Australis: Progress Report

International Nuclear Information System (INIS)

Sie, S.H.; Niklaus, T.R.; Suter, G.F.

1996-01-01

The first stage of the development of AUSTRALIS, a microbeam AMS system at the HIGF laboratory at North Ryde, Sydney has been completed. The system is designed to enable in-situ microanalysis of geological samples for ultra-traces and for isotopic data for minerals exploration research. The negative ions for analysis are produced by sputtering with a microbeam of Cs + from a modified General Ionex model 834 HICONEX ion source. The source features a novel intermediate or 'screen' electrode to correct for the effect of the secondary ion extraction field on the trajectory of the primary beam,in order to bring the primary beam to the geometric centre. The high energy analysis system of AUSTRALIS features a pair of deflector systems to permit fast switching of isotopes without altering the magnet setting. The paper describes the initial tests' results showing good agreement with the design parameters. 5 refs., 4 figs

Geographic variation in growth responses in Phragmites australis

NARCIS (Netherlands)

Clevering, O.A.; Brix, H.; Lukavska, J.

2001-01-01

Phragmites australis is a cosmopolitan wetlands species occurring in a wide range of climatic habitats, It can be assumed that adaptations to climate have evolved to enable the synchronization of growth with the seasonality of the environment. To study these adaptations, European P. australis was

Quince años de sucesión después de corta experimental en brezales de Erica australis L. en la provincia de León (España

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Calvo, L.

2000-12-01

Full Text Available The response of the woody species to experimental cutting was studied for a period of fifteen years in a shrub community of NW Spain. This treatment represents the disturbance most frequently imposed by humans on these shrub communities throughout history. The dominant species, Erica australis, influences the regeneration patterns of the rest of the species which make up the community. There is a significant increase in the cover values of the woody species until the fourth year and of the herbaceous ones until the third year. Since then Erica australis attains the spatial occupancy and cover values it originally had, removing the herbaceous species and negatively influencing the growth of some woody ones like Halimium umbellatum and H. alyssoides. Both Erica australis and Genistella tridentata sprout after cutting. Arctostaphylos uva-ursi does not recover. Halimium alyssoides, H. umbellatum. Erica umbellata and Calluna vulgaris regenerate by germination. These shrubland communities have a high degree of resilience due to the strong sprouting potential of the component species.

[fr]
L'étude porte sur la régénération des espèces ligneuses après coupe, sur une durée de 15 ans, dans une lande dominée par Erica australis. Ce traitement experimental est l'un des plus fréquemment utilisés dans ce type de commimautés. L'espèce dominante Erica australis agit sur les types de régénération des autres espèces. On observe un accroisement significatif des taux de couverture pour les espèces ligneuses jusqu'au 4ème. année et jusqu'au Sème, année pour les herbacées. À partir de ce moment. Erica australis retrouve les valeurs d' origine, en limitant les taux des herbacées et en diminuant la croissance de quelques espèces ligneuses comme Halimium umbellatum et H. alyssoides. La régénération par rejet est le m

The presence of eucalyptol in Artemisia australis validates its use in traditional Hawaiian medicine

Institute of Scientific and Technical Information of China (English)

David Zant; Daniel A. Gubler

2014-01-01

Objective: To identify the major organic compounds of Artemisia australis (A. australis), a plant used in traditional Hawaiian medicine for the treatment of asthma.Methods:The dichloromethane extract of A. australis was analyzed by gas chromatography-mass spectroscopy and major compounds were identified by a National Institute of Standards and Technology library search and confirmed by peak enhancement.Results:The major chemical components of A. australis include eucalyptol, borneol, and caryophyllene.Conclusions:The presence and biological activity of eucalyptol correlate very well with the usage of this plant in traditional Hawaiian medicine.

Observations of the ipogean part of Typha Latifolia and Phragmites Australis; Osservazioni sull'apparato ipogeo di Typha Latifolia e Phragmites Australis

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Borin, M.; Bonaiti, G. [Padua Univ., Padua (Italy). Dipt. di Agronomia Ambientale e Produzioni Vegetali

2000-06-01

Since the interest on the use of wetlands to provide treatment of wastewaters is increasing in Italy, and the role of plants for the high performance of such systems is essential, observations on the ipogean part of Typha latifolia and Phragmites australis have been conducted after one year of growth in cubic containers (0,8 cm each side) filled with loamy textured soil. The length of rhizomes, the rhizomes and roots biomass production, and the TKN immobilisation in rhizomes and roots have been measured in soil layers of 10 cm wide. Typha latifolia and Phragmites australis produced high quantities of biomass (33 and 39 t {center_dot} ha{sup 1} of dry weight respectively) and showed a high immobilisation of nitrogen (270 and 250 kg {center_dot} ha{sup 1} respectively). The hypogeal part of Typha latifolia was developed especially in the first layers, whereas the one of Phragmites australis was more distributed along the soil profile (94 and 69% of the total biomass in the first 30 cm respectively). [Italian] Considerato l'interesse crescente che si sta osservando in Italia per la fitodepurazione delle acque inquinate e vista l'importanza che le piante esercitano in questa tecnologia, si sono condotte delle osservazioni sullo sviluppo dell'apparato ipogeo di Typha latifolia L. e Phragmites australis dopo un anno di accrescimento in cassoni cubici (0,8 m di lato) riempiti con terreno a grana media. Sono stati rilevati, per strati di 10 cm di profondita', la lunghezza dei rizomi, la biomassa di rizomi e radici ed il contenuto di TKN in rizomi e radici. Typha latifolia e Phragmites australis hanno prodotto molta biomassa (33 e 39 t {center_dot} ha{sup 1}di sostanza secca rispettivamente) ed hanno immagazinato una notevole quantita' di azoto (270 e 250 kg {center_dot} ha{sup 1} rispettivamente). Lungo il profilo del terreno, l'apparato ipogeo di Typha latifolia e' risultato piu' concentrato nei primi strati di quanto osservato in

Transcriptome Expression Profiling in Response to Drought Stress in Paulownia australis

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Yanpeng Dong

2014-03-01

Full Text Available The response and adaptation to drought remains poorly understood for Paulownia australis. To investigate this issue, transcriptome profiling of four P. australis accessions (two diploid and the other two autotetraploid under water stress condition were studied using Illumina Genome Analyzer IIx analysis. The current study aimed to identify genes of P. australis metabolism pathways that might be involved in this plant’s response to water deficit. Potted seedlings were subjected to well-watered conditions and drought stress, respectively. More than 290 million raw transcript reads were assembled into 111,660 unigenes, with a mean length of 1013 bp. Clusters of orthologous groups, gene ontology and the Kyoto Encyclopedia of Genes and Genomes annotations analyses were performed on the unigenes. Many differentially expressed genes and several metabolic pathways were identified. Quantitative real-time polymerase chain reaction was used to verify the expression patterns of 14 genes. Our study identified altered gene expression in P. australis induced by drought stress and provided a comprehensive map of drought-responsive genes and pathways in this species. To our knowledge, this is the first publicly available global transcriptome study of P. australis. This study provides a valuable genetic resource for this species.

Moving from a regional to a continental perspective of Phragmites australis invasion in North America

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Kettenring, Karin M.; de Blois, Sylvie; Hauber, Donald P.

2012-01-01

Aims We use a regional comparison of Phragmites australis (common reed) subsp. americanus, P. australis subsp. berlandieri and introduced P. australis (possibly five sublineages) in the Chesapeake Bay, the St Lawrence River, Utah and the Gulf Coast to inform a North American perspective on P. australis invasion patterns, drivers, impacts and research needs. Findings and research needs Our regional assessments reveal substantial diversity within and between the three main lineages of P. australis in terms of mode of reproduction and the types of environment occupied. For introduced P. australis, the timing of introduction also differed between the regions. Nevertheless, a common finding in these regions reinforces the notion that introduced P. australis is opportunistic and thrives in disturbed habitats. Thus, we expect to see substantial expansion of introduced P. australis with increasing anthropogenic disturbances in each of these regions. Although there have been some studies documenting the negative impacts of introduced P. australis, it also plays a beneficial role in some regions, and in some cases, the purported negative impacts are unproven. There is also a broader need to clarify the genetic and ecological relationships between the different introduced sublineages observed in North America, and their relative competitive ability and potential for admixture. This may be done through regional studies that use similar methodologies and share results to uncover common patterns and processes. To our knowledge, such studies have not been performed on P. australis in spite of the broad attention given to this species. Such research could advance theoretical knowledge on biological invasion by helping to determine the extent to which the patterns observed can be generalized or are sublineage specific or region specific. Synthesis Given what appears to be sometimes idiosyncratic invasion patterns when interpreted in isolation in the regions that we analysed, it may

[Allelopathic interactions between invasive plant Solidago canadensis and native plant Phragmites australis].

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Li, Yu-Zhe; Fan, Jiang-Wen; Yin, Xin; Yang, En-Yi; Wei, Wei; Tian, Zhi-Hui; Da, Liang-Jun

2011-05-01

Taking the seeds of invasive plant Solidago canadensis and native plant Phragmites australis from their mono- and co-dominant communities as allelopathic acceptors, this paper analyzed the differences in the seed germination rate and sprout length after treated with five level (12.5, 25, 50, 100, and 200 mg x mL(-1)) S. canadensis and P. australis extracts, aimed to understand the allelopathic interactions between the two species. The 1000-grain weight and seed germination rate under distilled water treatment of the two species in co-dominated community were greater than those in mono-dominant community. Low level (12.5 and 25 mg x mL(-1)) S. canadensi extracts slightly promoted the seed germination rates of S. canadensis in both mono- and co-dominant communities, but high level (50, 100, and 200 mg x mL(-1)) S. canadensi extracts had strong inhibition effect, especially for the S. canadensis in co-dominated community. No significant patterns were observed about the effects of P. australis extract on S. canadensis seed germination. The sprout length of S. canadensis seeds in both mono- and co-dominant communities decreased with increasing level of S. canadensis extract, but decreased in a fluctuation way with increasing level of P. australis extract. After treated with the extracts of P. australis or S. canadensis, the seed germination rate of P. australis in mono-dominant community was significantly greater than that in co-dominant community (P < 0.05), but there was no significant difference between these two extracts.

Phragmites australis root secreted phytotoxin undergoes photo-degradation to execute severe phytotoxicity.

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Rudrappa, Thimmaraju; Choi, Yong Seok; Levia, Delphis F; Legates, David R; Lee, Kelvin H; Bais, Harsh P

2009-06-01

Our study organism, Phragmites australis (common reed), is a unique invader in that both native and introduced lineages are found coexisting in North America. This allows one to make direct assessments of physiological differences between these different subspecies and examine how this relates to invasiveness. Recent efforts to understand plant invasive behavior show that some invasive plants secrete a phytotoxin to ward-off encroachment by neighboring plants (allelopathy) and thus provide the invaders with a competitive edge in a given habitat. Here we show that a varying climatic factor like ultraviolet (UV) light leads to photo-degradation of secreted phytotoxin (gallic acid) in P. australis rhizosphere inducing higher mortality of susceptible seedlings. The photo-degraded product of gallic acid (hereafter GA), identified as mesoxalic acid (hereafter MOA), triggered a similar cell death cascade in susceptible seedlings as observed previously with GA. Further, we detected the biological concentrations of MOA in the natural stands of exotic and native P. australis. Our studies also show that the UV degradation of GA is facilitated at an alkaline pH, suggesting that the natural habitat of P. australis may facilitate the photo-degradation of GA. The study highlights the persistence of the photo-degraded phytotoxin in the P. australis's rhizosphere and its inhibitory effects against the native plants.

Phylogeographic analyses and genetic structure illustrate the complex evolutionary history of Phragmites australis in Mexico.

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Colin, Ricardo; Eguiarte, Luis E

2016-05-01

Genetic data suggest that three lineages of Phragmites australis are found in North America: the Native North American lineage, the Gulf Coast lineage, and the Invasive lineage. In Mexico, P. australis is a common species, but nothing is known about the distribution or ecology of these lineages. We examined the phylogeography of P. australis to analyze the current geographic distribution of genetic variation, demographic history, and dispersal patterns to better understand its evolutionary history in Mexico. We sampled 427 individuals from 28 populations. We used two noncoding regions of chloroplast DNA to estimate the levels of genetic variation and identified the genetic groups across the species' geographical range in Mexico. We compared the genealogical relationships among haplotypes with those previously reported. A hypothesis of demographic expansion was also tested for the Mexican P. australis lineages. We found 13 new haplotypes native to Mexico that might be undergoing an active process of expansion and diversification. Genealogical analyses provided evidence that two independent lineages of P. australis are present in Mexico. The invasive lineage was not detected with our sampling. Our estimates of population expansions in Mexico ranged from 0.202 to 0.726 mya. Phragmites australis is a native species that has been in Mexico for thousands of years. Genetic data suggest that climatic changes during the Pleistocene played an important role in the demographic expansion of the populations that constitute the different genetic groups of P. australis in Mexico. © 2016 Botanical Society of America.

Functional role of bacteria from invasive Phragmites australis in promotion of host growth

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Soares, M. A.; Li, H-Y; Kowalski, Kurt P.; Bergen, M.; Torres, M. S.; White, J. F.

2016-01-01

We hypothesize that bacterial endophytes may enhance the competitiveness and invasiveness of Phragmites australis. To evaluate this hypothesis, endophytic bacteria were isolated from P. australis. The majority of the shoot meristem isolates represent species from phyla Firmicutes, Proteobacteria, and Actinobacteria. We chose one species from each phylum to characterize further and to conduct growth promotion experiments in Phragmites. Bacteria tested include Bacillus amyloliquefaciens A9a, Achromobacter spanius B1, and Microbacterium oxydans B2. Isolates were characterized for known growth promotional traits, including indole acetic acid (IAA) production, secretion of hydrolytic enzymes, phosphate solubilization, and antibiosis activity. Potentially defensive antimicrobial lipopeptides were assayed for through application of co-culturing experiments and mass spectrometer analysis. B. amyloliquefaciens A9a and M. oxydans B2 produced IAA. B. amyloliquefaciens A9a secreted antifungal lipopeptides. Capability to promote growth of P. australis under low nitrogen conditions was evaluated in greenhouse experiments. All three isolates were found to increase the growth of P. australis under low soil nitrogen conditions and showed increased absorption of isotopic nitrogen into plants. This suggests that the Phragmites microbes we evaluated most likely promote growth of Phragmites by enhanced scavenging of nitrogenous compounds from the rhizosphere and transfer to host roots. Collectively, our results support the hypothesis that endophytic bacteria play a role in enhancing growth of P. australis in natural populations. Gaining a better understanding of the precise contributions and mechanisms of endophytes in enabling P. australis to develop high densities rapidly could lead to new symbiosis-based strategies for management and control of the host.

Description of the immature stages of the planthopper Lacertinella australis (Hemiptera: Delphacidae)

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Batiz, M. F. Rossi; Marino de Remes Lenicov, A. M.; Hagedorn, Henry

2014-01-01

Abstract The five immature stages of the planthopper Lacertinella australis (Remes Lenicov and Rossi Batiz) (Hemiptera: Delphacidae: Saccharosydnini) are described and illustrated. The main characters that allowed us to distinguish the various stages were body size, number of tarsomeres and metatibial spines, and number of teeth on the spur. New biological data based on laboratory rearing and field observations showed that L. australis can carry out its biological cycle successfully on the graminaceous pampas grass ( Cortaderia spp. Stapf (Poales: Poaceae)). In addition, the efficient rearing in captivity, the high survivorship registered, and overwintering only on this host plant suggests that L. australis is a potential biocontrol agent of this invasive graminaceous weed. This study provides information about the immature stages , including a key for their identification, based on laboratory reared specimens and field observations. Resumen Se describen e ilustran las cinco etapas inmaduras de la especie de Saccharisydnini Lacertinella australis (Remes Lenicov and Rossi Batiz) (Hemiptera: Delphacidae). Los principales caracteres que permitieron distinguir las diferentes etapas fueron: tamaño corporal, número de espinas en los tarsómeros y metatibia y número de dientes en el espolón tibial. Nuevos datos biológicos, basados en la cría de laboratorio y observaciones de campo, mostraron que L. australis puede realizar su ciclo biológico exitosamente en la graminácea cortadera ( Cortaderia spp. Stapf (Poales: Poaceae)). Además, la eficiente crianza en cautive-rio y la alta supervivencia registrada en esta planta hospedera, sugieren que L. australis podría ser usada como un potencial agente de control biológico de esta maleza invasora. Este estudio proporciona informa-ción sobre las etapas inmaduras, incluyendo una clave para su identificación, basada en individuos provenientes de la cría de laboratorio y de campo. PMID:25199992

Genetics, novel weapons and rhizospheric microcosmal signaling in the invasion of Phragmites australis.

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Rudrappa, Thimmaraju; Bais, Harsh P

2008-01-01

Chemical communication and perception strategies between plants are highly sophisticated but are only partly understood. Among the different interactions, the suppressive interaction of a class of chemicals released by one plant through root exudates against the neighbouring plants (allelopathy) have been implicated in the invasiveness of many exotic weedy species. Phragmites australis (common reed) is one of the dominant colonizers of the North American wetland marshes and exhibits invasive behavior by virtually replacing the entire native vegetation in its niche. Recently, by adopting a systematic bioassay driven approach we elucidated the role of root derived allelopathy as one of the important mechanisms by which P. australis exerts its invasive behavior. Additionally, our recent preliminary data indicates the involvement of rhizobacterial signaling in the invasive success of P. australis. A better understanding of biochemical weaponry used by P. australis will aid scientists and technologists in addressing the impact of root secretions in invasiveness of weedy species and thus promote a more informed environmental stewardship.

The presence of eucalyptol in Artemisia australis validates its use in traditional Hawaiian medicine

Institute of Scientific and Technical Information of China (English)

David; Zant; Daniel; A.Gubler

2014-01-01

Objective:To identify the major organic compounds of Artemisia austeralis(A.australis),a plant used in traditional Hawaiian medicine for the treatment of asthma.Methods:The dichloromethane extract of A.australis was analyzed by gas chromatography—mass spectroscopy and major compounds were identified by a National Institute of Standards and Technology library search and confirmed by peak enhancement Results:The major chemical components of A.australis include eucalyptol.borneol,and caryophyllene.Conclusions:The presence and biological activity of eucalyptol correlate very well with the usage of this plant in traditional Hawaiian medicine.

Cosmopolitan Species As Models for Ecophysiological Responses to Global Change: The Common Reed Phragmites australis

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Franziska Eller

2017-11-01

Full Text Available Phragmites australis is a cosmopolitan grass and often the dominant species in the ecosystems it inhabits. Due to high intraspecific diversity and phenotypic plasticity, P. australis has an extensive ecological amplitude and a great capacity to acclimate to adverse environmental conditions; it can therefore offer valuable insights into plant responses to global change. Here we review the ecology and ecophysiology of prominent P. australis lineages and their responses to multiple forms of global change. Key findings of our review are that: (1 P. australis lineages are well-adapted to regions of their phylogeographic origin and therefore respond differently to changes in climatic conditions such as temperature or atmospheric CO2; (2 each lineage consists of populations that may occur in geographically different habitats and contain multiple genotypes; (3 the phenotypic plasticity of functional and fitness-related traits of a genotype determine the responses to global change factors; (4 genotypes with high plasticity to environmental drivers may acclimate or even vastly expand their ranges, genotypes of medium plasticity must acclimate or experience range-shifts, and those with low plasticity may face local extinction; (5 responses to ancillary types of global change, like shifting levels of soil salinity, flooding, and drought, are not consistent within lineages and depend on adaptation of individual genotypes. These patterns suggest that the diverse lineages of P. australis will undergo intense selective pressure in the face of global change such that the distributions and interactions of co-occurring lineages, as well as those of genotypes within-lineages, are very likely to be altered. We propose that the strong latitudinal clines within and between P. australis lineages can be a useful tool for predicting plant responses to climate change in general and present a conceptual framework for using P. australis lineages to predict plant responses

Simulating the effect of emex australis densities and sowing dates on agronomic traits of wheat

International Nuclear Information System (INIS)

Abbas, R.N.; Tanveer, A.; Ali, A.; Zaheer, Z.A.

2010-01-01

Reduction in yield and quality of wheat is major problem caused by the delayed sowing and interference of weeds. The effects of sowing dates (Nov 8, Nov 16, and Nov 24) and Emex australis Steinh. density (0, 1, 2, 3, 4 plants per pot) on growth and yield of wheat were evaluated over two seasons (2005-06, 2006-07). The statistical analysis of data exhibited non-significant effect of weed density on number of days taken to initiate flowering by E. australis. Highest values for E. australis plant height, dry biomass, number of seed per plant and seed weight were recorded by sowing wheat on November 8, at E. australis density of one plant per pot in both years. Maximum number of spike bearing tillers per pot, plant height, number of grains per spike, 1000-grain weight and grain yield were observed in November 8, sowing with zero E. australis density and minimum values for these parameters were recorded in late sowing ( November 24) at maximum weed density of 4 plants per pot. Early sowing ( Nov. 8) and weed free pots increased wheat grain yield compared to later sowings (Nov. 16 and Nov. 24) and higher weed density. (author)

JST Thesaurus Headwords and Synonyms: Phragmites australis [MeCab user dictionary for science technology term[Archive

Lifescience Database Archive (English)

Full Text Available MeCab user dictionary for science technology term Phragmites australis 名詞 一般 * * * ...* ヨシ ヨシ ヨシ Thesaurus2015 200906077254295905 C LS06 UNKNOWN_2 Phragmites australis

Comparative Hepatoprotective Activity of Ethanolic Extracts of Cuscuta australis against Acetaminophen Intoxication in Wistar Rats.

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Folarin, Rachael O; Omirinde, Jamiu O; Bejide, Ronald; Isola, Tajudeen O; Usende, Levi I; Basiru, Afisu

2014-01-01

This study investigates the comparative hepatoprotective activity of crude ethanol extracts of Cuscuta australis against acetaminophen (APAP) intoxication. Thirty-six rats were randomly divided into six groups of 6 replicates: Group 1 which served as control received water. Group 2 was orally administered 835 mg/kg body wt. of paracetamol on day 8. Groups 3 and 4 were orally administered ethanolic extracts of the seed of Cuscuta australis in doses of 125 mg/kg and 250 mg/kg, respectively, for 7 days and then intoxicated as in Group 2 on the 8th day. Groups 5 and 6 received similar oral doses of Cuscuta australis stem extracts for 7 days and then intoxicated as in Groups 3 and 4. Group 2 rats showed severe periportal hepatic necrosis, significantly elevated serum hepatic injury markers, markedly increased lipid peroxidation, and decreased hepatic antioxidant enzymes activities. Remarkably, Cuscuta australis (seed and stem) extract pretreatments in Groups 3, 4, 5, and 6, most especially, the stem extract pretreatment in Groups 5 and 6, improved better the hepatic histoarchitecture, the hepatocellular, and the oxidative stress injury markers in a dose-dependent manner. Conclusively, ethanol extractions of Cuscuta australis stem appear to protect the liver from acetaminophen intoxication better than the seed counterpart.

Research Ship Aurora Australis Underway Meteorological Data, Quality Controlled

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National Oceanic and Atmospheric Administration, Department of Commerce — Research Ship Aurora Australis Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic...

Interspecific interactions between Phragmites australis and Spartina alterniflora along a tidal gradient in the Dongtan wetland, Eastern China.

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Yue Yuan

Full Text Available The invasive species Spartina alterniora Loisel was introduced to the eastern coast of China in the 1970s and 1980s for the purposes of land reclamation and the prevention of soil erosion. The resulting interspecific competition had an important influence on the distribution of native vegetation, which makes studying the patterns and mechanisms of the interactions between Spartina alterniora Loisel and the native species Phragmites australis (Cav. Trin ex Steud in this region very important. There have been some researches on the interspecific interactions between P. australis and S. alterniora in the Dongtan wetland of Chongming, east China, most of which has focused on the comparison of their physiological characteristics. In this paper, we conducted a neighbor removal experiment along a tidal gradient to evaluate the relative competitive abilities of the two species by calculating their relative neighbor effect (RNE index. We also looked at the influence of environmental stress and disturbance on the competitive abilities of the two species by comparing interaction strength (I among different tidal zones both for P. australis and S. alterniora. Finally, we measured physiological characteristics of the two species to assess the physiological mechanisms behind their different competitive abilities. Both negative and positive interactions were found between P. australis and S. alterniora along the environmental gradient. When the direction of the competitive intensity index for P. australis and S. alterniora was consistent, the competitive or facilitative effect of S. alterniora on P. australis was stronger than that of P. australis on S. alterniora. The interspecific interactions of P. australis and S. alterniora varied with environmental conditions, as well as with the method used, to measure interspecific interactions.

Exposure dose response relationships of the freshwater bivalve Hyridella australis to cadmium spiked sediments

International Nuclear Information System (INIS)

Marasinghe Wadige, Chamani P.M.; Maher, William A.; Taylor, Anne M.; Krikowa, Frank

2014-01-01

Highlights: • The exposure–dose–response approach was used to assess cadmium exposure and toxicity. • Accumulated cadmium in H. australis reflected the sediment cadmium exposure. • Spill over of cadmium into the biologically active pool was observed. • Increased cadmium resulted in measurable biological effects. • H. australis has the potential to be a cadmium biomonitor in freshwater environments. - Abstract: To understand how benthic biota may respond to the additive or antagonistic effects of metal mixtures in the environment it is first necessary to examine their responses to the individual metals. In this context, laboratory controlled single metal-spiked sediment toxicity tests are useful to assess this. The exposure–dose–response relationships of Hyridella australis to cadmium-spiked sediments were, therefore, investigated in laboratory microcosms. H. australis was exposed to individual cadmium spiked sediments (<0.05 (control), 4 ± 0.3 (low) and 15 ± 1 (high) μg/g dry mass) for 28 days. Dose was measured as cadmium accumulation in whole soft body and individual tissues at weekly intervals over the exposure period. Dose was further examined as sub-cellular localisation of cadmium in hepatopancreas tissues. The biological responses in terms of enzymatic and cellular biomarkers were measured in hepatopancreas tissues at day 28. H. australis accumulated cadmium from spiked sediments with an 8-fold (low exposure organisms) and 16-fold (high exposure organisms) increase at day 28 compared to control organisms. The accumulated tissue cadmium concentrations reflected the sediment cadmium exposure at day 28. Cadmium accumulation in high exposure organisms was inversely related to the tissue calcium concentrations. Gills of H. australis showed significantly higher cadmium accumulation than the other tissues. Accumulated cadmium in biologically active and biologically detoxified metal pools was not significantly different in cadmium exposed

Humans, Fish, and Whales: How Right Whales Modify Calling Behavior in Response to Shifting Background Noise Conditions.

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Parks, Susan E; Groch, Karina; Flores, Paulo; Sousa-Lima, Renata; Urazghildiiev, Ildar R

2016-01-01

This study investigates the role of behavioral plasticity in the variation of sound production of southern right whales (Eubalaena australis) in response to changes in the ambient background noise conditions. Data were collected from southern right whales in Brazilian waters in October and November 2011. The goal of this study was to quantify differences in right whale vocalizations recorded in low background noise as a control, fish chorus noise, and vessel noise. Variation in call parameters were detected among the three background noise conditions and have implications for future studies of noise effects on whale sound production.

Identification, Development, and Release of Insect Biocontrol Agents for the Management of Phragmites australis

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2014-07-01

currently testing the pathogenicity of different isolates on P. australis germination and results are extremely diverse. Isolates and P. australis...pathogenicity. While these Pythium species have large effects on seed germination , it is doubtful that they can contribute to reductions in P...potential agents for in-depth study; (2) outline and report initial testing procedures and results of host-specificity studies of identified agents; (3

Histomorphology of the digestive tract of Chonopeltis australis ...

African Journals Online (AJOL)

The morphology and histology of the digestive tract of the branchiuran crustacean, Chonopeltis australis Box shall, 1976 are described from serial sections. The foregut is differentiated into a preoral cavity, containing the mandibles and tongue, an ascending oesophagus, with an H-shaped lumen invested with longitudinal, ...

Short-term Responses of Posidonia australis to Changes in Light Quality

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Simone Strydom

2018-01-01

Full Text Available Seagrass meadows are highly productive ecosystems that provide ecosystem services to the coastal zone but are declining globally, particularly due to anthropogenic activities that reduce the quantity of light reaching seagrasses, such as dredging, river discharge and eutrophication. Light quality (the spectral composition of the light is also altered by these anthropogenic stressors as the differential attenuation of wavelengths of light is caused by materials within the water column. This study addressed the effect of altered light quality on different life-history stages of the seagrass Posidonia australis, a persistent, habitat-forming species in Australia. Aquarium-based experiments were conducted to determine how adult shoots and seedlings respond to blue (peak λ = 451 nm; green (peak λ = 522 nm; yellow (peak λ = 596 nm and red (peak λ = 673 nm wavelengths with a control of full-spectrum light (λ = 400 – 700 nm, at 200 μmol photons m-2 s-1. Posidonia australis adults did not respond to changes in light quality relative to full-spectrum light, demonstrating a capacity to obtain enough photons from a range of wavelengths across the visible spectrum to maintain short-term growth at high irradiances. Posidonia australis seedlings (<4 months old grown in blue light showed a significant increase in xanthophyll concentrations when compared to plants grown in full-spectrum, demonstrating a pigment acclimation response to blue light. These results differed significantly from negative responses to changes in light quality recently described for Halophila ovalis, a colonizing seagrass species. Persistent seagrasses such as P. australis, appear to be better at tolerating short-term changes in light quality compared to colonizing species when sufficient PPFD is present.

Zooarqueologia dos mamíferos aquáticos e semi-aquáticos da Ilha de Santa Catarina, sul do Brasil

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Pedro Volkmer de Castilho

2001-09-01

Full Text Available This study analyzes the use of aquatic mammals by prehistoric societies of Santa Catarina Island, Southern Brazil. Samples from two archaeological sites were examined: Rio do Meio (RM and Porto do Rio Vermelho (SCPRV. Nine aquatic mammal species were found: a pinnipeds: Arctocephalus australis (Zimmerman, 1783 and A. tropicalis (Gray, 1872, and b cetaceans: Eubalaena australis (Desmoulins, 1822, Delphinus delphis Linnaeus, 1758, Stenella frontalis (Cuvier, 1829, Steno bredanensis (Lesson, 1828, Tursiops truncatus (Montagu, 1821, Pontoporia blainvillei (Gervais & d'Orbigny, 1844 and a non-identified rorqual from the genus Balaenoptera Lacépède, 1804. Three especies of semi-aquatic mammals were also recorded: Hydrochoerus hydrochaeris (Linnaeus, 1758, Tapirus terrestris (Linnaeus, 1758 and Lontra longicaudis (Olfers,1818. Both sites presented similar species diversity, although abundance was greater at the most recent site (RM. There were more samples from axial skeletons, but in genera the anatomical regions were homogeneously distributed among the identified taxa.

Heavy metal contents and transfer capacities of Phragmites australis and Suaeda salsa in the Yellow River Delta, China

Science.gov (United States)

Zhang, Shuai; Bai, Junhong; Wang, Wei; Huang, Laibing; Zhang, Guangliang; Wang, Dawei

2018-04-01

Plant samples including roots, stems and leaves of Phragmites australis and Suaeda salsa were collected in the short-term flooding and tidal flooding wetlands of the Yellow River Delta of China. Six heavy metals (e.g., As, Cd, Cr, Cu, Pb, and Zn) were measured in roots, stems and leaves of each plant species using inductively coupled plasma atomic absorption spectrometry (ICP-AAS) to investigate the levels, and transfer capabilities of heavy metals in these two plant species. Our results showed that in the tidal flooding wetlands, the contents of As, Cr and Cd in roots of Phragmites australis and Suaeda salsa were higher than those in their stems and leaves. Suaeda salsa showed higher contents of Pb and Zn in leaves than those in roots and stems, whereas lower levels of Pb and Zn were observed in Phragmites australis. In the short-term flooding wetlands, heavy metal contents exhibited a big difference between different tissues of Phragmites australis and Suaeda salsa, and both plant species showed higher levels of Pb and Zn in leaves. Suaeda salsa roots enriched more As and Cd, whereas higher enrichment levels were observed in Phragmites australis leaves, which indicated different transfer capacities of these two wetland plants. The transfer factors for stems and leaves of Phragmites australis in the tidal flooding wetlands significantly differed from those in the short-term flooding wetlands, however, no significant differences in transfer factors for stems and leaves of Suaeda salsa were observed between these two types of wetlands.

Root-secreted allelochemical in the noxious weed Phragmites australis deploys a reactive oxygen species response and microtubule assembly disruption to execute rhizotoxicity.

Science.gov (United States)

Rudrappa, Thimmaraju; Bonsall, Justin; Gallagher, John L; Seliskar, Denise M; Bais, Harsh P

2007-10-01

Phragmites australis is considered the most invasive plant in marsh and wetland communities in the eastern United States. Although allelopathy has been considered as a possible displacing mechanism in P. australis, there has been minimal success in characterizing the responsible allelochemical. We tested the occurrence of root-derived allelopathy in the invasiveness of P. australis. To this end, root exudates of two P. australis genotypes, BB (native) and P38 (an exotic) were tested for phytotoxicity on different plant species. The treatment of the susceptible plants with P. australis root exudates resulted in acute rhizotoxicity. It is interesting to note that the root exudates of P38 were more effective in causing root death in susceptible plants compared to the native BB exudates. The active ingredient in the P. australis exudates was identified as 3,4,5-trihydroxybenzoic acid (gallic acid). We tested the phytotoxic efficacy of gallic acid on various plant systems, including the model plant Arabidopsis thaliana. Most tested plants succumbed to the gallic acid treatment with the exception of P. australis itself. Mechanistically, gallic acid treatment generated elevated levels of reactive oxygen species (ROS) in the treated plant roots. Furthermore, the triggered ROS mediated the disruption of the root architecture of the susceptible plants by damaging the microtubule assembly. The study also highlights the persistence of the exuded gallic acid in P. australis's rhizosphere and its inhibitory effects against A. thaliana in the soil. In addition, gallic acid demonstrated an inhibitory effect on Spartina alterniflora, one of the salt marsh species it successfully invades.

Maternal body size and condition determine calf growth rates in southern right whales

DEFF Research Database (Denmark)

Christiansen, Fredrik; Vivier, Fabien; Charlton, Claire

2018-01-01

The cost of reproduction is a key parameter determining a species' life history strategy. Despite exhibiting some of the fastest offspring growth rates among mammals, the cost of reproduction in baleen whales is largely unknown since standard field metabolic techniques cannot be applied. We...... quantified the cost of reproduction for southern right whales Eubalaena australis over a 3 mo breeding season. We did this by determining the relationship between calf growth rate and maternal rate of loss in energy reserves, using repeated measurements of body volume obtained from unmanned aerial vehicle...... period, and highlights the importance of sufficient maternal energy reserves for reproduction in this capital breeding species....

Understanding Super-Earths with MINERVA-Australis at USQ's Mount Kent Observatory

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Wittenmyer, Robert; Horner, Jonathan; Kane, Stephen; Plavchan, Peter; Ciardi, David; Eastman, Jason; Johnson, John Asher; Wright, Jason; McCrady, Nate; MINERVA Collaboration

2018-01-01

Super Earths, planets between 5-10 Earth masses, are the most common types of planets known, yet are completely absent from our Solar system. As a result, their detailed properties, compositions, and formation mechanisms are poorly understood. NASA's Transiting Exoplanet Survey Satellite (TESS) will identify hundreds of Super-Earths orbiting bright stars, for the first time allowing in-depth characterisation of these planets. At the University of Southern Queensland, we are host to the MINERVA-Australis project, dedicated wholly to the follow-up characterisation and mass measurement of TESS planets. We give an update on the status of MINERVA-Australis and our expected performance. We also present results from the fully operational Northern MINERVA array, with the primary mission of discovering rocky planets orbiting 80 nearby bright stars.

The effects of litter on growth and plasticity of Phragmites australis clones originating from infertile, fertile or eutrophicated habitats

NARCIS (Netherlands)

Clevering, O.A.

1999-01-01

In many European countries a strong decline of Phragmites australis (Cav.) Trin. Ex Steudel (common reed) has been observed. In some instances this decline has been related to the accumulation of litter. A greenhouse experiment was conducted with P. australis cuttings from different stable and

Seasonal changes in metal accumulation and distribution in the organs of Phragmites australis (common reed from Lake Skadar, Montenegro

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Kastratović Vlatko

2013-01-01

Full Text Available Due to its ability to accumulate metals, availability throughout the year and its large biomass, Phragmites australis (common reed is suitable for biomonitoring studies for the evaluation of load level of water ecosystem with trace metals. The heavy metals concentration in P.australis tissue can be several ten to several thousand times higher than those in the surrounding water. In this study we examined the content of heavy metals (Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn, Sr and V in sediment, water and different organs of Phragmites australis collected from Lake Skadar, Montenegro, during different seasons of the year 2011. The highest concentrations of Sr were found in the leaves, while the other studied metals showed their highest concentrations in the roots. Thus, P. australis is considered a root bioaccumulation species. For most metals the concentration in roots and stems increases over time until the end of the growing season, and then decreases, while the concentration in leaves increases even after the growing season of the plant. If P. australis is used for phytoremediation purposes, then it should be harvested after the growing season because then the concentration of metals in the aboveground parts is maximal.

The Composition and The Content of The Main Pigments on Dodders Plant Cuscuta australis R.Br. and Cassytha filiformis L.

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Heriyanto

2006-11-01

Full Text Available Research on dodders plant Cuscuta australis R.Br. and Cassytha filiformis L was done to analyze their pigment composition and content. The pigment composition was analyzed by the use of thin layer chromatography (TLC method based on spot color and retardation factor. The water content was measured according to Sudarmadji et. al. The chlorophylls and carotenoid contents were calculated by Porra et. al. and Gross equation, respectively. Result showed that Cuscuta australis R.Br. (green yellowish and orange and Cassytha filiformis L. (green and brown reddish had similar pigment composition consist of carotene, pheophytin a, chlorophyll a, chlorophyll b and xanthophyll. The average of the chlorophyll content from the highest to the lowest one was Cassytha filiformis L. green followed by Cuscuta australis R.Br. green yellowish and orange, while the total chlorophyll of Cassytha filiformis L. brown reddish was relatively similar with other dodders plant. The average of the carotenoid content from the highest to the lowest was Cuscuta australis R.Br. orange followed by Cuscuta australis R.Br. green yellowish. The pigment content of Cassytha filiformis L. was relatively similar to Cassytha filiformis L. brown reddish.

Isolation of fucoxanthin and fatty acids analysis of Padina australis ...

African Journals Online (AJOL)

Fucoxanthin has been successfully isolated from species of Malaysian brown seaweed, namely Padina australis. The purity of the fucoxanthin is >98% as indicated by high performance liquid chromatography analysis. This seaweed also contains a considerable amount of unsaturated fatty acids. Thirteen fatty acids were ...

Monitoring Phragmites australis increases from 1937 to 1976 in the Siyai Lagoon (Natal, South Africa by means of air photo interpretation

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P. J. Weisser

1981-11-01

Full Text Available The colonization o f the Siyai Lagoon on the north coast of Natal by Phragmites australis was studied by means of  air photo interpretation. It was possible to locate and estimate P. australis areas for 1957 (0,74 ha, 1965 (1,65 ha, 1969 (1,93 ha and 1976 (2,94 ha. Phragmites australis first inhabited the shores of the middle section o f the lagoon followed by rapid expansion in the lower section. The upper section was colonized only at its lower end by expansion from the middle section. It is suggested that P. australis was unsuccessful in this section because of competition by the  Hibiscus tiliaceus—Barringtonia racemosa  Lagoon Fringe Forest. This same community is shading out  P. australis in some places. The notable increase in the rate of advance of land and littoral vegetation into the Siyai Lagoon was caused by sugar farming activities leading to erosion and sedimentation in the lagoon. A vegetation age gradient was observed from the upper section to the mouth region. The colonization of most of the Siyai Lagoon except the immediate mouth zone by  P. australis Reedswamp and  Hibiscus tiliaceus—Barringtonia racemosa Lagoon Fringe Forest, can be expected before the turn of the century. Dredging and mechanical control of vegetation will become necessary if major open water spaces are to be maintained.

[Effects of Cuscuta australis parasitism on the growth, reproduction and defense of Solidago canadensis].

Science.gov (United States)

Yang, Bei-fen; Du, Le-shan; Li, Jun-min

2015-11-01

In order to find out how parasitic Cuscuta australis influences the growth and reproduction of Solidago canadensis, the effects of the parasitism of C. australis on the morphological, growth and reproductive traits of S. canadensis were examined and the relationships between the biomass and the contents of the secondary metabolites were analyzed. The results showed that the parasitism significantly reduced the plant height, basal diameter, root length, root diameter, root biomass, stem biomass, leaf biomass, total biomass, number of inflorescences branches, axis length of inflorescence, and number of inflorescence. In particular, plant height, number of inflorescence and the stem biomass of parasitized S. canadensis were only 1/2, 1/5 and 1/8 of non-parasitized plants, respectively. There was no significant difference of plant height, root length, stem biomass and total biomass between plants parasitized with high and low intensities. But the basal diameter, root volume, leaf biomass, root biomass, the number of inflorescences branches, axis length of inflorescence and number of inflorescence of S. canadensis parasitized with high intensity were significantly lower than those of plants parasitized with low intensity. The parasitism of C. australis significantly increased the tannins content in the root and the flavonoids content in the stem of S. canadensis. The biomass of S. canadensis was significantly negatively correlated with the tannin content in the root and the flavonoids content in the stem. These results indicated that the parasitism of C. australis could inhibit the growth of S. canadensis by changing the resources allocation patterns as well as reducing the resources obtained by S. canadensis.

Pembentukan mother plant Bacopa australis secara In-vitro dan aklimatisasi dalam aquascape air tawar

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Media Fitri Isma Nugraha

2017-12-01

Full Text Available Tanaman air adalah bagian penting dari ekosistem air tawar. Salah satu spesies yang terkenal adalah Bacopa australis. Hobiis aquascape saat ini memiliki ketertarikan tinggi terhadap tanaman air dengan kualitas yang bagus dari setiap spesiesnya. Metode perbanyakan tanaman air tanpa tanah, lahan pertanian dan air perlu dilakukan untuk memenuhi keinginan tersebut. Tujuan dari penelitian ini adalah untuk mendapatkan formula media kultur jaringan dan zat pengatur tumbuh yang tepat untuk multiplikasi dalam perakitan mother plant (tanaman induk Bacopa australis, serta mendapatkan media terbaik untuk aklimatisasi. Media yang digunakan adalah media Murashige dan Skoog (MS A padat dengan perbedaan konsentrasi zat pengatur tumbuh. Perlakuan uji dalam kombinasi zat pengatur tumbuh (a 0,50 mg/L BAP + 0,50 mg/L kinetin; (b 0,50 mg/L BAP; dan (c 0,50 mg/L 2,4-D. Aklimatisasi tanaman induk dilakukan pada berbagai media antara lain 1 pasir silika + pupuk aqua soil amazonia, 2. pasir malang + pupuk aqua soil amazonia, 3 pasir silika + pupuk cair; 4 pasir malang + pupuk. Hasil yang diperoleh, yaitu formula media kultur terbaik untuk multiplikasi tunas tanaman B. australis secara in-vitro adalah media MS (A yang diperkaya dengan 0,5 mg/L BAP + 0,5 mg/L kinetin, sedangkan aklimatisasi terbaik pada media pasir malang + pupuk aqua soil amazonia. Water plant is an important part of freshwater ecosystems. One of the famous species is Bacopa australis. Today, many aquascape hobbyists have a high interest in aquatic plant species that have good aesthetic appearances. To answer this challenge, a new method in-vitro propagation of aquatic plants, planted without soil, agricultural land and water was conducted. The aim of this research was to find the best growth regulator hormon formula and aclimatisation medium, in creating the mother plant Bacopa australis. The medium used was MS (Murashige and Skoog, 1974 with different growth regulator hormon, i.e: (a 0.50 mg L-1 BAP

Differentiation of Cuscuta chinensis and Cuscuta australis by HPLC-DAD-MS analysis and HPLC-UV quantitation.

Science.gov (United States)

He, Xianghui; Yang, Wenzhi; Ye, Min; Wang, Qing; Guo, Dean

2011-11-01

Cuscuta chinensis and Cuscuta australis, the two botanical sources of the Chinese herbal medicine Tu-Si-Zi, were distinguished from each other based on qualitative and quantitative chemical analysis. By HPLC‑DAD‑MS, a total of 36 compounds were characterized from these two Cuscuta species, including 14 flavonoids, 17 quinic acid derivatives, and 5 lignans. In addition, HPLC‑UV was applied to determine seven major compounds (6 flavonoids plus chlorogenic acid) in 27 batches of Tu-Si-Zi. The results revealed that the amounts of the three classes of compounds varied significantly between the species. C. australis contained more flavonoids but less quinic acid derivatives and lignans than C. chinensis. Particularly, the amounts of kaempferol and astragalin in C. australis were remarkably higher than in C. chinensis. This finding could be valuable for the quality control of Tu-Si-Zi. © Georg Thieme Verlag KG Stuttgart · New York.

Accumulation of Metals and Boron in Phragmites australis Planted in Constructed Wetlands Polishing Real Electroplating Wastewater.

Science.gov (United States)

Sochacki, Adam; Guy, Bernard; Faure, Olivier; Surmacz-Górska, Joanna

2015-01-01

The concentration of metals (Al, Cu, Fe, Mn, Ni, Zn) and B were determined in the above- and belowground biomass of Phragmites australis collected from the microcosm constructed wetland system used for the polishing of real electroplating wastewater. Translocation factor and bioconcentration factor were determined. Pearson correlation test was used to determine correlation between metal concentration in substrate and above- and belowground parts of Phragmites australis. The obtained results suggested that Phragmites australis did not play a major role as an accumulator of metals. It was observed also that the substrate could have exerted an effect on the translocation of Ni, Cu, Zn and Mn. The analysed concentrations of metals and B in biomass were in the range or even below the concentrations reported in the literature with the exception of Ni. The aboveground biomass was found suitable as a composting input in terms of metals concentrations.

Globalisation and the Australian Aborigines: gain or strain? La Mondialisation : une chance pour les Aborigènes d’Australie ?

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Ludivine Royer

2009-10-01

Full Text Available La mondialisation est un phénomène très complexe, qui implique à la fois l’émergence de l’économie de marché, l’accélération du commerce international, l’ouverture des frontières, la libre circulation des personnes et des biens, le développement extraordinaire des transports et de la technologie de l’information, la montée en puissance des télécommunications et des médias à l’échelle planétaire, l’expansion des cultures occidentales et le déclin des États-nations au profit d’institutions internationales en plein essor. Un nouvel ordre mondial est né, et comme la plupart des autres pays, l’Australie a connu de profonds changements depuis la fin des années 1980. Cet article se propose de montrer l’impact direct et indirect de la mondialisation économique, culturelle, technologique et politique sur le peuple aborigène. Bien entendu, il ne s’agit pas de présenter de manière exhaustive les conséquences multiples et complexes de la mondialisation sur les droits, cultures, et sociétés aborigènes, leur développement économique et leur statut politique. Il s’attelle en revanche à mettre en évidence les logiques politiques et socio-culturelles que la mondialisation a favorisées dans les affaires aborigènes, de l’assimilation à l’auto-détermination.

Role of Phragmites australis (common reed) for heavy metals phytoremediation of estuarine sediments.

Science.gov (United States)

Cicero-Fernández, Diego; Peña-Fernández, Manuel; Expósito-Camargo, Jose A; Antizar-Ladislao, Blanca

2016-01-01

The ability of Phragmites australis to take up heavy metals (Co, Ni, Mo, Cd, Pb, Cr, Cu, Fe, Mn, Zn, and Hg) and other trace elements (As, Se, Ba), from estuarine sediments was investigated using a pilot plant experimental approach. Bioaccumulation (BCF) and translocation factors (TF) were calculated in vegetative and senescence periods for two populations of P. australis, from contaminated (MIC) and non-contaminated (GAL) estuarine sediments, respectively, both growing in estuarine contaminated sediment (RIA) from ría del Carmen y Boo, Santander Bay, Spain. The highest BCF values were obtained for Ni (0.43), Ba (0.43) Mo (0.36), Cr (0.35), and Cd (0.31) for plants collected from site GAL following the senescence period. The highest BCF values recorded for plants collected from MIC following the senescence period were for Mo (0.22) and Cu (0.22). Following senescence, plants collected from GAL and MIC presented TF>1 for Ni, Mo, Se, and Zn, and in addition plants collected from MIC presented TF>1 for Ba, Cr, and Mn. A substantial increase of Micedo's rhizosphere, six times higher than Galizano's rhizosphere, suggested adaptation to contaminated sediment. The evaluated communities of P. australis demonstrated their suitability for phytoremediation of heavy metals contaminated estuarine sediments.

Genital morphology of the male South American fur seal (Arctocephalus australis and biological implications

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Alex Sander D. Machado

2012-12-01

Full Text Available Male capacity for spreading genes to a great number of descendents and to determine population dynamics depend directly on the genital organs. Morphological studies in pinnipeds are scarce and the functional meaning of some characteristics has never been discussed. We hypothesized that Arctocephalus australis (A. australis shows morphophysiological adaptations in order to guarantee the perpetuation of the species in the unique annual mating season. Seven males, dead from natural causes, had their genital organs collected and fixed for morphological description. Some features differ from other described mammalian males and are closely related to the biology and reproductive cycle of this species, as the scrotal epidermis, absence of glandular portion in the ductus deferens and spermatogenic epithelium suggest a recrudescent testis period. The corona glandis exhibits a singular arrangement: its erectile border looks like a formation of petals and its association with the os penis gives a "lily-flower" form to this region. We propose the name margo petaliformis to this particular erectile border of the corona glandis because of its similarity to a flower corola. The male genital organs of A. australis show morphological features compatible with adaptation to environment requirements and reproductive efficiency.

Contamination of Soil with Pb and Sb at a Lead-Acid Battery Dumpsite and Their Potential Early Uptake by Phragmites australis

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Abraham Jera

2017-01-01

Full Text Available Recycling of spent Lead-Acid Batteries (LABs and disposal of process slag potentially contaminate soil with Pb and Sb. Total and available concentrations of Pb and Sb in three soil treatments and parts of Phragmites australis were determined by atomic absorption spectrophotometry. Soil with nonrecycled slag (NR had higher total metal concentrations than that with recycled slag (RS. Low available fractions of Pb and Sb were found in the soil treatments before planting P. australis. After 16 weeks of growth of P. australis, the available fractions of Pb had no statistical difference from initial values (p>0.05 while available Sb fractions were significantly lower when compared with their initial values (p<0.05. Metal transfer factors showed that P. australis poorly accumulate Pb and Sb in roots and very poorly translocate them to leaves after growing for 8 and 16 weeks. It may be a poor phytoextractor of Pb and Sb in metal-contaminated soil at least for the 16 weeks of its initial growth. However, the plant established itself on the metalliferous site where all vegetation had been destroyed. This could be useful for potential ecological restoration. The long-term phytoextraction potential of P. australis in such environments as LABs may need further investigation.

Temporal variations of potential fecundity of southern blue whiting (Micromesistius australis australis) in the Southeast Pacific

Science.gov (United States)

Flores, Andrés; Wiff, Rodrigo; Díaz, Eduardo; Carvajal, Bernardita

2017-08-01

Fecundity is a key aspect of fish species reproductive biology because it relates directly to total egg production. Yet, despite such importance, fecundity estimates are lacking or scarce for several fish species. The gravimetric method is the most-used one to estimate fecundity by essentially scaling up the oocyte density to the ovary weight. It is a relatively simple and precise technique, but also time consuming because it requires counting all oocytes in an ovary subsample. The auto-diametric method, on the other hand, is relatively new for estimating fecundity, representing a rapid alternative, because it requires only an estimation of mean oocyte density from mean oocyte diameter. Using the extensive database available from commercial fishery and design surveys for southern blue whiting Micromesistius australis australis in the Southeast Pacific, we compared estimates of fecundity using both gravimetric and auto-diametric methods. Temporal variations in potential fecundity from the auto-diametric method were evaluated using generalised linear models considering predictors from maternal characteristics such as female size, condition factor, oocyte size, and gonadosomatic index. A global and time-invariant auto-diametric equation was evaluated using a simulation procedure based on non-parametric bootstrap. Results indicated there were not significant differences regarding fecundity estimates between the gravimetric and auto-diametric method (p > 0.05). Simulation showed the application of a global equation is unbiased and sufficiently precise to estimate time-invariant fecundity of this species. Temporal variations on fecundity were explained by maternal characteristic, revealing signals of fecundity down-regulation. We discuss how oocyte size and nutritional condition (measured as condition factor) are one of the important factors determining fecundity. We highlighted also the relevance of choosing the appropriate sampling period to conduct maturity studies

The Effect of Artificial Mowing on the Competition of Phragmites australis and Spartina alterniflora in the Yangtze Estuary

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Yue Yuan

2017-01-01

Full Text Available Spartina alterniflora Loisel. is one of the most invasive species in the world. However, little is known about the role of artificial mowing in its invasiveness and competiveness. In this work, we studied the effect of mowing on its interspecific interactions with native species Phragmites australis (Cav. Trin ex Steud of the Yangtze Estuary, China. We calculated their relative neighbor effect (RNE index, effect of relative crowding (Dr index, and interaction strength (I index. The results showed that the RNE of Phragmites australis and Spartina alterniflora was 0.354 and 0.619, respectively, and they have competitive interactions. The mowing treatments can significantly influence the RNE of Phragmites australis and Spartina alterniflora on each other. Concretely, the RNE of Spartina alterniflora in the removal treatments was significantly higher than the value in the controls. But the RNE of Phragmites australis in the removal treatments was significantly lower than the value in the controls. Meanwhile, Dr of the two species on the targets was higher in the removal treatments than that in the controls, and the opposite was for I. We concluded that artificial mowing could promote the invasion of Spartina alterniflora by increasing its competitive performance compared with native species.

Incorporation of 2H-labelled cadaverines into the quinolizidine alkaloids in Baptisia australis

International Nuclear Information System (INIS)

Robins, D.J.; Sheldrake, G.N.

1988-01-01

The incorporation of 2 H-labelled cadaverines into the quinolizidine alkaloids, sparteine and N-methylcytisine, in Baptisia australis has been studied in order to gain more information about the formation of these alkaloids. (author)

Reproductive behavior in the squid Sepioteuthis australis from South Australia: interactions on the spawning grounds.

Science.gov (United States)

Jantzen, Troy M; Havenhand, Jon N

2003-06-01

Squid behavior is synonymous with distinctive body patterns, postures, and movements that constitute a complex visual communication system. These communications are particularly obvious during reproduction. They are important for sexual selection and have been identified as a potential means of species differentiation. Here we present a detailed account of copulation, mating, and egg deposition behaviors from in situ observations of the squid Sepioteuthis australis from South Australia. We identified four mating types from 85 separate mating attempts: "Male-upturned mating" (64% of mating attempts); "Sneaker mating" (33%); "Male-parallel" (2%); and "Head-to-head" (1%). Intervals between successive egg deposition behaviors were clearly bimodal, with modes at 2.5 s and 70.0 s. Ninety-three percent of egg capsules contained 3 or 4 eggs (mean = 3.54), and each egg cluster contained between 218 and 1922 egg capsules (mean = 893.9). The reproductive behavior of S. australis from South Australia was different from that described for other cephalopod species. More importantly, comparison between these results and those for other populations of S. australis suggests that behavior may differ from one population to another.

Isolation and amino acid sequence of a short-chain neurotoxin from an Australian elapid snake, Pseudechis australis.

OpenAIRE

Takasaki, C; Tamiya, N

1985-01-01

A short-chain neurotoxin Pseudechis australis a (toxin Pa a) was isolated from the venom of an Australian elapid snake Pseudechis australis (king brown snake) by sequential chromatography on CM-cellulose, Sephadex G-50 and CM-cellulose columns. Toxin Pa a has an LD50 (intravenous) value of 76 micrograms/kg body wt. in mice and consists of 62 amino acid residues. The amino acid sequence of Pa a shows considerable homology with those of short-chain neurotoxins of elapid snakes, especially of tr...

Warm gas towards young stellar objects in Corona Australis

DEFF Research Database (Denmark)

Lindberg, Johan; Jørgensen, Jes Kristian; D. Green, Joel

2014-01-01

The effects of external irradiation on the chemistry and physics in the protostellar envelope around low-mass young stellar objects are poorly understood. The Corona Australis star-forming region contains the R CrA dark cloud, comprising several low-mass protostellar cores irradiated by an interm......The effects of external irradiation on the chemistry and physics in the protostellar envelope around low-mass young stellar objects are poorly understood. The Corona Australis star-forming region contains the R CrA dark cloud, comprising several low-mass protostellar cores irradiated...... by an intermediate-mass young star. We study the effects on the warm gas and dust in a group of low-mass young stellar objects from the irradiation by the young luminous Herbig Be star R CrA. Herschel/PACS far-infrared datacubes of two low-mass star-forming regions in the R CrA dark cloud are presented...... Be star R CrA. Our results show that a nearby luminous star does not increase the molecular excitation temperatures in the warm gas around a young stellar object (YSO). However, the emission from photodissociation products of H2O, such as OH and O, is enhanced in the warm gas associated...

Seasonal changes of metal accumulation and distribution in common club rush (Schoenoplectus lacustris) and common reed (Phragmites australis).

Science.gov (United States)

Duman, Fatih; Cicek, Mehmet; Sezen, Goksal

2007-08-01

In this study, two aquatic macrophytes Phragmites australis and Schoenoplectus lacustris and corresponding sediment samples were collected every three months from Lake Sapanca (Turkey) and analysed for their heavy-metal contents (Pb, Cr, Cu, Mn, Ni, Zn and Cd). Accumulation factor ratios of plant parts were calculated for all metals, and the two species were compared in terms of accumulation properties. The highest concentrations were measured in the root systems while relatively low concentrations were found in the rhizome and above-ground parts of the plants. The accumulation ratios of root for P. australis were usually higher than the ratios for S. lacustris. While the accumulation ratios of root were higher in winter than in the other seasons for P. australis, for S. lacustris the highest accumulation ratios were found in the autumn. Both plant species were found to be root accumulators of Pb, Cu, Mn, Ni, Zn and Cd.

Water and Energy Balance in Response to the Removal of Invasive Phragmites Australis in a Riparian Wetland

Science.gov (United States)

Mykleby, P.; Lenters, J. D.; Cutrell, G. J.; Herrman, K.; Istanbulluoglu, E.; Scott, D.

2011-12-01

Vegetation plays an important role in the surface energy and water balance of wetlands. Transpiration from phreatophytes, in particular, withdraws water directly from groundwater, often impacting streamflow rates in adjacent tributaries. In the Republican River basin of the Central Plains (USA), streamflow has declined significantly in the past 30-40 years. Invasive vegetation species (such as Phragmites australis) have been removed from portions of the riparian corridor in an effort to halt or reverse the downward trend in streamflow. In this study, we investigated the energy and water balance of a P. australis-dominated riparian wetland in south-central Nebraska to assess the potential effectiveness of such an approach. Evapotranspiration (ET) rates were measured during two growing seasons - one being 2009, when the P. australis was at full growth, and the other during 2010, after the vegetation had been sprayed with herbicide (and remained only as dead, standing biomass). Energy balance measurements at the field site included net radiation, heat storage rates in the canopy, soil, and standing water, and sensible heat flux, which was measured using a large-aperture scintillometer (LAS). Latent heat flux (i.e., ET) was calculated as a residual of the energy balance, and comparisons were made between the two growing seasons. As a result of the spraying of the P. australis vegetation, season-mean ET rates dropped from 4.4 mm day-1 in 2009 to 3.0 mm day-1 in 2010. This decrease in ET was associated with a large increase in sensible heat flux, which more than doubled between the two years (from 33 W m-2 in 2009 to 76 W m-2 in 2010). Meteorological conditions at the site were slightly different from one year to the next, but the differences were not large enough to account for the dramatic changes in latent and sensible heat flux that were observed. We conclude, therefore, that the majority of the ~30% decrease in ET (and ~130% increase in sensible heat flux) was the

Phragmites australis + Typha latifolia Community Enhanced the Enrichment of Nitrogen and Phosphorus in the Soil of Qin Lake Wetland

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Zhiwei Ge

2017-01-01

Full Text Available Aquatic plants play an essential role and are effective in mitigating lake eutrophication by forming complex plant-soil system and retaining total nitrogen (TN and phosphorus (TP in soils to ultimately reduce their quantities in aquatic systems. Two main vegetation types (Phragmites australis community and P. australis + Typha latifolia community of Qin Lake wetland were sampled in this study for the analysis of TN and TP contents and reserves in the wetland soils. The results showed that (1 the consumption effect of Qin Lake wetland on soluble N was much more significant than on soluble P. (2 The efficiency of TN enrichment in wetland soil was enhanced by vegetation covering of P. australis and T. latifolia. (3 Wetland soil P was consumed by P. australis community and this pattern was relieved with the introduction of T. latifolia. (4 According to the grey relativity analysis, the most intensive interaction between plants and soil occurred in summer. In addition, the exchange of N in soil-vegetation system primarily occurred in the 0–15 cm soil layer. Our results indicated that vegetation covering was essential to the enrichment of TN and TP, referring to the biology-related fixation in the wetland soil.

Assessment of the antiproliferative and antigenotoxic activity and phytochemical screening of aqueous extracts of Sambucus australis Cham. & Schltdl. (ADOXACEAE).

Science.gov (United States)

Tedesco, Marília; Kuhn, Andrielle W; Frescura, Viviane Dal-Souto; Boligon, Aline A; Athayde, Margareth L; Tedesco, Solange B; Silva, Antonio C F DA

2017-01-01

The purpose of this study was to evaluate the antiproliferative and antigenotoxic activity of Sambucus australis Cham. & Schltdl. aqueous extracts on the cell cycle of Allium cepa L. as well as determine the phenolic compounds in such extracts. S. australis inflorescences and leaves of two accessions were used for aqueous extract preparation at concentrations: 0.003 g/ml and 0.012 g/ml. A. cepa bulbs were rooted in distilled water and, subsequently, placed in treatments for 24 hours. Rootlets were collected and fixed in modified Carnoy's solution for 24 hours and kept. The squash technique was performed for slide preparation. Root tips were smashed and stained with 2% acetic orcein, and a total of 4000 cells per treatment were analyzed. The phenolic compounds were determined using high-performance liquid chromatography and data was analyzed using the Scott-Knott test. The results show that S. australis aqueous extracts have antiproliferative potential. Besides, the extracts prepared from S. australis leaves of both accessions at a concentration of 0.012 g/ml have shown antigenotoxic activity. The phytochemical analysis allowed us to determine the presence of flavonoids and phenolic acids, of which kaempferol and chrologenic acid were the most predominant compounds in the extracts from the inflorescences and leaves, respectively.

Xe CONGRES INTERNATIONAL SUR LE COLZA Développement et impacts des OGM

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Chevre Anne-Marie

2000-01-01

Full Text Available Le dernier congrès du Groupe consultatif international de recherches sur le colza s’est déroulé à Canberra (Australie du 26 septembre au 1er octobre 1999. Pour sa dixième édition, cette manifestation, quadriennale, a réuni plus de 600 participants originaires de 28 pays. La délégation australienne mise en part (35 % des participants, le Canada (15 % et l’Allemagne (14 % étaient les pays producteurs les mieux representés suivis de la Grande-Bretagne (6 %, de la France (6 % et de la Chine (5 %. Résumé en chiffre, le contenu scientifique de ces journées a été apporté par 550 présentations de résultats sous forme d’exposés (166 et de posters (384. Parmi les différents thèmes développés, le thème « amélioration des plantes et biotechnologies » a occupé en nombre d’interventions, à peu près la moitié du congrès (44 %. Les notes suivantes reviennent sur les aspects significatifs de ces présentations. Elles seront suivies dans une prochaine livraison des comptes rendus des thèmes « agronomie », « protection des cultures » et « nutrition ». (Les références au sein des articles renvoient aux textes du CDrom du colloque disponible auprès du Dr Rodney Mailer  : mailerr@agric.nsw.gov.au

Genital morphology of the male South American fur seal (Arctocephalus australis and biological implications Morfologia dos órgãos genitais do macho do Lobo marinho (Arctocephalus australis e implicações biológicas

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Alex Sander D. Machado

2012-12-01

Full Text Available Male capacity for spreading genes to a great number of descendents and to determine population dynamics depend directly on the genital organs. Morphological studies in pinnipeds are scarce and the functional meaning of some characteristics has never been discussed. We hypothesized that Arctocephalus australis (A. australis shows morphophysiological adaptations in order to guarantee the perpetuation of the species in the unique annual mating season. Seven males, dead from natural causes, had their genital organs collected and fixed for morphological description. Some features differ from other described mammalian males and are closely related to the biology and reproductive cycle of this species, as the scrotal epidermis, absence of glandular portion in the ductus deferens and spermatogenic epithelium suggest a recrudescent testis period. The corona glandis exhibits a singular arrangement: its erectile border looks like a formation of petals and its association with the os penis gives a "lily-flower" form to this region. We propose the name margo petaliformis to this particular erectile border of the corona glandis because of its similarity to a flower corola. The male genital organs of A. australis show morphological features compatible with adaptation to environment requirements and reproductive efficiency.A capacidade do macho de espalhar seus genes a um grande número de descendentes e determinar a dinâmica populacional depende diretamente dos seus órgãos genitais. Estudos morfológicos em pinípedes são escassos e o significado funcional de algumas de suas características ecológicas ainda foi pouco discutido. Nossa hipótese é que Arctocephalus australis (A. australis apresenta adaptações morfofisiológicas em seus órgãos genitais capazes de interagir com o meio e garantir a perpetuação da espécie que apresenta apenas uma época de acasalamento que ocorre uma vez a cada ano. Sete A. australis machos, mortos recentes por causas

Skull morphometrics of adult male Antartic fur seal, Arctocephalus gazella, and South American fur seal A. australis Morfometría craneana comparada de ejemplares machos adultos de lobo fino antártico, Arctocephalus gazella y lobo fino sudamericano, A. australis

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Gustavo A. Daneri

2005-09-01

Full Text Available The skull morphometrics of adult male Antarctic fur seal, Arctocephalus gazella (Peters, 1875 and South American fur seal, A. australis (Zimmermann, 1783 were investigated using a collection of 45 and 38 skulls, respectively. Eighteen measurements were taken for each specimen. Comparative univariate and multivariate statistical analyses included standard statistics, one-way analysis of variance, principal component analysis and discriminant analysis. Individual variation was relatively high for some variables, as expressed by the coefficient of variation. Skulls of A. gazella were larger than those of A. australis for all but two variables: squamosal jugal suture and rostral length. Both species differed significantly as shown by both univariate and multivariate analyses. The discriminant function correctly classified all specimens. The standardized canonical coefficients showed that the variables which most contribute to the differentiation between species were, in decreasing order, the rostral length, palatal length, palatal width at postcanine 5 and braincase width. The present study corroborates that A. gazella and A. australis are phenotipically distinct species.Se estudió la morfometría craneana de especímenes machos adultos de lobo fino Antártico, Arctocephalus gazella (Peters, 1875 y lobo fino sudamericano, A. australis (Zimmermann, 1783, consultando una colección de 45 y 38 cráneos respectivamente. Para cada ejemplar se tomó un total de 18 medidas. El análisis comparativo univariado y multivariado incluyó estadística standard, análisis de varianza, análisis de componentes principales y análisis discriminante. La variación individual, según lo expresado por el coeficiente de variación, fue relativamente alta para algunas variables. Los cráneos de A. gazella fueron proporcionalmente más grandes que aquellos de A. australis para todas las variables estudiadas, excepto dos: longitud de la sutura escamoso-yugal y longitud

Taxonomy Icon Data: North Pacific right whale [Taxonomy Icon

Lifescience Database Archive (English)

Full Text Available North Pacific right whale Eubalaena japonica Chordata/Vertebrata/Mammalia/Theria/Eu...theria/Cetacea Eubalaena_japonica_L.png Eubalaena_japonica_NL.png Eubalaena_japonica_S.png Eubalaena_japonic...a_NS.png http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Eubalaena+japonica&t=L http://biosciencedbc.jp/tax...onomy_icon/icon.cgi?i=Eubalaena+japonica&t=NL http://biosciencedbc.jp/taxonomy_ic...on/icon.cgi?i=Eubalaena+japonica&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Eubalaena+japonica&t=NS ...

Primary structure of the oligosaccharide moiety of hemocyanin from the scorpion Androctonus australis

NARCIS (Netherlands)

Vliegenthart, J.F.G.; Debeire, P.; Montreuil, J.; Goyffon, M.; Kuik, J.A. van; Halbeek, H. van

1986-01-01

Hemocyanin, the copper-containing glycoprotein that serves as an oxygen carrier in the hemolymph of some arthropods and molluscs, was obtained from the blood of the scorpion Androctonus australis. Sugar analysis of the glycoprotein revealed that its carbohydrate moiety is of the N-glycosylic type.

Decomposition processes in soil of a healthy and a declining Phragmites australis stand

Czech Academy of Sciences Publication Activity Database

Šantrůčková, Hana; Picek, Tomáš; Šimek, Miloslav; Bauer, Václav; Kopecký, Jiří; Pechar, Libor; Lukavská, Jaroslava; Čížková, Hana

2001-01-01

Roč. 69, - (2001), s. 217-234 ISSN 0304-3770 R&D Projects: GA ČR GA206/96/0589 Institutional research plan: CEZ:AV0Z6066911 Keywords : decomposition * eutrophication * Phragmites australis Subject RIV: EH - Ecology, Behaviour Impact factor: 1.361, year: 2001

Aphid (Myzus persicae) feeding on the parasitic plant dodder (Cuscuta australis) activates defense responses in both the parasite and soybean host.

Science.gov (United States)

Zhuang, Huifu; Li, Juan; Song, Juan; Hettenhausen, Christian; Schuman, Meredith C; Sun, Guiling; Zhang, Cuiping; Li, Jing; Song, Dunlun; Wu, Jianqiang

2018-06-01

Dodders (Cuscuta spp.) are shoot holoparasites, whose haustoria penetrate host tissues to enable fusion between the parasite and host vascular systems, allowing Cuscuta to extract water, nutrients and other molecules from hosts. Aphids are piercing-sucking herbivores that use specialized stylets to feed on phloem sap. Aphids are known to feed on Cuscuta, but how Cuscuta and its host plant respond to aphids attacking the parasite was unknown. Phytohormone quantification, transcriptomic analysis and bioassays were performed to determine the responses of Cuscuta australis and its soybean (Glycine max) hosts to the feeding of green peach aphid (GPA; Myzus persicae) on C. australis. Decreased salicylic acid levels and 172 differentially expressed genes (DEGs) were found in GPA-attacked C. australis, and the soybean hosts exhibited increased jasmonic acid contents and 1015 DEGs, including > 100 transcription factor genes. Importantly, GPA feeding on C. australis increased the resistance of the soybean host to subsequent feeding by the leafworm Spodoptera litura and soybean aphid Aphis glycines, resulting in 21% decreased leafworm mass and 41% reduced aphid survival rate. These data strongly suggest that GPA feeding on Cuscuta induces a systemic signal, which is translocated to hosts and activates defense against herbivores. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

Chonopeltis australis (Crustacea) male reproductive system morphology; sperm transfer and review of reproduction in Branchiura.

Science.gov (United States)

Neethling, Lourelle Alicia Martins; Avenant-Oldewage, Annemariè

2015-02-01

The morphology of the male reproductive system as well as sperm transfer in Branchiura has been described for Dolops ranarum and Argulus japonicus. In this study, the reproductive system and accessory structures are described for male Chonopeltis australis using histology, light microscopy, and scanning electron microscopy. For the first time, we describe sperm transfer by means of a spermatophore in this genus. The internal and external morphology and mechanism of sperm transfer is compared with other Branchiura, where it has been described. The morphology of the reproductive system of C. australis is similar to that of D. ranarum while the accessory structures and the spermatophore produced are similar to that of A. japonicus. A revision of the definition of Branchiura with respect to reproduction is provided. © 2014 Wiley Periodicals, Inc.

Effects of sediment burial disturbance on macro and microelement dynamics in decomposing litter of Phragmites australis in the coastal marsh of the Yellow River estuary, China.

Science.gov (United States)

Sun, Zhigao; Mou, Xiaojie

2016-03-01

From April 2008 to November 2009, a field decomposition experiment was conducted to investigate the effects of sediment burial on macro (C, N) and microelement (Pb, Cr, Cu, Zn, Ni, and Mn) variations in decomposing litter of Phragmites australis in the coastal marsh of the Yellow River estuary. Three one-off sediment burial treatments [no sediment burial (0 mm year(-1), S0), current sediment burial (100 mm year(-1), S10), and strong sediment burial (200 mm year(-1), S20)] were laid in different decomposition sites. Results showed that sediment burials showed significant influence on the decomposition rate of P. australis, in the order of S10 (0.001990 day(-1)) ≈ S20 (0.001710 day(-1)) > S0 (0.000768 day(-1)) (p macro and microelement in decomposing litters of the three burial depths exhibited different temporal variations except for Cu, Zn, and Ni. No significant differences in C, N, Pb, Cr, Zn, and Mn concentrations were observed among the three burial treatments except for Cu and Ni (p > 0.05). With increasing burial depth, N, Cr, Cu, Ni, and Mn concentrations generally increased, while C, Pb, and Zn concentrations varied insignificantly. Sediment burial was favorable for C and N release from P. australis, and, with increasing burial depth, the C release from litter significantly increased, and the N in litter shifted from accumulation to release. With a few exceptions, Pb, Cr, Zn, and Mn stocks in P. australis in the three treatments evidenced the export of metals from litter to environment, and, with increasing burial depth, the export amounts increased greatly. Stocks of Cu and Ni in P. australis in the S10 and S20 treatments were generally positive, evidencing incorporation of the two metals in most sampling times. Except for Ni, the variations of C, N, Pb, Cr, Cu, Zn, and Mn stocks in P. australis in the S10 and S20 treatments were approximated, indicating that the strong burial episodes (S20) occurred in P. australis marsh in the future

Allelopathy and resource competition: the effects of Phragmites australis invasion in plant communities.

Science.gov (United States)

Uddin, Md Nazim; Robinson, Randall William

2017-12-01

Phragmites australis, a ubiquitous wetland plant, has been considered one of the most invasive species in the world. Allelopathy appears to be one of the invasion mechanisms, however, the effects could be masked by resource competition among target plants. The difficulty of distinguishing allelopathy from resource competition among plants has hindered investigations of the role of phytotoxic allelochemicals in plant communities. This has been addressed via experiments conducted in both the greenhouse and laboratory by growing associated plants, Melaleuca ericifolia, Rumex conglomeratus, and model plant, Lactuca sativa at varying densities with the allelopathic plant, P. australis, its litter and leachate of P. australis litter. This study investigated the potential interacting influences of allelopathy and resource competition on plant growth-density relationships. In greenhouse, the root exudates mediated effects showed the strongest growth inhibition of M. ericifolia at high density whereas litter mediated results revealed increased growth at medium density treatments compared to low and high density. Again, laboratory experiments related to seed germination and seedling growth of L. sativa and R. conglomeratus exhibited phytotoxicity decreased showing positive growth as plant density increased and vice versa. Overall, the differential effects were observed among experiments but maximum individual plant biomass and some other positive effects on plant traits such as root and shoot length, chlorophyll content occurred at an intermediate density. This was attributed to the sharing of the available phytotoxin among plants at high densities which is compatible to density-dependent phytotoxicity model. The results demonstrated that plant-plant interference is the combined effect of allelopathy and resource competition with many other factors but this experimental design, target-neighbor mixed-culture in combination of plant grown at varying densities with varying

Effect of gamma irradiation on toxicity and immunogenicity of Androctonus australis hector venom

International Nuclear Information System (INIS)

Abib, L.; Laraba-Djebari, F.

2003-01-01

An investigation was made of the radiosensitivity of the toxic and immunological properties of Androctonus australis hector venom. This venom was irradiated with two doses of gamma rays (1 and 2 kGy) from a 60 Co source. The results showed that venom toxicity was abolished for the two radiation doses (1 and 2 kGy) with, respectively, 10 and 25 times its initial LD50 value. However, irradiated venoms were immunogenic, and the antibodies elicited by them were able to recognize the native venom by enzyme-linked immunosorbent assay. Antisera raised against these toxoids (1 and 2 kGy) had a higher neutralizing capacity and immunoreactivity against all components of native venom than did the antiserum produced against the native venom. The antiserum of rabbits immunized with 2-kGy-irradiated venom was more efficient than 1-kGy-irradiated toxoid antiserum. Indeed, in vivo protection assays showed that the mice immunized with 2-kGy-irradiated venom resisted lethal doses (i.p.) of A. australis hector venom. (author)

Discovery of a new subclass of alpha-conotoxins in the venom of Conus australis

Digital Repository Service at National Institute of Oceanography (India)

Lebbe, E; Peigneur, S.; Maiti, M.; Mille, B.G.; Prabhadevi; Ravichandran, S.; Lescrinier, E; Waelkens, E; DeSouza, L.; Herdewijn, P.; Tytgat, J.

-conotoxin family. We purified the venom of a yet unexplored cone snail species, i.e. Conus australis, and we isolated a 16-amino acid peptide named alpha-conotoxin AusIA. The peptide has the typical alpha-conotoxin CC-X_m-C-X_n-C framework...

Phytoextraction of chloride from a cement kiln dust (CKD) contaminated landfill with Phragmites australis.

Science.gov (United States)

McSorley, Kaitlin; Rutter, Allison; Cumming, Robert; Zeeb, Barbara A

2016-05-01

Cement kiln dust (CKD) is a globally produced by-product from cement manufacturing that is stockpiled or landfilled. Elevated concentrations of chloride pose toxic threats to plants and aquatic communities, as the anion is highly mobile in water and can leach into surrounding water sources. Re-vegetation and in situ phytoextraction of chloride from a CKD landfill in Bath, ON, Canada, was investigated with the resident invasive species Phragmites australis (haplotype M). Existing stands of P. australis were transplanted from the perimeter of the site into the highest areas of contamination (5.9×10(3)μg/g). Accumulation in the shoots of P. australis was quantified over one growing season by collecting samples from the site on a bi-weekly basis and analyzing for chloride. Concentrations decreased significantly from early May (24±2.2×10(3)μg/g) until mid-June (15±2.5×10(3)μg/g), and then remained stable from June to August. Shoot chloride accumulation was not significantly affected by water level fluctuations at the site, however elevated potassium concentrations in the soil may have contributed to uptake. Based on shoot chloride accumulation and total biomass, it was determined that phytoextraction from the CKD landfill can remove 65±4kg/km(2) of chloride per season. Based on this extraction rate, removal of chloride present in the highly contaminated top 10cm of soil can be achieved in 3-9years. This is the first study to apply phytotechnologies at a CKD landfill, and to successfully demonstrate in situ phytoextraction of chloride. Copyright © 2015 Elsevier Ltd. All rights reserved.

Bioavailability of cadmium adsorbed on various oxides minerals to wetland plant species Phragmites australis

International Nuclear Information System (INIS)

Wang He; Jia Yongfeng; Wang Shaofeng; Zhu Huijie; Wu Xing

2009-01-01

The bioavailability of heavy metals strongly depends on their speciation in the environment. The effect of different chemical speciations of cadmium ions (i.e. adsorbed on different oxide minerals) on its bioavailability to wetland plant Phragmites australis was studied. Goethite, magnetite, gibbsite, alumina, and manganese oxide were chosen as representatives of metal (hydr)oxides commonly present in sediment. The cultivar system with Hoagland solution as nutrition supply, and single metal oxide with adsorbed Cd as contaminant was applied to study Cd accumulation by P. australis. The bioaccumulation degree in root after the 45-day treatment followed the order: Al(OH) 3 > Al 2 O 3 > Fe 3 O 4 > MnO 2 > FeOOH. The concentration of Cd in stem and leaf followed a similar order although it was considerably lower than that in root. Low-molecular-weight organic acids (LMWOAs), acetic acid, malic acid and citric acid were used to evaluate the desorbability of Cd from different oxides, which can be indicative of Cd-oxide bonding strength and Cd bioavailability. Desorption of Cd by acetic acid and malic acid followed the order: Al(OH) 3 > Fe 3 O 4 > Al 2 O 3 > FeOOH > MnO 2 , while by citric acid: Al(OH) 3 ≥ Al 2 O 3 > Fe 3 O 4 > FeOOH > MnO 2 . This was consistent with the Cd accumulation degree in the plant. Cd adsorbed on Al(OH) 3 was the most easily desorbable species and most bioavailable to P. australis among the oxide minerals, whereas MnO 2 adsorbed Cd was least desorbable by LMWOAs hence constituted the least bioavailable Cd species adsorbed on the oxide minerals.

Effects of arbuscular mycorrhizal fungi and soil nutrient addition on the growth of Phragmites australis under different drying-rewetting cycles.

Science.gov (United States)

Liang, Jin-Feng; An, Jing; Gao, Jun-Qin; Zhang, Xiao-Ya; Yu, Fei-Hai

2018-01-01

The frequency of soil drying-rewetting cycles is predicted to increase under future global climate change, and arbuscular mycorrhizal fungi (AMF) are symbiotic with most plants. However, it remains unknown how AMF affect plant growth under different frequencies of soil drying-rewetting cycles. We subjected a clonal wetland plant Phragmites australis to three frequencies of drying-rewetting cycles (1, 2, or 4 cycles), two nutrient treatments (with or without), and two AMF treatments (with or without) for 64 days. AMF promoted the growth of P. australis, especially in the 2 cycles of the drying-rewetting treatment. AMF had a significant positive effect on leaf mass and number of ramets in the 2 cycles of the drying-rewetting treatment with nutrient addition. In the 2 cycles of drying-rewetting treatment without nutrient addition, AMF increased leaf area and decreased belowground to aboveground biomass ratio. These results indicate that AMF may assist P. australis in coping with medium frequency of drying-rewetting cycles, and provide theoretical guidance for predicting how wetland plants respond to future global climate change.

Non-linear growth in tree ferns, Dicksonia antarctica and Cyathea australis

OpenAIRE

Blair, David P.; Blanchard, Wade; Banks, Sam C.; Lindenmayer, David B.

2017-01-01

Tree ferns are an important structural component of forests in many countries. However, because their regeneration is often unrelated to major disturbances, their age is often difficult to determine. In addition, rates of growth may not be uniform, which further complicates attempts to determine their age. In this study, we measured 5 years of growth of Cyathea australis and Dicksonia antarctica after a large wildfire in 2009 in south-eastern Australia. We found growth rates of these two spec...

Removal of Cu, Zn, Pb, and Cr from Yangtze Estuary Using the Phragmites australis Artificial Floating Wetlands

Directory of Open Access Journals (Sweden)

Xiaofeng Huang

2017-01-01

Full Text Available Contamination of heavy metals would threaten the water and soil resources; phytoremediation can be potentially used to remediate metal contaminated sites. We constructed the Phragmites australis artificial floating wetlands outside the Qingcaosha Reservoir in the Yangtze Estuary. Water characteristic variables were measured in situ by using YSI Professional Pro Meter. Four heavy metals (copper, zinc, lead, and chromium in both water and plant tissues were determined. Four heavy metals in estuary water were as follows: 0.03 mg/Kg, 0.016 mg/Kg, 0.0015 mg/Kg, and 0.004 mg/Kg. These heavy metals were largely retained in the belowground tissues of P. australis. The bioaccumulation (BAF and translation factor (TF value of four heavy metals were affected by the salinity, temperature, and dissolved oxygen. The highest BAF of each metal calculated was as follows: Cr (0.091 in winter > Cu (0.054 in autumn > Pb (0.016 in summer > Zn (0.011 in summer. Highest root-rhizome TF values were recorded for four metals: 6.450 for Cu in autumn, 2.895 for Zn in summer, 7.031 for Pb in autumn, and 2.012 for Cr in autumn. This indicates that the P. australis AFW has potential to be used to protect the water of Qingcaosha Reservoir from heavy metal contamination.

Effect of Plantago australis leaves on different gastric ulcer models

Directory of Open Access Journals (Sweden)

M.E. Bürger

Full Text Available The anti-ulcerogenic effect of the crude ethanolic extract (CEE of Plantago australis leaves was tested against ethanol-, indomethacin-, and cold restrain-induced stress ulcers. The CEE (500 and 1000 mg/kg reduced the lesion index (LI and the ulcer index in ethanol-induced ulcers, and the dose of 1000 mg/kg increased the amount of mucous. The highest dose of the CEE reduced the LI of cold restraint-induced stress ulcers when compared to the control group. The indomethacin-induced ulcers were not affected by this extract.

[Effects of water table manipulation on leaf photosynthesis, morphology and growth of Phragmites australis and Imperata cylindrica in the reclaimed tidal wetland at Dongtan of Chongming Island, China].

Science.gov (United States)

Zhong, Qi-Cheng; Wang, Jiang-Tao; Zhou, Jian-Hong; Ou, Qiang; Wang, Kai-Yun

2014-02-01

During the growing season of 2011, the leaf photosynthesis, morphological and growth traits of Phragmites australis and Imperata cylindrica were investigated along a gradient of water table (low, medium and high) in the reclaimed tidal wetland at the Dongtan of Chongming Island in the Yangtze Estuary of China. A series of soil factors, i. e., soil temperature, moisture, salinity and inorganic nitrogen content, were also measured. During the peak growing season, leaf photosynthetic capacity of P. australis in the wetland with high water table was significantly lower than those in the wetland with low and medium water tables, and no difference was observed in leaf photosynthetic capacity of I. cylindrica at the three water tables. During the entire growing season, at the shoot level, the morphological and growth traits of P. australis got the optimum in the wetland with medium water table, but most of the morphological and growth traits of I. cylindrica had no significant differences at the three water tables. At the population level, the shoot density, leaf area index and aboveground biomass per unit area were the highest in the wetland with high water table for P. australis, but all of the three traits were the highest in the wetland with low water table for I. cylindrica. At the early growing season, the rhizome biomass of P. australis in the 0-20 cm soil layer had no difference at the three water tables, and the rhizome biomass of I. cylindrica in the 0-20 cm soil layer in the wetland with high water table was significantly lower than those in the wetland with low and medium water table. As a native hygrophyte before the reclamation, the variations of performances of P. australis at the three water tables were probably attributed to the differences in the soil factors as well as the intensity of competition from I. cylindrica. To appropriately manipulate water table in the reclaimed tidal wetland may restrict the growth and propagation of the mesophyte I

Bioavailability of cadmium adsorbed on various oxides minerals to wetland plant species Phragmites australis

Energy Technology Data Exchange (ETDEWEB)

Wang He, E-mail: he.wangworld@yahoo.com.cn [Key Laboratory of Terrestrial Ecological Process, Institute of Applied Ecology, Chinese Academy of Sciences, No. 72 Wenhua Road, Shenyang 110016 (China); Graduate School, Chinese Academy of Sciences, Beijing 100049 (China); Jia Yongfeng, E-mail: yongfeng.jia@iae.ac.cn [Key Laboratory of Terrestrial Ecological Process, Institute of Applied Ecology, Chinese Academy of Sciences, No. 72 Wenhua Road, Shenyang 110016 (China); Wang Shaofeng [Key Laboratory of Terrestrial Ecological Process, Institute of Applied Ecology, Chinese Academy of Sciences, No. 72 Wenhua Road, Shenyang 110016 (China); Zhu Huijie; Wu Xing [Key Laboratory of Terrestrial Ecological Process, Institute of Applied Ecology, Chinese Academy of Sciences, No. 72 Wenhua Road, Shenyang 110016 (China); Graduate School, Chinese Academy of Sciences, Beijing 100049 (China)

2009-08-15

The bioavailability of heavy metals strongly depends on their speciation in the environment. The effect of different chemical speciations of cadmium ions (i.e. adsorbed on different oxide minerals) on its bioavailability to wetland plant Phragmites australis was studied. Goethite, magnetite, gibbsite, alumina, and manganese oxide were chosen as representatives of metal (hydr)oxides commonly present in sediment. The cultivar system with Hoagland solution as nutrition supply, and single metal oxide with adsorbed Cd as contaminant was applied to study Cd accumulation by P. australis. The bioaccumulation degree in root after the 45-day treatment followed the order: Al(OH){sub 3} > Al{sub 2}O{sub 3} > Fe{sub 3}O{sub 4} > MnO{sub 2} > FeOOH. The concentration of Cd in stem and leaf followed a similar order although it was considerably lower than that in root. Low-molecular-weight organic acids (LMWOAs), acetic acid, malic acid and citric acid were used to evaluate the desorbability of Cd from different oxides, which can be indicative of Cd-oxide bonding strength and Cd bioavailability. Desorption of Cd by acetic acid and malic acid followed the order: Al(OH){sub 3} > Fe{sub 3}O{sub 4} > Al{sub 2}O{sub 3} > FeOOH > MnO{sub 2}, while by citric acid: Al(OH){sub 3} {>=} Al{sub 2}O{sub 3} > Fe{sub 3}O{sub 4} > FeOOH > MnO{sub 2}. This was consistent with the Cd accumulation degree in the plant. Cd adsorbed on Al(OH){sub 3} was the most easily desorbable species and most bioavailable to P. australis among the oxide minerals, whereas MnO{sub 2} adsorbed Cd was least desorbable by LMWOAs hence constituted the least bioavailable Cd species adsorbed on the oxide minerals.

Phytotoxic potential of celtis australis L. (family ulmaceae) against four crop species

International Nuclear Information System (INIS)

Ahmad, I.; Hussain, F.

2014-01-01

Bioassays were conducted to test the phytotoxic potential of Celtis australis against Trifolium alexandrinum, Brassica campestris, Triticum aestivum and Lactuca sativa under laboratory condition. Aqueous extracts from twigs and leaves were obtained by soaking 5 and 10g plant material in 100 ml distilled water for 24 and 48hr durations. Aqueous extracts significantly delayed/retarded the germination and reduced the plumule and radicle growth of all the four test species. Generally, extracts soaked for 48h especially 10 gm/100ml were inhibitory than 24h extracts of 5 or 10gm material. Extracts from twigs were inhibitory to germination of wheat while same extracts inhibited the plumule growth of B. campestris. Radicle growth of T. alexandrinum was inhibited more by twig extracts. Hot water extracts from twigs were less inhibitory than leaf extracts. Litter and mulch also significantly delayed the seed germination and retarded the overall growth of seedlings of all test species. The number and length of seminal roots of T. aestivum was suppressed by all aqueous extracts, added litter and mulch. The inhibitory response depended upon the test species, concentration, soaking duration and physiological parameters. The results suggested that Celtis australis has strong phytotoxic potential. (author)

Analyse de l'effet de la suréducation sur l'efficacité technique des ...

African Journals Online (AJOL)

de tire-au-flanc, et l'état de santé (Vroom 1964 ; Sheppard & Herrick 1972 ; ... impact négatif significatif de la suréducation sur la satisfaction au travail ; son ..... présence syndicale sur la performance financière de 250 entreprises américaines.

Varamiento de cetáceos en Tacna, Perú (2002-2010

Directory of Open Access Journals (Sweden)

José Pizarro-Neyra

2011-05-01

Full Text Available Se presentan datos de varamientos de cetáceos producidos entre abril del año 2002 y enero de 2010 en las localidades de Los Palos, Vila-vila, Morro Sama e Ite, ubicadas en la región Tacna. Los resultados indican que: 85% de los ejemplares varados corresponden a Phocoena spinipinnis, 8% a Tursiops truncatus, y el resto a cetáceos de las especies: Grampus griseus, Eubalaena australis y Physeter macrocephalus. Los varamientos de cetáceos grandes solo se observaron en Los Palos, mientras la mayor cantidad de varamientos observados se produjeron en Ite (80%. La causa del varamiento de algunas marsopas (P. spinipinnis es la captura incidental en redes usadas por la pesca artesanal. Se relaciona el varamiento de P. macrocephalus con anomalías de la temperatura superficial del mar.

Genetic and epigenetic diversity and structure of Phragmites australis from local habitats of the Songnen Prairie using amplified fragment length polymorphism markers.

Science.gov (United States)

Qiu, T; Jiang, L L; Yang, Y F

2016-08-19

The genetic and epigenetic diversity and structure of naturally occurring Phragmites australis populations occupying two different habitats on a small spatial scale in the Songnen Prairie in northeastern China were investigated by assessing amplified fragment length polymorphisms (AFLPs) and methylation-sensitive amplified polymorphisms (MSAPs) through fluorescent capillary detection. The two groups of P. australis were located in a seasonal waterlogged low-lying and alkalized meadow with a pH of 8-8.5 and in an alkaline patch without accumulated rainwater and with a pH greater than 10. These groups showed high levels of genetic diversity at the habitat level based on the percentage of polymorphic bands (90.32, 82.56%), Nei's gene diversity index (0.262, 0.248), and the Shannon diversity index (0.407, 0.383). Although little is known about the between-habitat genetic differentiation of P. australis on a small spatial scale, our results implied significant genetic differentiation between habitats. Extensive epigenetic diversity within habitats, along with clear differentiation, was found. Specifically, the former habitat (Habitat 1, designated H1) harbored higher levels of genetic and epigenetic diversity than the latter (Habitat 2, designated H2), and population-level diversity was also high. This study represents one of few attempts to predict habitat-based genetic differentiation of reeds on a small scale. These assessments of genetic and epigenetic variation are integral aspects of molecular ecological studies on P. australis. Possible causes for within- and between-habitat genetic and epigenetic variations are discussed.

Use of gamma irradiation as a quarantine control method for Frankliniella australis (Morgan) (Thysanoptera: Thripidae)

International Nuclear Information System (INIS)

Araya, J.E.; Curkovic, T.; Cayo, A.

2007-01-01

The black flower thrips, Frankliniella australis (Morgan), a Chilean species, causes quarantine rejections of fresh fruits for export. Today, fumigation with CH3Br is efficient to avoid these rejections, but is questioned because it affects the ozone layer, irradiation of foods being an alternative. The effect of gamma irradiation was studied in the laboratory on F. australis adults, at dosages of 250, 500, 750, and 1000 Gy, followed by storage at 0-5 deg C to simulate shipping conditions. Mortality immediately after irradiation was low (1.5 to 22.3% at 250 and 1000 Gy, respectively), but increased an hour later (15.8, 33.4, 44.5, and 51.7% with 250, 500, 750, and 1000 Gy, respectively). In this evaluation, mortality with the greatest dosage was significantly larger than with 500 and 250 Gy, while results with 750 and 500 Gy were not different between them but different with the smallest dosage. At 24 hours, mortality with all dosages surpassed 91%, although only that at 1000 Gy was significantly greater than at 250 Gy. At day 4th (96 hours) there was at least 98.8% mortality for the irradiation treatments, with significant differences with the control, which then presented only 12.8% mortality. Using logit regression with results up to day 4, a probit 9 (LD99.9968) for adults was estimated at 188 Gy. This dosage is slightly less to those indicated in the literature for control of other thrips, which may be explained because of the combined use of cold storage, although more studies are necessary of this technology under commercial conditions to verify its applicability for quarantine control of F. australis. (author) [es

La cooperación Sur-Sur agrícola argentina con África Subsahariana: una historia que comienza

OpenAIRE

Morasso, Carla

2015-01-01

[es] En la última década Argentina ha sido un actor dinámico de la cooperación Sur-Sur. Sus acciones se han dirigido principalmente hacia América Latina, pero también se han promovido los vínculos con Asia y África. El artículo analiza particularmente la cooperación Sur-Sur entre Argentina y países de África Subsahariana en materia de desarrollo agrícola en el período 2003-2013, donde se destacan los roles del Fondo Argentino de Cooperación Sur-Sur y Triangula...

DNA hybridization evidence for the Australasian affinity of the American marsupial Dromiciops australis.

OpenAIRE

Kirsch, J A; Dickerman, A W; Reig, O A; Springer, M S

1991-01-01

DNA hybridization was used to compare representatives of the major groups of marsupials and a eutherian outgroup. Because of the large genetic distances separating marsupial families, trees were calculated from normalized percentages of hybridization; thermal-melting statistics, however, gave identical topologies for the well-supported clades. The most notable results were the association of the only extant microbiotheriid, Dromiciops australis, an American marsupial, with the Australasian Di...

Isolation, cloning, and characterization of a partial novel aro A gene in common reed (Phragmites australis).

Science.gov (United States)

Taravat, Elham; Zebarjadi, Alireza; Kahrizi, Danial; Yari, Kheirollah

2015-05-01

Among the essential amino acids, phenylalanine, tryptophan, and tyrosine are aromatic amino acids which are synthesized by the shikimate pathway in plants and bacteria. Herbicide glyphosate can inhibit the biosynthesis of these amino acids. So, identification of the gene tolerant to glyphosate is very important. It has been shown that the common reed or Phragmites australis Cav. (Poaceae) is relatively tolerant to glyphosate. The aim of the current research is identification, cloning, sequencing, and registering of partial aro A gene of the common reed P. australis. The partial aro A gene of common reed (P. australis) was cloned in Escherichia coli and the amino acid sequence was identified/determined for the first time. This is the first report for isolation, cloning, and sequencing of a part of aro A gene from the common reed. A 670 bp fragment including two introns (86 bp and 289 bp) was obtained. The open reading frame (ORF) region in part of gene was encoded for 98 amino acids. Alignment showed high similarity among this region with Zea mays (L.) (Poaceae) (94.6%), Eleusine indica L. Gaertn (Poaceae) (94.2%), and Zoysia japonica Steud. (Poaceae) (94.2%). The alignment of amino acid sequence of the investigated part of the gene showed a homology with aro A from several other plants. This conserved region forms the enzyme active site. The alignment results of nucleotide and amino acid residues with related sequences showed that there are some differences among them. The relative glyphosate tolerance in the common reed may be related to these differences.

Unión del magreb, un caso de regionalismo Sur-Sur

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SofianE Bouhdiba

2009-01-01

Full Text Available Se exploran brevemente las fuerzas y limitaciones de la Unión del Magreb (UMA como una experiencia de regionalismo Sur-Sur, en el marco de mayor extensión. Se plantea la necesidad de que la UMA redireccione sus intereses, estrategias y alianzas hacia el sur, puesto que se ha vuelto un instrumento de intercambios comerciales con la Unión Europea y un eje estratégico de lucha contra el terrorismo para Estados Unidos. Además se invita a la misma UMA a que considere los alcances de instituciones de integración en América Latina y Asia a fin de fortalecerse como bloque.

Allelopathy and resource competition: the effects of Phragmites australis invasion in plant communities

OpenAIRE

Uddin, Md Nazim; Robinson, Randall William

2017-01-01

Background Phragmites australis, a ubiquitous wetland plant, has been considered one of the most invasive species in the world. Allelopathy appears to be one of the invasion mechanisms, however, the effects could be masked by resource competition among target plants. The difficulty of distinguishing allelopathy from resource competition among plants has hindered investigations of the role of phytotoxic allelochemicals in plant communities. This has been addressed via experiments conducted in ...

A sub-fossil kauri (Agathis australis) tree-ring chronology

International Nuclear Information System (INIS)

Bridge, M.C.; Ogden, J.

1986-01-01

A 491-year floating tree-ring chronology was constructed using sub-fossil bog kauris, Agathis australis, from a site near Huntly, North Island, New Zealand. The chronology has been approximately dated to within the period 3,500 B.P. to 3,000 B.P. by radiocarbon dating. This is the first sub-fossil New Zealand chronology, and shows the potential for the formation of a long chronology from the present back over several millenia. The applications of this chronology and its possible extensions include radiocarbon calibration for the Southern Hemisphere, and climatic reconstructions based on ring-widths. It will also assist interpretation of the history of the Waikato Valley over the last few millenia

BAROMETRIC PRESSURE and Other Data from AURORA AUSTRALIS and Other Platforms from 19910106 to 19920306 (NODC Accession 9500152)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Conductivity, Temperature and Depth (CTD) and other data were collected from Ship AURORA AUSTRALIS. The data was collected over a period spanning from January 6,...

Conditions for selective degradation of lignin by the fungus Ganoderma australis

Energy Technology Data Exchange (ETDEWEB)

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

1992-08-01

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

Tabla de vida y parámetros poblacionales de Lacertinella australis (Insecta-Hemiptera-Fulgoromorpha

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Maria F. ROSSI BATIZ

2016-01-01

Full Text Available Lacertinella australis ha sido capturada en 11 provincias de la Argentina y fue mencionada como una especie de interés fitosanitario por su potencial para vehiculizar fitopatógenos. Atendiendo al amplio rango de distribución, su potencial importancia fitosanitaria y el carácter invasivo de su principal planta hospedera, Cor - taderia spp., se evaluaron aspectos del ciclo de vida a través de una tabla de vida vertical bajo condiciones controladas en el laboratorio y se confeccionó una segunda tabla de vida sobre la base de un muestreo de una población natural. Se estimaron los atributos poblacionales: tasa reproductiva básica o tasa de reemplazo ( R 0 , tasa finita de crecimiento poblacional ( λ , capacidad de incremento poblacional ( r c , valor reproductivo ( V x , tiempo generacional de la cohorte ( T c y el promedio del tiempo de desarrollo por estadios. Se mencionan y comparan aspectos comportamentales y de la bionomía de L. australis compartidos con las dos especies de la tribu cuya biología se conoce: Saccharosydne procerus y Saccharosydne saccharivora.

Genetic variation within three populations of Phycella australis (Phil. Ravenna from Biobío Region, Chile, evaluated using ISSR markers

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Cristian Flores

2013-03-01

Full Text Available Phycella australis (Phil. Ravenna is a Chilean plant with high ornamental potential; however, the intensive extraction as a cut flower might be detrimental for the conservational state by ignoring the state of genetic variation. The objective of this investigation was to assess genetic variability within and between three populations of P. australis in the Biobío Region using inter-simple sequence repeat (ISSR markers. The evaluated areas correspond to three locations in the province of Concepción, Biobío Region: Desembocadura (36°48' S, 73°10' W, Santa Juana (36°58' S, 72°58' W, and Lipinhue (37°00' S, 72°58' W. Six ISSR primers were used obtaining 51 fragments, from which 72.5% were polymorphic. From the three evaluated sites Santa Juana showed a higher percentage of polymorphic loci (76.47%. From this variability, 83% belong to within population variability and only 17% belong to variability between populations. The dendrogram generated using the unweighted pair group method with arithmetic mean (UPGMA method, grouped Lipinhue and Santa Juana sites together, which agrees with the geographic locations. This investigation proved that P. australis has high genetic variability despite the exploitation for economic purposes.

Quantification of environment-driven changes in epiphytic macroinvertebrate communities associated to Phragmites australis

OpenAIRE

Miguel CAÑEDO-ARGÜELLES; Maria RIERADEVALL

2009-01-01

The epiphytic macroinvertebrate communities associated with the Common Reed, Phragmites australis (Cav.) Trin. ex Steudel, were examined seasonally from summer 2004 to spring 2005 in eleven coastal lagoons of the Llobregat Delta (NE Spain) following the method proposed by Kornijów & Kairesalo (1994). The aims of the study were to: 1) characterise and quantify changes in epiphytic macroinvertebrate communities along environmental gradients; 2) assess the contribution of elements of the epi...

A sulphated flavone glycoside from Livistona australis and its antioxidant and cytotoxic activity.

Science.gov (United States)

Kassem, Mona E S; Shoela, Soha; Marzouk, Mona M; Sleem, Amany A

2012-01-01

A new flavone glycoside tricin 7-O-β-glucopyranoside-2″-sulphate sodium salt along with 14 known flavonoid compounds were isolated and identified from the aqueous methanol extract of Livistona australis leaves. Their structures were established on the basis of extensive NMR (¹H, ¹³C, HSQC and H-H COSY) and ESIMS data. Antioxidant and cytotoxicity properties of the methanol extract of the leaves as well as the new compound were investigated.

Más allá de los mitos: análisis de la Cooperación Sur-Sur y Norte-Sur en el Ecuador. Sector Educación, período 2003- 2008

OpenAIRE

Escobar Sánchez, Wladimir Alexander

2012-01-01

La presente tesis de maestría analiza a la cooperación Norte-Sur y Sur-Sur como los dos principales modelos de funcionamiento de la cooperación hoy en día, a través de dos programas de ayuda internacional en el sector educación, en el período 2003-2008. El uno referente a la cooperación Norte-Sur, y el otro a la cooperación Sur-Sur. El propósito que presenta este trabajo académico es explicar a la cooperación internacional al desarrollo tomando en consideración a la teoría real...

Étude sur l'entrepreneuriat dalit : Regard sur 25 % de la population ...

International Development Research Centre (IDRC) Digital Library (Canada)

Étude sur l'entrepreneuriat dalit : Regard sur 25 % de la population indienne. Cette étude, pilotée par Udit Raj, député du parlement indien, aide à mieux comprendre les contraintes que rencontrent les entrepreneurs dalits. Elle permettra de sonder 12 000 entrepreneurs dalits dans 14 états et de recueillir des données ...

Bioactivity and chemical composition of the essential oil from the leaves of Guatteria australis A.St.-Hil.

Science.gov (United States)

Siqueira, Carlos Alberto Theodoro; Serain, Alessandra Freitas; Pascoal, Aislan Cristina Rheder Fagundes; Andreazza, Nathalia Luiza; de Lourenço, Caroline Caramano; Ruiz, Ana Lúcia T Góis; de Carvalho, João Ernesto; de Souza, Ana Cláudia Oliveira; Mesquita, Juliana Tonini; Tempone, Andre Gustavo; Salvador, Marcos José

2015-01-01

Essential oil from the leaves of Guatteria australis was obtained by hydrodistillation, analyzed by Gas Chromatography coupled to Mass Spectromery (GC-MS) and their antiproliferative, antileishmanial, antibacterial, antifungal and antioxidant activities were also evaluated. Twenty-three compounds were identified among which germacrene B (50.66%), germacrene D (22.22%) and (E)-caryophyllene (8.99%) were the main compounds. The highest antiproliferative activity was observed against NCI-ADR/RES (TGI = 31.08 μg/ml) and HT-29 (TGI = 32.81 μg/ml) cell lines. It also showed good antileishmanial activity against Leishmania infantum (IC50 = 30.71 μg/ml). On the other hand, the oil exhibited a small effect against Staphylococcus aureus ATCC 6538, S. aureus ATCC 14458 and Escherichia coli ATCC 10799 (MIC = 250 μg/ml), as well as small antioxidant activity (457 μmol TE/g) assessed through ORACFL assay. These results represent the first report regarding chemical composition and bioactivity of G. australis essential oil.

Phylogeography of Australia's king brown snake (Pseudechis australis) reveals Pliocene divergence and Pleistocene dispersal of a top predator

Science.gov (United States)

Kuch, Ulrich; Keogh, J. Scott; Weigel, John; Smith, Laurie A.; Mebs, Dietrich

2005-03-01

King brown snakes or mulga snakes (Pseudechis australis) are the largest and among the most dangerous and wide-ranging venomous snakes in Australia and New Guinea. They occur in diverse habitats, are important predators, and exhibit considerable morphological variation. We infer the relationships and historical biogeography of P. australis based on phylogenetic analysis of 1,249 base pairs from the mitochondrial cytochrome b, NADH dehydrogenase subunit 4 and three adjacent tRNA genes using Bayesian, maximum-likelihood, and maximum-parsimony methods. All methods reveal deep phylogenetic structure with four strongly supported clades comprising snakes from New Guinea (I), localities all over Australia (II), the Kimberleys of Western Australia (III), and north-central Australia (IV), suggesting a much more ancient radiation than previously believed. This conclusion is robust to different molecular clock estimations indicating divergence in Pliocene or Late Miocene, after landbridge dispersal to New Guinea had occurred. While members of clades I, III and IV are medium-sized, slender snakes, those of clade II attain large sizes and a robust build, rendering them top predators in their ecosystems. Genetic differentiation within clade II is low and haplotype distribution largely incongruent with geography or colour morphs, suggesting Pleistocene dispersal and recent ecomorph evolution. Significant haplotype diversity exists in clades III and IV, implying that clade IV comprises two species. Members of clade II are broadly sympatric with members of both northern Australian clades. Thus, our data support the recognition of at least five species from within P. australis (auct.) under various criteria. We discuss biogeographical, ecological and medical implications of our findings.

Comparative morphophysiological evaluation of the testis of adult Wistar rats fed low protein-energy diet and dosed with aqueous extracts of Cuscuta australis.

Science.gov (United States)

Ozegbe, P C; Omirinde, J O

2012-12-18

Cuscuta australis (C. australis) seed and stem are historically used by the local population as dietary supplement for the management of infertility. This study, therefore, evaluated the effect of orally administered aqueous extracts of C. australis seed and stem, 300 mg/kg body weight/day for seven days, on the testis of the adult Wistar rat fed either low or normal protein-energy diets. The control group received water. The relative weight of the testis was non-significantly increased (p>0.05) in the Low Protein-energy diet-Water-treated (LPWA), Low Protein-energy diet-Seed-treated (LPSE) and Normal Protein-energy diet-Seed-treated (NPSE) groups relative to the Normal Protein-energy diet-Water-treated (NPWA). The weight of the testis was also non-significantly increased (p˃0.05) in the Low Protein-energy diet-Stem-treated (LPST), but decreased in the Normal Protein-energy diet-Stem-treated (NPST), relative to LPWA and NPWA. Heights of germinal epithelium were significantly decreased (p<0.05) in the LPWA, LPSE and LPST relative to the NPWA, NPSE and NPST. Diet significantly influenced (p<0.001) the effect of stem extract on the height of germinal epithelium. The NPSE, LPSE, NPST, LPST and LPWA showed significantly decreased (p<0.001) plasma levels of luteinizing hormone (LH) and follicle stimulating hormone (FSH) relative to NPWA. The LPWA, LPSE and NPST also showed significantly decreased (p<0.001) levels of testosterone relative to NPWA and LPST. Diet significantly influenced (p<0.001) the effect of seed on the level of LH. Seed-diet interactions significantly affected the levels of FSH (p<0.001) and LH (p<0.05), but not testosterone. Diet significantly influenced (p<0.001) the effects of stem extract on the levels of FSH, LH and testosterone. Stem-diet interactions significantly affected (p<0.001) the levels of FSH, LH and testosterone. Our data suggest that the aqueous extract of C. australis stem is more potent than the seed extract and that dietary protein

Étude du Partenariat de recherche sur l'influenza aviaire en Asie sur ...

International Development Research Centre (IDRC) Digital Library (Canada)

Étude du Partenariat de recherche sur l'influenza aviaire en Asie sur l'efficacité des mesures de lutte. L'influenza aviaire hautement pathogène (H5N1) est une grave maladie qui touche la volaille et contamine les êtres humains dans une faible proportion. L'Organisation mondiale de la santé croit que le virus pourrait subir ...

The effects of short term exposure to Bass Strait crude oil and Corexit 8667 on benthic community metabolism in Posidonia australis Hook. f. dominated microcosms

Energy Technology Data Exchange (ETDEWEB)

Hatcher, A.I.; Larkum, A.W.D.

1982-03-01

Microcosms consisting of a sublittoral seagrass meadow from Botany Bay, N.S.W. were maintained in aquaria in a controlled environment room from March to August 1979. Oxygen production and consumption in the microcosms and leaf turnover of the seagrass, Posidonia australis Hook.f. were measured before, during and after a 7-day treatment in June with Bass Strait crude oil and the dispersant Corexit 8667. Four microcosms received oil and two of these received dispersant. The leaf turnover of P. australis was not significantly affected by the addition of oil and dispersant. Photosynthetic oxygen production decreased and respiration increased in the microcosms during treatment. In August, 40 days after treatment, oxygen production rates and P/R ratios in the oil-treated microcosms were higher than rates measured before treatment. The oil-and-dispersant-treated microcosms did not show this trend. The results of this study indicate that a more severe stress is placed on the P. australis dominated benthic community by oil and dispersant than by oil alone.

Parasite body volume and infracommunity patterns in the southern pomfret Brama australis (Pisces: Bramidae Volumen corporal del parásito y patrones infracomunitarios en la reineta Brama australis (Pisces: Bramidae

Directory of Open Access Journals (Sweden)

MARIO GEORGE-NASCIMENTO

2002-12-01

Full Text Available The patterns of infracommunity descriptors (diversity, dominance, abundance are compared when calculated with the number and body volume of the parasites in a sample of 26 southern pomfrets Brama australis collected in the area off Talcahuano, Chile. No numerical infracommunity descriptor was correlated with its corresponding volumetric descriptor. This single result casts doubts about the general validity of the infracommunity patterns described in the literature so far, because they are almost exclusively based on the number of parasite individuals per individual host, restricting communication with ecologists that use density or other measures of ecological abundanceLos patrones de los descriptores infracomunitarios (diversidad, dominancia, abundancia son comparados cuando son calculados en base a los números o al volumen corporal de los parásitos en una muestra de 26 reinetas Brama australis recolectadas en el área de Talcahuano, Chile. Ningún descriptor infracomunitario calculado con el número de parásitos estuvo correlacionado con los basados en el volumen corporal de los parásitos. Este resultado siembra dudas acerca de la validez general que pueden tener los patrones infracomunitarios registrados en la literatura ya que están casi exclusivamente calculados con el número de parásitos por individuo hospedador, lo que dificulta aún más la comunicación con los ecólogos, que usan la densidad u otras medidas de abundancia ecológica

Accumulation of nutrients and heavy metals in Phragmites australis (Cav.) Trin. ex Steudel and Bolboschoenus maritimus (L.) Palla in a constructed wetland of the Venice lagoon watershed

International Nuclear Information System (INIS)

Bragato, Claudia; Brix, Hans; Malagoli, Mario

2006-01-01

A recently constructed wetland, located in the Venice lagoon watershed, was monitored to investigate growth dynamics, nutrient and heavy metal shoot accumulation of the two dominating macrophytes: Phragmites australis and Bolboschoenus maritimus. Investigations were conducted over a vegetative season at three locations with different distance to the inlet point to assess effects on vegetation. The distance from the inlet did not affect either shoot biomass or nutrients (N, P, K and Na) and heavy metals (Cr, Ni, Cu and Zn) shoot content. With the exception of Na, nutrient and heavy metal concentrations were higher in shoots of P. australis than in B. maritimus. Heavy metal concentration in the incoming water and in the soil was not correlated to the plant content of either species. Shoot heavy metal concentrations were similar to those reported in the current literature, but accumulation generally increased towards the end of the growing season. - Heavy metal shoot concentration in Phragmites australis and Bolboschoenus maritimus increased significantly at the end of the growing season

Sur la plurifonctionnalité du discours direct

OpenAIRE

Cigada Sara

2012-01-01

La comparaison entre les résultats de nombreux travaux sur le dialogue dans le texte littéraire, sur l’attestation linguistique de la subjectivité, sur la fonction argumentative des émotions dans le discours et sur les effets de polyphonie, suggère que la structure sémiotique et linguistique du discours direct (DD) se trouve au croisement stratégique de plusieurs axes de la construction discursive. Nous étudions donc l’insertion du DD dans le discours (cf. Rosier 2008: Le discours rapporté en...

Temperature, energy acquisition and energy use in the Chilean silverside Basilichthys australis Eigenmann (Atherinopsidae Temperatura, adquisición de energía y uso de energía en el pejerrey chileno Basilichthys australis Eigenmann (Atherinopsidae

Directory of Open Access Journals (Sweden)

LEOPOLDO FUENTES

2005-06-01

Full Text Available We evaluated the influence of water temperature (Tw on the energy acquisition and use in the chilean silverside Basilichthys australis (Eigenmann 1927, an endemic species inhabiting freshwater ecosystems in Chile. We tested the effect of Tw (11.5, 14.0, 18.0, 22.0 and 26.0 °C on food intake, digestibility, food transit time and metabolic rate. As expected, this study demonstrated that many physiological variables under study were significantly affected by Tw, as well as the net energy balance of this species. Nevertheless, the net energy balance was not strictly related to the range of Tws evaluated. At Tws lower than 14 °C the energy budget was depressed, because food intake was lower than at Tws between 14 and 26 °C, where food intake was higher and independent of Tw. Consequently, at these temperatures the energy balance was positive and also independent of Tw. Physiologically, B. australis appears to be a tolerant species with respect to the wide range of water temperature in habitats at different depths. Thus, its distributions may extend through the entire profile of lakes and rivers, even in systems characterised by spatial and temporal thermal variabilityEn este trabajo evaluamos la influencia de la temperatura del agua (Ta en la adquisición de energía y su uso por parte del pejerrey chileno Basilichthys australis (Eigenmann 1927, una especie endémica que habita los ecosistemas dulceacuícolas de Chile. Investigamos el efecto de Ta (11,5, 14,0, 18,0, 22,0 y 26,0 °C en la ingesta de alimento, digestibilidad, tiempo de transito del alimento y tasa metabólica. De acuerdo a lo esperado, este estudio demostró que varias de las variables fisiológicas bajo estudio fueron significativamente afectadas por Ta, así como el balance energético de esta especie. Sin embargo, el balance neto de energía no estuvo estrictamente relacionado al rango de Tas evaluadas. En Tas inferiores a 14 °C el presupuesto de energía fue deprimido, debido a

Uptake of Carbamazepine by rhizomes and endophytic bacteria of Phragmites australis

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Andres eSauvetre

2015-02-01

Full Text Available Carbamazepine is an antiepileptic and mood-stabilizing drug which is used widely in Europe and North America. In the environment, it is found as a persistent and recalcitrant conta¬mi-nant, being one of the most prominent hazardous pharmaceuticals and personal care products (PPCPs in effluents of wastewater treatment plants (WWTPs. Phragmites australis is one of the species with both, the highest potential of detoxification and phytoremediation. It has been used successfully in the treatment of industrial and municipal wastewater. Recently, the identification of endophytic micro¬organisms from different plant species growing in contaminated sites has provided a list of candidates which could be used as bio-inoculants for bioremediation of difficult compounds. In this study, Phragmites australis plants were exposed to 5 mg/L of carbamazepine. After 9 days the plants had removed 90% of the initial concentration. Endophytic bacteria were isolated from these plants and further characterized. Phylogenetic analysis based on 16S rDNA sequencing revealed that the majority of these isolates belong to three groups: Proteobacteria, Actinobacteria and Bacteroidetes. Carbamazepine uptake and plant growth promoting (PGP traits were analyzed among the isolates. Ninety percent of the isolates produce indole acetic acid (IAA and all of them possess at least one of the PGP traits tested. One isolate identified as Chryseobacterium taeanense combines good carbamazepine uptake and all of the PGP traits. Rhizobium daejeonense can remove carbamazepine and produces 23 µg/mL of IAA. Diaphorobacter nitroreducens and Achromobacter mucicolens are suitable for carbamazepine removal while both, Pseudomonas veronii and Pseudomonas lini show high siderophore production and phosphate solubilization. Alone or in combination, these isolates might be applied as inoculates in constructed wetlands in order to enhance the phyto-remediation of carbamazepine during wastewater

Non-linear growth in tree ferns, Dicksonia antarctica and Cyathea australis.

Science.gov (United States)

Blair, David P; Blanchard, Wade; Banks, Sam C; Lindenmayer, David B

2017-01-01

Tree ferns are an important structural component of forests in many countries. However, because their regeneration is often unrelated to major disturbances, their age is often difficult to determine. In addition, rates of growth may not be uniform, which further complicates attempts to determine their age. In this study, we measured 5 years of growth of Cyathea australis and Dicksonia antarctica after a large wildfire in 2009 in south-eastern Australia. We found growth rates of these two species were unaffected by aspect and elevation but slope had a minor effect with D. antarctica growing 0.3mm faster for each additional degree of slope. Geographic location influenced growth in both species by up to 12 - 14mm/yr. The most consistent factor influencing growth rate, however, was initial height at the time of the 2009 fire; a finding consistent in both species and all geographic locations. For both tree fern species, individuals that were taller at the commencement of the study had greater overall growth for the duration of the study. This effect did not decrease even among the tallest tree ferns in our study (up to 6 metres tall). Overall, Cyathea australis averaged 73 (± 22)mm/year of growth (± 1SD), with the rate increasing 5mm/yr per metre of additional height. Dicksonia antarctica averaged 33 (± 13)mm/year, increasing by 6mm/yr/m. Growth rates dependent on initial height were unexpected and we discuss possible reasons for this finding. Variable growth rates also suggest that common age estimation methods of dividing height by average growth rate are likely to underestimate the age of short tree ferns, while overestimating the age of tall tree ferns, particularly if they have been subject to a fire.

Retinal amino acid neurochemistry of the southern hemisphere lamprey, Geotria australis.

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Lisa Nivison-Smith

Full Text Available Lampreys are one of the two surviving groups of the agnathan (jawless stages in vertebrate evolution and are thus ideal candidates for elucidating the evolution of visual systems. This study investigated the retinal amino acid neurochemistry of the southern hemisphere lamprey Geotria australis during the downstream migration of the young, recently-metamorphosed juveniles to the sea and during the upstream migration of the fully-grown and sexually-maturing adults to their spawning areas. Glutamate and taurine were distributed throughout the retina, whilst GABA and glycine were confined to neurons of the inner retina matching patterns seen in most other vertebrates. Glutamine and aspartate immunoreactivity was closely matched to Müller cell morphology. Between the migratory phases, few differences were observed in the distribution of major neurotransmitters i.e. glutamate, GABA and glycine, but changes in amino acids associated with retinal metabolism i.e. glutamine and aspartate, were evident. Taurine immunoreactivity was mostly conserved between migrant stages, consistent with its role in primary cell functions such as osmoregulation. Further investigation of glutamate signalling using the probe agmatine (AGB to map cation channel permeability revealed entry of AGB into photoreceptors and horizontal cells followed by accumulation in inner retinal neurons. Similarities in AGB profiles between upstream and downstream migrant of G. australis confirmed the conservation of glutamate neurotransmission. Finally, calcium binding proteins, calbindin and calretinin were localized to the inner retina whilst recoverin was localized to photoreceptors. Overall, conservation of major amino acid neurotransmitters and calcium-associated proteins in the lamprey retina confirms these elements as essential features of the vertebrate visual system. On the other hand, metabolic elements of the retina such as neurotransmitter precursor amino acids and Müller cells

Non-linear growth in tree ferns, Dicksonia antarctica and Cyathea australis.

Directory of Open Access Journals (Sweden)

David P Blair

Full Text Available Tree ferns are an important structural component of forests in many countries. However, because their regeneration is often unrelated to major disturbances, their age is often difficult to determine. In addition, rates of growth may not be uniform, which further complicates attempts to determine their age. In this study, we measured 5 years of growth of Cyathea australis and Dicksonia antarctica after a large wildfire in 2009 in south-eastern Australia. We found growth rates of these two species were unaffected by aspect and elevation but slope had a minor effect with D. antarctica growing 0.3mm faster for each additional degree of slope. Geographic location influenced growth in both species by up to 12 - 14mm/yr. The most consistent factor influencing growth rate, however, was initial height at the time of the 2009 fire; a finding consistent in both species and all geographic locations. For both tree fern species, individuals that were taller at the commencement of the study had greater overall growth for the duration of the study. This effect did not decrease even among the tallest tree ferns in our study (up to 6 metres tall. Overall, Cyathea australis averaged 73 (± 22mm/year of growth (± 1SD, with the rate increasing 5mm/yr per metre of additional height. Dicksonia antarctica averaged 33 (± 13mm/year, increasing by 6mm/yr/m. Growth rates dependent on initial height were unexpected and we discuss possible reasons for this finding. Variable growth rates also suggest that common age estimation methods of dividing height by average growth rate are likely to underestimate the age of short tree ferns, while overestimating the age of tall tree ferns, particularly if they have been subject to a fire.

Kir6.2 activation by sulfonylurea receptors: a different mechanism of action for SUR1 and SUR2A subunits via the same residues

Science.gov (United States)

Principalli, Maria A; Dupuis, Julien P; Moreau, Christophe J; Vivaudou, Michel; Revilloud, Jean

2015-01-01

ATP-sensitive potassium channels (K-ATP channels) play a key role in adjusting the membrane potential to the metabolic state of cells. They result from the unique combination of two proteins: the sulfonylurea receptor (SUR), an ATP-binding cassette (ABC) protein, and the inward rectifier K+ channel Kir6.2. Both subunits associate to form a heterooctamer (4 SUR/4 Kir6.2). SUR modulates channel gating in response to the binding of nucleotides or drugs and Kir6.2 conducts potassium ions. The activity of K-ATP channels varies with their localization. In pancreatic β-cells, SUR1/Kir6.2 channels are partly active at rest while in cardiomyocytes SUR2A/Kir6.2 channels are mostly closed. This divergence of function could be related to differences in the interaction of SUR1 and SUR2A with Kir6.2. Three residues (E1305, I1310, L1313) located in the linker region between transmembrane domain 2 and nucleotide-binding domain 2 of SUR2A were previously found to be involved in the activation pathway linking binding of openers onto SUR2A and channel opening. To determine the role of the equivalent residues in the SUR1 isoform, we designed chimeras between SUR1 and the ABC transporter multidrug resistance-associated protein 1 (MRP1), and used patch clamp recordings on Xenopus oocytes to assess the functionality of SUR1/MRP1 chimeric K-ATP channels. Our results reveal that the same residues in SUR1 and SUR2A are involved in the functional association with Kir6.2, but they display unexpected side-chain specificities which could account for the contrasted properties of pancreatic and cardiac K-ATP channels. PMID:26416970

Effects of Organic and Inorganic Nitrogen on the Growth and Production of Domoic Acid by Pseudo-nitzschia multiseries and P. australis (Bacillariophyceae) in Culture.

Science.gov (United States)

Martin-Jézéquel, Véronique; Calu, Guillaume; Candela, Leo; Amzil, Zouher; Jauffrais, Thierry; Séchet, Véronique; Weigel, Pierre

2015-11-26

Over the last century, human activities have altered the global nitrogen cycle, and anthropogenic inputs of both inorganic and organic nitrogen species have increased around the world, causing significant changes to the functioning of aquatic ecosystems. The increasing frequency of Pseudo-nitzschia spp. in estuarine and coastal waters reinforces the need to understand better the environmental control of its growth and domoic acid (DA) production. Here, we document Pseudo-nitzschia spp. growth and toxicity on a large set of inorganic and organic nitrogen (nitrate, ammonium, urea, glutamate, glutamine, arginine and taurine). Our study focused on two species isolated from European coastal waters: P. multiseries CCL70 and P. australis PNC1. The nitrogen sources induced broad differences between the two species with respect to growth rate, biomass and cellular DA, but no specific variation could be attributed to any of the inorganic or organic nitrogen substrates. Enrichment with ammonium resulted in an enhanced growth rate and cell yield, whereas glutamate did not support the growth of P. multiseries. Arginine, glutamine and taurine enabled good growth of P. australis, but without toxin production. The highest DA content was produced when P. multiseries grew with urea and P. australis grew with glutamate. For both species, growth rate was not correlated with DA content but more toxin was produced when the nitrogen source could not sustain a high biomass. A significant negative correlation was found between cell biomass and DA content in P. australis. This study shows that Pseudo-nitzschia can readily utilize organic nitrogen in the form of amino acids, and confirms that both inorganic and organic nitrogen affect growth and DA production. Our results contribute to our understanding of the ecophysiology of Pseudo-nitzschia spp. and may help to predict toxic events in the natural environment.

Invasion of Old World Phragmites australis in the New World: precipitation and temperature patterns combined with human influences redesign the invasive niche.

Science.gov (United States)

Guo, Wen-Yong; Lambertini, Carla; Li, Xiu-Zhen; Meyerson, Laura A; Brix, Hans

2013-11-01

After its introduction into North America, Euro-Asian Phragmites australis became an aggressive invasive wetland grass along the Atlantic coast of North America. Its distribution range has since expanded to the middle, south and southwest of North America, where invasive P. australis has replaced millions of hectares of native plants in inland and tidal wetlands. Another P. australis invasion from the Mediterranean region is simultaneously occurring in the Gulf region of the United States and some countries in South America. Here, we analysed the occurrence records of the two Old World invasive lineages of P. australis (Haplotype M and Med) in both their native and introduced ranges using environmental niche models (ENMs) to assess (i) whether a niche shift accompanied the invasions in the New World; (ii) the role of biologically relevant climatic variables and human influence in the process of invasion; and (iii) the current potential distribution of these two lineages. We detected local niche shifts along the East Coast of North America and the Gulf Coast of the United States for Haplotype M and around the Mississippi Delta and Florida of the United States for Med. The new niche of the introduced Haplotype M accounts for temperature fluctuations and increased precipitation. The introduced Med lineage has enlarged its original subtropical niche to the tropics-subtropics, invading regions with a high annual mean temperature (> ca. 10 °C) and high precipitation in the driest period. Human influence is an important factor for both niches. We suggest that an increase in precipitation in the 20th century, global warming and human-made habitats have shaped the invasive niches of the two lineages in the New World. However, as the invasions are ongoing and human and natural disturbances occur concomitantly, the future distribution ranges of the two lineages may diverge from the potential distribution ranges detected in this study. © 2013 John Wiley & Sons Ltd.

Debregeasia australis sp. nov. (Urticaceae), with a new synopsis of and a new key to the genus

DEFF Research Database (Denmark)

Wilmot-Dear, Christine Melanie; Friis, Ib

2012-01-01

A new species in the Old World genus Debregeasia (Urticaceae), D. australis Friis, Wilmot-Dear & C.J.Chen, based on material from forest habitats in eastern Queensland, Australia, is described, illustrated and mapped. A new synopsis of the genus and a new key to species recognised is provided as ...

Australis: AMS for ultra sensitive trace element and isotopic studies

Energy Technology Data Exchange (ETDEWEB)

Sie, S H; Suter, G F [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience

1994-12-31

The accelerator mass spectrometer (AMS) at the CSIRO HIAF laboratory is being upgraded to enable in-situ measurements of ultratraces and isotopic-ratios in mineralogical applications. The upgraded system will include a microbeam Cs ion source which is designed to produce better than 50 micrometre diameter Cs beam to enable analyses of monomineralic grains. The Cs primary beam will be mass analysed in order to minimize contamination of the sample. The detection system will be upgraded to enable analyses of elements up to U, at 2 MV terminal voltage for charge states 4 and 5. The system will be known as AUSTRALIS: A.M.S. for Ultra Sensitive TRAce eLement and Isotopic Studies. An overview of the system and the anticipated applications in minerals exploration and mining research are presented. 4 refs., 1 fig.

Australis: AMS for ultra sensitive trace element and isotopic studies

International Nuclear Information System (INIS)

Sie, S.H.; Suter, G.F.

1993-01-01

The accelerator mass spectrometer (AMS) at the CSIRO HIAF laboratory is being upgraded to enable in-situ measurements of ultratraces and isotopic-ratios in mineralogical applications. The upgraded system will include a microbeam Cs ion source which is designed to produce better than 50 micrometre diameter Cs beam to enable analyses of monomineralic grains. The Cs primary beam will be mass analysed in order to minimize contamination of the sample. The detection system will be upgraded to enable analyses of elements up to U, at 2 MV terminal voltage for charge states 4 and 5. The system will be known as AUSTRALIS: A.M.S. for Ultra Sensitive TRAce eLement and Isotopic Studies. An overview of the system and the anticipated applications in minerals exploration and mining research are presented. 4 refs., 1 fig

Australis: AMS for ultra sensitive trace element and isotopic studies

Energy Technology Data Exchange (ETDEWEB)

Sie, S.H.; Suter, G.F. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience

1993-12-31

The accelerator mass spectrometer (AMS) at the CSIRO HIAF laboratory is being upgraded to enable in-situ measurements of ultratraces and isotopic-ratios in mineralogical applications. The upgraded system will include a microbeam Cs ion source which is designed to produce better than 50 micrometre diameter Cs beam to enable analyses of monomineralic grains. The Cs primary beam will be mass analysed in order to minimize contamination of the sample. The detection system will be upgraded to enable analyses of elements up to U, at 2 MV terminal voltage for charge states 4 and 5. The system will be known as AUSTRALIS: A.M.S. for Ultra Sensitive TRAce eLement and Isotopic Studies. An overview of the system and the anticipated applications in minerals exploration and mining research are presented. 4 refs., 1 fig.

Preliminary Study On Gonad Maturity Stages of the Sea Cucumber Paracaudina australis from Kenjeran Water, Surabaya, Indonesia

Science.gov (United States)

Widianingsih, Widianingsih; Zaenuri, Muhammad; Anggoro, Sutrisno; Pancasakti Kusumaningrum, Hermin; Hartati, Retno

2018-02-01

The holothurian Paracaudina australis is belong to family Caudinidae, ordo Molpadida and class Holothuroidea. This species is among the most common holothurian widely distributed in the tropical water. The purpose of this reseach is to do preliminary study on maturity stages of sea cucumber Paracaudina australis from Kenjeran Water, Surabaya, Indonesia. This research was conducted on April 2016. Samples were collected randomly on the Kenjeran Water, Surabaya. The result showed that there are five stages of gonad maturity. At the stage of maturity 1, the gonad was not clearly distinguished, there were unbranched small tubule. At the stage of maturity 2, there were small branched of tubules. At this stage, gonad can be differentiated between male and female. At the stage of maturity 3, tubule can been branched not only for male but also female. At the stage of maturity 4, the gonad was good mature, there were clearly branched tubule. At the stage of matury 5, there were generally had empty tubule except for a few relict unreleased spermatozoa. At female gonad, there were shrunken tubule and relict oocytes were presented in the lumen of the tubule.

Comparative evaluation of the sperm characteristics and morphology of adult Wistar rats fed either low or normal protein-energy diets and orally dosed with aqueous Cuscuta australis extracts.

Science.gov (United States)

Omirinde, J O; Ozegbe, P C; Oyeyemi, M O

2014-06-19

Cuscuta australis (C. australis) seed and stem are commonly used as dietary supplements in a maize-meal, "Ogi", by the local population for the management of male and female reproductive dysfunctions. This study, as a part of on-going efforts, therefore, evaluated and compared the effects of Low Protein-energy (LP) and Normal Protein-energy (NP) diets on the sperm morphology and characteristics of adult Wistar rats orally dosed aqueous extracts of C. australis seed (LPSE and NPSE) and stem (LPST and NPST), 300 mg of extract/kg body weight of rat/day, for seven days. The control groups (LPWA and NPWA) received vehicle, water. Live-dead ratio and percentage of sperms with curved tail were significantly decreased (p<0.01) in the NPST relative to the NPWA, LPWA, LPST, NPSE and LPSE. Total abnormal sperm counts, acephalic sperms and tailless head sperms were significantly decreased (p<0.001, p<0.05 and p<0.001, respectively) in the LPST and NPST relative to LPSE, NPSE, LPWA and NPWA. The LPSE, LPST and NPST showed significantly decreased (p<0.05) percentages of sperms with either bent mid-piece or curved mid-piece relative to the LPWA. Significantly decreased (p<0.05) percentage of sperms with curved mid-piece was also observed in the NPSE relative to LPWA. Protein-energy diet significantly influenced (at least p<0.05) the effect of each extract on sperm motility and percentage of sperms with curved tail. Stem extract significantly decreased (p<0.01) the percentages of acephalic sperms and tailless head sperms. Diet-stem extract interaction significantly influenced (p<0.05) live-dead ratio. Our data suggest that orally administered aqueous extracts of C. australis generally enhanced the sperm morphology and characteristics of the male Wistar rat and that the stem extract maintained sperm morphology better than the seed extract. It also showed that the stem extract decreased live-dead ratio and that the efficacy of orally administered aqueous C. australis stem extract

Evaluación de la Remoción de Nitrógeno, Fósforo y Sulfuros en Agua Residual Doméstica, Utilizando Phragmites australis en Bioreactores

OpenAIRE

Correa-Torres, Sandra N; Gamarra, Yolanda; Salazar, Andrés A; Pitta, Natalia M

2015-01-01

En el presente estudio se evaluó la remoción de nitrógeno, fósforo y sulfuros en un agua residual doméstica mediante fitorremediación utilizando Phragmites australis en bioreactores a escala de laboratorio. Se determinó el estudio las condiciones hidráulicas en reactores analizando las variables de relación geométrica largo:ancho (4:1 y 1:4) y usando un medio filtrante (grava/arena). Adicionalmente se evaluó el crecimiento de P. australis en los reactores y se analizó los porcentajes de remoc...

The effect of sampling methods on the apparent constituents of ink from the squid Sepioteuthis australis.

Science.gov (United States)

Madaras, F; Gerber, J P; Peddie, F; Kokkinn, M J

2010-11-01

Results of experiments conducted on ink recovered from the squid Sepioteuthis australis indicate that there is no epinephrine or protein naturally present in the ink as it would be ejected in vivo. Protein content was effectively zero when ink was syringed from the duct end of the ink sac of freshly killed animals. By contrast, there were proteins in samples collected from dead specimens where ink was collected by a stripping method. From these samples, a single large molecular weight protein was identified as having tyrosinase activity. Digestion of syringed ink did not yield signs of melanin-bound proteins. Analysis of supernatants after centrifugation of squid ink consistently revealed the presence of DOPA, dopamine, and taurine, whereas epinephrine and nor-epinephrine were recorded from what was believed to be contaminated ink. Histological investigations of the ink sac revealed a compartmentalised glandular structure distal to the duct end. Closer observation of the glandular tissue showed that compartments increased in size as they matured and moved further into the lumen. It was concluded that the presence of epinephrine and tyrosinase (or a related protein) in the ink of S. australis could be attributed to rupturing of basal glandular compartments or contamination from other sources during the extraction process.

Marine water mites (Acari: Hydrachnidia: Pontarachnidae) from Taiwan, Korea and India, with the first description of the male of Pontarachna australis Smit, 2003

Digital Repository Service at National Institute of Oceanography (India)

Pesic, V.; Chatterjee, T.; Chan, B.K.K.; Ingole, B.S.

he hitherto unknown male of the marine water mite Pontarachna australis Smit, 2003 (Acari: Hydrachnidia: Pontarachnidae) is described and recorded from Taiwan for the first time. Another marine water mite, Litarachna denhami (Lohmann, 1909...

Radio emission from pre-main-sequence stars in Corona Australis

International Nuclear Information System (INIS)

Brown, A.

1987-01-01

The central region of the Corona Australis molecular cloud surrounding the stars R and TY CrA has been studied using the VLA at 6 cm. Eleven radio sources are detected including five associated with pre-main-sequence objects. The most striking is associated with the near-IR source IRS 7 and shows a complex structure comprising two strong pointlike sources positioned either side of the deeply embedded IR source and two extended lobes of radio emission. The IRS 7 radio source appears to be similar to that associated with Lynds 1551 IRS 5 but has a considerably larger angular size. The other detected sources include the massive pre-main-sequence star TY CrA, the near-IR sources IRS 1 and IRS 5, and the Herbig-Haro object HH 101. The stars R and T CrA were not detected. 35 references

Agir sur la langue pour agir sur le monde : Micropolitiques linguistiques autogérées du genre dans les brochures libertaires

OpenAIRE

Abbou, Julie

2015-01-01

La dimension agissante de la langue sur le monde entraîne avec elle, comme un appel d'air, l'action sur la langue elle-même, et l'action sur la langue n'est jamais loin de se faire action politique. Les politiques linguistiques de féminisation en sont un exemple, où l'action politique se concentre sur la catégorisation du genre. Dans de nombreux cas, la politique linguistique se fait planification linguistique, cherchant de nouvelles normes. Dans de nombreux cas, mais pas toujours. Il existe ...

Decomposition of Phragmites australis litter retarded by invasive Solidago canadensis in mixtures: an antagonistic non-additive effect

OpenAIRE

Zhang, Ling; Zhang, Yaojun; Zou, Jianwen; Siemann, Evan

2014-01-01

Solidago canadensis is an aggressive invader in China. Solidago invasion success is partially attributed to allelopathic compounds release and more benefits from AM fungi, which potentially makes the properties of Solidago litter different from co-occurring natives. These properties may comprehensively affect litter decomposition of co-occurring natives. We conducted a field experiment to examine litter mixing effects in a Phragmites australis dominated community invaded by Solidago in southe...

CARACTERIZACIÓN DEL CONSUMO DE HORTALIZAS EN LAS FAMILIAS DEL SUR-SUR DE COSTA RICA

Directory of Open Access Journals (Sweden)

Alexis Villalobos-Monge

2013-01-01

Full Text Available El objetivo de este trabajo fue determinar los diferentes aspectos cuantitativos y cualitativos que explican la cultura de consumo actual de hortalizas en las familias residentes en la zona sur-sur de Costa Rica. Este trabajo expone resultados relacionados a la caracterización realizada en el 2011 en familias residentes en la denominada zona sur-sur de Costa Rica sobre la cultura de consumo de productos hortícolas. Se aplicaron cuestionarios a una muestra estratificada de familias; lo que permitió establecer la valoración de los precios de mercado, por parte de las familias, para consumir estos alimentos, donde se determinó un valor máximo de US$1,74 millones por semana. Los principales rubros de consumo de acuerdo al valor pagado fueron el tomate, la papa, el plátano, la cebolla y el brócoli, para citar los cinco principales. También fue posible establecer valoraciones cualitativas sobre el consumo de estos productos; por ejemplo se determinó que para el 71,2% de las familias, la frescura representa la característica de mayor valor, además, el principal sitio donde los núcleos familiares realizan las compras de estos alimentos corresponde a supermercados (38,4% de los casos.

Uptake and Bioaccumulation of Pentachlorophenol by Emergent Wetland Plant Phragmites australis (Common Reed) in Cadmium Co-contaminated Soil.

Science.gov (United States)

Hechmi, Nejla; Ben Aissa, Nadhira; Abdenaceur, Hassen; Jedidi, Naceur

2015-01-01

Despite many studies on phytoremediation of soils contaminated with either heavy metals or organics, little information is available on the effectiveness of phytoremediation of co-occurring metal and organic pollutants especially by using wetland species. Phragmites australis is a common wetland plant and its potential for phytoremediation of cadmium pentachlorophenol (Cd-PCP) co-contaminated soil was investigated. A greenhouse study was executed to elucidate the effects of Cd (0, 10, and 20 mg kg(-1)) without or with PCP (0, 50, and 250 mg kg(-1)) on the growth of the wetland plant P. australis and its uptake, accumulation and removal of pollutant from soils. After 75 days, plant biomass was significantly influenced by interaction of Cd and PCP and the effect of Cd on plant growth being stronger than that of PCP. Coexistence of PCP at low level lessened Cd toxicity to plants, resulting in improved plant growth and increased Cd accumulation in plant tissues. The dissipation of PCP in soils was significantly influenced by interactions of Cd, PCP and plant presence or absence. As an evaluation of soil biological activities after remediation soil enzyme was measured.

Early successional stages of reed Phragmites australis vegetations and its importance for the Bearded Reedling Panurus biarmicus in Oostvaardersplassen, The Netherlands

NARCIS (Netherlands)

Beemster, Nico; Troost, Els; Platteeuw, Maarten

2010-01-01

A study on Bearded Reed ling Panurus biarmicus feeding habits in combination with a sample-wise breeding bird survey of the marshland zones of the Dutch wetland Oostvaardersplassen shows clear-cut spatial differences in densities and habitat use. The more mature stands of Reed Phragmites australis

The effect of kauri (Agathis australis) on grain size distribution and clay mineralogy of andesitic soils in the Waitakere Ranges, New Zealand

NARCIS (Netherlands)

Jongkind, A.G.; Buurman, P.

2006-01-01

Kauri (Agathis australis) is generally associated with intense podzolisation, but little research has been carried out to substantiate this. We studied soil profiles, grain size distribution patterns and clay mineralogy under kauri and broadleaf/tree fern vegetation in the Waitakere Ranges, North

The Spitzer survey of interstellar clouds in the Gould Belt. III. A multi-wavelength view of Corona Australis

DEFF Research Database (Denmark)

Peterson, Dawn E.; Caratti o Garatti, Alessio; Bourke, Tyler L.

2011-01-01

We present Spitzer Space Telescope IRAC and MIPS observations of a 0.85 deg2 field including the Corona Australis (CrA) star-forming region. At a distance of 130 pc, CrA is one of the closest regions known to be actively forming stars, particularly within its embedded association, the Coronet. Us...

Role of solid-phase microextraction in the identification of highly volatile pheromones of two Rhinoceros beetles Scapanes australis and Strategus aloeus (Coleoptera, Scarabaeidae, Dynastinae).

Science.gov (United States)

Rochat, D; Ramirez-Lucas, P; Malosse, C; Aldana, R; Kakul, T; Morin, J P

2000-07-14

Solid-phase microextraction (SPME) samplings from live insects or natural secretion allowed one to identify the aggregation pheromones of the pest beetles Scapanes australis and Strategus aloeus by efficient and rapid isolation of their highly volatile (72 < M(r) < 116) components. S. australis male pheromone was identified as a 84:12:4 (w/w) mixture of 2-butanol [67:33 (R)-(-):(S)-(+) ratio], 3-hydroxy-2-butanone and 2,3-butanediol [43:17:40 (R,R)-(-):(S,S)-(+):meso ratio], and S. aloeus pheromone as a 95.5:4.0:0.5 (w/w) mixture of 2-butanone, 3-pentanone and sec.-butyl acetate by GC-MS using conventional and chiral capillary columns. This is the first report of Scarabaeidae pheromones based on such small and common molecules.

Uptake of inorganic phosphorus by the aquatic plant Isoetes australis inhabiting oligotrophic vernal rock pools

DEFF Research Database (Denmark)

Christiansen, Nina Høj; Pulido, Cristina; Pedersen, Ole

2017-01-01

The submerged aquatic freshwater macrophyte Isoetes australis S. Williams grows in rock pools situated in south-western Australia, an environment where dissolved inorganic phosphorus (Pi) availability possibly limits growth. In contrast to the two coexisting aquatic species, Glossostigma drummundii...... experiment revealed high amounts of Pi translocation internally in the plant which seemed to go from roots and oldest leaves to younger leaves. As a result of the high root to shoot ratio, high surface area, root uptake kinetics, and sediment Pi availability, roots accounted for 87% of plant Pi uptake...

Short-term and long-term effects of tannins on nitrogen mineralisation and litter decomposition in kauri (Agathis australis (D. Don) Lindl.) forests

NARCIS (Netherlands)

Verkaik, E.; Jongkind, A.G.; Berendse, F.

2006-01-01

Kauri (Agathis australis (D. Don) Lindl.) occurs naturally in the warm temperate forest of northern New Zealand where it grows mixed with angiosperm tree species. Below mature kauri trees thick organic layers develop in which large amounts of nitrogen are accumulated. This nitrogen seems to be

The parasitic plant Cuscuta australis is highly insensitive to abscisic acid-induced suppression of hypocotyl elongation and seed germination.

Science.gov (United States)

Li, Juan; Hettenhausen, Christian; Sun, Guiling; Zhuang, Huifu; Li, Jian-Hong; Wu, Jianqiang

2015-01-01

Around 1% of angiosperms are parasitic plants. Their growth and development solely or partly depend on host plants from which they extract water, nutrients, and other molecules using a parasitic plant-specific organ, the haustorium. Strong depletion of nutrients can result in serious growth retardation and in some cases, death of the hosts. The genus Cuscuta (dodder) comprises about 200 holoparasitic species occurring on all continents. Their seedlings have no roots and cotyledons but are only string-like hypocotyls. When they contact suitable host plants, haustoria are formed and thereafter seedlings rapidly develop into vigorously growing branches without roots and leaves. This highly specialized lifestyle suggests that Cuscuta plants likely have unique physiology in development and stress responses. Using germination and seedling growth assays, we show that C. australis seeds and seedlings are highly insensitive to abscisic acid (ABA). Transcriptome analysis and protein sequence alignment with Arabidopsis, tomato, and rice homologs revealed that C. australis most likely consists of only four functional ABA receptors. Given that Cuscuta plants are no longer severely challenged by drought stress, we hypothesize that the ABA-mediated drought resistance pathway in Cuscuta spp. might have had degenerated over time during evolution.

The parasitic plant Cuscuta australis is highly insensitive to abscisic acid-induced suppression of hypocotyl elongation and seed germination.

Directory of Open Access Journals (Sweden)

Juan Li

Full Text Available Around 1% of angiosperms are parasitic plants. Their growth and development solely or partly depend on host plants from which they extract water, nutrients, and other molecules using a parasitic plant-specific organ, the haustorium. Strong depletion of nutrients can result in serious growth retardation and in some cases, death of the hosts. The genus Cuscuta (dodder comprises about 200 holoparasitic species occurring on all continents. Their seedlings have no roots and cotyledons but are only string-like hypocotyls. When they contact suitable host plants, haustoria are formed and thereafter seedlings rapidly develop into vigorously growing branches without roots and leaves. This highly specialized lifestyle suggests that Cuscuta plants likely have unique physiology in development and stress responses. Using germination and seedling growth assays, we show that C. australis seeds and seedlings are highly insensitive to abscisic acid (ABA. Transcriptome analysis and protein sequence alignment with Arabidopsis, tomato, and rice homologs revealed that C. australis most likely consists of only four functional ABA receptors. Given that Cuscuta plants are no longer severely challenged by drought stress, we hypothesize that the ABA-mediated drought resistance pathway in Cuscuta spp. might have had degenerated over time during evolution.

El (los Sur buscando al Sur. Una construcción entre estereotipos y realidad.

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Mabel Franzone

2010-11-01

Full Text Available Todas las lecturas que podamos hacer del Sur, de sus propias representaciones, de aquellas vehiculizadas por el Norte, de sus creaciones, de sus reacciones, de su búsqueda constante de identidad, son lecturas de múltiples situaciones, que llaman a cruces insoslayables entre pueblos, entre distintas etnias, entre disciplinas, entre sentimientos que van desde el rechazo hasta la atracción casi magnética entre los dos hemisferios. Nuestra intención primera era la de reunir de manera aproximativa las problemáticas actuales de los Sur, ligadas a lo imaginario.

Wintering habitat model for the North Atlantic Right Whale (Eubalaena glacialis) in the southeastern United States.

Science.gov (United States)

Gowan, Timothy A; Ortega-Ortiz, Joel G

2014-01-01

The coastal waters off the southeastern United States (SEUS) are a primary wintering ground for the endangered North Atlantic right whale (Eubalaena glacialis), used by calving females along with other adult and juvenile whales. Management actions implemented in this area for the recovery of the right whale population rely on accurate habitat characterization and the ability to predict whale distribution over time. We developed a temporally dynamic habitat model to predict wintering right whale distribution in the SEUS using a generalized additive model framework and aerial survey data from 2003/2004 through 2012/2013. We built upon previous habitat models for right whales in the SEUS and include data from new aerial surveys that extend the spatial coverage of the analysis, particularly in the northern portion of this wintering ground. We summarized whale sightings, survey effort corrected for probability of whale detection, and environmental data at a semimonthly resolution. Consistent with previous studies, sea surface temperature (SST), water depth, and survey year were significant predictors of right whale relative abundance. Additionally, distance to shore, distance to the 22°C SST isotherm, and an interaction between time of year and latitude (to account for the latitudinal migration of whales) were also selected in the analysis presented here. Predictions from the model revealed that the location of preferred habitat differs within and between years in correspondence with variation in environmental conditions. Although cow-calf pairs were rarely sighted in the company of other whales, there was minimal evidence that the preferred habitat of cow-calf pairs was different than that of whale groups without calves at the scale of this study. The results of this updated habitat model can be used to inform management decisions for a migratory species in a dynamic oceanic environment.

Egg discrimination in the Australian reed warbler (Acrocephalus australis) : rejection response toward model and conspecific eggs depending on timing and mode of artificial parasitism

NARCIS (Netherlands)

Welbergen, J; Komdeur, J; Kats, R; Berg, M

2001-01-01

In a coevolutionary arms race between an interspecific brood parasite and its host species, bath are expected to evolve adaptations and counteradaptations. We studied egg discrimination in the Australian warbler (Acrocephalus australis). This species is currently not significantly parasitized by the

Multi-year longitudinal profiles of cortisol and corticosterone recovered from baleen of North Atlantic right whales (Eubalaena glacialis).

Science.gov (United States)

Hunt, Kathleen E; Lysiak, Nadine S; Moore, Michael; Rolland, Rosalind M

2017-12-01

Research into stress physiology of mysticete whales has been hampered by difficulty in obtaining repeated physiological samples from individuals over time. We investigated whether multi-year longitudinal records of glucocorticoids can be reconstructed from serial sampling along full-length baleen plates (representing ∼10years of baleen growth), using baleen recovered from two female North Atlantic right whales (Eubalaena glacialis) of known reproductive history. Cortisol and corticosterone were quantified with immunoassay of subsamples taken every 4cm (representing ∼60d time intervals) along a full-length baleen plate from each female. In both whales, corticosterone was significantly elevated during known pregnancies (inferred from calf sightings and necropsy data) as compared to intercalving intervals; cortisol was significantly elevated during pregnancies in one female but not the other. Within intercalving intervals, corticosterone was significantly elevated during the first year (lactation year) and/or the second year (post-lactation year) as compared to later years of the intercalving interval, while cortisol showed more variable patterns. Cortisol occasionally showed brief high elevations ("spikes") not paralleled by corticosterone, suggesting that the two glucocorticoids might be differentially responsive to certain stressors. Generally, immunoreactive corticosterone was present in higher concentration in baleen than immunoreactive cortisol; corticosterone:cortisol ratio was usually >4 and was highly variable in both individuals. Further investigation of baleen cortisol and corticosterone profiles could prove fruitful for elucidating long-term, multi-year patterns in stress physiology of large whales, determined retrospectively from stranded or archived specimens. Copyright © 2017 Elsevier Inc. All rights reserved.

Decomposition of Phragmites australis rhizomes in artificial land-water transitional zones (ALWTZs) and management implications

Science.gov (United States)

Han, Zhen; Cui, Baoshan; Zhang, Yongtao

2015-09-01

Rhizomes are essential organs for growth and expansion of Phragmites australis. They function as an important source of organic matter and as a nutrient source, especially in the artificial land-water transitional zones (ALWTZs) of shallow lakes. In this study, decomposition experiments on 1- to 6-year-old P. australis rhizomes were conducted in the ALWTZ of Lake Baiyangdian to evaluate the contribution of the rhizomes to organic matter accumulation and nutrient release. Mass loss and changes in nutrient content were measured after 3, 7, 15, 30, 60, 90, 120, and 180 days. The decomposition process was modeled with a composite exponential model. The Pearson correlation analysis was used to analyze the relationships between mass loss and litter quality factors. A multiple stepwise regression model was utilized to determine the dominant factors that affect mass loss. Results showed that the decomposition rates in water were significantly higher than those in soil for 1- to 6-year-old rhizomes. However, the sequence of decomposition rates was identical in both water and soil. Significant relationships between mass loss and litter quality factors were observed at a later stage, and P-related factors proved to have a more significant impact than N-related factors on mass loss. According to multiple stepwise models, the C/P ratio was found to be the dominant factor affecting the mass loss in water, and the C/N and C/P ratios were the main factors affecting the mass loss in soil. The combined effects of harvesting, ditch broadening, and control of water depth should be considered for lake administrators.

CO2 and CH4 exchange by Phragmites australis under different climates

Science.gov (United States)

Serrano Ortiz, Penélope; Chojnickic, Bogdan H.; Sánchez-Cañete, Enrique P.; Kowalska, Natalia; López-Ballesteros, Ana; Fernández, Néstor; Urbaniak, Marek; Olejnik, Janusz; Kowalski, Andrew S.

2015-04-01

The key role of wetlands regarding global warming is the resulting balance between net CO2 assimilation, via photosynthesis, and CO2 and CH4 emissions, given the potential to release stored carbon, because of the high temperature sensitivity of heterotrophic soil respiration and anoxic conditions. However, it is still unknown whether wetlands will convert from long-term carbon sinks to sources as a result of climate change and other anthropogenic effects such as land use changes. Phragmites australis is one of the most common species found in wetlands and is considered the most globally widespread and productive plant species in this type of ecosystem. In this context, the main objective of this study is to analyse the GHG exchange (CO2 and CH4) of two wetlands with Phragmites australis as the dominant species under different climates using the eddy covariance (EC) technique. The first site, Padul, is located in southern Spain, with a sub-humid warm climate, characterised by a mean annual temperature of 16°C and annual precipitation of ca. 470 mm, with a very dry summer. The second site, Rzecin is located in Poland with a mean annual temperature of 8°C, and annual precipitation around 600mm with no dry season. The Padul EC station is equipped with two infrared gas analysers to measure CO2 and CH4 fluxes (LI-7200 and LI-7700 respectively) while the Rzecin EC station has the same CH4 sensor as Padul, but also a sensor measuring both GHG fluxes (DLT-100 Fast Methane Analyser, Los Gatos). In this study, we present: i) the results of a CH4 analyser inter-comparison campaign (LI-7700 vs. Los Gatos), ii) a comparative analysis of the functional behaviour of respiration and photosynthesis in both sites testing relationships between CO2 fluxes measured with the EC technique and meteorological variables such as temperature and direct or diffuse radiation and iii) the CH4 dynamicsat both sites by identifying, when possible, annual, seasonal and diurnal patterns.

Preparation and Adsorption Performances of Phragmites australis Activated Carbon with High Acidity

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FU Cheng-kai

2017-03-01

Full Text Available For removal of heavy metals from wastewater and recycling the wetland plants, the present study investigated the viability of using silage of Phragmites australis (PA to prepare activated carbons (ACs with high acidity. BET surface area, porous texture and surface functional characteristics of ACs were analyzed by N2 adsorption/desorption, elemental analysis and Boehm titration method. ACs presented well-developed micro-porosity and favorable surface acidity. The sorption equilibrium data for Ni (Ⅱ and Cd (Ⅱ sorption onto ACs were analyzed by the Langmuir and Freundlich models. The Langmuir model was fitted well to the adsorption behavior. The properties of high surface acidity promoted the adsorption of heavy metals by the silage-treated ACs and the chemical sorption played the key role in the sorption process.

Sexualidad, migraciones y fronteras en contextos de integración sur-sur

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Martha Cecilia Ruiz

Full Text Available Resumen Este artículo se pregunta sobre los procesos de diferenciación, jerarquización e inclusión/exclusión de poblaciones migrantes en contextos migratorios sur-sur, y sobre el rol que juega la sexualidad en estos procesos. Partiendo de un estudio etnográfico sobre las migrantes peruanas y colombianas en el sector del comercio sexual de Ecuador, se analiza la manera en que la sexualidad se convierte en un sitio privilegiado para re-imaginar las diferencias y jerarquías nacionales en un mundo globalizado e integrado regionalmente, y se explica cómo los regímenes de control sobre las migraciones y la sexualidad femenina se articulan entre sí para restablecer el orden idealizado de la nación.

Bioinformatic prediction of G protein-coupled receptor encoding sequences from the transcriptome of the foreleg, including the Haller's organ, of the cattle tick, Rhipicephalus australis.

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Sergio Munoz

Full Text Available The cattle tick of Australia, Rhipicephalus australis, is a vector for microbial parasites that cause serious bovine diseases. The Haller's organ, located in the tick's forelegs, is crucial for host detection and mating. To facilitate the development of new technologies for better control of this agricultural pest, we aimed to sequence and annotate the transcriptome of the R. australis forelegs and associated tissues, including the Haller's organ. As G protein-coupled receptors (GPCRs are an important family of eukaryotic proteins studied as pharmaceutical targets in humans, we prioritized the identification and classification of the GPCRs expressed in the foreleg tissues. The two forelegs from adult R. australis were excised, RNA extracted, and pyrosequenced with 454 technology. Reads were assembled into unigenes and annotated by sequence similarity. Python scripts were written to find open reading frames (ORFs from each unigene. These ORFs were analyzed by different GPCR prediction approaches based on sequence alignments, support vector machines, hidden Markov models, and principal component analysis. GPCRs consistently predicted by multiple methods were further studied by phylogenetic analysis and 3D homology modeling. From 4,782 assembled unigenes, 40,907 possible ORFs were predicted. Using Blastp, Pfam, GPCRpred, TMHMM, and PCA-GPCR, a basic set of 46 GPCR candidates were compiled and a phylogenetic tree was constructed. With further screening of tertiary structures predicted by RaptorX, 6 likely GPCRs emerged and the strongest candidate was classified by PCA-GPCR to be a GABAB receptor.

BOOK REVIEW: European Perceptions of Terra Australis

Science.gov (United States)

Sterken, Christiaan

2012-12-01

Terra Australis - the southern land - has been one of the most widespread concepts in European geography from the sixteenth to the eighteenth century. This book comprises a set of 14 interdisciplinary scholarly contributions that deal with personal perceptions of Terra Australis by cartographers and explorers, and with putting these perceptions in their historical and cultural environments. This book seems, at a first glance, to be very remote from astronomy - and even from the history of astronomy - however, as it also offers an excellent background to Captain James Cook's second voyage to observe the 1769 transit of Venus from Tahiti, it definitely is a work of truly interdisciplinary character. Cook's voyages, in fact, became a model in which key scientists of many nationalities and disciplines traveled together on ships. In these voyages, art, science, technology and political power were centralised and united. The chapters range across history, the visual arts, literature, popular culture, technology, politics and science. Issues of scientific reasoning are raised in the description of how people did think about the south before there even existed a perception of the unknown land - quite comparable to how ancient and early-modern astronomers had their thought about cosmology even before any observational data were available. Several early map systems - like the zonal and T-O maps (medieval world maps with the letter T inside an O representing the lands inside a circle of oceans) - are described, and the description of Roman geography shows the amazing fact that theory and practice were not unified, and existed independently of each other insofar that a real paradox between theory and observation had persisted for a very long time. The maps and charts also exemplify the long-lasting consequences of early modern copy-paste practice: navigators copied original sketch charts of coasts that were previously unknown to them, herewith committing many translation and

Identités nationales, identités « raciales » en Océanie

OpenAIRE

Rodd, Adrien

2016-01-01

La tentation de fonder une affirmation identitaire nationale sur une adéquation entre ‘race’ et nation a marqué les discours et les politiques en Océanie, à l’instar d’autres régions du monde. Cet article se donne pour objectif d’analyser la manière dont l’impératif d’unité nationale s’y est appuyé sur la perception ou la mise en avant d’une homogénéité non seulement culturelle mais ethnique ou « raciale », accompagnée parfois de politiques d’exclusion des minorités. En Australie et en Nouvel...

Die-back of Phragmites australis in European wetlands: an overview of the European Research Programme on Reed Die-Back and Progression (1993-1994)

NARCIS (Netherlands)

Van der Putten, W.H.

1997-01-01

Reed (Phragmites australis (Cav.) Trin. ex Steudel) is one of the dominant plant species in European land-water ecotones. During the past decades reed belts have died back, especially in central and eastern Europe. The aim of the European Research Programme on Reed Die-back and Progression (EUREED),

Effet de la composition de différents substrats culturaux sur ...

African Journals Online (AJOL)

SARAH

31 janv. 2014 ... Effet de la substrats culturaux sur paramètres de croissance ... des graines, mais ce substrat a donné des performances acceptables sur la croissance longitudinale des ..... élevés en conteneurs sur différents types de.

Root parasitic plant Orobanche aegyptiaca and shoot parasitic plant Cuscuta australis obtained Brassicaceae-specific strictosidine synthase-like genes by horizontal gene transfer.

Science.gov (United States)

Zhang, Dale; Qi, Jinfeng; Yue, Jipei; Huang, Jinling; Sun, Ting; Li, Suoping; Wen, Jian-Fan; Hettenhausen, Christian; Wu, Jinsong; Wang, Lei; Zhuang, Huifu; Wu, Jianqiang; Sun, Guiling

2014-01-13

Besides gene duplication and de novo gene generation, horizontal gene transfer (HGT) is another important way of acquiring new genes. HGT may endow the recipients with novel phenotypic traits that are important for species evolution and adaption to new ecological niches. Parasitic systems expectedly allow the occurrence of HGT at relatively high frequencies due to their long-term physical contact. In plants, a number of HGT events have been reported between the organelles of parasites and the hosts, but HGT between host and parasite nuclear genomes has rarely been found. A thorough transcriptome screening revealed that a strictosidine synthase-like (SSL) gene in the root parasitic plant Orobanche aegyptiaca and the shoot parasitic plant Cuscuta australis showed much higher sequence similarities with those in Brassicaceae than with those in their close relatives, suggesting independent gene horizontal transfer events from Brassicaceae to these parasites. These findings were strongly supported by phylogenetic analysis and their identical unique amino acid residues and deletions. Intriguingly, the nucleus-located SSL genes in Brassicaceae belonged to a new member of SSL gene family, which were originated from gene duplication. The presence of introns indicated that the transfer occurred directly by DNA integration in both parasites. Furthermore, positive selection was detected in the foreign SSL gene in O. aegyptiaca but not in C. australis. The expression of the foreign SSL genes in these two parasitic plants was detected in multiple development stages and tissues, and the foreign SSL gene was induced after wounding treatment in C. australis stems. These data imply that the foreign genes may still retain certain functions in the recipient species. Our study strongly supports that parasitic plants can gain novel nuclear genes from distantly related host species by HGT and the foreign genes may execute certain functions in the new hosts.

Osmotic and ionic effects of NaCl and Na₂SO₄ salinity on Phragmites australis

DEFF Research Database (Denmark)

Pagter, Majken; Bragato, Claudia; Malagoli, Mario

2009-01-01

Osmotic and ion-specific effects of NaCl and Na2SO4 on Phragmites australis (Cav.) Trin ex. Steud. were investigated in a laboratory experiment by examining effects of iso-osmotic solutions of NaCl and Na2SO4 on growth, osmolality of cell sap, proline content, elemental composition and gas exchange....... Plants were supplied with a control standard nutrient solution (Ψ = -0.09 MPa) or solutions of NaCl or Na2SO4 at water potentials of -0.50, -1.09 or -1.74 MPa. Salt treatments increased root concentrations of Na and S or Cl, whereas P. australis had efficient mechanisms for exclusion of Na and S...... and partly Cl ions from the leaves. Incomplete exclusion of Cl from the leaves may affect aboveground biomass production, which was significantly more reduced by NaCl than Na2SO4. Stomatal conductance was negatively influenced by decreasing water potentials caused by NaCl or Na2SO4, implying that a non...

SUR. Breve informe de la Expedición Yelcho al Polo Sur (1909-1910

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Ursula K. Le Guin

2013-12-01

Full Text Available Ursula K. Le Guin Escritora norteamericana, famosa por sus obras de ciencia fi cción y fantasía, en las cuales el tema de género ocupa una posición central. Ganadora de los premios Hugo y Nébula que la catapultaron a la fama. “SUR. A summary report of the Yelcho expedition to the Antarctic, 1909-1910”. Apáreció publicado por primera vez en la revista New Yorker, el 1° de febrero de 1982. La palabra SUR aparece en español en el original. (http://www.newyorker.com/ar Traducción de Susana E. Matallana Peláez

Sur terre comme sur mer: organisations spatiales en mer du Nord et mer de Norvège

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Maryvonne LE BERRE

1998-09-01

Full Text Available L'article montre, au moyen de représentations cartographiques et graphiques, les structures spatiales développées en mer pour l'exploitation des hydrocarbures. Malgré les différences de milieu, l'appropriation et l'occupation territoriales du domaine maritime s'effectuent selon les mêmes principes que sur le continent, à ceci près que ce qui s'étale en surface sur le continent se développe à la verticale en mer.

A right whale pootree: classification trees of faecal hormones identify reproductive states in North Atlantic right whales (Eubalaena glacialis).

Science.gov (United States)

Corkeron, Peter; Rolland, Rosalind M; Hunt, Kathleen E; Kraus, Scott D

2017-01-01

Immunoassay of hormone metabolites extracted from faecal samples of free-ranging large whales can provide biologically relevant information on reproductive state and stress responses. North Atlantic right whales ( Eubalaena glacialis Müller 1776) are an ideal model for testing the conservation value of faecal metabolites. Almost all North Atlantic right whales are individually identified, most of the population is sighted each year, and systematic survey effort extends back to 1986. North Atlantic right whales number trees as an alternative method of analysing multiple-hormone data sets, building on univariate models that have previously been used to describe hormone profiles of individual North Atlantic right whales of known reproductive state. Our tree correctly classified the age class, sex and reproductive state of 83% of 112 faecal samples from known individual whales. Pregnant females, lactating females and both mature and immature males were classified reliably using our model. Non-reproductive [i.e. 'resting' (not pregnant and not lactating) and immature] females proved the most unreliable to distinguish. There were three individual males that, given their age, would traditionally be considered immature but that our tree classed as mature males, possibly calling for a re-evaluation of their reproductive status. Our analysis reiterates the importance of considering the reproductive state of whales when assessing the relationship between cortisol concentrations and stress. Overall, these results confirm findings from previous univariate statistical analyses, but with a more robust multivariate approach that may prove useful for the multiple-analyte data sets that are increasingly used by conservation physiologists.

Prolonged particulate chromate exposure does not inhibit homologous recombination repair in North Atlantic right whale (Eubalaena glacialis) lung cells.

Science.gov (United States)

Browning, Cynthia L; Wise, Catherine F; Wise, John Pierce

2017-09-15

Chromosome instability is a common feature of cancers that forms due to the misrepair of DNA double strand breaks. Homologous recombination (HR) repair is a high fidelity DNA repair pathway that utilizes a homologous DNA sequence to accurately repair such damage and protect the genome. Prolonged exposure (>72h) to the human lung carcinogen, particulate hexavalent chromium (Cr(VI)), inhibits HR repair, resulting in increased chromosome instability in human cells. Comparative studies have shown acute Cr(VI) exposure induces less chromosome damage in whale cells than human cells, suggesting investigating the effect of this carcinogen in other species may inform efforts to prevent Cr(VI)-induced chromosome instability. Thus, the goal of this study was to determine the effect of prolonged Cr(VI) exposure on HR repair and clastogenesis in North Atlantic right whale (Eubalaena glacialis) lung cells. We show particulate Cr(VI) induces HR repair activity after both acute (24h) and prolonged (120h) exposure in North Atlantic right whale cells. Although the RAD51 response was lower following prolonged Cr(VI) exposure compared to acute exposure, the response was sufficient for HR repair to occur. In accordance with active HR repair, no increase in Cr(VI)-induced clastogenesis was observed with increased exposure time. These results suggest prolonged Cr(VI) exposure affects HR repair and genomic stability differently in whale and human lung cells. Future investigation of the differences in how human and whale cells respond to chemical carcinogens may provide valuable insight into mechanisms of preventing chemical carcinogenesis. Copyright © 2017. Published by Elsevier Inc.

Hausse des taxes sur le tabac et politiques de lutte antitabac au ...

International Development Research Centre (IDRC) Digital Library (Canada)

Par ailleurs, les études existantes sur les effets des taxes sur le tabac sont fondées sur l'" élasticité de la demande en fonction du prix ", une mesure qui indique l'évolution de la demande globale de cigarettes en réaction à une modification des prix, mais qui ne tient pas compte des effets d'une augmentation des taxes sur ...

Characterization and structural analysis of a potent anticoagulant phospholipase A2 from Pseudechis australis snake venom.

Science.gov (United States)

Du, Qianyun Sharon; Trabi, Manuela; Richards, Renée Stirling; Mirtschin, Peter; Madaras, Frank; Nouwens, Amanda; Zhao, Kong-Nan; de Jersey, John; Lavin, Martin F; Guddat, Luke W; Masci, Paul P

2016-03-01

Pseudechis australis is one of the most venomous and lethal snakes in Australia. Numerous phospholipase A2 (PLA2) isoforms constitute a major portion of its venom, some of which have previously been shown to exhibit not only enzymatic, but also haemolytic, neurotoxic and anticoagulant activities. Here, we have purified a potent anticoagulant PLA2 (identified as PA11) from P. australis venom to investigate its phospholipase, anticoagulant, haemolytic and cytotoxic activities and shown that addition of 11 nM PA11 resulted in a doubling of the clotting time of recalcified whole blood. We have also demonstrated that PA11 has high PLA2 enzymatic activity (10.9 × 10(4) Units/mg), but low haemolytic activity (0.6% of red blood cells hydrolysed in the presence of 1 nM PA11). PA11 at a concentration lower than 600 nM is not cytotoxic towards human cultured cells. Chemical modification experiments using p-bromophenacyl bromide have provided evidence that the catalytic histidine of PA11 is critical for the anticoagulant activity of this PLA2. PA11 that was subjected to trypsin digestion without previous reduction and alkylation of the disulfide bonds maintained enzymatic and anticoagulant activity, suggesting that proteolysis alone cannot abolish these properties. Consistent with these results, administration of PA11 by gavage in a rabbit stasis thrombosis model increased the clotting time of recalcified citrated whole blood by a factor of four. These data suggest that PA11 has potential to be developed as an anticoagulant in a clinical setting. Copyright © 2015. Published by Elsevier Ltd.

Effets de six composts sur les réponses physiologiques ...

African Journals Online (AJOL)

Les effets de ces six composts sur le potentiel hydrique, la fuite d'électrolyte, la teneur en amidon des feuilles et sur quelques paramètres agronomiques ont été évalués sur les plantes stressées en comparaison avec les plantes témoins. Les résultats indiquent des valeurs du potentiel hydrique foliaire très faibles et une ...

Sur un deplacement de valeurs: traire et tirer

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André Burger

1972-12-01

Full Text Available L'étymologie de firer est inconnue. Celie que le regretté W. von Wart burg a ern pouvoir avancer est inacceptable: firer serait sorti de marty rier par la grâce d'une fausse coupure mar tirier. Il est plus qu'improbable que cette «étymologie populaire» eût pu se produire si la langue ne possédait pas au préalable un verbe tirier. Au surplus aucun fait n'appuie cette hypothèse. Le FEW, t. VI, 1, p. 396, donne bien pour firer le sens de «torturer sur un treteam>, au XIIIe siècle, et p. 403, «démembrer en faisant tirer les quatre membles par des chevaux» et «torturer (qn en l'étendant sur un tréteau” au XIVe siècle; ces sens sont évidemment trop tardifs pour permettre des conclusions sur l'origine de firer, d'autant plus qu'ils s'expliquent sans peine par la valeur normale du mot, attesté dès la Chanson de Roland, sans aucun rapport avec martirie, mot savant de clerc, qui, dans le même texte s'applique deux fois sur quatre exemples aux Sarrasins, vv. 501 et 1467, où il ne signifie pas «martyre» mais <sur son étymologie et non sur les textes, que tirer aurait à l'origine »einen starken affektiven unterton« (FEW XIII, 2, p. 185. L'étude des exemples de la Chanson de Roland, confrontés avec ceux de traire, nons amènera à une conclusion toute différente.

Effets de l'audit clinique basé sur des critères sur de la qualité de la ...

African Journals Online (AJOL)

Effets de l'audit clinique basé sur des critères sur de la qualité de la prise en charge de la prééclampsie sévère dans le Département de Gynécologie Obstétrique du Centre Hospitalier Universitaire Yalgado Ouédraogo, Ouagadougou (Burkina Faso). Sibraogo Kiemtoré, Adama Dembélé, Adama Ouattara, Hyacinthe1,2 ...

Conférence sur l'efficacité

CERN Document Server

Jullien, François

2005-01-01

Philosophe et sinologue, François Jullien présente ici une conférence qu'il a prononcée auprès de chefs d'entreprise et dans le milieu du management. D'un côté, la conception européenne de l'efficacité est liée à la modélisation comme à la finalité et revendique l'action jusqu'à l'héroïsme ; de l'autre, la pensée chinoise de l'efficience, indirecte et discrète, s'appuie sur le potentiel de situation et induit des " transformations silencieuses ", sans éclat ni même événement. Par-delà cet écart, il s'agira d'interroger la nature de l'effectivité ; ou comment l'intervention humaine réussit à se brancher sur la propension des choses et s'y laisse intégrer. Ce propos se garde donc de séparer tant soit peu l'art d'opérer sur des situations et l'exercice de la philosophie ; en résultent des effets de lecture portant sur l'histoire du XXe siècle ainsi que la géopolitique - et géoéthique - à venir.

Metazoan parasites of Brama australis from southern Chile: a tool for stock discrimination?

Science.gov (United States)

Oliva, M E; Espinola, J F; Ñacari, L A

2016-03-01

The metazoan parasites of 403 specimens of the southern ray's bream Brama australis from three localities in southern Chile (Lebu 36° 70' S; 73° 40' W, Calbuco 41° 50' S; 73° 08' W and Punta Arenas 53° 10' S; 70° 50' W) were recorded. More than 23 400 parasite specimens belonging to 12 taxa were registered. Metazoan parasites were dominated by the copepod Hatschekia conifera, constituting 97% of the total number of parasites; the larval cestode Hepatoxylon trichiuri was the second most important parasite (2·1% of the total number of parasites). The remaining 10 species constituted parasites. Parasitological evidence, based on univariate and multivariate analysis, does not support the existence of discrete stocks in the studied zone. © 2016 The Fisheries Society of the British Isles.

Human consumption of a vagrant South American Fur Seal Arctocephalus australis (Carnivora: Otariidae in Brazil

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S. Siciliano

2016-04-01

Full Text Available The South American Fur Seal Arctocephalus australis is one of the most widely distributed South American otariid species. In Brazil, during austral winter months specimens of A. australis are regularly found along the Rio Grande do Sul and Santa Catarina coasts. Occasionally, vagrants have been recorded along the southeastern coast but rarely moves north of Rio de Janeiro, at 23°S. On 01 May 2015, fishermen noticed in the surf zone an unidentified large animal in Ilhéus, Bahia, northeastern Brazil. Severely wounded, it was still alive when first spotted. Numerous shark bites were observed in the rostrum and flippers, the peduncle was severely lacerated and the intestines were protruding. The specimen was identified as an adult of South American Fur Seal based on the combination of the characteristic coloration of the pelage, head shape, body size, the relatively large eye size, and mainly due to the pronounced three cusped teeth in post canines. Fishermen decided to butcher the carcass and share the meat among their companions. The present record, however, is of special concern as human consumption South American Fur Seal seems to be unusual in Brazil. Pieces of meat were shared among fishermen. In addition, small pieces of blubber were used as bait in the local shark long-line fishery. Consumption of an injured and presumably weak marine mammal carcass points to an increasing risk of contact between potentially harmful viruses, bacteria and fungi and humans. This note represents an alert to public health specialists and wildlife authorities in Brazil. It calls the urgency of an outreach campaign advertising to the potential risks of ingesting bushmeat either from land or aquatic sources. 

Taxes sur les cigarettes en Tanzanie | IDRC - International ...

International Development Research Centre (IDRC) Digital Library (Canada)

Taxes sur les cigarettes en Tanzanie. De 2002 à 2007, le tabagisme a connu une hausse de 20 % en Tanzanie, une augmentation qui devrait atteindre 46 % en 2016 si la tendance se maintient. On s'attend à ce que cette hausse du tabagisme ait d'importantes répercussions sur la santé publique et le développement ...

Geographic distribution and description of four pelagic barnacles along the south east Pacific coast of Chile - a zoogeographical approximation Distribución geográfica y descripción de cuatro especies de cirripedios pelágicos a lo largo de la costa chilena del Pacífico sur este - una aproximación zoogeográfica

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IVÁN HINOJOSA

2006-03-01

Full Text Available The majority of zoogeographic studies along the Chilean Pacific coast have focused on benthic organisms and oceanographic conditions are considered the main factors influencing their distributions. Herein we examined the geographic distribution of pelagic barnacles of the family Lepadidae collected from floating macroalgae at seven sampling areas between 23 and 50° S. Four species were encountered and they are briefly described herein. The most abundant northern species was Lepas anatifera, and it diminished in abundance towards the south (33° S. Moreover, this species was not found in waters with a sea surface temperature (SST of less than ~18 °C. Lepas australis, primarily a circumpolar West Wind Drift species, diminished in abundance towards the north (33° S. This species was restricted to waters of La mayoría de los estudios de zoogeografía a lo largo de la costa chilena del Pacífico sur este se han enfocado en organismos bentónicos y las condiciones oceanográficas se sugieren como factores principales que modulan su distribución. Aquí examinamos la distribución geográfica de especies de cirripedios pelágicos de la familia Lepadidae, asociadas a macroalgas flotando a la deriva, en siete áreas de muestreo entre los 23 y 50° S. Se encontraron cuatro especies de cirripedios lepádidos y cada una se describe brevemente. La especie del norte más abundantes fue Lepas anatifera y disminuye su abundancia hacia el sur (33° S. Además, esta especie no se encontró en temperatura superficial del mar (SST inferior a ~18 °C. Lepas australis, que posee una distribución circumpolar, atenúa su abundancia hacia el norte (33° S. Esta especie se restringe a SST < 18 °C. La tercera especie, L. pectinata se extiende en la mayor parte del área de estudio, pero posee su mayor abundancia relativa en el área central, entre 29 y 33° S. La cuarta especie, Dosima fascicularis, solo se encontró en dos lugares de muestreo, en 27 y 33° S, y es

Caracterización estructural de un bosque de Podocarpus parlatorei y Juglans australis en Salta, Argentina

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M.A. Pinazo

2003-06-01

Full Text Available Se estudió la estructura de bosques montanos ubicados en áreas con distinto grado de modificación humana en el Noroeste de Argentina (22º24’ S, 1550 msnm. Se utilizaron parcelas circulares para caracterizar los rodales. Los rodales fueron clasificados en función del área basal por especie. Se reconocieron cinco estructuras diferenciadas por la proporción de Juglans australis, Podocarpus parlatorei y de las especies tolerantes a la sombra Blepharocalyx salicifolius, Myrcianthes sp y Allophylus edulis. Se presentan datos de densidad y área basal de individuos con diámetro a la altura del pecho (DAP> 10 cm y la densidad de individuos con DAPStands of Subtropical Montane Cloud Forest were studied in areas under different land use regimes near Los Toldos (NW Argentina. Circular plots were used to calculate density and basal area of trees with dbh > 10 cm; and density of trees with dbh < 10 cm. The stands were classified and grouped as a function of basal area. Five structures were recognized, with different proportions of Juglans australis, Podocarpus parlatorei and shade-tolerant species like Blepharocalyx salicifolius, Allophylus edulis and Myrcianthes sp. Less disturbed area stands had a higher basal area and greater dbh for all species, and shade-tolerant species in the canopy. In the most disturbed area, all canopy species were shade intolerant and regeneration was dominated by shade-tolerant species. The differences in composition, basal area, stem diameter class distribution and regeneration indicate that the structure types corresponded to different stages of the successional process, and the regeneration of the most disturbed areas suggest a tendency towards the composition of mature forest.

Transcriptome and Degradome of microRNAs and Their Targets in Response to Drought Stress in the Plants of a Diploid and Its Autotetraploid Paulownia australis.

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Suyan Niu

Full Text Available MicroRNAs (miRNAs are small, non-coding RNAs that play vital roles in plant growth, development, and stress response. Increasing numbers of studies aimed at discovering miRNAs and analyzing their functions in plants are being reported. In this study, we investigated the effect of drought stress on the expression of miRNAs and their targets in plants of a diploid and derived autotetraploid Paulownia australis. Four small RNA (sRNA libraries and four degradome libraries were constructed from diploid and autotetraploid P. australis plants treated with either 75% or 25% relative soil water content. A total of 33 conserved and 104 novel miRNAs (processing precision value > 0.1 were identified, and 125 target genes were identified for 36 of the miRNAs by using the degradome sequencing. Among the identified miRNAs, 54 and 68 were differentially expressed in diploid and autotetraploid plants under drought stress (25% relative soil water content, respectively. The expressions of miRNAs and target genes were also validated by quantitative real-time PCR. The results showed that the relative expression trends of the randomly selected miRNAs were similar to the trends predicted by Illumina sequencing. And the correlations between miRNAs and their target genes were also analyzed. Furthermore, the functional analysis showed that most of these miRNAs and target genes were associated with plant development and environmental stress response. This study provided molecular evidence for the possible involvement of certain miRNAs in the drought response and/or tolerance in P. australis, and certain level of differential expression between diploid and autotetraploid plants.

Intensificación de la circulación atmosférica meridional en la región subtropical de América del sur inferida a partir de registros dendroclimatológicos

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1998-01-01

Full Text Available RENFORCEMENT DE LA CIRCULATION ATMOSPHERIQUE MERIDIONALE D’AMERIQUE DU SUD DEDUITE DE DONNEES DENDROCLIMATOLOGIQUES. L’objectif principal de cette étude est de montrer comment on peut utiliser la dendroclimatologie pour caractériser les variations climatiques qui ont affecté ces deux derniers siècles la région subtropicale de montagne de l’Amérique du Sud. Nous avons utilisé des chroniques de largeur d’anneaux de croissance obtenues sur du nogal criollo (Juglans australis et du Cèdre Tumaco (Cedrela lilloi pour estimer les variations mensuelles de température et de précipitation depuis 1800. Comme les mesures météorologiques directes, les séries dendroclimatologiques sensibles aux précipitations montrent un accroissement soutenu des précipitations dans la région montagneuse subtropicale qui démarre vers 1950, que l’on n’avait pas du tout observé au cours des 200 années précédentes. Le gradient de pression atmosphérique entre les régions tropicales et subtropicales mesuré par les différences de pression entre Cuiaba (15°S et Reconquista (29°S s’est accru progressivement depuis 1950. Ce renforcement du gradient de pression, associé à une augmentation des températures dans les zones subtropicales paraît avoir induit un déplacement vers le sud de la cellule continentale de basse pression sur l’Amérique du Sud. Ce déplacement pourrait avoir provoqué une augmentation des précipitations et une réduction de la durée de la saison sèche dans le subtropique montagneux. Les corrélations spatiales entre l’épaisseur des anneaux de croissance et la Température de Surface de l’Océan (SST indiquent également que l’augmentation des précipitations subtropicales pourrait aussi être reliée à une augmentation significative de la SST de l’Atlantique sud survenue au cours des 4 dernières décades. Ces résultats montrent de manière claire le potentiel des méthodes dendroclimatologiques pour reconstituer les

Archaeological Remains Accounting for the Presence and Exploitation of the North Atlantic Right Whale Eubalaena glacialis on the Portuguese Coast (Peniche, West Iberia), 16th to 17th Century

Science.gov (United States)

Teixeira, António; Venâncio, Rui; Brito, Cristina

2014-01-01

The former occurrence of the North Atlantic right whale Eubalaena glacialis on the Portuguese coast may be inferred from the historical range of that species in Europe and in NW Africa. It is generally accepted that it was the main prey of coastal whaling in the Middle Ages and in the pre-modern period, but this assumption still needs firming up based on biological and archaeological evidence. We describe the skeletal remains of right whales excavated at Peniche in 2001–2002, in association with archaeological artefacts. The whale bones were covered by sandy sediments on the old seashore and they have been tentatively dated around the 16th to 17th centuries. This study contributes material evidence to the former occurrence of E. glacialis in Portugal (West Iberia). Some whale bones show unequivocal man-made scars. These are associated to wounds from instruments with a sharp-cutting blade. This evidence for past human interaction may suggest that whaling for that species was active at Peniche around the early 17th century. PMID:24505251

Archaeological remains accounting for the presence and exploitation of the North Atlantic right whale Eubalaena glacialis on the Portuguese Coast (Peniche, West Iberia, 16th to 17th Century.

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António Teixeira

Full Text Available The former occurrence of the North Atlantic right whale Eubalaena glacialis on the Portuguese coast may be inferred from the historical range of that species in Europe and in NW Africa. It is generally accepted that it was the main prey of coastal whaling in the Middle Ages and in the pre-modern period, but this assumption still needs firming up based on biological and archaeological evidence. We describe the skeletal remains of right whales excavated at Peniche in 2001-2002, in association with archaeological artefacts. The whale bones were covered by sandy sediments on the old seashore and they have been tentatively dated around the 16th to 17th centuries. This study contributes material evidence to the former occurrence of E. glacialis in Portugal (West Iberia. Some whale bones show unequivocal man-made scars. These are associated to wounds from instruments with a sharp-cutting blade. This evidence for past human interaction may suggest that whaling for that species was active at Peniche around the early 17th century.

Le Projet d’Ole Lando sur les Contrats

DEFF Research Database (Denmark)

Holle, Marie-Louise

2017-01-01

En 2016 le projet de recherche le plus important jusqu’à présent sur le droit nordique des contrats a pris fin et un livre, de presque 400 pages, en a marqué l’aboutissement. Le résultat du projet est un « restatement » tel qu’il existe aux États-Unis. Le Restatement porte sur les règles et les...

DNA hybridization evidence for the Australasian affinity of the American marsupial Dromiciops australis.

Science.gov (United States)

Kirsch, J A; Dickerman, A W; Reig, O A; Springer, M S

1991-01-01

DNA hybridization was used to compare representatives of the major groups of marsupials and a eutherian outgroup. Because of the large genetic distances separating marsupial families, trees were calculated from normalized percentages of hybridization; thermal-melting statistics, however, gave identical topologies for the well-supported clades. The most notable results were the association of the only extant microbiotheriid, Dromiciops australis, an American marsupial, with the Australasian Diprotodontia, and of both together with the Dasyuridae. Estimates of the rate of divergence among marsupial genomes suggest that the Dromiciops-Diprotodontia split occurred approximately 50 million years ago, well after the establishment of the major clades of marsupials but before deep oceanic barriers prohibited dispersal among Australia, Antarctica, and South America. Because Dromiciops is nested within an Australasian group, it seems likely that dispersal from Australia accounts for its present distribution. Images PMID:1961710

Extracts from Cladiella australis, Clavularia viridis and Klyxum simplex (Soft Corals are Capable of Inhibiting the Growth of Human Oral Squamous Cell Carcinoma Cells

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Guey-Horng Wang

2008-11-01

Full Text Available Many biomedical products have already been obtained from marine organisms. In order to search more therapeutic drugs against cancer, this study demonstrates the cytotoxicity effects of Cladiella australis, Clavularia viridis and Klyxum simplex extractson human oral squamous cell carcinoma (SCC4, SCC9 and SCC25 cells using cell adhesion and cell viability assay. The morphological alterations in SCCs cells after treatment with three extracts, such as typical nuclear condensation, nuclear fragmentation and apoptotic bodies of cells were demonstrated by Hoechst stain. Flow cytometry indicated that three extracts sensitized SCC25 cells in the G0/G1 and S-G2/M phases with a concomitant significantly increased sub-G1 fraction, indicating cell death by apoptosis. This apoptosis process was accompanied by activation of caspase-3 expression after SCC25 cells were treated with three extracts. Thereby, it is possible that extracts of C. australis, C. viridis and K. simplex cause apoptosis of SCCs and warrant further research investigating the possible anti-oral cancer compounds in these soft corals.

Droits, justice et réseaux sociaux sur Internet (Amérique latine ...

International Development Research Centre (IDRC) Digital Library (Canada)

... sur la question de la protection des renseignements personnels sur Internet, ... Derechos y justicia y el movimiento social en internet (5 de agosto de 2009 ... Programme de recherche sur le virus Zika Canada-Amérique latine et Caraïbes.

Proteomic analysis of blue light-induced twining response in Cuscuta australis.

Science.gov (United States)

Li, Dongxiao; Wang, Liangjiang; Yang, Xiaopo; Zhang, Guoguang; Chen, Liang

2010-01-01

The parasitic plant Cuscuta australis (dodder) invades a variety of species by entwining the stem and leaves of a host and developing haustoria. The twining response prior to haustoria formation is regarded as the first sign for dodders to parasitize host plants, and thus has been the focus of studies on the host-parasite interaction. However, the molecular mechanism is still poorly understood. In the present work, we have investigated the different effects of blue and white light on the twining response, and identified a set of proteins that were differentially expressed in dodder seedlings using a proteomic approach. Approximately 1,800 protein spots were detected on each 2-D gel, and 47 spots with increased or decreased protein levels were selected and analyzed with MALDI-TOF-MS. Peptide mass fingerprints (PMFs) obtained for these spots were used for protein identification through cross-species database searches. The results suggest that the blue light-induced twining response in dodder seedlings may be mediated by proteins involved in light signal transduction, cell wall degradation, cell structure, and metabolism.

Molecular phylogeny and taxonomic revision of the genus Wittrockiella (Pithophoraceae, Cladophorales), including the descriptions of W. australis sp. nov. and W. zosterae sp. nov.

Science.gov (United States)

Boedeker, Christian; O'Kelly, Charles J; West, John A; Hanyuda, Takeaki; Neale, Adele; Wakana, Isamu; Wilcox, Mike D; Karsten, Ulf; Zuccarello, Giuseppe C

2017-06-01

Wittrockiella is a small genus of filamentous green algae that occurs in habitats with reduced or fluctuating salinities. Many aspects of the basic biology of these algae are still unknown and the phylogenetic relationships within the genus have not been fully explored. We provide a phylogeny based on three ribosomal markers (ITS, LSU, and SSU rDNA) of the genus, including broad intraspecific sampling for W. lyallii and W. salina, recommendations for the use of existing names are made, and highlight aspects of their physiology and life cycle. Molecular data indicate that there are five species of Wittrockiella. Two new species, W. australis and W. zosterae, are described, both are endophytes. Although W. lyallii and W. salina can be identified morphologically, there are no diagnostic morphological characters to distinguish between W. amphibia, W. australis, and W. zosterae. A range of low molecular weight carbohydrates were analyzed but proved to not be taxonomically informative. The distribution range of W. salina is extended to the Northern Hemisphere as this species has been found in brackish lakes in Japan. Furthermore, it is shown that there are no grounds to recognize W. salina var. kraftii, which was described as an endemic variety from a freshwater habitat on Lord Howe Island, Australia. Culture experiments indicate that W. australis has a preference for growth in lower salinities over full seawater. For W. amphibia and W. zosterae, sexual reproduction is documented, and the split of these species is possibly attributable to polyploidization. © 2017 Phycological Society of America.

Recherche en partenariat sur la transition nutritionnelle et les ...

International Development Research Centre (IDRC) Digital Library (Canada)

l'évolution du risque a suivi et a débouché sur une stratégie de prévention ... de recherche ont pu avoir un impact sur les politiques et pro- .... Deux études étaient donc entreprises ..... à la même thématique et de recruter par eux-mêmes les.

Renforcement de l'influence de la recherche sur l'élaboration des ...

International Development Research Centre (IDRC) Digital Library (Canada)

Réflexions

influent sur les politiques, mais de façons différentes. Le lien entre recherche et influence sur les politiques n'est ... Renforcement de l'influence de la recherche sur l'élaboration des politiques d'adaptation. PA. NOS. /G .... ceux de la CMAE ont dit avoir besoin de soutien technique. Il était malheureusement difficile pour le ...

Pharmacokinetics and pharmacodynamics of the myotoxic venom of Pseudechis australis (mulga snake) in the anesthetised rat.

Science.gov (United States)

Hart, A J; Hodgson, W C; O'Leary, M; Isbister, G K

2014-07-01

Myotoxicity is a common clinical effect of snake envenoming and results from either local or systemic myotoxins in snake venoms. Although numerous myotoxins have been isolated from snake venoms, there has been limited study on the relationship between the time course of venom concentrations (pharmacokinetics) and the time course of muscle injury measured as a rise in creatine kinase (CK) (pharmacodynamics). The aim of this study was to develop an in vivo model of myotoxicity to investigate the time course of myotoxicity and the effect of antivenom. Anesthetised rats were administered Pseudechis australis (mulga snake) venom either through i.v., i.m. or s.d. route, including a range of doses (5-100 μg/kg). Serial blood samples were collected for measurement of venom using enzyme immunoassay and measurement of CK and creatinine. Antivenom was administered before, 1 and 6 h after venom administration to investigate its effect on muscle injury. Plots of venom and CK versus time were made and the area under the curve (AUC) was calculated. There was a significant dose-dependent increase in CK concentration after administration of P. australis venom, which was greatest for i.v. administration. Timed measurement of venom concentrations showed a rapid absorption through s.d. and i.m. routes and a delayed rise in CK concentrations following any route. Antivenom prevented myotoxicity shown by a decrease in the CK AUC, which was most effective if given earliest. There was a rise in creatinine following i.v. venom administration. The study shows the delayed relationship between venom absorption and the rise in CK, consistent with the delayed onset of myotoxicity in human envenoming. Antivenom prevented myotoxicity more effectively if given earlier.

Otolith shape analysis as a tool for stock identification of the southern blue whiting, Micromesistius australis

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Javier Leguá

2013-07-01

Full Text Available The southern blue whiting, Micromesistius australis (Norman, 1937, is an important demersal resource associated with the slope and continental shelf of southern Chile, Argentina and the Malvinas/Falkland Islands. Recent studies have reported schools of adult fish from Atlantic waters migrating along the southern Chilean coast in mid-winter, moving northwards to spawn in August (47°-51°S, and then returning to Atlantic waters, presumably to feed. The migratory pattern suggests the presence of one or more stock units associated with the South American coast. In the present study, "otolith morphometry" is used to determine the stock structure of M. australis based on applications of basic size descriptors (SDs (area, perimeter and otolith size, shape indices (SIs (circularity, squareness, shape factor, roundness, ellipticity, and normalised elliptical Fourier descriptors (NEFDs. Samples were collected during the winter and spring of 2010, during the reproductive period, in the economic zone of southern Chile (36°-57°S, in the Pacific Ocean and around the Falkland Islands economic zone (50°-52°S in the Atlantic Ocean. Analyses were conducted to include the effects of size, sex and age. A stepwise canonical discriminant analysis showed that fish were successfully discriminated with SDs, SIs and NEFDs. In this analysis, 86.4% and 70.1% of the fish were correctly classified as belonging to the Atlantic and Pacific stocks, respectively. A multivariate analysis of variance showed that the mean values of the NEFDs, SDs, and SIs did not vary significantly between sexes within areas (P > 0.05, but varied significantly between the Pacific and Atlantic oceans (P < 0.05. These results highlighted that otolith shape analysis can be a useful tool to evaluate the potential level of mixing in feeding areas where both stocks, the Pacific and Atlantic units, are expected to co-occur.

Components of SurA required for outer membrane biogenesis in uropathogenic Escherichia coli.

Directory of Open Access Journals (Sweden)

Kristin M Watts

2008-10-01

Full Text Available SurA is a periplasmic peptidyl-prolyl isomerase (PPIase and chaperone of Escherichia coli and other Gram-negative bacteria. In contrast to other PPIases, SurA appears to have a distinct role in chaperoning newly synthesized porins destined for insertion into the outer membrane. Previous studies have indicated that the chaperone activity of SurA rests in its "core module" (the N- plus C-terminal domains, based on in vivo envelope phenotypes and in vitro binding and protection of non-native substrates.In this study, we determined the components of SurA required for chaperone activity using in vivo phenotypes relevant to disease causation by uropathogenic E. coli (UPEC, namely membrane resistance to permeation by antimicrobials and maturation of the type 1 pilus usher FimD. FimD is a SurA-dependent, integral outer membrane protein through which heteropolymeric type 1 pili, which confer bladder epithelial binding and invasion capacity upon uropathogenic E. coli, are assembled and extruded. Consistent with prior results, the in vivo chaperone activity of SurA in UPEC rested primarily in the core module. However, the PPIase domains I and II were not expendable for wild-type resistance to novobiocin in broth culture. Steady-state levels of FimD were substantially restored in the UPEC surA mutant complemented with the SurA N- plus C-terminal domains. The addition of PPIase domain I augmented FimD maturation into the outer membrane, consistent with a model in which domain I enhances stability of and/or substrate binding by the core module.Our results confirm the core module of E. coli SurA as a potential target for novel anti-infective development.

Akkumulation von L-Malat und D-Lactat in Arabidopsis thaliana und Laccase/HBT-vermittelte Delignifizierung von Spartina alterniflora und Phragmites australis

OpenAIRE

Heil, Alexander

2016-01-01

The current work contains two projects "Accumulation of L-malate and D-lactate in Arabidopsis thaliana" (A) "Laccase/HBT mediated delignification of Spartina alterniflora and Phragmites australis" (B). In project A, L-malate and D-lactate accumulated in A. thaliana plants. The accumulation of L-malate is carried out by modification of the plant metabolism with the enzymes PEPC, MDH and the tonoplast dicarboxylate transporter (TDT). Gene pepci2 (Hydrilla verticillata), mdh5 (Zea mays) and tdt ...

Changes in soluble metal concentrations induced by variable water table levels as response to liming and Phragmites australis growth in metal-polluted wetland soils: Management effectiveness

NARCIS (Netherlands)

Gonzalez Alcaraz, M.N.; van Gestel, C.A.M.

2016-01-01

This study aimed to assess the effectiveness of liming and Phragmites australis growth for the management of metal-polluted wetland soils under fluctuating water table levels. Soil columns (20 cm in diameter and 60 cm high) were constructed with two soil types (pH ~ 6.4 and pH ~ 3.1) and four

Espacio herido, tiempo acelerado, imaginario conmovido. Interrogantes sobre la postmodernidad del Sur.

Directory of Open Access Journals (Sweden)

Mabel Franzone

2010-11-01

Full Text Available Estableciendo una relación estrecha entre espacio, tiempo e imaginario, este escrito intenta tratar la gran separación Norte- Sur, acaecida con la hipermodernidad y sus consecuencias sobre la destrucción del espacio del Sur ; la cuestión de fondo encara las huellas que puede dejar en los cuerpos y en los imaginarios. Los límites impuestos se tratan en cuatro niveles : históricos, geográficos, económicos- sociales y de la representación. Para una crítica de la modernidad se han tomado parámetros de pensamiento que operan en una trama mediana, forma de pensar propia al Sur y que muestran la necesidad de una epistemología también propia al Sur, que refleje las cuestiones fundamentales y que tenga en cuenta la emancipación y la solidaridad como categorías para repensar el Sur.

Estilos estructurales del Subandino Sur de Bolivia

OpenAIRE

Rocha, Emilio

2013-01-01

El Subandino Sur de Bolivia es una típica faja plegada y corrida de lámina delgada, con una notable regularidad en la geometría de las estructuras. Esta es una característica típica de las fajas plegadas en las que no se involucra el basamento en la deformación. Sin embargo, cuando se analiza en detalle la geometría y evolución de la deformación del Subandino Sur, se verifica que existen numerosas desviaciones de dicha regularidad. En el presente trabajo se estudiaron los diferentes procesos ...

Le lancement canadien du Rapport sur les politiques alimentaires ...

International Development Research Centre (IDRC) Digital Library (Canada)

1 mai 2018 ... Cet événement sera filmé, puis accessible en ligne sur la chaîne YouTube du CRDI. Le Rapport sur les politiques alimentaires mondiales 2018 passe en revue les principaux faits nouveaux et événements en matière de politiques alimentaires survenus au cours de l'année. D'éminents chercheurs ...

Analyse technico–économique des Aliments densifies sur les ...

African Journals Online (AJOL)

Une étude portant sur l'influence des aliments densifiés sur la performance de croissance des boucs roux de Maradi a été conduite entre juillet 2016 à septembre 2016. Quarante deux (42) boucs ont été répartis au hasard en six lots de sept individus. Chaque lot correspond à un aliment ou traitement préparé à partir des.

Concilier plaisir et nutrition. Travaux des groupes de travail PNNS sur les lipides et sur le goût

OpenAIRE

Souliac , L.; Bizet, G.; Remy, S.

2010-01-01

Les ministères chargés de l'alimentation et de la santé ont incité les opérateurs à mettre sur le marché des aliments moins riches en lipides, par la signature avec l'État de chartes d'engagement sur la composition nutritionnelle. L'observatoire de la qualité de l'alimentation suit l'évolution de ces efforts. Les lipides ont un rôle technologique et sensoriel important qu'il convient de prendre en considération. Il est aujourd'hui possible d'améliorer le profil nutritionnel des aliments, tout...

Données préliminaires sur le paludisme humain en zones rurale et ...

African Journals Online (AJOL)

SARAH

31 juil. 2017 ... axée sur le diagnostic précoce et la prise en charge rapide des ... recherche investigue sur les connaissances, attitudes et ... paludisme et (vi) sur la source de traitement du paludisme. ... technique ELISA (Burkot et al., 1984).

Моrрhоlоgy of inflorescensce and bluming peculiarities of Baptisia australis (L. R.Br. (Fabaceae introduced in М.М. Grishko National Botanical Garden NAS of Ukraine

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Vira G. Mikolajchuk

2014-04-01

Full Text Available The structure of inflorescence in Baptisia australis introduced in conditions of M.M. Grishko National Botanical Garden in Kyiv has been studied. The dynamics of blooming and inflorescence development were analyzed.

Enquêtes sur les soucoupes volantes

OpenAIRE

Lagrange, Pierre

2007-01-01

La dispute autour du mot « preuve » se réduit à une question : Qu'est-ce qui constitue une preuve ? Faut-il qu'un ovni atterrisse à l'entrée du Pentagone, près des bureaux des chefs d'État-Major ? Ou bien est-ce une preuve quand une station de radar au sol détecte un ovni, envoie un jet l'intercepter, que le pilote du jet le voit et le suit sur son radar pour finir par le voir disparaître à une vitesse phénoménale ? Ou est-ce une preuve quand un pilote tire sur un ovni et maintient son histoi...

Submillimeter Spectroscopy of the R Coronae Australis Molecular Cloud Region

Science.gov (United States)

Dunn, Marina Madeline; Walker, Christopher K.; Pat, Terrance; Sirsi, Siddhartha; Swift, Brandon J.; Peters, William L.

2018-01-01

The Interstellar Medium is comprised of large amounts of gas and dust which coalesce to form stars. Observing in the Terahertz regime of the electromagnetic spectrum, approximately 0.3 -300 microns, allows astronomers to study the ISM in unprecedented detail. Using the high spectral resolution imaging system of the SuperCam receiver, a 64-pixel array previously installed on the Submillimeter Telescope on Mt. Graham, AZ, we have begun a 500 square degree survey of the galactic plane. This instrument was designed to do a complete survey of the Milky Way from the ground, with the main focus being to observe two specific transitions of the carbon monoxide molecule, 12CO(3-2) and 13CO(3-2), at 345 GHz. In this work, we present results from these observations for the R Coronae Australis (R Cr A) complex, a region in the southern hemisphere of the sky, using spectroscopic data from a portion of the survey to gain better insight into the life cycle of the ISM. The majority of stars being formed here are similar to the stellar class of the Sun, making it an excellent area of observing interest. Using these results, we attempt to better ascertain the large-scale structure and kinematics inside of the molecular cloud.

Hausse des taxes sur le tabac dans trois pays d'Amérique centrale ...

International Development Research Centre (IDRC) Digital Library (Canada)

Les chercheurs mèneront des études sur la demande de produits du tabac dans le ... sur les techniques modernes de contrôle de la chaîne d'approvisionnement, ... IWRA/CRDI sur les changements climatiques et la gestion adaptive de l'eau.

Une nouvelle ouverture sur le monde pour les femmes | CRDI ...

International Development Research Centre (IDRC) Digital Library (Canada)

'appellent ailleurs dans le dédale d'étals et d'allées serrés. En plus de son travail sur le marché, Jertrudes est également secrétaire de l'association des femmes qui vendent sur ce marché. Le groupe est un endroit où elles ...

Influence de l'irrigation sur le rendement et sur la qualité des raisins

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J. Cerny

1968-12-01

 Le travail présenté résume les résultats de l'expérience avec l'irrigation supplémentaire de la vigne dans le domaine sec du Sud de la Moravie ainsi que son influence sur le rendement et la qualité des raisins.

Image collection: 93 [Togo Picture Gallery[Archive

Lifescience Database Archive (English)

Full Text Available 93 Eubalaena_japonica_NL.png セミクジラ Right whale Eubalaena japonica 302098 生物アイコン,脊索動物門,脊椎動物亜門,哺乳綱,獣亜綱,真獣下綱,クジラ目

A new dolphin species, the Burrunan Dolphin Tursiops australis sp. nov., endemic to southern Australian coastal waters.

Science.gov (United States)

Charlton-Robb, Kate; Gershwin, Lisa-ann; Thompson, Ross; Austin, Jeremy; Owen, Kylie; McKechnie, Stephen

2011-01-01

Small coastal dolphins endemic to south-eastern Australia have variously been assigned to described species Tursiops truncatus, T. aduncus or T. maugeanus; however the specific affinities of these animals is controversial and have recently been questioned. Historically 'the southern Australian Tursiops' was identified as unique and was formally named Tursiops maugeanus but was later synonymised with T. truncatus. Morphologically, these coastal dolphins share some characters with both aforementioned recognised Tursiops species, but they also possess unique characters not found in either. Recent mtDNA and microsatellite genetic evidence indicates deep evolutionary divergence between this dolphin and the two currently recognised Tursiops species. However, in accordance with the recommendations of the Workshop on Cetacean Systematics, and the Unified Species Concept the use of molecular evidence alone is inadequate for describing new species. Here we describe the macro-morphological, colouration and cranial characters of these animals, assess the available and new genetic data, and conclude that multiple lines of evidence clearly indicate a new species of dolphin. We demonstrate that the syntype material of T. maugeanus comprises two different species, one of which is the historical 'southern form of Tursiops' most similar to T. truncatus, and the other is representative of the new species and requires formal classification. These dolphins are here described as Tursiops australis sp. nov., with the common name of 'Burrunan Dolphin' following Australian aboriginal narrative. The recognition of T. australis sp. nov. is particularly significant given the endemism of this new species to a small geographic region of southern and south-eastern Australia, where only two small resident populations in close proximity to a major urban and agricultural centre are known, giving them a high conservation value and making them susceptible to numerous anthropogenic threats.

A new dolphin species, the Burrunan Dolphin Tursiops australis sp. nov., endemic to southern Australian coastal waters.

Directory of Open Access Journals (Sweden)

Kate Charlton-Robb

Full Text Available Small coastal dolphins endemic to south-eastern Australia have variously been assigned to described species Tursiops truncatus, T. aduncus or T. maugeanus; however the specific affinities of these animals is controversial and have recently been questioned. Historically 'the southern Australian Tursiops' was identified as unique and was formally named Tursiops maugeanus but was later synonymised with T. truncatus. Morphologically, these coastal dolphins share some characters with both aforementioned recognised Tursiops species, but they also possess unique characters not found in either. Recent mtDNA and microsatellite genetic evidence indicates deep evolutionary divergence between this dolphin and the two currently recognised Tursiops species. However, in accordance with the recommendations of the Workshop on Cetacean Systematics, and the Unified Species Concept the use of molecular evidence alone is inadequate for describing new species. Here we describe the macro-morphological, colouration and cranial characters of these animals, assess the available and new genetic data, and conclude that multiple lines of evidence clearly indicate a new species of dolphin. We demonstrate that the syntype material of T. maugeanus comprises two different species, one of which is the historical 'southern form of Tursiops' most similar to T. truncatus, and the other is representative of the new species and requires formal classification. These dolphins are here described as Tursiops australis sp. nov., with the common name of 'Burrunan Dolphin' following Australian aboriginal narrative. The recognition of T. australis sp. nov. is particularly significant given the endemism of this new species to a small geographic region of southern and south-eastern Australia, where only two small resident populations in close proximity to a major urban and agricultural centre are known, giving them a high conservation value and making them susceptible to numerous anthropogenic

Chaire de recherche trilatérale Canada – Afrique du Sud sur les ...

International Development Research Centre (IDRC) Digital Library (Canada)

Le présent projet met l'accent sur les interactions entre l'humain et la faune, notamment sur les pauvres des zones rurales en pays tropical et sur l'effet des changements climatiques que ces derniers subiront. Puisant dans la recherche menée à la station de biologie expérimentale de l'Université Makere, près du parc ...

Rapport annuel au Parlement Loi sur la protection des ...

International Development Research Centre (IDRC) Digital Library (Canada)

Larocque, Samia

1 juil. 1983 ... TBS/SCT 350-63 (Rév. 2011/03). 31/03/2014. 01/04/2013. Période visée par le rapport : Reçues pendant la période visée par le rapport. Total. En suspens à la fin de la période de rapport précédente. Rapport statistique sur la Loi sur la protection des renseignements personnels. Nom de l'institution :.

Des pratiques culturales influent sur les attaques de deux ravageurs ...

African Journals Online (AJOL)

La culture de tomate est attaquée par plusieurs ravageurs dont Helicoverpa armigera et Tuta absoluta. Dans le but d'évaluer l'effet des pratiques culturales de la tomate sur ces principaux ravageurs dans les Niayes (Sénégal), un échantillonnage de 98 parcelles est effectué, sur quatre cycles de culture en saison sèche, de ...

SurR9C84A protects and recovers human cardiomyocytes from hypoxia induced apoptosis

Energy Technology Data Exchange (ETDEWEB)

Ashok, Ajay [Nanomedicine-Laboratory of Immunology and Molecular Biomedical Research (NLIMBR), School of Medicine (SoM), Faculty of Health, Centre for Molecular and Medical Research - C-MMR, Deakin University, Waurn Ponds, Victoria 3216 (Australia); Department of Pathology, Case Western Reserve University, 2103 Cornell Rd. WRB 5128, Cleveland, OH 44106-7288 (United States); Kanwar, Jagat Rakesh [Nanomedicine-Laboratory of Immunology and Molecular Biomedical Research (NLIMBR), School of Medicine (SoM), Faculty of Health, Centre for Molecular and Medical Research - C-MMR, Deakin University, Waurn Ponds, Victoria 3216 (Australia); Krishnan, Uma Maheswari [Centre for Nanotechnology & Advanced Biomaterials (CeNTAB), School of Chemical & Biotechnology (SCBT), SASTRA University, Thanjavur 613401 (India); Kanwar, Rupinder Kaur, E-mail: rupinder.kanwar@deakin.edu.au [Nanomedicine-Laboratory of Immunology and Molecular Biomedical Research (NLIMBR), School of Medicine (SoM), Faculty of Health, Centre for Molecular and Medical Research - C-MMR, Deakin University, Waurn Ponds, Victoria 3216 (Australia)

2017-01-01

Survivin, as an anti-apoptotic protein and a cell cycle regulator, is recently gaining importance for its regenerative potential in salvaging injured hypoxic cells of vital organs such as heart. Different strategies are being employed to upregulate survivin expression in dying hypoxic cardiomyocytes. We investigated the cardioprotective potential of a cell permeable survivin mutant protein SurR9C84A, for the management of hypoxia mediated cardiomyocyte apoptosis, in a novel and clinically relevant model employing primary human cardiomyocytes (HCM). The aim of this research work was to study the efficacy and mechanism of SurR9C84A facilitated cardioprotection and regeneration in hypoxic HCM. To mimic hypoxic microenvironment in vitro, well characterized HCM were treated with 100 µm (48 h) cobalt chloride to induce hypoxia. Hypoxia induced (HI) HCM were further treated with SurR9C84A (1 µg/mL) in order to analyse its cardioprotective efficacy. Confocal microscopy showed rapid internalization of SurR9C84A and scanning electron microscopy revealed the reinstatement of cytoskeleton projections in HI HCM. SurR9C84A treatment increased cell viability, reduced cell death via, apoptosis (Annexin-V assay), and downregulated free cardiac troponin T and MMP-9 expression. SurR9C84A also upregulated the expression of proliferation markers (PCNA and Ki-67) and downregulated mitochondrial depolarization and ROS levels thereby, impeding cell death. Human Apoptosis Array further revealed that SurR9C84A downregulated expression of pro-apoptotic markers and augmented expression of HSPs and HTRA2/Omi. SurR9C84A treatment led to enhanced levels of survivin, VEGF, PI3K and pAkt. SurR9C84A proved non-toxic to normoxic HCM, as validated through unaltered cell proliferation and other marker levels. Its pre-treatment exhibited lesser susceptibility to hypoxia/damage. SurR9C84A holds a promising clinical potential for human cardiomyocyte survival and proliferation following hypoxic injury

Les mesures de gel et de confiscation en vertu de la Loi sur les embargos

OpenAIRE

Schnyder, Nicolas

2009-01-01

Etude du mécanisme d'adoption des mesures de gel et de confiscation en vertu de la Loi sur les embargos et leurs conséquences tant sur la personne principalement touchée par ces mesures que sur les tiers.

Commission des Nations Unies sur les produits indispensables aux ...

International Development Research Centre (IDRC) Digital Library (Canada)

Étude des soins de santé primaires dispensés dans les pays du cône Sud. Les pays membres du Réseau de recherche sur les systèmes et services de santé dans les pays du cône Sud (Red de Investigación en Sistemas y Servicios de Salud en el Cono Sur) ont des systèmes de... Voir davantageÉtude des soins de santé ...

Estimasi Model Seemingly Unrelated Regression (SUR dengan Metode Generalized Least Square (GLS

Directory of Open Access Journals (Sweden)

Ade Widyaningsih

2015-04-01

Full Text Available Regression analysis is a statistical tool that is used to determine the relationship between two or more quantitative variables so that one variable can be predicted from the other variables. A method that can used to obtain a good estimation in the regression analysis is ordinary least squares method. The least squares method is used to estimate the parameters of one or more regression but relationships among the errors in the response of other estimators are not allowed. One way to overcome this problem is Seemingly Unrelated Regression model (SUR in which parameters are estimated using Generalized Least Square (GLS. In this study, the author applies SUR model using GLS method on world gasoline demand data. The author obtains that SUR using GLS is better than OLS because SUR produce smaller errors than the OLS.

Estimasi Model Seemingly Unrelated Regression (SUR dengan Metode Generalized Least Square (GLS

Directory of Open Access Journals (Sweden)

Ade Widyaningsih

2014-06-01

Full Text Available Regression analysis is a statistical tool that is used to determine the relationship between two or more quantitative variables so that one variable can be predicted from the other variables. A method that can used to obtain a good estimation in the regression analysis is ordinary least squares method. The least squares method is used to estimate the parameters of one or more regression but relationships among the errors in the response of other estimators are not allowed. One way to overcome this problem is Seemingly Unrelated Regression model (SUR in which parameters are estimated using Generalized Least Square (GLS. In this study, the author applies SUR model using GLS method on world gasoline demand data. The author obtains that SUR using GLS is better than OLS because SUR produce smaller errors than the OLS.

Effet du compost à base de Calotropis procera (Aiton) W.T. Aiton sur ...

African Journals Online (AJOL)

Objectifs: Une étude à base de compost de Calotropis procera a été menée afin de mesurer l'effet sur la production de l'arachide sur de sols pauvres. Méthodologie et résultats: L'essai a été conduit sur le site de Doyaba au niveau des zones marginales du Tchad avec la variété fleur 11 d'arachide (Arachis hypogaea L.) ...

Gestion des agroecosystemes sur le mont agou en zone forestiere ...

African Journals Online (AJOL)

Dans le but d'une meilleure mise en valeur de l'espace, plusieurs espèces végétales sont cultivées en association essentiellement avec Persea americana. L'approche méthodologique est basée sur des inventaires floristiques et écologiques sur 45 placettes de 25 m x 25 m dans les agrosystèmes. Une diversité de 85 ...

Taxes sur les cigarettes en Tanzanie | CRDI - Centre de recherches ...

International Development Research Centre (IDRC) Digital Library (Canada)

On s'attend à ce que cette hausse du tabagisme ait d'importantes répercussions sur la santé publique et le développement économique. Il ressort de l'expérience d'autres régions que le moyen le plus efficace de renverser une telle tendance consiste à augmenter les taxes sur les cigarettes. Toutefois, les responsables des ...

Carbon dioxide, temperature, salinity, and other variables collected via surface underway survey from Volunteer Observing Ship AURORA AUSTRALIS in the Southern Oceans (> 60 degrees South) from 1992-10-19 to 2001-12-12 (NODC Accession 0081031)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Surface and Atmospheric fCO2 measurements in the Southern Ocean during the VOS Project line onboard the oceanographic ship Aurora Australis.

A comparison of the impact of 'seagrass-friendly' boat mooring systems on Posidonia australis.

Science.gov (United States)

Demers, Marie-Claire A; Davis, Andrew R; Knott, Nathan A

2013-02-01

Permanent boat moorings have contributed to the decline of seagrasses worldwide, prompting the development of 'seagrass-friendly' moorings. We contrasted seagrass cover and density (predominantly Posidonia australis) in the vicinity of three mooring types and nearby reference areas lacking moorings in Jervis Bay, Australia. We examined two types of 'seagrass-friendly' mooring and a conventional 'swing' mooring. 'Swing' moorings produced significant seagrass scour, denuding patches of ~9 m radius. Seagrass-friendly 'cyclone' moorings produced extensive denuded patches (average radius of ~18 m). Seagrass-friendly 'screw' moorings, conversely, had similar seagrass cover to nearby reference areas. Our findings reinforce previous work highlighting the negative effects of 'swing' and 'cyclone' moorings. In contrast, the previously unstudied 'screw' moorings were highly effective. We conclude that regular maintenance of moorings and the monitoring of surrounding seagrass are required to ensure that 'seagrass-friendly' moorings are operating effectively. This is important, as following damage Posidonia will take many decades to recover. Copyright © 2012 Elsevier Ltd. All rights reserved.

Influence du système de logement sur quelques performances ...

African Journals Online (AJOL)

Les effets de deux systèmes de logement (batterie de cages et sol sur litière) sur les performances zootechniques et économiques des poules pondeuses ont été évalués en zone tropicale humide, au sud du Benin. Un total de 180 poules pondeuses (Isa Brown) de 26 semaines d'âge était réparti en deux groupes de 108 et ...

Echolocation in sympatric Peale's dolphins (Lagenorhynchus australis) and Commerson's dolphins (Cephalorhynchus commersonii) producing narrow-bandhigh-frequency clicks

DEFF Research Database (Denmark)

Kyhn, Line Anker; Jensen, Frants Havmand; Beedholm, Kristian

2010-01-01

-element hydrophone array from wild Peale's (Lagenorhynchus australis) and Commerson's (Cephalorhynchus commersonii) dolphins off the Falkland Islands. The centroid frequency was different between Commerson's (133±2kHz) and Peale's (129±3kHz) dolphins. The r.m.s. bandwidth was 12±3kHz for both species. The source...... level was higher for Peale's dolphin (185±6dB re 1 uPa p.-p.) than for Commerson's(177±5 dB re 1 uPa p.-p.). The mean directivity indexes were 25dB for both species. The relatively low source levels in combination with the high directivity index may be an adaptation to reduce clutter when foraging...

Reconfiguración de la Cooperación Sur-Sur en la región latinoamericana y la participación internacional de los actores subnacionales

Directory of Open Access Journals (Sweden)

Mariana Calvento

2015-01-01

Full Text Available El presente trabajo describe y analiza las actua-les características de la Cooperación Sur-Sur en América Latina, especialmente el papel de los actores subnacionales en dicha dinámica. A su vez, analiza las modalidades que adquiere esta cooperación en el contexto político regio-nal de la última década, donde se evidencia un importante avance de la integración de los países latinoamericanos. Finalmente, estudila relación existente entre los principios de la Cooperación Sur-Sur con la participación in-ternacional de los actores subnacionales a partir de la relevancia que adquieren algunas de es-tas formas de cooperación, como es el caso de la Red mercociudades, el Foro Consultivo de Municipios, Estados Federados, Provincias y Departamentos del mercosur (fccr mer-cosur y la Federación Latinoamericana de Ciudades, Municipios y Asociaciones de Go-biernos Locales (flacma, que nuclean a estos actores y promueven mecanismos institucionales que favorecen la participación de las ciudades a través de diferentes instrumentos de intercambio y cooperación.

Controverses sur les sucres [Controversies about sugars

Directory of Open Access Journals (Sweden)

Malika BOUCHENAK

2016-12-01

Full Text Available La surconsommation de sucres ajoutés et leurs effets putatifs sur diverses pathologies cardiométaboliques continuent de susciter des controverses. Dans les années 1950, le taux élevé de maladies cardiovasculaires (MCV, chez les hommes Américains a conduit à des études sur le rôle des facteurs alimentaires, tels que le cholestérol, les phytostérols, l'excès de calories, les acides aminés, les graisses, les glucides, les vitamines et les minéraux, à influencer le risque de MCV. Dans les années 60, deux éminents physiologistes, plaidant pour des hypothèses causales divergentes de MCV, John Yudkin a identifié les sucres ajoutés comme agent primaire, tandis que Ancel Keys identifiait les graisses totales, les graisses saturées et le cholestérol alimentaire. Cependant, dans les années 80, peu de scientifiques croyaient que les sucres ajoutés jouaient un rôle important dans la maladie coronarienne, et les premiers conseils nutritionnels de 1980 (1980 Dietary Guidelines for americans étaient axés sur la réduction des graisses totales, des graisses saturées et du cholestérol alimentaire pour la prévention des MCV.

Mapping the change of Phragmites australis live biomass in the lower Mississippi River Delta marshes

Science.gov (United States)

Ramsey, Elijah W.; Rangoonwala, Amina

2017-07-28

Multiyear remote sensing mapping of the normalized difference vegetation index (NDVI) was carried out as an indicator of live biomass composition of the Phragmites australis (hereafter Phragmites) marsh in the lower Mississippi River Delta (hereafter delta) from 2014 to 2017. Maps of NDVI change showed that the Phragmites condition was fairly stable between May 2014 and July 2015. From July 2015 to April 2016 NDVI change indicated Phragmites suffered a widespread decline in the live biomass proportion.  Between April and September 2016, most marsh remained unchanged from the earlier period or showed improvement; although there were pockets of continued decline scattered throughout the lower delta. From September 2016 to May 2017 a pronounced and widely exhibited decline in the condition of Phragmites marsh again occurred throughout the lower delta. This final NDVI change mapping supported field observations of Phragmites decline during the same period.

Swim speed, behavior, and movement of North Atlantic right whales (Eubalaena glacialis in coastal waters of northeastern Florida, USA.

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James H W Hain

Full Text Available In a portion of the coastal waters of northeastern Florida, North Atlantic right whales (Eubalaena glacialis occur close to shore from December through March. These waters are included within the designated critical habitat for right whales. Data on swim speed, behavior, and direction of movement--with photo-identification of individual whales--were gathered by a volunteer sighting network working alongside experienced scientists and supplemented by aerial observations. In seven years (2001-2007, 109 tracking periods or "follows" were conducted on right whales during 600 hours of observation from shore-based observers. The whales were categorized as mother-calf pairs, singles and non-mother-calf pairs, and groups of 3 or more individuals. Sample size and amount of information obtained was largest for mother-calf pairs. Swim speeds varied within and across observation periods, individuals, and categories. One category, singles and non mother-calf pairs, was significantly different from the other two--and had the largest variability and the fastest swim speeds. Median swim speed for all categories was 1.3 km/h (0.7 kn, with examples that suggest swim speeds differ between within-habitat movement and migration-mode travel. Within-habitat right whales often travel back-and-forth in a north-south, along-coast, direction, which may cause an individual to pass by a given point on several occasions, potentially increasing anthropogenic risk exposure (e.g., vessel collision, fishing gear entanglement, harassment. At times, mothers and calves engaged in lengthy stationary periods (up to 7.5 h that included rest, nursing, and play. These mother-calf interactions have implications for communication, learning, and survival. Overall, these behaviors are relevant to population status, distribution, calving success, correlation to environmental parameters, survey efficacy, and human-impacts mitigation. These observations contribute important parameters to

La estrategia de liderazgo regional de la India a través de la cooperación sur-sur (2003-2012)

OpenAIRE

Jaime Garzón, Carlos Felipe

2014-01-01

La presente investigación tiene como objetivo analizar en qué medida la estrategia de liderazgo regional de la India ha sido impulsada a través de los programas y proyectos de cooperación sur-sur ofrecidos por este país en el periodo de 2003-2012. De igual forma se pretende indagar sobre el papel histórico que ha jugado la India en el establecimiento y posterior evolución de esta nueva forma de cooperación que ha sido vista por la mayoría de los académicos como un complemento de la cooperació...

Enjeux de territoires sur une frontière méconnue

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Françoise Grenand

2012-11-01

Full Text Available « J’ai travaillé dans le temps sur le chantier d’un pont sur le Zambèze. Je me suis toujours demandé pourquoi ils avaient décidé de faire un pont à cet endroit : c’est la même chose sur les deux rives… ». Humphrey Bogart, in African Queen, de John Huston, 1951.Il y a encore quatre décennies, la Guyane ignorait superbement qu’elle eût un voisin nommé Brésil. Une frontière en commun ? Et même la plus longue frontière terrestre de la France ? Les deux seules librairies du département ne proposai...

Peronism and political citizenship in the Patagonia: the look of the magazine Argentina Austral> (1946-1955)