G. mosseae > G. margarita). The concentration of phosphorus in pinnae and roots was enhanced by both fungi (G. margarita > G. mosseae). The quantitatively different effects of the two AM fungi on plant growth as well as on As and P distribution in the fern suggest that the As hyperaccumulation in P. vittata can be optimized by a careful choice of the symbiont.

  2. Progressive migration and anagenesis in Drimys confertifolia of the Juan Fernández Archipelago, Chile.

    Science.gov (United States)

    López-Sepúlveda, Patricio; Takayama, Koji; Greimler, Josef; Crawford, Daniel J; Peñailillo, Patricio; Baeza, Marcelo; Ruiz, Eduardo; Kohl, Gudrun; Tremetsberger, Karin; Gatica, Alejandro; Letelier, Luis; Novoa, Patricio; Novak, Johannes; Stuessy, Tod F

    2015-01-01

    A common mode of speciation in oceanic islands is by anagenesis, wherein an immigrant arrives and through time transforms by mutation, recombination, and drift into a morphologically and genetically distinct species, with the new species accumulating a high level of genetic diversity. We investigate speciation in Drimys confertifolia, endemic to the two major islands of the Juan Fernández Archipelago, Chile, to determine genetic consequences of anagenesis, to examine relationships among populations of D. confertifolia and the continental species D. winteri and D. andina, and to test probable migration routes between the major islands. Population genetic analyses were conducted using AFLPs and nuclear microsatellites of 421 individuals from 42 populations from the Juan Fernández islands and the continent. Drimys confertifolia shows a wide genetic variation within populations on both islands, and values of genetic diversity within populations are similar to those found within populations of the continental progenitor. The genetic results are compatible with the hypothesis of high levels of genetic variation accumulating within anagenetically derived species in oceanic islands, and with the concept of little or no geographical partitioning of this variation over the landscape. Analysis of the probability of migration within the archipelago confirms colonization from the older island, Robinson Crusoe, to the younger island Alejandro Selkirk.

  3. Leaf micromorphology of four medicinal ferns species in Tasik Chini, Pahang

    Energy Technology Data Exchange (ETDEWEB)

    Nurnida, M. K., E-mail: nurnidakamal@gmail.com; Noraini, T.; Ruzi, A. R.; Idris, S. [School of Environmental and Natural Resource Sciences Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2015-09-25

    A leaf micromorphology study was conducted on four selected medicinal ferns species in Tasik Chini, Pahang. The four chosen species were Adiantum latifolium Lam., Lygodium flexuosum (L.) Sw., Lygodium microphyllum (Cav.) R. Br. and Tectaria singaporeana (Wall.) Ching. The objective of this study is to identify the leaf micromorphological characteristics that can be used as supportive scientific data especially in authentification of medicinal ferns species. The procedures involved such as dehydration, critical point drying, gold coated and examination under scanning electron microscope. Results in this study have shown some similarities and variations in the leaf micromorphological characteristics such as presence of cuticular striation, type of epicuticular waxes, structural feature of stomata and also in the presence or absence and type of trichomes. Four types of epicuticular waxes and only one type of trichome were observed, that were specific for some species. As a conclusion, the results of this study definitely proven that leaf micromorphology can be used for species authentification and might useful as preliminary scientific data for future references and further study.

  4. A study of the carcinogenicity of glycidol in Syrian hamsters.

    Science.gov (United States)

    Lijinsky, W; Kovatch, R M

    1992-01-01

    The industrial chemical glycidol is a directly acting mutagen and a broadly acting carcinogen in rats. It was administered to Syrian golden hamsters (20 male and 20 female) by gavage of 12 mg twice a week for 60 weeks. The total dose per animal was 1.45 g or 20 mmol. Survival was not different from control hamsters treated with corn oil/ethyl acetate. Of the treated males, 9 had tumors and 13 of the treated females had tumors, some of which were adrenal cortex tumors seen in controls. More tumors were seen in the glycidol-treated hamsters than in controls, but the spleen was the only notable target organ and the number of animals with spleen hemangiosarcomas was small. Glycidol appeared to be less carcinogenic in hamsters than in rats or mice.

  5. 4-Dimethylaminoazobenzenes: carcinogenicities and reductive cleavage by microsomal azo reductase.

    Science.gov (United States)

    Lambooy, J P; Koffman, B M

    1985-01-01

    Twenty-four 4-dimethylaminoazobenzenes (DABs) in which systematic structural modifications have been made in the prime ring have been studied for substrate specificity for microsomal azo reductase. The DABs were also evaluated for carcinogenicity and it was found that there was no correlation between carcinogenicity and extent of azo bond cleavage by azo reductase. While any substituent in the prime ring reduces the rate of cleavage of the azo bond relative to the unsubstituted dye, there is a correlation between substituent size and susceptibility to the enzyme. Substituent size was also found to be a significant factor in the induction of hepatomas by the dyes. Preliminary studies have shown that there appears to be a positive correlation between microsomal riboflavin content and the activity of the azo reductase.

  6. A gene encoding a vicilin-like protein is specifically expressed in fern spores. Evolutionary pathway of seed storage globulins.

    Science.gov (United States)

    Shutov, A D; Braun, H; Chesnokov, Y V; Bäumlein, H

    1998-02-15

    The isolation and characterisation of a cDNA coding for a vicilin-like protein of the fern Matteuccia struthiopteris is described. The corresponding gene is specifically expressed during late stages of spore development. Extensive sequence comparisons suggest that the fern protein can be considered as a molecular missing link between single-domain germin/spherulin-like proteins and two-domain seed storage globulins of gymnosperms and angiosperms. Further, evidence is provided for the existence of a superfamily of structurally related, functionally different proteins which includes storage globulins of the vicilin and legumin families, a membrane-associated sucrose-binding protein of soybean, a Forssman antigen-binding lectin of velvet bean, the precursor of the vacuolar membrane bound proteins MP27/MP32 of pumpkin, the embryogenesis-specific protein Gea8 of carrot, the fern-spore-specific protein described here as well as the functionally diverse family of germins/germin-like proteins and the spherulins of myxomycetes. We propose that seed storage globulins of spermatophytes evolved from desiccation-related single-domain proteins of prokaryotes via a duplicated two-domain ancestor that is best represented by the extant fern spore-specific vicilin-like protein.

  7. Chemical Composition of Soil Horizons and Aggregate Size Fractions Under the Hawaiian Fern Dicranopteris and Angiosperm Cheirodendrom

    Science.gov (United States)

    Stewart, C. E.; Amatangelo, K.; Neff, J.

    2007-12-01

    Soil organic matter (SOM) inherits much of its chemical nature from the dominant vegetation, including phenolic (lignin-derived), aromatic, and aliphatic (cutin and wax-derived) compounds. However, relatively stable recalcitrant compounds may also be formed as a result of condensation and complexation reactions through decomposition and protected with association with mineral particles. The Hawaiian fern species Dicranopteris decomposes more slowly than the angiosperm, Cheirodendrom due to high concentrations of recalcitrant C compounds. These aliphatic fern leaf waxes are well-preserved and may comprise a large portion of the recalcitrant organic matter in these soils. Our objective was to determine the chemical composition of the SOM under the O- (litter-dominated) and the A- (mineral) horizons formed under fern and angiosperm vegetation. To determine the effect of mineral-association, we fractioned the soil into four size classes; 850-590 μm, 590-180 μm, 180-53 μm and cutin and leaf waxes (alkene and alkanes structures) occurred in the 180-53 μm fraction, which has been shown to be the most stable of the aggregate-size fractions. Soils developed under fern versus angiosperm vegetation have distinct chemical signatures, which likely determine the recalcitrance of the SOM.

  8. Alpha-expansins in the semiaquatic ferns Marsilea quadrifolia and Regnellidium diphyllum: evolutionary aspects and physiological role in rachis elongation.

    Science.gov (United States)

    Kim, J H; Cho, H T; Kende, H

    2000-12-01

    To investigate the evolutionary history of expansins and their role in cell elongation in early land plants, we isolated two alpha-expansin genes, Mq-EXP1 and Rd-EXP1, respectively, from the semiaquatic ferns Marsilea quacdrifolia L. and Regnellidium diphyllum Lindm. The deduced amino acid sequences of the fern expansins exhibit a high degree of identity to those of seed plants, showing that expansin genes were conserved during the evolution of vascular plants. Gel-blot analysis of M. quadrifolia and R. diphyllum genomic DNA indicated that, in both ferns, alpha-expansins are encoded by multigene families. Expression of alpha-expansin genes probed with Mq-EXP1 was confined to the elongating region of the Marsilea rachis. Cell-wall proteins of M. quadrifolia induced in-vitro extension of acidified cucumber cell walls. In R. diphyllum, expression of Rd-EXP1 increased when elongation of the rachis was enhanced by submergence or ethylene. These results indicate that alpha-expansins act as wall-loosening proteins in ferns, as has been proposed for angiosperms. In addition, Rd-EXP1 may play a role in mediating elongation of the rachis in submerged plants.

  9. Antibacterial activity of the terrestrial fern Lygodium flexuosum (L. Sw. against multidrug resistant enteric- and uro-pathogenic bacteria

    Directory of Open Access Journals (Sweden)

    Nabakishore Nayak

    2013-01-01

    Conclusions: Phytochemical analysis of the water-extract of L. flexuosum confirmed the presence of glycosides and carbohydrates, but alkaloids, terpenoids, steroids, saponins, tannins, and flavonoids were absent. L. flexuosum, being a fern, is a suitable non-microbial source of antimicrobial for MDR strains of major enteric and uro-pathogens.

  10. Biodiversity and spatial distribution of epiphytic ferns on Alsophila setosa Kaulf. (Cyatheaceae caudices in Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    JL. Schmitt

    Full Text Available The extractive exploitation of the tree fern Alsophila setosa Kaulf. alters forest formations and diminishes the availability of micro-habitat for epiphytes. A survey of epiphytic fern communities on A. setosa at 16 study sites in different forest formations in the State of Rio Grande do Sul, Brazil, documented the occurrence of 31 species representing 16 genera and six families. The greatest richness of species occurred in Polypodiaceae (39% and in the genus Asplenium L. (22%. Habitual holoepiphyte was the predominant ecological category, representing 61% of the species. Similarity analysis demonstrated heterogeneity in the composition of the epiphytic ferns at the study sites and indicated that the vegetation type is not the main factor for floristic difference. The lowest total specific richness (5 was recorded for the seasonal deciduous forest site. The majority of the sites presented similar averages of phorophyte height and epiphyte richness per caudex. In 25% of the sites the height of the host plants presented significant correlation with specific richness. Considering that the majority of the epiphytes are habitual and that some of them occur exclusively or preferentially on tree ferns, the maintenance of these host plants in the vegetation is essential for the conservation of epiphytic species.

  11. Epiphytic ferns in swamp forest remnants of the coastal plain of southern Brazil: latitudinal effects on the plant community

    Directory of Open Access Journals (Sweden)

    Letícia S. Machado

    Full Text Available ABSTRACT Community structure and spatial distribution of epiphytic ferns in swamp forest remnants along the coastal plain of the state of Rio Grande do Sul were analyzed. A total of 440 trees were sampled in fifty-seven 10 x 10 m plots. Each phorophyte was divided into five ecological zones (strata, where all species of epiphytic ferns were recorded. A total of 34 species representing 18 genera in six families were recorded. Polypodiaceae was the most represented family with 17 species, and Microgramma vacciniifolia had the highest epiphytic importance value. Characteristic holoepiphyte was the predominant ecological category, representing 70 % of the species. Ordination analysis showed a gradual change in floristic composition between ecological zones with richness differing significantly between strata. We observed that with increasing latitude there was a decrease in mean temperature and total rainfall, but an increase in frosts. These climatic and phytogeography changes result in a reduction in species richness and a change in the structure of epiphytic fern communities in a north-to-south direction. The importance of swamp forest remnants of the coastal plain to the diversity of epiphytic ferns is discussed.

  12. The freshwater fern Azolla (Azollaceae) from Eocene Arctic and Nordic Sea sediments: New species and their stratigraphic distribution

    NARCIS (Netherlands)

    van der Burgh, J.; Collinson, M.E.; van Konijnenburg-van Cittert, J.H.A.; Barke, J.; Brinkhuis, H.

    2013-01-01

    Three new species of the freshwater fern Azolla are described from Eocene marine deposits of the Arctic and Nordic seas, bringing the total number of species now documented from these areas to five. Azolla arctica Collinson et al., Azolla jutlandica Collinson et al., Azolla nova sp. nov. and Azolla

  13. Macrobenthos of Vembanad estuary in relation to the deposition of degraded water fern Salvinia and other macrophytes

    Digital Repository Service at National Institute of Oceanography (India)

    Gopalan, U.K.; Meenakshikunjamma, P.P.; Vengayil, D.T.

    Composition and seasonal abundance of macrobenthos in Vembanad estuary (India) seems to be influenced by the density of decaying macrophytes, especially the water fern Salvinia , deposited at the bottom of the estuary at the rate of 356.76 g/m super...

  14. Prevention of Carcinogen-Induced Oral Cancer by Sulforaphane.

    Science.gov (United States)

    Bauman, Julie E; Zang, Yan; Sen, Malabika; Li, Changyou; Wang, Lin; Egner, Patricia A; Fahey, Jed W; Normolle, Daniel P; Grandis, Jennifer R; Kensler, Thomas W; Johnson, Daniel E

    2016-07-01

    Chronic exposure to carcinogens represents the major risk factor for head and neck squamous cell carcinoma (HNSCC). Beverages derived from broccoli sprout extracts (BSE) that are rich in glucoraphanin and its bioactive metabolite sulforaphane promote detoxication of airborne pollutants in humans. Herein, we investigated the potential chemopreventive activity of sulforaphane using in vitro models of normal and malignant mucosal epithelial cells and an in vivo model of murine oral cancer resulting from the carcinogen 4-nitroquinoline-1-oxide (4NQO). Sulforaphane treatment of Het-1A, a normal mucosal epithelial cell line, and 4 HNSCC cell lines led to dose- and time-dependent induction of NRF2 and the NRF2 target genes NQO1 and GCLC, known mediators of carcinogen detoxication. Sulforaphane also promoted NRF2-independent dephosphorylation/inactivation of pSTAT3, a key oncogenic factor in HNSCC. Compared with vehicle, sulforaphane significantly reduced the incidence and size of 4NQO-induced tongue tumors in mice. A pilot clinical trial in 10 healthy volunteers evaluated the bioavailability and pharmacodynamic activity of three different BSE regimens, based upon urinary sulforaphane metabolites and NQO1 transcripts in buccal scrapings, respectively. Ingestion of sulforaphane-rich BSE demonstrated the greatest, most consistent bioavailability. Mucosal bioactivity, defined as 2-fold or greater upregulation of NQO1 mRNA, was observed in 6 of 9 evaluable participants ingesting glucoraphanin-rich BSE; 3 of 6 ingesting sulforaphane-rich BSE; and 3 of 9 after topical-only exposure to sulforaphane-rich BSE. Together, our findings demonstrate preclinical chemopreventive activity of sulforaphane against carcinogen-induced oral cancer, and support further mechanistic and clinical investigation of sulforaphane as a chemopreventive agent against tobacco-related HNSCC. Cancer Prev Res; 9(7); 547-57. ©2016 AACR.

  15. The Role of Tobacco-Derived Carcinogens in Pancreas Cancer

    OpenAIRE

    Lochan, Rajiv; Reeves, Helen L.; Daly, Anne K.; Charnley, Richard M

    2011-01-01

    The extremely poor outcome from pancreas cancer is well known. However, its aetiology less well appreciated, and the molecular mechanisms underlying this are poorly understood. Tobacco usage is one of the strongest risk factors for this disease, and this is a completely avoidable hazard. In addition, there are well described hereditary diseases which predispose, and familial pancreas cancer. We have sought here to summarise the role of tobacco-derived carcinogens and the mode of their tumorig...

  16. Dose-response relationships for carcinogens: a review.

    OpenAIRE

    Zeise, L; Wilson, R.; Crouch, E A

    1987-01-01

    We review the experimental evidence for various shapes of dose-response relationships for carcinogens and summarize those experiments that give the most information on relatively low doses. A brief review of some models is given to illustrate the shapes of dose-response curve expected from them. Our major interest is in the use of dose-response relationships to estimate risks to humans at low doses, and so we pay special attention to experimentally observed and theoretically expected nonlinea...

  17. Overview of bioassays for mutagens, carcinogens, and teratogens

    Energy Technology Data Exchange (ETDEWEB)

    Dumont, J.N.

    1982-01-01

    Bioassays to determine the risk of health hazards of man-made chemical substances are reviewed. The standard approach to testing a substance is the tier system, consisting of three levels of testing that are increasingly complex, lengthy, and costly. The paper describes the biological basis of bioassays, identifies various assays for mutagens, carcinogens and teratogens, and explains the problems involved in extrapolating test data to human risk estimates. Future improvements in assay techniques are discussed. (CR)

  18. Critical factors in assessing risk from exposure to nasal carcinogens.

    Science.gov (United States)

    Bogdanffy, M S; Mathison, B H; Kuykendall, J R; Harman, A E

    1997-10-31

    Anatomical, physiological, biochemical and molecular factors that contribute to chemical-induced nasal carcinogenesis are either largely divergent between test species and humans, or we know very little of them. These factors, let alone the uncertainty associated with our knowledge gap, present a risk assessor with the formidable task of making judgments about risks to human health from exposure to chemicals that have been identified in rodent studies to be nasal carcinogens. This paper summarizes some of the critical attributes of the hazard identification and dose-response aspects of risk assessments for nasal carcinogens that must be accounted for by risk assessors in order to make informed decisions. Data on two example compounds, dimethyl sulfate and hexamethylphosphoramide, are discussed to illustrate the diversity of information that can be used to develop informed hypotheses about mode of action and decisions on appropriate dosimeters for interspecies extrapolation. Default approaches to interspecies dosimetry extrapolation are described briefly and are followed by a discussion of a generalized physiologically based pharmacokinetic model that, unlike default approaches, is flexible and capable of incorporating many of the critical species-specific factors. Recent advancements in interspecies nasal dosimetry modeling are remarkable. However, it is concluded that without the development of research programs aimed at understanding carcinogenic susceptibility factors in human and rodent nasal tissues, development of plausible modes of action will lag behind the advancements made in dosimetry modeling.

  19. The dermal carcinogenic potential of unrefined and hydrotreated lubricating oils.

    Science.gov (United States)

    McKee, R H; Daughtrey, W C; Freeman, J J; Federici, T M; Phillips, R D; Plutnick, R T

    1989-08-01

    Unrefined lubricating oils contain relatively high levels of polycyclic aromatic hydrocarbons (PAH) and have been shown to induce tumors in mouse skin. Exxon has developed a new method of refining these materials, a severe hydrotreatment process that is optimized for PAH removal. The specific objectives of the current study were to assess PAH reduction and then to evaluate directly the dermal carcinogenic potential of the materials that spanned the range of products produced by this method. The test samples included unrefined light and heavy vacuum distillates from a naphthenic crude oil, as well as the corresponding severely hydrotreated products. Two sets of samples were prepared to assess the effects of various operating parameters in the reactor. Additionally, positive (benzo[a]pyrene), negative (white mineral oil) and vehicle (toluene) control groups were included to assess the sensitivity and specificity of the bioassay. Each sample was applied in twice-weekly aliquots to the backs of 40 male C3H mice. In the analytical studies, significant reductions in the levels of several specific PAH were demonstrated. In the dermal carcinogenesis studies, the unrefined oils and the positive control induced tumors and also significantly reduced survival. None of the mice treated with severely hydrotreated oils or with the negative or vehicle controls developed skin tumors, and survival of these mice was not significantly different from the control. Thus, the data demonstrated that this new, severe hydrotreatment process was an effective means of converting carcinogenic feedstocks to non-carcinogenic products.

  20. Workplace carcinogen and pesticide exposures in Costa Rica.

    Science.gov (United States)

    Partanen, Timo; Chaves, Jorge; Wesseling, Catharina; Chaverri, Fabio; Monge, Patricia; Ruepert, Clemens; Aragón, Aurora; Kogevinas, Manolis; Hogstedt, Christer; Kauppinen, Timo

    2003-01-01

    The CAREX data system converts national workforce volumes and proportions of workers exposed to workplace carcinogens into numbers of exposed in 55 industrial categories. CAREX was adapted for Costa Rica for 27 carcinogens and seven groups of pesticides. Widespread workplace carcinogens in the 1.3 million workforce of Costa Rica are solar radiation (333,000 workers), diesel engine exhaust (278,000), environmental tobacco smoke (71,000), hexavalent chromium compounds (55,000), benzene (52,000), wood dust (32,000), silica dust (27,000), lead and inorganic lead compounds (19,000), and polycyclic aromatic compounds (17,000). The most ubiquitous pesticides were paraquat and diquat (175,000), mancozeb, maneb, and zineb (49,000), chlorothalonil (38,000), benomyl (19,000), and chlorophenoxy herbicides (11,000). Among women, formaldehyde, radon, and methylene chloride overrode pesticides, chromium, wood dust, and silica dust in numbers of exposed. High-risk sectors included agriculture, construction, personal and household services, land and water transport and allied services, pottery and similar industries, woodworks, mining, forestry and logging, fishing, manufacturing of electrical machinery, and bar and restaurant personnel.

  1. Linearity of dose-response relationships for human carcinogenic exposures

    Energy Technology Data Exchange (ETDEWEB)

    Smith, A.H. (Univ. of California, Berkeley (USA))

    The shape of dose-response relationships is a critical factor in considering cancer risks for the work place and environmental exposure to carcinogens. Markedly different risk estimates result from assumptions of linearity versus sublinear and threshold assumptions. This paper presents evidence that the relationship between the relative risk of development of cancer and the dose rate to carcinogenic exposures is frequently linear with no evidence for thresholds. Dose-response relationships from four studies of asbestos and lung cancer were examined, all of which were consistent with a linear relationship. Analysis of the relationship between the relative risk of lung cancer and exposure to nickel in a smelter study, selected because of relatively good exposure data, demonstrated a close agreement with a linear relationship. The relationship between the level of arsenic in drinking wter and the prevalence of skin cancer also was linear for males in the highest prevalence age group in Taiwan, although there was some evidence of sublinearity for females and younger persons. Also, the relationships between the number of cigarettes smoked per day and the relative risk of lung cancer was very close to linear in many studies. The analysis of these and other studies involving human exposure to carcinogens provides empirical evidence for linearity when the response variable is a rate ratio measure, rather than a risk difference measure. Linearity in dose-response is biologically plausible, without invoking a one-hit model. Except in special circumstances. the epidemiological evidence supports linear extrapolation of cancer relative risks.

  2. Artificial sweeteners--do they bear a carcinogenic risk?

    Science.gov (United States)

    Weihrauch, M R; Diehl, V

    2004-10-01

    Artificial sweeteners are added to a wide variety of food, drinks, drugs and hygiene products. Since their introduction, the mass media have reported about potential cancer risks, which has contributed to undermine the public's sense of security. It can be assumed that every citizen of Western countries uses artificial sweeteners, knowingly or not. A cancer-inducing activity of one of these substances would mean a health risk to an entire population. We performed several PubMed searches of the National Library of Medicine for articles in English about artificial sweeteners. These articles included 'first generation' sweeteners such as saccharin, cyclamate and aspartame, as well as 'new generation' sweeteners such as acesulfame-K, sucralose, alitame and neotame. Epidemiological studies in humans did not find the bladder cancer-inducing effects of saccharin and cyclamate that had been reported from animal studies in rats. Despite some rather unscientific assumptions, there is no evidence that aspartame is carcinogenic. Case-control studies showed an elevated relative risk of 1.3 for heavy artificial sweetener use (no specific substances specified) of >1.7 g/day. For new generation sweeteners, it is too early to establish any epidemiological evidence about possible carcinogenic risks. As many artificial sweeteners are combined in today's products, the carcinogenic risk of a single substance is difficult to assess. However, according to the current literature, the possible risk of artificial sweeteners to induce cancer seems to be negligible.

  3. Host range and genetic relatedness of Colletotrichum acutatum isolates from fruit crops and leatherleaf fern in Florida.

    Science.gov (United States)

    MacKenzie, S J; Peres, N A; Barquero, M P; Arauz, L F; Timmer, L W

    2009-05-01

    Isolates of Colletotrichum acutatum were collected from anthracnose-affected strawberry, leatherleaf fern, and Key lime; ripe-rot-affected blueberry; and postbloom fruit drop (PFD)-affected sweet orange in Florida. Additional isolates from ripe-rot-affected blueberry were collected from Georgia and North Carolina and from anthracnose-affected leatherleaf fern in Costa Rica. Pathogenicity tests on blueberry and strawberry fruit; foliage of Key lime, leatherleaf fern, and strawberry; and citrus flowers showed that isolates were highly pathogenic to their host of origin. Isolates were not pathogenic on foliage of heterologous hosts; however, several nonhomologous isolates were mildly or moderately pathogenic to citrus flowers and blueberry isolates were pathogenic to strawberry fruit. Based on sequence data from the internal transcribed spacer (ITS)1-5.8S rRNA-ITS2 region of the rDNA repeat, the glutaraldehyde-3-phosphate dehydrogenase intron 2 (G3PD), and the glutamine synthase intron 2 (GS), isolates from the same host were identical or very similar to each other and distinct from those isolated from other hosts. Isolates from leatherleaf fern in Florida were the only exception. Among these isolates, there were two distinct G3PD and GS sequences that occurred in three of four possible combinations. Only one of these combinations occurred in Costa Rica. Although maximum parsimony trees constructed from genomic regions individually displayed little or no homoplasy, there was a lack of concordance among genealogies that was consistent with a history of recombination. This lack of concordance was particularly evident within a clade containing PFD, Key lime, and leatherleaf fern isolates. Overall, the data indicated that it is unlikely that a pathogenic strain from one of the hosts examined would move to another of these hosts and produce an epidemic.

  4. FERNS ON MAOERSHAN MOUNTAINDISTRICT IN HEILONGJIANG PROVINCE%黑龙江省帽儿山地区的蕨类植物

    Institute of Scientific and Technical Information of China (English)

    曹建国; 王雪艳; 戴绍军

    2000-01-01

    In this paper the classification and the key to the ferns on Maoershan Mountain district have been done. More than 40 species of ferns are listed, and the relation between the different ferns and their environmental factors are also discussed.%本文对帽儿山地区的蕨类植物进行了分类检索,记述了帽儿山地区蕨类植物40余种,并阐明它们的分布与环境因子的关系.

  5. Carcinogenicity of azo colorants: influence of solubility and bioavailability.

    Science.gov (United States)

    Golka, Klaus; Kopps, Silke; Myslak, Zdislaw W

    2004-06-15

    In the past, azo colorants based on benzidine, 3,3'-dichlorobenzidine, 3,3'-dimethylbenzidine (o-tolidine), and 3,3'-dimethoxybenzidine (o-dianisidine) have been synthesized in large amounts and numbers. Studies in exposed workers have demonstrated that the azoreduction of benzidine-based dyes occurs in man. The metabolic conversion of benzidine-, 3,3'-dimethylbenzidine- and 3,3'-dimethoxybenzidine-based dyes to their (carcinogenic) amine precursors in vivo is a general phenomenon that must be considered for each member of this class of chemicals. Several epidemiological studies have demonstrated that the use of the benzidine-based dyes has caused bladder cancer in humans. However, in contrast to water-soluble dyes, the question of biological azoreduction of (practically insoluble) pigments has been a matter of discussion. As a majority of azo pigments are based on 3,3'-dichlorobenzidine, much of the available experimental data are focused on this group. Long-term animal carcinogenicity studies performed with pigments based on 3,3'-dichlorobenzidine did not show a carcinogenic effect. The absence of a genotoxic effect has been supported by mutagenicity studies with the 3,3'-dichlorobenzidine-based Pigment Yellow 12. Studies in which azo pigments based on 3,3'-dichlorobenzidine had been orally administered to rats, hamsters, rabbits and monkeys could generally not detect significant amounts of 3,3'-dichlorobenzidine in the urine. It, therefore, appears well established that the aromatic amine components from azo pigments based on 3,3'-dichlorobenzidine are practically not bioavailable. Hence, it is very unlikely that occupational exposure to insoluble azo pigments would be associated with a substantial risk of (bladder) cancer in man. According to current EU regulations, azo dyes based on benzidine, 3,3'-dimethoxybenzidine and 3,3'-dimethylbenzidine have been classified as carcinogens of category 2 as "substances which should be regarded as if they are carcinogenic

  6. Polycyclic Aromatic Hydrocarbons In Edible Mushrooms from Niger Delta, Nigeria: Carcinogenic and Non-Carcinogenic Health Risk Assessment

    Science.gov (United States)

    Igbiri, Sorbari; Udowelle, Nnaemeka Arinze; Ekhator, Osazuwa Clinton; Asomugha, Rose Ngozi; Igweze, Zelinjo Nkeiruka; Orisakwe, Orish Ebere

    2017-02-01

    In the oil-rich Niger Delta, hydrocarbon pollution and oil spillages, gas flaring and sundry anthropogenic activities constitute sources of polycyclic aromatic hydrocarbons (PAHs), with food contamination playing a major role in human exposure. In this study we assessed PAH levels in wild and cultivated edible mushroom species consumed by the general population from the oil producing Niger Delta, Nigeria. The concentrations of USEPA-16 PAHs were determined by gas chromatography and carcinogenic and non-carcinogenic health risks were calculated. The concentrations of USEPA-16 PAHs ranged from 0.02 mg/kg – 3.37 mg/kg. The dietary intake of carcinogenic and non-carcinogenic USEPA-16 PAHs (Naphthalene, Acenaphthylene, Acenaphthene, Anthracene, Phenanthrene, Flourene, Flouranthene, Pyrene, Benzo[a]Anthracene, Chrysene, Benzo[a]Pyrene, Benzo[b]Flouranthene, Benzo[K]Flouranthene, Benzo[g,h,i] Perylene, Dibenz[a,h]Anthracene and Ideno[1,2,3-cd]Pyrene) for adults, adolescents and seniors ranged from 0.00 – 0.05 mg/kg/day, 0.00 – 0.06 mg/kg/day and 0.00 – 0.07 mg/kg/day. The BaPeq ranged from 0.02 – 2.76 with margin of exposure MOE values of BaP ranging from 3,500,000 to 700,000, 3,500,000 and 3,500,000 to 7,000,000 for adults, adolescents and seniors indicating very insignificant health risk. The incremental lifetime cancer risk was within the safe range of 1.56x10-8 – 1.73x10-6 with the highest calculated risk found for wild Pleurotus ostreatus mushroom species from the study area. Creative Commons Attribution License

  7. Microsite-limited recruitment controls fern colonization of post-agricultural forests.

    Science.gov (United States)

    Flinn, Kathryn M

    2007-12-01

    Assessing the relative roles of dispersal limitation and environmental effects in population dynamics and community assembly is fundamental to understanding patterns of species distribution and diversity. In forests growing on abandoned agricultural lands, both legacies of vegetation disturbance and changes in the abiotic environment shape the diversity and composition of recovering communities. Here I specify how interactions among historical, environmental, and biological factors influence species distributions, focusing on three fern species with contrasting distributions across forests of different history in central New York, USA: Dryopteris carthusiana, Dryopteris intermedia, and Polystichum acrostichoides. Using population surveys, spore-trap and spore-bank studies, and a three-year field experiment, I compare demographic rates among species and between forest types to determine which life history stages limit colonization and which traits explain species distributions. Adult plants of all three species were larger and more likely to produce spores in post-agricultural forests than in adjacent, uncleared stands. Though lower population densities led to fewer spores in post-agricultural soils, spore availability still exceeded recruitment by four to five orders of magnitude. Sowing additional spores had relatively little effect, while microhabitat conditions had the greatest impact on establishment rates. Given similar microsites, the two forest types had equal rates of establishment, but some forest-floor features preferentially occupied by juvenile plants were less frequent in post-agricultural stands. The availability of suitable sites for establishment, created by small-scale heterogeneity on forest floors, thus limits both the growth of fern populations and the colonization of new habitats. In fact, reduced microtopographic variation in post-agricultural forests may represent a greater hindrance to plant establishment than changes in mean environmental

  8. Macedonio Fernández o el primer mentiroso del Río de la Plata

    Directory of Open Access Journals (Sweden)

    Diego Vecchio

    2006-07-01

    Full Text Available 1- Lingüística y cartografíaComo corresponde a un “filósofo” idealista, Macedonio Fernández también fue un lingüista. En 1928, en No toda es vigilia, en el capítulo intitulado “Definiciones de ideas y vocablos”, elabora una primera teoría del lenguaje :La palabra es un signo para comunicación. Esta es sólo, más que comunicación, suscitación de imagen por signo. Y el orden de lo así comunicable es puramente el de las imágenes, aunque haciendo nacer en otra mente las imágenes que tenemos ahora ...

  9. Conocer el Nuevo Mundo: referencialidad en las ilustraciones de Fernández de Oviedo

    Directory of Open Access Journals (Sweden)

    Vanina M. Teglia

    2014-12-01

    Full Text Available The illustrations drawn by the official chronicler of the Indies, Gonzalo Fernández de Oviedo, to accompany his sections on American flora were the first of this type to appear on a printed edition. Between the paradigms of medieval bookish hermeneutics and the growing appreciation for the witness testimony, the Veedor del Oro in the New World, writer and illustrator employs visual language devices to offer reliable proof of the nature he observed and, simultaneously, apprehend it through the imperial discourse’s forms of discernment. In this paper, we will analyze the images that Oviedo merged into his manuscripts and printed editions to show several amazingly significant references concentrated in them: references to American reality, by means of mimesis and similitude; references to the familiar schemes of Western pictorial traditions, and, finally, to Christian imperial hierarchies. This whole referential complex is finally put to the service of imperial expansion

  10. El tratado de estadística de Fernández-Baños

    OpenAIRE

    Arenzana, Víctor

    1997-01-01

    El Tratado de Estadística de Olegario Fernández Baños fue el primer libro de Estadística Matemática en sentido moderno que se publicó en España. Anteriormente, se habían publicado libros de estadística para la asignatura de geógrafa y estadística industrial y Mercantil de las Escuelas de Comercio y para la de Economía Política de las Facultades de Derecho. tos libros de texto para esas asignaturas trataban, generalmente, temas de carácter administrativa, descripción de los métodos estadístic...

  11. Colombia en cuatro tiempos : Carmelo Fernández 1809-1887

    OpenAIRE

    1991-01-01

    San José de Guama (estado de Yaracuy, Venezuela), 30 de junio de 1809 - Caracas, 9 de febrero de 1887. En 1983 a los 96 años de su muerte y dentro de las conmemoraciones de los 200 años del nacimiento de Simón Bolívar, fueron trasladados los restos del artista y militar Carmelo Fernández al Panteón Nacional de Caracas, donde reposan cercanos a los del Libertador Cuando se observa la baldosa del piso que a manera de tumba presenta su nombre, se recuerda su fidelidad y admiración por Bolívar. N...

  12. Arsenic speciation for the phytoremediation by the Chinese brake fern, Pteris vittata

    Institute of Scientific and Technical Information of China (English)

    R. Shoji; R. Yajima; Y. Yano

    2008-01-01

    Arsenic (As) speciation for the phytoremediation by the Chinese brake fern was studied. In particular, the mechanism of how plants induce compounds containing thiol (SH) and proteins by As exposure in terms of the relationship between As and phosphate uptaken into plant cells was examined. Pteris vittata callus could efficiently reduce As(V) to As(Ill) by the rapid introduction of reductase and synthesize thiols leading to phytoehelatins production. Furthermore, Pteris vittata could control phosphate concentration in the cells corresponding to the concentration of arsenite and arsenate. To our best knowledge, this is the first report to show the mechanisms of such high As tolerance of Pteris vittata using their callus in terms of in vitro approach for the analysis of As speciation and metabolism route.

  13. Colombia en cuatro tiempos : Carmelo Fernández 1809-1887

    Directory of Open Access Journals (Sweden)

    Beatriz González

    1991-09-01

    Full Text Available San José de Guama (estado de Yaracuy, Venezuela, 30 de junio de 1809 - Caracas, 9 de febrero de 1887. En 1983 a los 96 años de su muerte y dentro de las conmemoraciones de los 200 años del nacimiento de Simón Bolívar, fueron trasladados los restos del artista y militar Carmelo Fernández al Panteón Nacional de Caracas, donde reposan cercanos a los del Libertador Cuando se observa la baldosa del piso que a manera de tumba presenta su nombre, se recuerda su fidelidad y admiración por Bolívar. Nunca debió de pasar por la mente de este hombre humilde y singular que sus restos descansarían en tan notable sitio de veneración y culto.

  14. Arsenic speciation for the phytoremediation by the Chinese brake fern, Pteris vittata.

    Science.gov (United States)

    Shoji, R; Yajima, R; Yano, Y

    2008-01-01

    Arsenic (As) speciation for the phytoremediation by the Chinese brake fern was studied. In particular, the mechanism of how plants induce compounds containing thiol (SH) and proteins by As exposure in terms of the relationship between As and phosphate uptaken into plant cells was examined. Pteris vittata callus could efficiently reduce As(V) to As(III) by the rapid introduction of reductase and synthesize thiols leading to phytochelatins production. Furthermore, Pteris vittata could control phosphate concentration in the cells corresponding to the concentration of arsenite and arsenate. To our best knowledge, this is the first report to show the mechanisms of such high As tolerance of Pteris vittata using their callus in terms of in vitro approach for the analysis of As speciation and metabolism route.

  15. Development and characterization of 27 microsatellite markers for the mangrove fern, Acrostichum aureum (Pteridaceae)1

    Science.gov (United States)

    Yamamoto, Takashi; Tsuda, Yoshiaki; Mori, Gustavo Maruyama; Cruz, Mariana Vargas; Shinmura, Yoshimi; Wee, Alison K. S.; Takayama, Koji; Asakawa, Takeshi; Yamakawa, Takeru; Suleiman, Monica; Núñez-Farfán, Juan; Webb, Edward L.; Watano, Yasuyuki; Kajita, Tadashi

    2016-01-01

    Premise of the study: Twenty-seven nuclear microsatellite markers were developed for the mangrove fern, Acrostichum aureum (Pteridaceae), to investigate the genetic structure and demographic history of the only pantropical mangrove plant. Methods and Results: Fifty-six A. aureum individuals from three populations were sampled and genotyped to characterize the 27 loci. The number of alleles and expected heterozygosity ranged from one to 15 and 0.000 to 0.893, respectively. Across the 26 polymorphic loci, the Malaysian population showed much higher levels of polymorphism compared to the other two populations in Guam and Brazil. Cross-amplification tests in the other two species from the genus determined that seven and six loci were amplifiable in A. danaeifolium and A. speciosum, respectively. Conclusions: The 26 polymorphic microsatellite markers will be useful for future studies investigating the genetic structure and demographic history of of A. aureum, which has the widest distributional range of all mangrove plants. PMID:27672519

  16. Ferns, mosses and liverworts as model systems for light-mediated chloroplast movements.

    Science.gov (United States)

    Suetsugu, Noriyuki; Higa, Takeshi; Wada, Masamitsu

    2016-11-17

    Light-induced chloroplast movement is found in most plant species, including algae and land plants. In land plants with multiple small chloroplasts, under weak light conditions, the chloroplasts move towards the light and accumulate on the periclinal cell walls to efficiently perceive light for photosynthesis (the accumulation response). Under strong light conditions, chloroplasts escape from light to avoid photodamage (the avoidance response). In most plant species, blue light induces chloroplast movement, and phototropin receptor kinases are the blue light receptors. Molecular mechanisms for photoreceptors, signal transduction and chloroplast motility systems are being studied using the model plant Arabidopsis thaliana. However, to further understand the molecular mechanisms and evolutionary history of chloroplast movement in green plants, analyses using other plant systems are required. Here, we review recent works on chloroplast movement in green algae, liverwort, mosses and ferns that provide new insights on chloroplast movement.

  17. Evidence for radiations of cheilanthoid ferns in the Greater Cape Floristic Region

    DEFF Research Database (Denmark)

    Eiserhardt, Wolf L.; Rohwer, Jens G.; Russell, Stephen J.

    2011-01-01

    The Greater Cape Floristic Region (GCFR) of southern Africa is characterised by large, endemic radiations of flowering plants, the so-called ‘Cape Clades’, but it is unknown whether such radiations are also found in non-angiosperms. We hypothesise that GCFR-endemic lineages exist in the xeric...... cheilanthoid fern species occurring in the GCFR. With two exceptions, all GCFR-endemics are part of two clades that diversified in the Afro-Madagascan region. The GCFR-endemics are further concentrated in three high-endemism subclades that did not originate simultaneously, but within the timeframe...... of angiosperm Cape Clades diversification. According to ancestral area reconstructions the ancestors of the two larger Afro-Madagascan clades were likely GCFR-endemic, and a substantial part of the diversification history of these clades took place in the GCFR. The high diversity of cheilanthoids in the GCFR...

  18. Casa Fernández Oks : Casa mirando el río

    OpenAIRE

    2000-01-01

    Esta casa fue el resultado de un pedido de la familia Fernández-Oks cuando su hija era aún una niña, por lo tanto, el programa es muy sencillo: estar, comedor, cocina, espacios exteriores preparados para los festejos familiares o con amigos, dos dormitorios y garage. Cuando la hija creció se agregó un tercer dormitorio para los visitantes. El desafío más importante del proyecto, lo planteó la ubicación del Río de La Plata y las vistas hacia él. Por lo tanto era casi una obligación abrir la ca...

  19. Dos cuentos de Fernández Guardia: "El estreno" y "La política"

    OpenAIRE

    2006-01-01

    En Fernández Guardia tenemos un autor mucho más complejo y menos homogéneo que sus contemporáneos, desde el punto de vista del género de sus obras y del estilo reacio a la clasificación y al análisis según los patrones tradicionales aplicables a los autores de su época. La importancia tanto en calidad como en cantidad de su obra de historiador, ha ocultado, inmerecidamente a nuestro juicio, el valor de su obra literaria.

  20. El desencuentro de la novela argentina: Macedonio Fernández y el texto nacional

    OpenAIRE

    Castellarnau, Ariadna

    2012-01-01

    Macedonio Fernández dedicó más de tres décadas a la escritura de una novela extraña, inclasificable y cuya terminación fue postergada a lo largo de sucesivos manuscritos. Museo de la novela de la Eterna se mantuvo inédito hasta su publicación póstuma en 1974. Casi toda la bibliografía macedoniana coincide en el análisis de Museo de la novela de la Eterna como la obra fundamental del autor y, a la vez, como uno de los textos más renovadores de la literatura latinoamericana. Macedonio de...

  1. Microstructural features of water fern Salvinia natans (L. All. organ surfaces

    Directory of Open Access Journals (Sweden)

    M.M. Shcherbatiuk

    2015-05-01

    Full Text Available The microstructure of the organs surface of the water fern Salvinia natans (L. All. has been studied under scanning electron microscope. It was established that the existence on the border between air and water environments is suported by specific microstructure of floating leaves. The adaxial side of floating leaves has well-developed cuticle and stomata placed below the level of epidermis, while abaxial surface of such leaves and submerged modified leaves are characterized by ultra-thin cell walls of the epidermis and numerous filamentous trichomes. We calculated number of stomata per unit area of leaves and the average diameter of stomata. It is claimed that the structure of wall of the sporocarp promotes the passage of the annual summer-green rhythm. Sporocarp provides diving of mega- and microsporangia to the bottom of the water reservoir in autumn and their raising on the water surface in the spring after destruction of its walls.

  2. La importancia de 1958 en la obra de Rafa Fernández

    Directory of Open Access Journals (Sweden)

    Mauricio Oviedo Salazar

    2015-05-01

    Full Text Available El ensayo trata la importancia que tuvo 1958 para la producción artística del costarricense Rafa Fernández. En dicho año el artista estudió en Nicaragua, bajo la dirección de Rodrigo Peñalba, en la Escuela Nacional de Bellas Artes de Managua. Este fue un periodo determinante en su carrera, ya que consigue herramientas pictóricas que serán empleadas en sus pinturas procedentes de la década de los sesenta, por ejemplo, el uso de disímiles texturas y el manejo de colores oscuros que le proporcionaban a sus cuadros una estética grotesca y violenta.

  3. Accelerated rate of molecular evolution for vittarioid ferns is strong and not driven by selection.

    Science.gov (United States)

    Rothfels, Carl J; Schuettpelz, Eric

    2014-01-01

    Molecular evolutionary rate heterogeneity-the violation of a molecular clock-is a prominent feature of many phylogenetic data sets. It has particular importance to systematists not only because of its biological implications, but also for its practical effects on our ability to infer and date evolutionary events. Here we show, using both maximum likelihood and Bayesian approaches, that a remarkably strong increase in substitution rate in the vittarioid ferns is consistent across the nuclear and plastid genomes. Contrary to some expectations, this rate increase is not due to selective forces acting at the protein level on our focal loci. The vittarioids bear no signature of the change in the relative strengths of selection and drift that one would expect if the rate increase was caused by altered post-mutation fixation rates. Instead, the substitution rate increase appears to stem from an elevated supply of mutations, perhaps limited to the vittarioid ancestral branch. This generalized rate increase is accompanied by extensive fine-scale heterogeneity in rates across loci, genomes, and taxa. Our analyses demonstrate the effectiveness and flexibility of trait-free investigations of rate heterogeneity within a model-selection framework, emphasize the importance of explicit tests for signatures of selection prior to invoking selection-related or demography-based explanations for patterns of rate variation, and illustrate some unexpected nuances in the behavior of relaxed clock methods for modeling rate heterogeneity, with implications for our ability to confidently date divergence events. In addition, our data provide strong support for the monophyly of Adiantum, and for the position of Calciphilopteris in the cheilanthoid ferns, two relationships for which convincing support was previously lacking.

  4. Mycorrhizal association in gametophytes and sporophytes of the fern Pteris vittata (Pteridaceae with Glomus intraradices

    Directory of Open Access Journals (Sweden)

    Alicia E Martinez

    2012-06-01

    Full Text Available Ferns, which are usually colonizing different environments and their roots frequently present mycorrhization, have two adult stages in their life cycle, the sporophytic and the gametophytic phase. This paper describes the experimental mycorrhizal association between Pteris vittata leptosporangiate fern and a strain of Glomus intraradices during the life cycle of the fern, from spore germination to the development of a mature sporophyte. The aim of this study was to compare the colonization pattern of in vitro cultures of G. intraradices along the fern life cycle with those found in nature. For this, mature spores were obtained from fertile P. vittata fronds growing in walls of Buenos Aires city, Argentina. Roots were stained and observed under the light microscope for arbuscular mycorrhizal colonization. Approximately, 75 fern spores were cultured in each pot filled with a sterile substrate and G. intraradices (BAFC N° 51.331 as inoculum on the surface. After germination took place, samples were taken every 15 days until the fern cycle was completed. In order to determine colonization dynamics each sample was observed under optical and confocal microscope after staining. Gametophyte was classified as Adiantum type. Male and female gametangia were limited to the lower face, mycorrhizal colonization started when they were differentiated and took place through the rhizoids. Spores and vesicles were not found in this cycle stage. Paris-type mycorrhizal colonization was established in the midrib and in the embrionary foot. It was colonized by external mycelium. When the first root was developed soil inoculum colonized de novo this structure and Arum-type colonization was observed. This study proves that the type of colonization is determined by the structure of the host, not by the fungus. Both the gametophyte and embryo foot have determined growth and Paris-type colonization, while, sporophyte roots have undetermined growth and Arum

  5. Water ferns Azolla spp. (Azollaceae as new host plants for the small China-mark moth, Cataclysta lemnata (Linnaeus, 1758 (Lepidoptera, Crambidae, Acentropinae

    Directory of Open Access Journals (Sweden)

    Atousa Farahpour-Haghani

    2017-01-01

    Full Text Available Water ferns (Azolla spp., Azollaceae are reported for the first time as host plants for the larvae of the small China-mark moth Cataclysta lemnata (Linnaeus (Lepidoptera: Crambidae: Acentropinae in rice fields and waterways of northern Iran. Cataclysta lemnata is a semi-aquatic species that has been recorded to feed on Lemnaceae and a few other aquatic plants. However, it has not been reported before on Azolla spp. Larvae use water fern as food source and shelter and, at high population density in the laboratory, they completely wiped water fern from the water surface. Feeding was confirmed after rearing more than eight continual generations of C. lemnata on water fern in the laboratory. Adults obtained this way are darker and have darker fuscous markings in both sexes compared with specimens previously reported and the pattern remains unchanged after several generations.

  6. Fern diversity and biomass at Chilapatta reserve forest of West Bengal Terai Duars in sub-humid tropical foothills of Indian eastern Himalayas

    Institute of Scientific and Technical Information of China (English)

    Gopal Shukla; Sumit Chakravarty

    2012-01-01

    We documented the status of fern diversity,biomass and carbon accumulation at Chilapatta Reserve Forest in Cooch Behar Wildlife Division,West Bengal.Stratified random nested quadrat sampling was adopted for analyzing the qualitative and quantitative characters.Nineteen fern species were recorded,of which two are yet to be identified.Identified species were of eight families and nine genera.Highest and lowest frequency recorded were 25.44 and 0.19 while relative frequency varied from 3.16 to 12.25.Fern density ranged from 93 to 13,403 individuals·ha-1.Most of the species were widely distributed.(IVI) values ranged from 7.54 to 37.45.The above ground portion of ferns accumulated the major portion ofbiomass and carbon.

  7. Cyclization of all-E- and 2Z-geranylfarnesols by a bacterial triterpene synthase: insight into sesterterpene biosynthesis in Aleuritopteris ferns.

    Science.gov (United States)

    Shinozaki, Junichi; Shibuya, Masaaki; Ebizuka, Yutaka; Masuda, Kazuo

    2013-01-01

    Aleuritopteris ferns produce triterpenes and sesterterpenes with tricyclic cheilanthane and tetracyclic 18-episcalarane skeletons. The structural and mechanistic similarities between both classes of fern terpene suggest that their biosynthetic enzymes may be closely related. We investigate here whether a triterpene synthase is capable of recognizing geranylfarnesols as a substrate, and is able to convert them to cyclic sesterterpenes. We found that a bacterial triterpene synthase converted all-E-geranylfarnesol (1b) into three scalarane sesterterpenes with 18αH stereochemistry (5, 7 and 8), as well as mono- and tricyclic sesterterpenes (6 and 9). In addition, 2Z-geranylfarnesol (4) was converted into an 18-episcalarane derivative (10), whose skeleton can be found in sesterterpenes isolated from Aleuritopteris ferns. These results provide insight into sesterterpene biosynthesis in Aleuritopteris ferns.

  8. Evaluation of angiosperm and fern contributions to soil organic matter using two methods of pyrolysis-gas chromatography-mass spectrometry

    Science.gov (United States)

    Plant biochemical characteristics influence decomposition rates and subsequently the biochemical composition of soil organic matter. Ferns, in particular have biochemical characteristics that could influence the stability of soil organic matter (SOM), such as high concentrations of aliphatic compou...

  9. Cytokinin-induced promotion of root meristem size in the fern Azolla supports a shoot-like origin of euphyllophyte roots

    NARCIS (Netherlands)

    de Vries, Jan; Fischer, Angela Melanie; Roettger, Mayo; Rommel, Sophie; Schluepmann, Henriette; Bräutigam, Andrea; Carlsbecker, Annelie; Gould, Sven Bernhard

    The phytohormones cytokinin and auxin orchestrate the root meristem development in angiosperms by determining embryonic bipolarity. Ferns, having the most basal euphyllophyte root, form neither bipolar embryos nor permanent embryonic primary roots but rather an adventitious root system. This raises

  10. Cytokinin-induced promotion of root meristem size in the fern Azolla supports a shoot-like origin of euphyllophyte roots

    NARCIS (Netherlands)

    de Vries, Jan; Fischer, Angela Melanie; Roettger, Mayo; Rommel, Sophie; Schluepmann, Henriette; Bräutigam, Andrea; Carlsbecker, Annelie; Gould, Sven Bernhard

    2016-01-01

    The phytohormones cytokinin and auxin orchestrate the root meristem development in angiosperms by determining embryonic bipolarity. Ferns, having the most basal euphyllophyte root, form neither bipolar embryos nor permanent embryonic primary roots but rather an adventitious root system. This raises

  11. Building an organ-specific carcinogenic database for SAR analyses.

    Science.gov (United States)

    Young, John; Tong, Weida; Fang, Hong; Xie, Qian; Pearce, Bruce; Hashemi, Ray; Beger, Richard; Cheeseman, Mitchell; Chen, James; Chang, Yuan-Chin; Kodell, Ralph

    2004-09-10

    FDA reviewers need a means to rapidly predict organ-specific carcinogenicity to aid in evaluating new chemicals submitted for approval. This research addressed the building of a database to use in developing a predictive model for such an application based on structure-activity relationships (SAR). The Internet availability of the Carcinogenic Potency Database (CPDB) provided a solid foundation on which to base such a model. The addition of molecular structures to the CPDB provided the extra ingredient necessary for SAR analyses. However, the CPDB had to be compressed from a multirecord to a single record per chemical database; multiple records representing each gender, species, route of administration, and organ-specific toxicity had to be summarized into a single record for each study. Multiple studies on a single chemical had to be further reduced based on a hierarchical scheme. Structural cleanup involved removal of all chemicals that would impede the accurate generation of SAR type descriptors from commercial software programs; that is, inorganic chemicals, mixtures, and organometallics were removed. Counterions such as Na, K, sulfates, hydrates, and salts were also removed for structural consistency. Structural modification sometimes resulted in duplicate records that also had to be reduced to a single record based on the hierarchical scheme. The modified database containing 999 chemicals was evaluated for liver-specific carcinogenicity using a variety of analysis techniques. These preliminary analyses all yielded approximately the same results with an overall predictability of about 63%, which was comprised of a sensitivity of about 30% and a specificity of about 77%. Copyright Taylor & Francis Inc.

  12. Historical reconstruction of climatic and elevation preferences and the evolution of cloud forest-adapted tree ferns in Mesoamerica

    Directory of Open Access Journals (Sweden)

    Victoria Sosa

    2016-11-01

    Full Text Available Background Cloud forests, characterized by a persistent, frequent or seasonal low-level cloud cover and fragmented distribution, are one of the most threatened habitats, especially in the Neotropics. Tree ferns are among the most conspicuous elements in these forests, and ferns are restricted to regions in which minimum temperatures rarely drop below freezing and rainfall is high and evenly distributed around the year. Current phylogeographic data suggest that some of the cloud forest-adapted species remained in situ or expanded to the lowlands during glacial cycles and contracted allopatrically during the interglacials. Although the observed genetic signals of population size changes of cloud forest-adapted species including tree ferns correspond to predicted changes by Pleistocene climate change dynamics, the observed patterns of intraspecific lineage divergence showed temporal incongruence. Methods Here we combined phylogenetic analyses, ancestral area reconstruction, and divergence time estimates with climatic and altitudinal data (environmental space for phenotypic traits of tree fern species to make inferences about evolutionary processes in deep time. We used phylogenetic Bayesian inference and geographic and altitudinal distribution of tree ferns to investigate ancestral area and elevation and environmental preferences of Mesoamerican tree ferns. The phylogeny was then used to estimate divergence times and ask whether the ancestral area and elevation and environmental shifts were linked to climatic events and historical climatic preferences. Results Bayesian trees retrieved Cyathea, Alsophyla, Gymnosphaera and Sphaeropteris in monophyletic clades. Splits for species in these genera found in Mesoamerican cloud forests are recent, from the Neogene to the Quaternary, Australia was identified as the ancestral area for the clades of these genera, except for Gymnosphaera that was Mesoamerica. Climate tolerance was not divergent from

  13. Bioaccumulation of selected heavy metals by the water fern, Azolla filiculoides Lam. in a wetland ecosystem affected by sewage, mine and industrial pollution

    Energy Technology Data Exchange (ETDEWEB)

    Wet, L.P.D. de; Schoonbee, H.J.; Pretorius, J.; Bezuidenhout, L.M. (Rand Afrikaans University, Johannesburg (South Africa). Depts. of Zoology and Botany, Research Unit for Aquatic and Terrestrial Ecosystems)

    1990-10-01

    The bio-accumulation of the heavy metals, Fe, Cu, Ni, Pb, Zn, Mn and Cr by the water fern, Azolla filiculoides Lam. in a wetland ecosystem polluted by effluents from sewage works, mines and industries was investigated. Results showed that the different metals can be accumulated by the water fern at concentration levels not necessarily related to their actual concentrations in the aquatic environment, as measured in this case, in the bottom sediments. 45 refs., 1 fig., 3 tabs.

  14. [Advances in non-carcinogenic toxicity of trichloroethylene].

    Science.gov (United States)

    Huang, Peiwu; Li, Xuan; Liu, Wei; Liu, Jianjun

    2015-09-01

    Trichloroethylene (TCE) is a widely used organic solvent and an important industrial material. Due to mass production and use, and improper waste disposal, TCE has become a common environmental contaminant, so there is a wide range of occupationally and environmentally exposed population. Occupational and environmental exposure to TCE can produce toxic effects on multiple organs and systems. This paper is a review of the immunotoxicity, reproductive toxicity, neurotoxicity, teratogenic effect and other non-carcinogenic toxic effects of TCE from the aspects of epidemiological study, experimental evidence on animals and toxic mechanisms.

  15. Genome size evolution in Ontario ferns (Polypodiidae): evolutionary correlations with cell size, spore size, and habitat type and an absence of genome downsizing.

    Science.gov (United States)

    Henry, Thomas A; Bainard, Jillian D; Newmaster, Steven G

    2014-10-01

    Genome size is known to correlate with a number of traits in angiosperms, but less is known about the phenotypic correlates of genome size in ferns. We explored genome size variation in relation to a suite of morphological and ecological traits in ferns. Thirty-six fern taxa were collected from wild populations in Ontario, Canada. 2C DNA content was measured using flow cytometry. We tested for genome downsizing following polyploidy using a phylogenetic comparative analysis to explore the correlation between 1Cx DNA content and ploidy. There was no compelling evidence for the occurrence of widespread genome downsizing during the evolution of Ontario ferns. The relationship between genome size and 11 morphological and ecological traits was explored using a phylogenetic principal component regression analysis. Genome size was found to be significantly associated with cell size, spore size, spore type, and habitat type. These results are timely as past and recent studies have found conflicting support for the association between ploidy/genome size and spore size in fern polyploid complexes; this study represents the first comparative analysis of the trend across a broad taxonomic group of ferns.

  16. KEYNOTE LECTURES-KL1 New development in risk assessment of genotoxic carcinogens in foods

    Institute of Scientific and Technical Information of China (English)

    CHEN Jun-Shi

    2006-01-01

    @@ The no-observed-effect level (NOEL) in a study of carcinogenicity for compounds that are both genotoxic and carcinogenic represents the limit of detection in that bioassay, rather than an estimate of a possible threshold. Therefore, for those genotoxic and carcinogenic contaminants (e.g. acrylamides, PAHs, etc.) in foods it is not possible to develop health-based guidance values (e.g. ADI or PTWI) using the traditional NOEL and safety/uncertainty factors.

  17. Comment on the significance of positive carcinogenicity studies using gavage as the route of exposure.

    OpenAIRE

    Perera, F.; Brennan, T. (Thomas); Fouts, J. R.

    1989-01-01

    There is continuing controversy, extending into regulatory matters, over the significance to human health of positive results in carcinogenicity studies in animals using the gavage technique as the route of exposure. Our review of a nonrandom sample of 117 chemicals or chemical processes listed as known or reasonably anticipated to be carcinogenic in the National Toxicology Program's Third Annual Report on Carcinogens provides support for the validity of the gavage route in such studies. Twen...

  18. DNA adducts in human tissues:biomarkers of exposure to carcinogens in tobacco smoke

    OpenAIRE

    Phillips, D.H.

    1996-01-01

    Tobacco smoking causes millions of cancer deaths annually. Tobacco smoke is a complex mixture of thousands of chemicals including many known animal carcinogens. Because many carcinogens from DNA adducts in target animal or human tissues, the detection of the formation of adducts using such methods as postlabeling, immunoassay, fluorescence spectroscopy, and mass spectrometry is a means of monitoring human exposure to tobacco carcinogens. Smokers are at increased risk of cancer in many organs,...

  19. It is time to regulate carcinogenic tobacco-specific nitrosamines in cigarette tobacco

    OpenAIRE

    Hecht, Stephen S.

    2014-01-01

    The Family Smoking Prevention and Tobacco Control Act gives the Food and Drug Administration power to regulate tobacco products. This commentary calls for immediate regulation of the carcinogenic tobacco-specific nitrosamines 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and N’-nitrosonornicotine (NNN) in cigarette tobacco as a logical path to cancer prevention. NNK and NNN, powerful carcinogens in laboratory animals, have been evaluated as “carcinogenic to humans” by the International...

  20. [The evaluation of carcinogenic effect in rats and mice after intraperitoneal administration of refractory ceramic fibers].

    Science.gov (United States)

    Krajnow, A; Lao, I; Stetkiewicz, J; Wiecek, E

    1998-01-01

    The carcinogenic effect of Langfaser and Thermowool ceramic fibres was assessed in Wistar rats and BALB/C mice. Fibres were administered into the animal peritoneal cavity in doses of 25 and 5 mg, and the animals were left for survival. Langfaser and Thermowool ceramic fibres were found carcinogenic. The carcinogenic properties of Thermowool ceramic fibre can be compared to those of Krokidoit UICC asbestos.

  1. Formaldehyde in dentistry: a review of mutagenic and carcinogenic potential

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, B.B.; Chestner, S.B.

    1981-09-01

    For many years there has been controversy over the value of antimicrobial drugs for intracanal dressings in endodontics. Formocresol, a formaldehyde compound, has evolved as the preferred drug for routine endodontic procedures, as well as pediatric endodontics. The increase in the use of formaldehyde has been complicated by the introduction of paraformaldehyde pastes for filling root canals. Neither of these formulas has ever been standardized. The doses are arbitrary, and the common dose of formocresol has been shown to be many times greater than the minimum dose needed for effect. The efficacy of paraformaldehyde pastes is questionable and remains clouded by inconclusive evidence, conflicting research, inadequate terminology, and a lack of convincing statistical evidence. The clinical use and delivery of formocresol and paraformaldehyde pastes remain arbitrary and unscientific. Formaldehyde has a known toxic mutagenic and carcinogenic potential. Many investigations have been conducted to measure the risk of exposure to formaldehyde; it is clear that formaldehyde poses a carcinogenic risk in humans. There is a need to reevaluate the rationale underlying the use of formaldehyde in dentistry particularly in light of its deleterious effects.

  2. The carcinogenicity of the biocide ortho-phenylphenol.

    Science.gov (United States)

    Appel, K E

    2000-04-01

    The biocides ortho-phenylphenol and its sodium salt (OPP and SOPP) are widely used as fungicides and antibacterial agents for commercial and consumer purposes. The carcinogenicity of OPP/SOPP toward the urinary bladder was demonstrated when rats were chronically fed concentrations of 0.5%-4% in their diet. Other species tested so far did not develop tumours. Understanding the mechanisms underlying OPP/SOPP-induced bladder carcinogenesis is critical to determine whether risks observed at high doses in rats are of relevance to humans exposed at much lower levels. This overview details experimental studies of carcinogenicity, genotoxicity as well as metabolism/toxicokinetics and other mechanistic studies which bear on cancer hazard and risk evaluation of exposure to humans. Based on the presently available knowledge, it is concluded that reactive quinoid metabolites exhibiting redox cycling activities are the crucial factors. At certain concentration levels, these metabolites are able to produce cytotoxic events with concomitant enhanced cell proliferation of the target tissue. Further important risk factors are probably promutagenic lesions induced by oxidative stress and a higher urinary pH. Supposed that these mechanisms are the basis for the tumourigenicity observed, then suitable low doses of OPP/SOPP will practically pose no cancer risk.

  3. Evidence supporting product standards for carcinogens in smokeless tobacco products.

    Science.gov (United States)

    Hatsukami, Dorothy K; Stepanov, Irina; Severson, Herb; Jensen, Joni A; Lindgren, Bruce R; Horn, Kimberly; Khariwala, Samir S; Martin, Julia; Carmella, Steven G; Murphy, Sharon E; Hecht, Stephen S

    2015-01-01

    Smokeless tobacco products sold in the United States vary significantly in yields of nicotine and tobacco-specific nitrosamines (TSNA). With the passage of the Family Smoking Prevention and Tobacco Control Act, the Food and Drug Administration now has the authority to establish product standards. However, limited data exist determining the relative roles of pattern of smokeless tobacco use versus constituent levels in the smokeless tobacco product in exposure of users to carcinogens. In this study, smokeless tobacco users of brands varying in nicotine and TSNA content were recruited from three different regions in the U.S. Participants underwent two assessment sessions. During these sessions, demographic and smokeless tobacco use history information along with urine samples to assess biomarkers of exposure and effect were collected. During the time between data collection, smokeless tobacco users recorded the amount and duration of smokeless tobacco use on a daily basis using their diary cards. Results showed that independent of pattern of smokeless tobacco use and nicotine yields, levels of TSNA in smokeless tobacco products played a significant role in carcinogen exposure levels. Product standards for reducing levels of TSNA in smokeless tobacco products are necessary to decrease exposure to these toxicants and potentially to reduce risk for cancer.

  4. Carcinogenic effects ofcircadian disruption:an epigenetic viewpoint

    Institute of Scientific and Technical Information of China (English)

    Abbas Salavaty

    2015-01-01

    Circadian rhythms refer to the endogenous rhythms that are generated to synchronize physiology and behavior with 24-h environmental cues. These rhythms are regulated by both external cues and molecular clock mechanisms in almost all cells. Disruption of circadian rhythms, which is called circadian disruption, affects many biological processes within the body and results in different long-term diseases, including cancer. Circadian regulatory pathways result in rhythmic epigenetic modiifcations and the formation of circadian epigenomes. Aberrant epigenetic modiifcations, such as hypermethylation, due to circadian disruption may be involved in the transformation of normal cells into cancer cells. Several studies have indicated an epigenetic basis for the carcinogenic effects of circadian disruption. In this review, I ifrst discuss some of the circadian genes and regulatory proteins. Then, I summarize the current evidence related to the epigenetic modiifcations that result in circadian disruption. In addition, I explain the carcinogenic effects of circadian disruption and highlight its potential role in different human cancers using an epigenetic view-point. Finally, the importance of chronotherapy in cancer treatment is highlighted.

  5. Carcinogenic effects of circadian disruption: an epigenetic viewpoint.

    Science.gov (United States)

    Salavaty, Abbas

    2015-08-08

    Circadian rhythms refer to the endogenous rhythms that are generated to synchronize physiology and behavior with 24-h environmental cues. These rhythms are regulated by both external cues and molecular clock mechanisms in almost all cells. Disruption of circadian rhythms, which is called circadian disruption, affects many biological processes within the body and results in different long-term diseases, including cancer. Circadian regulatory pathways result in rhythmic epigenetic modifications and the formation of circadian epigenomes. Aberrant epigenetic modifications, such as hypermethylation, due to circadian disruption may be involved in the transformation of normal cells into cancer cells. Several studies have indicated an epigenetic basis for the carcinogenic effects of circadian disruption. In this review, I first discuss some of the circadian genes and regulatory proteins. Then, I summarize the current evidence related to the epigenetic modifications that result in circadian disruption. In addition, I explain the carcinogenic effects of circadian disruption and highlight its potential role in different human cancers using an epigenetic viewpoint. Finally, the importance of chronotherapy in cancer treatment is highlighted.

  6. Predicting carcinogenicity of diverse chemicals using probabilistic neural network modeling approaches

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Kunwar P., E-mail: kpsingh_52@yahoo.com [Academy of Scientific and Innovative Research, Council of Scientific and Industrial Research, New Delhi (India); Environmental Chemistry Division, CSIR-Indian Institute of Toxicology Research, Post Box 80, Mahatma Gandhi Marg, Lucknow 226 001 (India); Gupta, Shikha; Rai, Premanjali [Academy of Scientific and Innovative Research, Council of Scientific and Industrial Research, New Delhi (India); Environmental Chemistry Division, CSIR-Indian Institute of Toxicology Research, Post Box 80, Mahatma Gandhi Marg, Lucknow 226 001 (India)

    2013-10-15

    Robust global models capable of discriminating positive and non-positive carcinogens; and predicting carcinogenic potency of chemicals in rodents were developed. The dataset of 834 structurally diverse chemicals extracted from Carcinogenic Potency Database (CPDB) was used which contained 466 positive and 368 non-positive carcinogens. Twelve non-quantum mechanical molecular descriptors were derived. Structural diversity of the chemicals and nonlinearity in the data were evaluated using Tanimoto similarity index and Brock–Dechert–Scheinkman statistics. Probabilistic neural network (PNN) and generalized regression neural network (GRNN) models were constructed for classification and function optimization problems using the carcinogenicity end point in rat. Validation of the models was performed using the internal and external procedures employing a wide series of statistical checks. PNN constructed using five descriptors rendered classification accuracy of 92.09% in complete rat data. The PNN model rendered classification accuracies of 91.77%, 80.70% and 92.08% in mouse, hamster and pesticide data, respectively. The GRNN constructed with nine descriptors yielded correlation coefficient of 0.896 between the measured and predicted carcinogenic potency with mean squared error (MSE) of 0.44 in complete rat data. The rat carcinogenicity model (GRNN) applied to the mouse and hamster data yielded correlation coefficient and MSE of 0.758, 0.71 and 0.760, 0.46, respectively. The results suggest for wide applicability of the inter-species models in predicting carcinogenic potency of chemicals. Both the PNN and GRNN (inter-species) models constructed here can be useful tools in predicting the carcinogenicity of new chemicals for regulatory purposes. - Graphical abstract: Figure (a) shows classification accuracies (positive and non-positive carcinogens) in rat, mouse, hamster, and pesticide data yielded by optimal PNN model. Figure (b) shows generalization and predictive

  7. Biodegradation of the metallic carcinogen hexavalent chromium Cr(VI) by an indigenously isolated bacterial strain

    National Research Council Canada - National Science Library

    Das, Alok Prasad; Mishra, Susmita

    2010-01-01

    Hexavalent chromium [Cr(VI)], a potential mutagen and carcinogen, is regularly introduced into the environment through diverse anthropogenic activities, including electroplating, leather tanning, and pigment manufacturing...

  8. Breast cancer in intraductal carcinogen-treated non-human primates.

    Science.gov (United States)

    Lillie, Madeline A; Ambrus, Clara M; Pickren, John W; Akhter, Selina; Islam, Abul; Ambrus, Julian L

    2004-01-01

    Eight female Macaca arctoides monkeys were given dimethylbenzanthracene (DMBA) directly into the milk ducts. During a 4-year observation period, ending with euthanasia and autopsy, no mammary cancers were noticed. However, one animal developed a superficial localized squamous cell carcinoma. DMBA is highly carcinogenic in rodents, e.g. producing a high incidence of breast cancer in C3H mice. It was concluded that carcinogenicity testing should be extended beyond testing in rodents to non-human primates in order to distinguish "primary rodent carcinogens" from those highly active in primates as well. Studies are in progress to study carcinogens in human cell lines transplanted into nu/nu mice.

  9. Methyl chloride emission from a fern growing in sub-tropical, temperate and cool-temperate climates

    Science.gov (United States)

    Yokouchi, Yoko; Takenaka, Akio; Miyazaki, Yuzo; Kawamura, Kimitaka; Hiura, Tsutomu

    2015-04-01

    Methyl chloride(CH3Cl) is the most abundant halocarbon in the troposphere, and is known as a natural stratospheric ozone depletion compound. Amongst its various sources, tropical forests are likely the largest contributor, followed by biomass burning, oceans and salt marshes. There have been unsolved questions why CH3Cl-emitting plants are dominated by tropical plants. Recently we found that a fern, Osmunda japonica, collected from temperate zone emits as high as several μg-g(dw)-1-h-1 of CH3Cl. This fern has a wide natural distribution, covering sub-tropical, temperate and cool-temperate climate, making it possible to study the CH3Cl emission rate from one species under different climate conditions. In this presentation, we report seasonal and spatial variation of the CH3Cl emission rate from O. japonica, and discuss its controlling factors.

  10. Mycorrhizal-like interaction between gametophytes and young sporophytes of the fern Dryopteris muenchii (Filicales) and its fungal endophyte.

    Science.gov (United States)

    Reyes-Jaramillo, Irma; Camargo-Ricalde, Sara Lucía; Aquiahuatl-Ramos, Ma de los Angeles

    2008-09-01

    The morphology of a Glomus-like fungus-host interaction in chlorophyllous gametophytes and young apogamic sporophytes of Dryopteris muenchii A.R. Sm. was studied from ferns cultivated in laboratory, using soil as substrate. An aseptate fungus colonized the gametophytes' tissue through the rhizoids, developing vesicles. The fungus penetrated the young sporophytes primary roots by developing appressoria. It spread forming inter- and intra-cellular hyphae through the epidermis and the outermost cortical cell layers, where it formed vesicles, hyphal coils-like and arbuscules. The fungus hyphae never colonized the gametophyte-sporophyte cellular junction. The fungal structures observed on D. muenchii during this study, are rather similar to those reported for the plant host-arbuscular mycorrhizal fungus (AMF) interaction, where the AMF described belonged to Phylum Glomeromycota. Therefore, this study is a contribution to the scarce knowledgement of the association between AMF and chlorophyllous gametophytes and young apogamic sporophytes of ferns.

  11. Effect of enhanced nitrogen input on release of nutrients and nutrient availability in stands of tall fern Athyrium distentifolium

    Science.gov (United States)

    Tå¯Ma, Ivan; Holuib, Petr; Záhora, Jaroslav; Fiala, Karel

    2010-05-01

    Improved light conditions, after destruction of tree canopy, soil acidification and increased nitrogen availability, support intensive spreading of acidophilous perennial grasses and stands of tall fern (Athyrium distentifolium) on deforested sites in the Moravian-Silesian Beskydy Mts. (the Czech Republic). The aim of the study was to determine how higher inputs of nitrogen affect the release of nutrients during decomposition processes of fern litter. The experimental site was chosen on a southwest-facing slope of the Kněhyně Mt. (49o31´ N, 18o 32´E, 1170 m a.s.l.) in the Moravian-Silesin Beskydy Mts. in the Czech Republic. The area is characterized by an annual mean air temperature of 5.6 oC and annual precipitation of 1110 mm. A large fern stand was divided in four blocks (5x3 m) and on two of them higher doses of nitrogen were applied (50 kgN/ha in five doses in the course of the growing season). Similarly, mesh-bags with fresh natural litter of fern were used to determine rate of litter decomposition during one year. Samples were inserted in both nitrogen treated and untreated fern stands in autumn 2006 and 2007 collected in autumn 2007 and 2008. On the basis of litter amount estimated at the start and at the end of exposure and of actual content of minerals in original and exposed litter, the release and/or accumulation of minerals during decomposition were calculated. The availability (more or less in the case of ammonia-nitrogen) and movement of percolated nitrogen (mainly in the case of nitrate-nitrogen) was estimated in situ by the trapping of mineral N into the ion exchange resin (IER) inserted into special cover. The decomposition rate of native A. distentifolium litter was approximately the same (29-30 %) at both nitrogen availability, however the element release from decomposed litter was higher for N, P and Ca in both years and for K and Mg in the first year as well. However, decomposition rate of cellulose was two times greater in fern stands

  12. Distribution of drimane sesquiterpenoids and tocopherols in liverworts, ferns and higher plants: Polygonaceae, Canellaceae and Winteraceae species.

    Science.gov (United States)

    Asakawa, Yoshinori; Ludwiczuk, Agnieszka; Harinantenaina, Liva; Toyota, Masao; Nishiki, Mayumi; Bardon, Alicia; Nii, Kaeko

    2012-06-01

    The liverwort, Porella vernicosa complex produces a very hot tasting polygodial, a drimane-type sesquiterpene dialdehyde. The same compound has been isolated from two ferns, Thelypteris hispidula and Blechnum fluviatile, as well as from the higher plants Polygonum hydropiper, P. hydropiper f. purpurascens (Polygonaceae), Cinnamosma, Caspicodendron, Canella and Warburgia species (Canellaceae), and Pseudowintera colorata, Tasmannia lanceolata, Drimys and Zygogynum species (Winteraceae). In addition, the liverworts and higher plants which elaborate polygodial and its related pungent drimane dials contain a small amount of alpha-tocopherol, gamma-tocopherol or delta-tocotrienol. The present paper gives the results of a comparative study on the drimane-type sesquiterpenoids in some liverworts, ferns and higher plants, and the role of tocopherols in these plant groups.

  13. El cálculo de estructuras en la obra de Carlos Fernández Casado

    Directory of Open Access Journals (Sweden)

    Alarcón, Enrique

    2008-03-01

    Full Text Available In the present paper the contributions of Carlos Fernández Casado to Structural Analysis are reviewed. After a description of the international context he was working in, his contributions and their relation to the academic training he received at the Civil Engineering Scholl in Madrid are described. Finally the most interesting aspects of his written work are commented.En este artículo se analizan las aportaciones de Carlos Fernández Casado al cálculo de estructuras. Tras exponer el contexto internacional, se describen sus contribuciones y su relación con la formación que recibió en la Escuela de Ingenieros de Caminos de Madrid. Se finaliza indicando algunos de los méritos más interesantes de su obra escrita.

  14. Arsenic bioavailability in the soil amended with leaves of arsenic hyperaccumulator, Chinese brake fern (Pteris vittata L).

    Science.gov (United States)

    Du, Xin; Cui, Yanshan; Weng, Liping; Cao, Qing; Zhu, Yongguan

    2008-01-01

    An incubation experiment was carried out to better understand the fate of As during the decomposition of As-rich Chinese brake fern (Pteris vittata L.) leaves and to assess As bioavailability in soil. Dried fern leaves with an As concentration of 1,150 +/- 14 microg/g were amended with unpolluted soil at 1 and 3%. After aging for one, three, and six months, germinated wheat was planted in the soil. After two months, wheat plants were harvested. Results showed that As concentration in shoots and roots significantly increased with increasing amounts of As-rich leaf additions in soil samples and decreased over the incubation time (p bioavailability. Arsenic concentrations in shoots and roots could be well described with linear functions of As concentrations distributed in different fractions. In conclusion, aging effect should be considered during risk assessment of As in soil-plant systems where As is recycled by the plant.

  15. Applying DNA Barcodes to Identify Closely Related Species of Ferns: A Case Study of the Chinese Adiantum (Pteridaceae).

    Science.gov (United States)

    Wang, Fan-Hong; Lu, Jin-Mei; Wen, Jun; Ebihara, Atsushi; Li, De-Zhu

    2016-01-01

    DNA barcoding is a fast-developing technique to identify species by using short and standard DNA sequences. Universal selection of DNA barcodes in ferns remains unresolved. In this study, five plastid regions (rbcL, matK, trnH-psbA, trnL-F and rps4-trnS) and eight nuclear regions (ITS, pgiC, gapC, LEAFY, ITS2, IBR3_2, DET1, and SQD1_1) were screened and evaluated in the fern genus Adiantum from China and neighboring areas. Due to low primer universality (matK) and/or the existence of multiple copies (ITS), the commonly used barcodes matK and ITS were not appropriate for Adiantum. The PCR amplification rate was extremely low in all nuclear genes except for IBR3_2. rbcL had the highest PCR amplification rate (94.33%) and sequencing success rate (90.78%), while trnH-psbA had the highest species identification rate (75%). With the consideration of discriminatory power, cost-efficiency and effort, the two-barcode combination of rbcL+ trnH-psbA seems to be the best choice for barcoding Adiantum, and perhaps basal polypod ferns in general. The nuclear IBR3_2 showed 100% PCR amplification success rate in Adiantum, however, it seemed that only diploid species could acquire clean sequences without cloning. With cloning, IBR3_2 can successfully distinguish cryptic species and hybrid species from their related species. Because hybridization and allopolyploidy are common in ferns, we argue for including a selected group of nuclear loci as barcodes, especially via the next-generation sequencing, as it is much more efficient to obtain single-copy nuclear loci without the cloning procedure.

  16. Impact of mycorrhization on the abundance, growth and leaf nutrient status of ferns along a tropical elevational gradient.

    Science.gov (United States)

    Kessler, Michael; Güdel, Ramona; Salazar, Laura; Homeier, Jürgen; Kluge, Jürgen

    2014-07-01

    Mycorrhizal fungi are crucial for the ecological success of land plants, providing their hosts with nutrients in exchange for organic C. However, not all plants are mycorrhizal, especially ferns, of which about one-third of the species lack this symbiosis. Because the mycorrhizal status is evolutionarily ancestral, this lack of mycorrhizae must have ecological advantages, but what these advantages are and how they affect the competitive ability of non-mycorrhizal plants under natural conditions is currently unknown. To address this uncertainty, we studied terrestrial fern assemblages and species abundances as well as their mycorrhization status, leaf nutrient concentration and relative annual growth along an elevational gradient in the Ecuadorian Andes (500-4,000 m). We surveyed the mycorrhizal status of 375 root samples belonging to 85 species, and found mycorrhizae in 89% of the samples. The degree of mycorrhization decreased with elevation but was unrelated to soil nutrients. Species with mycorrhizae were significantly more abundant than non-mycorrhizal species, but non-mycorrhizal species had significantly higher relative growth and concentrations of leaf N, P, Mg, and Ca. Our study thus shows that despite lower abundances, non-mycorrhizal fern species did not appear to be limited in their growth or nutrient supply relative to mycorrhizal ones. As a basis for future studies, we hypothesize that non-mycorrhizal fern species may be favoured in special microhabitats of the forest understory with high soil nutrient or water availability, or that the ecological benefit of mycorrhizae is not related to nutrient uptake but rather to, for example, pathogen resistance.

  17. Some New Records of Ferns from Vietnam (2)%越南蕨类植物新记载(2)

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Nine species of ferns are reported for the first time from Vietnam:Cyrtomium pachyphyllum (Rosenst.)C.Chr.,C.shingianum H.S.Kung et P.S.Wang,Dryopteri bodinieri (Christ) C.Chr.,D.gymnosora (Makino)C.Chr.,Teratophyllum aculeatum(Bl.) Mett.ex Kuhn,Elaphoglossunm sinii C.Chr.ex Wu,Tectaria herpetocaulos Holtt.,T.hokouensis Ching et C.H.Wang,Boniniella cardiophylla (Hance) Tagawa,distributions are discussed.

  18. Photoproduction of hydrogen by a non-sulphur bacterium isolated from root zones of water fern Azolla pinnata

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S.P.; Srivastava, S.C.; Pandey, K.D. (Banaras Hindu Univ., Varanasi (IN). Centre of Advanced Study in Botany)

    1990-01-01

    A photosynthetic bacterium Rhodopseudomonas sp. BHU strain 1 was isolated from the root zone of water fern Azolla pinnata. The bacterium was found to produce hydrogen with potato starch under phototrophic conditions. The immobilized bacterial cells showed sustained hydrogen production with a more than 4-fold difference over free cell suspensions. The data have been discussed in the light of possible utilization of relatively cheaper raw materials by non-sulphur bacteria to evolve hydrogen. (author).

  19. Rates of ecological divergence and body size evolution are correlated with species diversification in scaly tree ferns.

    Science.gov (United States)

    Ramírez-Barahona, Santiago; Barrera-Redondo, Josué; Eguiarte, Luis E

    2016-07-13

    Variation in species richness across regions and between different groups of organisms is a major feature of evolution. Several factors have been proposed to explain these differences, including heterogeneity in the rates of species diversification and the age of clades. It has been frequently assumed that rapid rates of diversification are coupled to high rates of ecological and morphological evolution, leading to a prediction that remains poorly explored for most species: the positive association between ecological niche divergence, morphological evolution and species diversification. We combined a time-calibrated phylogeny with distribution, ecological and body size data for scaly tree ferns (Cyatheaceae) to test whether rates of species diversification are predicted by the rates at which clades have evolved distinct ecological niches and body sizes. We found that rates of species diversification are positively correlated with rates of ecological and morphological evolution, with rapidly diversifying clades also showing rapidly evolving ecological niches and body sizes. Our results show that rapid diversification of scaly tree ferns is associated with the evolution of species with comparable morphologies that diversified into similar, yet distinct, environments. This suggests parallel evolutionary pathways opening in different tropical regions whenever ecological and geographical opportunities arise. Accordingly, rates of ecological niche and body size evolution are relevant to explain the current patterns of species richness in this 'ancient' fern lineage across the tropics. © 2016 The Author(s).

  20. Variable frequency of plastid RNA editing among ferns and repeated loss of uridine-to-cytidine editing from vascular plants.

    Science.gov (United States)

    Guo, Wenhu; Grewe, Felix; Mower, Jeffrey P

    2015-01-01

    The distinct distribution and abundance of C-to-U and U-to-C RNA editing among land plants suggest that these two processes originated and evolve independently, but the paucity of information from several key lineages limits our understanding of their evolution. To examine the evolutionary diversity of RNA editing among ferns, we sequenced the plastid transcriptomes from two early diverging species, Ophioglossum californicum and Psilotum nudum. Using a relaxed automated approach to minimize false negatives combined with manual inspection to eliminate false positives, we identified 297 C-to-U and three U-to-C edit sites in the O. californicum plastid transcriptome but only 27 C-to-U and no U-to-C edit sites in the P. nudum plastid transcriptome. A broader comparison of editing content with the leptosporangiate fern Adiantum capillus-veneris and the hornwort Anthoceros formosae uncovered large variance in the abundance of plastid editing, indicating that the frequency and type of RNA editing is highly labile in ferns. Edit sites that increase protein conservation among species are more abundant and more efficiently edited than silent and non-conservative sites, suggesting that selection maintains functionally important editing. The absence of U-to-C editing from P. nudum plastid transcripts and other vascular plants demonstrates that U-to-C editing loss is a recurrent phenomenon in vascular plant evolution.

  1. Inorganic and organic nitrogen acquisition by a fern Dicranopteris dichotoma in a subtropical forest in South China.

    Directory of Open Access Journals (Sweden)

    Xingliang Xu

    Full Text Available The fern Dicranopteris dichotoma is an important pioneer species of the understory in Masson pine (Pinus massoniana forests growing on acidic soils in the subtropical and tropical China. To improve our understanding of the role of D. dichotoma in nitrogen (N uptake of these forests, a short-term (15N experiment was conducted at mountain ridge (MR, with low N level and mountain foot (MF, with high N level. We injected (15N tracers as (15NH4, (15NO3 or (15N-glycine into the soil surrounding each plant at both MR and MF sites. Three hours after tracer injection, the fern D. dichotoma took up 15NH4+ significantly faster at MF than at MR, but it showed significantly slower uptake of (15NO3- at MF than at MR. Consequently, (15NO3- made greater contribution to the total N uptake (50% to the total N uptake at MR than at MF, but (15N-glycine only contributed around 11% at both sites. Twenty-four hours after tracer injection, D. dichotoma preferred (15NH4+ (63% at MR, whereas it preferred (15NO3- (47% at MF. We concluded that the D. dichotoma responds distinctly in its uptake pattern for three available N species over temporal and spatial scales, but mainly relies on inorganic N species in the subtropical forest. This suggests that the fern employs different strategies to acquire available N which depends on N levels and time.

  2. Arsenic accumulation by the aquatic fern Azolla: Comparison of arsenate uptake, speciation and efflux by A. caroliniana and A. filiculoides

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Xin [State Key Lab of Urban and ONAL Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Lin Aijun [Department of Environmental Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Zhao Fangjie [Soil Science Department, Rothamsted Research, Hertfordshire AL5 2JQ (United Kingdom); Xu Guozhong [Agricultural Ecology Institute, Fujian Academy of Agricultural Sciences, Fuzhou 350013 (China); Duan Guilan [State Key Lab of Urban and ONAL Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Zhu Yongguan [State Key Lab of Urban and ONAL Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361003 (China)], E-mail: ygzhu@rcees.ac.cn

    2008-12-15

    This study investigates As accumulation and tolerance of the aquatic fern Azolla. Fifty strains of Azolla showed a large variation in As accumulation. The highest- and lowest-accumulating ferns among the 50 strains were chosen for further investigations. Azolla caroliniana accumulated two times more As than Azolla filiculoides owing to a higher influx velocity for arsenate. A. filiculoides was more resistant to external arsenate due to a lower uptake. Both strains showed a similar degree of tolerance to internal As. Arsenate and arsenite were the dominant As species in both Azolla strains, with methlyated As species accounting for <5% of the total As. A. filiculoides had a higher proportion of arsenite than A. caroliniana. Both strains effluxed more arsenate than arsenite, and the amount of As efflux was proportional to the amount of As accumulation. The potential of growing Azolla in paddy fields to reduce As transfer from soil and water to rice should be further evaluated. - Arsenic accumulation and efflux differ between strains of the aquatic fern Azolla.

  3. Dynamics of asymmetrical hybridization in North American wood ferns: reconciling patterns of inheritance with gametophyte reproductive biology.

    Science.gov (United States)

    Testo, Weston L; Watkins, James E; Barrington, David S

    2015-04-01

    Hybridization is an important evolutionary force in plants, but the mechanisms underlying it have not been well studied for many groups. In particular, the drivers of non-random patterns of interspecific gene flow (asymmetrical hybridization) remain poorly understood, especially in the seed-free vascular plants. Here, we examine patterns of asymmetrical hybridization in two widespread fern hybrids from eastern North America and study the role of gametophyte ecology in the determination of hybridization bias. We characterized the maternal parentage of > 140 hybrid sporophytes by sequencing a c. 350-bp region of chloroplast DNA (cpDNA). To identify factors contributing to patterns of asymmetrical hybridization, we cultured gametophytes of the parental species and evaluated critical aspects of their reproductive biology. We found that asymmetrical hybridization was prevalent across the populations of both hybrids. Reproductive traits varied across species and suggest that selfing potential, antheridiogen responsiveness, sperm dispersal capacity and gamete size all contribute to the mediation of the direction of hybridization in this group. Our findings suggest that asymmetrical hybridization in ferns is driven by an array of reproductive traits. This study helps to sharpen and define a mechanistic understanding of patterns of hybridization in this group and demonstrates the importance of considering gametophyte biology when studying evolutionary processes in ferns.

  4. Plant Resource of Ornamental Fern in Jiangxi Province%江西省观赏蕨类植物资源

    Institute of Scientific and Technical Information of China (English)

    梁芳; 曹岚; 王治

    2011-01-01

    The plant resource of ornamental fem in Jiangxi Province was investigated, the results showed that there were 233 species, 97 genera , 47 families of ornamental ferns in Jiangxi Province, and they could be divided into 5 types (terrestrial fern, epiphytic fern, rock fem, vine fem and aquatic fem) according to the ecotype. Some have local characteristics could choose for development and utilization. Some have local characteristics could choose for development and utilization.%对江西省观赏蕨类植物资源进行了调查.结果表明,江西省共有观赏蕨类植物47科97属233种,按生态类型不同可将其分为陆生蕨、附生蕨、石生蕨、藤本蕨和水生蕨共5类,可应用于园林绿化、盆栽观赏、切花配叶等方面.可选择具有地方特色的种类进行开发利用.

  5. Use of rbcL and trnL-F as a two-locus DNA barcode for identification of NW-European ferns: an ecological perspective.

    Directory of Open Access Journals (Sweden)

    G Arjen de Groot

    Full Text Available Although consensus has now been reached on a general two-locus DNA barcode for land plants, the selected combination of markers (rbcL + matK is not applicable for ferns at the moment. Yet especially for ferns, DNA barcoding is potentially of great value since fern gametophytes--while playing an essential role in fern colonization and reproduction--generally lack the morphological complexity for morphology-based identification and have therefore been underappreciated in ecological studies. We evaluated the potential of a combination of rbcL with a noncoding plastid marker, trnL-F, to obtain DNA-identifications for fern species. A regional approach was adopted, by creating a reference database of trusted rbcL and trnL-F sequences for the wild-occurring homosporous ferns of NW-Europe. A combination of parsimony analyses and distance-based analyses was performed to evaluate the discriminatory power of the two-region barcode. DNA was successfully extracted from 86 tiny fern gametophytes and was used as a test case for the performance of DNA-based identification. Primer universality proved high for both markers. Based on the combined rbcL + trnL-F dataset, all genera as well as all species with non-equal chloroplast genomes formed their own well supported monophyletic clade, indicating a high discriminatory power. Interspecific distances were larger than intraspecific distances for all tested taxa. Identification tests on gametophytes showed a comparable result. All test samples could be identified to genus level, species identification was well possible unless they belonged to a pair of Dryopteris species with completely identical chloroplast genomes. Our results suggest a high potential of the combined use of rbcL and trnL-F as a two-locus cpDNA barcode for identification of fern species. A regional approach may be preferred for ecological tests. We here offer such a ready-to-use barcoding approach for ferns, which opens the way for answering a

  6. Use of rbcL and trnL-F as a two-locus DNA barcode for identification of NW-European ferns: an ecological perspective.

    Science.gov (United States)

    de Groot, G Arjen; During, Heinjo J; Maas, Jan W; Schneider, Harald; Vogel, Johannes C; Erkens, Roy H J

    2011-01-26

    Although consensus has now been reached on a general two-locus DNA barcode for land plants, the selected combination of markers (rbcL + matK) is not applicable for ferns at the moment. Yet especially for ferns, DNA barcoding is potentially of great value since fern gametophytes--while playing an essential role in fern colonization and reproduction--generally lack the morphological complexity for morphology-based identification and have therefore been underappreciated in ecological studies. We evaluated the potential of a combination of rbcL with a noncoding plastid marker, trnL-F, to obtain DNA-identifications for fern species. A regional approach was adopted, by creating a reference database of trusted rbcL and trnL-F sequences for the wild-occurring homosporous ferns of NW-Europe. A combination of parsimony analyses and distance-based analyses was performed to evaluate the discriminatory power of the two-region barcode. DNA was successfully extracted from 86 tiny fern gametophytes and was used as a test case for the performance of DNA-based identification. Primer universality proved high for both markers. Based on the combined rbcL + trnL-F dataset, all genera as well as all species with non-equal chloroplast genomes formed their own well supported monophyletic clade, indicating a high discriminatory power. Interspecific distances were larger than intraspecific distances for all tested taxa. Identification tests on gametophytes showed a comparable result. All test samples could be identified to genus level, species identification was well possible unless they belonged to a pair of Dryopteris species with completely identical chloroplast genomes. Our results suggest a high potential of the combined use of rbcL and trnL-F as a two-locus cpDNA barcode for identification of fern species. A regional approach may be preferred for ecological tests. We here offer such a ready-to-use barcoding approach for ferns, which opens the way for answering a whole range of

  7. La Galicia que vio nacer y crecer a Gregorio Fernández

    Directory of Open Access Journals (Sweden)

    Saavedra, Pegerto

    2010-12-01

    Full Text Available The great sculptor Gregorio Fernández was born in Galicia; that territory was very different from the city of Valladolid, where he worked and died. Fhe changes caused by the Catholici Reformation progressed slowly and with difficulty en the old Galician Kingdom. The absence of towns prevailed in that period, and most of Glaician people lived in small villages that were far from urban civilization. They were not instructed in Christian doctrine and besides they had their peculiar customs, such as feeding on brown bread and bacon. This cultural and social context generated a negative opinion about Galicia and Galician people in the middle of the XVIth century. Don Diego Samiento de Acuña, first earl of Gondomar, and Don Pedro Fernández de Castro, seventh earl of Lemos, were opposed to this negative opinion, although they had an unfortunate outcome. First, Gondomar -who owned an important library in his house in Valladolid- and his circle wrote spirited chorographical and historiographical works. On the other hand, Gondomar and Lemos presented several claims in the Royal Court from Galician nobility and clergy al the end of XVIth century and at the beginning of the XVIIth century.

    La Galicia en la que nació el formidable escultor Gregorio Fernández tenía poco que ver con la ciudad de Valladolid, en la desarrolló su trabajo y falleció. El viejo Reino gallego era un territorio ruralizado, en el que los cambios ligados a la reforma tridentina avanzaban con lentitud y dificultad. La ausencia de grandes núcleos de población y la rudeza de unos campesinos que vivían en minúsculos asentamientos dispersos, alejados de la civilización por su ignorancia de los rudimentos de la catequesis y por sus costumbres, entre ellas la de alimentarse de pan negro y tocino, son realidades que están en el origen de la caudalosa corriente de tópicos negativos que desde mediados del XVI comenzó a correr sobre el Reino y sus habitantes, y que, con poco

  8. Molecular circumscription and major evolutionary lineages of the fern genus Dryopteris (Dryopteridaceae

    Directory of Open Access Journals (Sweden)

    Zhang Li-Bing

    2012-09-01

    Full Text Available Abstract Background The fern genus Dryopteris (Dryopteridaceae is among the most common and species rich fern genera in temperate forests in the northern hemisphere containing 225–300 species worldwide. The circumscription of Dryopteris has been controversial and various related genera have, over the time, been included in and excluded from Dryopteris. The infrageneric phylogeny has largely remained unclear, and the placement of the majority of the supraspecific taxa of Dryopteris has never been tested using molecular data. Results In this study, DNA sequences of four plastid loci (rbcL gene, rps4-trnS spacer, trnL intron, trnL-F spacer were used to reconstruct the phylogeny of Dryopteris. A total of 122 accessions are sampled in our analysis and they represent 100 species of the expanded Dryopteris including Acrophorus, Acrorumohra, Diacalpe, Dryopsis, Nothoperanema, and Peranema. All four subgenera and 19 sections currently recognized in Dryopteris s.s. are included. One species each of Arachniodes, Leptorumohra, and Lithostegia of Dryopteridaceae are used as outgroups. Our study confirms the paraphyly of Dryopteris and provides the first strong molecular evidence on the monophyly of Acrophorus, Diacalpe, Dryopsis, Nothoperanema, and Peranema. However, all these monophyletic groups together with the paraphyletic Acrorumohra are suggested to be merged into Dryopteris based on both molecular and morphological evidence. Our analysis identified 13 well-supported monophyletic groups. Each of the 13 clades is additionally supported by morphological synapomophies and is inferred to represent a major evolutionary lineage in Dryopteris. In contrast, monophyly of the four subgenera and 15 out of 19 sections currently recognized in Dryopteris s.s is not supported by plastid data. Conclusions The genera, Acrophorus, Acrorumohra, Diacalpe, Dryopsis, Nothoperanema, and Peranema, should all be merged into Dryopteris. Most species of these genera share a

  9. Desiccation tolerance of Hymenophyllacea filmy ferns is mediated by constitutive and non-inducible cellular mechanisms.

    Science.gov (United States)

    Garcés Cea, Marcelo; Claverol, Stephan; Alvear Castillo, Carla; Rabert Pinilla, Claudia; Bravo Ramírez, León

    2014-04-01

    The Hymenophyllaceae is a primitive family within the Filicopsidae. One of the most exceptional features of this family of ferns is the presence of fronds with one or just a few cell layers (hence their name of filmy ferns), and the absence of stomata. Hymenophyllum caudiculatum and Hymenophyllum dentatum are able to lose more than 82% of their fully hydrated water content, to remain dry for extended periods of time (days or weeks), and to survive and remain viable following rehydration. The aim of this work was to understand whether the adaptive strategy of the Hymenophyllaceae for desiccation tolerance is constitutive or inducible. A proteomic approach was adopted in combination with physiological parameters to assess whether there were changes in the protein content during dehydration and following rehydration. Detached fronds were used to monitor the rates of photosynthesis in desiccation experiments, sugar accumulation, and high-resolution 2-DE to analyze proteome variation during a desiccation-rehydration cycle. The analyzed proteome exhibited little variation (3-4%) between hydrated and desiccated states, while variation was greater between the desiccated and rehydrated states (8.7-10%). Eighty-two discrete proteins were analyzed by MS/MS, and 65 were identified. About 21% of the analyzed proteins (17) were mixtures of two or more different polypeptides. Of the identified proteins, more than a half (33 spots, 55%) had functions related to energy-photosynthesis. The second largest category with known function (five spots, 8%) was related to cell rescue, defense, and virulence. More than one in every four proteins analyzed belonged to a group of hypothetical proteins (18 spots, 28%). The results suggest that the Hymenophyllaceae represent an example of a change in adaptive strategy from a typical vascular to the poikilohydric homoiochlorophyllous adaptation, which they share with the bryophytes that grow in profusion in the same habitats. The speed at which

  10. Molecular basis of carcinogenicity of tungsten alloy particles

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Robert M.; Williams, Tim D.; Waring, Rosemary H.; Hodges, Nikolas J., E-mail: n.hodges@bham.ac.uk

    2015-03-15

    The tungsten alloy of 91% tungsten, 6% nickel and 3% cobalt (WNC 91–6–3) induces rhabdomyosarcoma when implanted into a rat thigh muscle. To investigate whether this effect is species-specific human HSkMc primary muscle cells were exposed to WNC 91–6–3 particles and responses were compared with those from a rat skeletal muscle cell line (L6-C11). Toxicity was assessed by the adenylate kinase assay and microscopy, DNA damage by the Comet assay. Caspase 3 enzyme activity was measured and oligonucleotide microarrays were used for transcriptional profiling. WNC 91–6–3 particles caused toxicity in cells adjacent to the particles and also increased DNA strand breaks. Inhibition of caspase 3 by WNC 91–6–3 occurred in rat but not in human cells. In both rat and human cells, the transcriptional response to WNC 91–6–3 showed repression of transcripts encoding muscle-specific proteins with induction of glycolysis, hypoxia, stress responses and transcripts associated with DNA damage and cell death. In human cells, genes encoding metallothioneins were also induced, together with genes related to angiogenesis, dysregulation of apoptosis and proliferation consistent with pre-neoplastic changes. An alloy containing iron, WNF 97–2–1, which is non-carcinogenic in vivo in rats, did not show these transcriptional changes in vitro in either species while the corresponding cobalt-containing alloy, WNC 97–2–1 elicited similar responses to WNC 91–6–3. Tungsten alloys containing both nickel and cobalt therefore have the potential to be carcinogenic in man and in vitro assays coupled with transcriptomics can be used to identify alloys, which may lead to tumour formation, by dysregulation of biochemical processes. - Highlights: • Use of transcriptomics to identify likely carcinogenic tungsten alloys in vitro • Cobalt containing alloys cause oxidative stress, DNA-damage and perturb apoptosis. • Presence of cobalt causes changes in gene expression

  11. Can creatine supplementation form carcinogenic heterocyclic amines in humans?

    Science.gov (United States)

    Pereira, Renato Tavares dos Santos; Dörr, Felipe Augusto; Pinto, Ernani; Solis, Marina Yazigi; Artioli, Guilherme Giannini; Fernandes, Alan Lins; Murai, Igor Hisashi; Dantas, Wagner Silva; Seguro, Antônio Carlos; Santinho, Mirela Aparecida Rodrigues; Roschel, Hamilton; Carpentier, Alain; Poortmans, Jacques Remi; Gualano, Bruno

    2015-09-01

    There is a long-standing concern that creatine supplementation could be associated with cancer, possibly by facilitating the formation of carcinogenic heterocyclic amines (HCAs). This study provides compelling evidence that both low and high doses of creatine supplementation, given either acutely or chronically, does not cause a significant increase in HCA formation. HCAs detection was unrelated to creatine supplementation. Diet was likely to be the main factor responsible for HCAs formation after either placebo (n = 6) or creatine supplementation (n = 3). These results directly challenge the recently suggested biological plausibility for the association between creatine use and risk of testicular germ cell cancer. Creatine supplementation has been associated with increased cancer risk. In fact, there is evidence indicating that creatine and/or creatinine are important precursors of carcinogenic heterocyclic amines (HCAs). The present study aimed to investigate the acute and chronic effects of low- and high-dose creatine supplementation on the production of HCAs in healthy humans (i.e. 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (8-MeIQx), 2-amino-(1,6-dimethylfuro[3,2-e]imidazo[4,5-b])pyridine (IFP) and 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx)). This was a non-counterbalanced single-blind crossover study divided into two phases, in which low- and high-dose creatine protocols were tested. After acute (1 day) and chronic supplementation (30 days), the HCAs PhIP, 8-MeIQx, IFP and 4,8-DiMeIQx were assessed through a newly developed HPLC-MS/MS method. Dietary HCA intake and blood and urinary creatinine were also evaluated. Out of 576 assessments performed (from 149 urine samples), only nine (3 from creatine and 6 from placebo) showed quantifiable levels of HCAs (8-MeIQx: n = 3; 4,8-DiMeIQx: n = 2; PhIP: n = 4). Individual analyses revealed that diet rather than creatine supplementation was

  12. Synthesizing research and education: Ecology and genetics of independent fern gametophytes and teaching science inquiry and content through simulations

    Science.gov (United States)

    Duffy, Aaron M.

    Two of the main areas of focus in university academics are research and education. The mission statements of Utah State University and the Department of Biology emphasize both areas, as do the requirements of funding agencies. I attempted to integrate research and education by using tools that I developed to support and inform my biological research projects to teach science. Ferns have a life cycle with alternating haploid and diploid life stages, both of which are free-living and potentially long-lived. The haploid gametophytes of some ferns reproduce asexually and may have different environmental requirements than the diploid sporophytes, so it is possible for populations of gametophytes to exist without sporophytes. This dissertation includes a description of surveys for Hymenophyllum wrightii, a fern with independent gametophytes in the Pacific Northwest, and improves our understanding of the range, distribution, and habitat requirements of these plants which were previously assumed to be rare. It also describes an attempt to explore the population genetics of gametophytes of Crepidomanes intricatum, a widespread fern in the Appalachian Mountains for which no sporophytes have ever been found. To help visualize evolutionary processes in independent gametophyte populations I developed the Virtual Population Genetics Simulator (VPGsim) to simulate populations of ferns in a 3-dimensional environment. This dissertation includes a description of VPGsim, a learning module using it to teach undergraduate genetics, and a study demonstrating its effectiveness at improving students' understanding of science content and confidence in their ability to perform science inquiry. That simulation tool led to a collaboration to find other ways to teach science with simulations, and to the development of a Virtual Plant Community simulator (VPCsim) for teaching middle school students about the effects of the environment and human impacts on living organisms. This dissertation

  13. Inter-and intraspecific variation in fern mating systems after long-distance colonization: the importance of selfing

    Directory of Open Access Journals (Sweden)

    de Groot G Arjen

    2012-01-01

    Full Text Available Abstract Background Previous studies on the reproductive biology of ferns showed that mating strategies vary among species, and that polyploid species often show higher capacity for self-fertilization than diploid species. However, the amount of intraspecific variation in mating strategy and selfing capacity has only been assessed for a few species. Yet, such variation may have important consequences during colonization, as the establishment of any selfing genotypes may be favoured after long-distance dispersal (an idea known as Baker's law. Results We examined intra-and interspecific variation in potential for self-fertilization among four rare fern species, of which two were diploids and two were tetraploids: Asplenium scolopendrium (2n, Asplenium trichomanes subsp. quadrivalens (4n, Polystichum setiferum (2n and Polystichum aculeatum (4n. Sporophyte production was tested at different levels of inbreeding, by culturing gametophytes in isolation, as well as in paired cultures with a genetically different gametophyte. We tested gametophytes derived from various genetically different sporophytes from populations in a recently planted forest colonized through long-distance dispersal (Kuinderbos, the Netherlands, as well as from older, less disjunct populations. Sporophyte production in isolation was high for Kuinderbos genotypes of all four species. Selfing capacity did not differ significantly between diploids and polyploids, nor between species in general. Rather selfing capacity differed between genotypes within species. Intraspecific variation in mating system was found in all four species. In two species one genotype from the Kuinderbos showed enhanced sporophyte production in paired cultures. For the other species, including a renowned out crosser, selfing capacity was consistently high. Conclusions Our results for four different species suggest that intraspecific variation in mating system may be common, at least among temperate calcicole

  14. Carcinogenic risks associated with radiation pollution. [UV radiation, sunlight

    Energy Technology Data Exchange (ETDEWEB)

    Latarjet, R.

    1976-01-01

    The cancerogenic pollution by non-ionizing radiations is limited to the case of solar ultraviolet, whose activity at ground level may be increased as a consequence of the stratospheric depletion of ozone, produced by certain chemical pollutants: nitrogen oxides from supersonic aircrafts, freon. As regards ionizing radiations, the discussion is focused on the fundamental problem of the threshold, and on the means by which one may obtain some quantitative data related to carcinogenesis by small radiation doses in man. A new concept, that of a practical threshold, is proposed. A theory which links radiocancerogenesis, as well as chemical cancerogenesis, to errors produced in the repair of lesions in the DNA is discussed. The rads-equivalent project for chemical mutagens and carcinogens is described.

  15. [Thoughts on carcinogenic pollution caused by ionizing radiation].

    Science.gov (United States)

    Latarjet, R

    1976-01-01

    The pollution phenomenon groups the effects of small doses of radiation on large populations. These effects on Man are not directly accessible. One must: a) consider some epidemiological statistics (cosmic radiation at high altitudes; radioactivity from granitic surroundings); b) extrapolate from datas obtained with high doses; c) extrapolate from datas obtained with low doses in micro-organisms or mammalian cells in vitro. The interpolation scheme of Abrahamson et al. is so available for mutagenicity. The question of a threshold remains theoretical, although radiation-induced carcinogenesis often displays a dose-effects curve with a well market threshold. A new concept, that of a "practical threshold" is developped, which may be of great usefulness. The main genetic considerations are listed upon which the present international admissible doses are based. Finally, in order to establish quantitative comparisons between chemical and radiation carcinogenic pollution, the concept of "rad equivalents" for the main chemical mutagens is stressed.

  16. Carcinogenicity, allergenicity, and lupus-inducibility of arylamines.

    Science.gov (United States)

    Chung, King-Thom

    2016-01-01

    Arylamines are widely used in food, drugs, and cosmetics as well as other industries. These chemicals are present ubiquitously in cigarette smoke, smoke emitted from cooking fume hoods as well as are generated by diverse industries. Arylamines can be generated by cleavage of azo dyes by intestinal and skin microbiota. Some arylamines are used as drugs while others are constituents of human metabolism. Many of the arylamines are mutagenic and carcinogenic. They are generally recognized as the major cause of human bladder cancer, but arylamines can induce cancers of other organs in humans and animals. Some arylamines are allergenic, causing lupus like syndrome, or other maladies. In view of their unbiquitious nature and the diseases they cause, arylamines are probably the most important chemicals causing health problems.

  17. Retraction: Evaluation of carcinogenic effects of electromagnetic fields (EMF).

    Science.gov (United States)

    Mehic, Bakir

    2010-11-01

    The Editor-in-chief of the Bosnian Journal of Basic Medical Sciences has decided to retract the article from Bayazit V et al. [1] entitled as: "Evaluation of carcinogenic effects of electromagnetic fields (EMF)" published in Bosn J Basic Med Sci. 2010 Aug;10(3):245-50. After the editorial office was alerted of possible plagiarism in the article, it conducted thorough investigation and concluded that the article apparently represents plagiarized material from two World Health Organization reports, one European Commission report and other sources. Since this is considered scientific plagiarism and scientific misconduct, Editor-in-chief has decided to withdraw the article. The authors have agreed with the editorial office decision.

  18. OVERVIEW OF DRINKING WATER MUTAGENICITY AND CARCINOGENICITY AND RISK FOR BLADDER CANCER

    Science.gov (United States)

    Among the 11 disinfection by-products (DBPs) in drinking water that are regulated by the U.S. EPA, (a) 2 DBPs (chloroacetic acid and chlorite) are not carcinogenic-in either of 2 species; (b) chlorite is not carcinogenic in 3 rodent assays and has never been tested for genotoxici...

  19. The carcinogenicity of dietary acrylamide intake: A comparative discussion of epidemiological and experimental animal research

    NARCIS (Netherlands)

    Hogervorst, J.G.F.; Baars, B.-J.; Schouten, L.J.; Konings, E.J.M.; Goldbohm, R.A.; Brandt, P.A. van den

    2010-01-01

    Since 2002, it is known that the probable human carcinogen acrylamide is present in commonly consumed carbohydrate-rich foods, such as French fries and potato chips. In this review, the authors discuss the body of evidence on acrylamide carcinogenicity from both epidemiological and rodent studies, i

  20. [Evaluation of the carcinogenic effect of ceramic fibers in experiments on rats and mice].

    Science.gov (United States)

    Krajnow, A; Lao, I; Stetkiewicz, J

    1997-01-01

    The carcinogenic effect of Kaowoll raw and thermally used ceramic fibres was assessed in experiments on rats and mice. The fibers were applied intraperitoneally in doses by 25 and 5 mg, and the animals were observed over their life-span. It was found that Kaowoll fibers were carcinogenic and that high temperature did not change these properties.