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Sample records for macrophyte vallisneria americana

  1. Oxidative stress responses of submerged macrophyte Vallisneria asiatica to different concentrations of cyanobacteria

    Science.gov (United States)

    Kang, Caixia; Kuba, Takahiro; Hao, Aimin; Iseri, Yasushi; Li, Chunjie; Zhang, Zhenjia

    2015-03-01

    In a 10-day aquarium experiment, this investigation examines macrophyte restoration in eutrophic Lake Taihu, the physiological effects of different plant biomass levels and of increasing natural cyanobacterial concentrations on a submerged macrophyte, Vallisneria asiatica. Cyanobacterial stress suppressed the superoxide dismutase (SOD) activity of the plant's leaves and induced the catalase (CAT) and peroxidase (POD) activities of its roots. The soluble protein content in V. asiatica decreased with an increase in natural cyanobacterial concentrations, whereas the malonaldehyde (MDA) increased significantly at chlorophyll a (Chl a) concentrations of 222 and 262 μg/L in water. V. asiatica adapted to the stress caused by cyanobacterial concentrations by adjusting its antioxidant defense system to remove the excessive reactive oxygen species when the algal Chl a concentration was >109 μg/L. Additionally, high biomass of V. asiatica (2 222 g FW/m2) can inhibit the reproduction of cyanobacteria more significantly than low biomass (1 111 g FW/m2). High biomass of V. asiatica increased the oxidative stress in an individual plant when the initial Chl a concentration in the water reached 222 and 262 μg/L, as expressed by the increased MDA in leaves, compared with low biomass of V. asiatica. This provides a basis for controlling cyanobacterial concentrations and V. asiatica biomass for the recovery of V. asiatica in eutrophic Lake Taihu.

  2. Vallisneria 2003-2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — We compared nekton use of Vallisneria americana Michx. (submerged aquatic vegetation, SAV) with marsh shoreline vegetation and subtidal nonvegetated bottom (SNB)...

  3. Using Seeds to Propagate and Restore Vallisneria americana Michaux (Wild Celery) in the Chesapeake Bay

    Science.gov (United States)

    2007-12-01

    1982, Catling et al. 1994). It is a dioecious plant that can reproduce asexually through the spreading of rhizomes and stolons, which produce...Gloucester Point, VA. Catling , P. M., K. W. Spicer, M. Biernacki, and J. Lovett-Doust. 1994. The biology of Canadian weeds. 103. Vallisneria...and S. Wyllie-Echeverria. 2005. Buoy-deployed seeding: Demonstration of a new eelgrass (Zostera marina L.) planting method. Ecological Engineering

  4. Effects of Pb stress on nutrient uptake and secondary metabolism in submerged macrophyte Vallisneria natans.

    Science.gov (United States)

    Wang, Chao; Lu, Jie; Zhang, Songhe; Wang, Peifang; Hou, Jun; Qian, Jin

    2011-07-01

    For better understanding the metabolic adaptations to Pb stress in submerged plants, the alterations in mineral elements uptake and in secondary metabolism were studied in leaves of Vallisneria natans (Lour.) Hara exposed to 0-100μM Pb for 0-7d. Pb content increased in leaves in a dose-dependent way. The increase of calcium, magnesium and iron content and the decrease of phosphorus, potassium and manganese content were detected in leaves of V. natans under Pb stress, while no significant changes were detected in copper and zinc concentration. Meanwhile, there was an increase in the concentrations of total phenolic and flavonoids. Pb treatment caused an increase in the catalytic activities of shikimate dehydrogenase, phenylalanine ammonialyase and polyphenol oxidase. The results suggest that nutrient uptake and secondary metabolism were actively regulated by V. natans plants in response to Pb stress.

  5. 苦草对NH_4~+的吸收动力学%Ammonia Uptake Kinetics of a Submerged Macrophyte Vallisneria natans

    Institute of Scientific and Technical Information of China (English)

    张松; 何绪刚; 谢从新; 胡雄; 陈见; 黄海平; 李佩

    2011-01-01

    In order to investigate the effect of light, pH and temperature on ammonia uptake ability of Vallisneria natans, this paper studied the effects of three levels, pH, temperature and light on the ammonia uptake kinetics of nitrogen. In weak acidic(pH 5.5), the affinity and maximum ammonia uptake rate of V.natans is much higher than the other two groups(pH 7.0 and pH 8.5). In the experiments on light, the affinity increased with increasing illumination, but the maximum ammonia uptake rate is higher only at medium illumination. In the experiments on temperature, the affinity and maximum ammonia uptake rate is increasing with the temperature at first, and then decreased when the temperature is higher. The Leaves had a majority of the NH+4 absorbed by the plant, and so the 3 environmental factors mentioned above exert more influence on leaf other than root on absorption of NH+4.%以苦草为试验材料,研究了3种光照、3种pH和3种温度条件下苦草对NH4+的吸收动力学以及苦草根叶的吸收差异。结果表明:弱酸性组(pH5.5)最大吸收速率和亲和力显著高于中性组(pH7.0)和弱碱性组(pH8.5);亲和力随照度增大而增大,但中等光强组的最大吸收速率显著高于其他2组;温度试验中,最大吸收速率和亲和力先随着温度的上升而升高,然后随着温度的上升而降低;叶在苦草全株对NH4+的吸收中占主导地位,3种环境因子通过对叶的作用来影响全株对NH4+的吸收效率。

  6. Habitat modification by the stream macrophyte Justicia americana and its effects on biota.

    Science.gov (United States)

    Fritz, Ken M; Gangloff, Michael M; Feminella, Jack W

    2004-08-01

    We conducted an in-stream experiment to determine if and by what mechanisms the emergent macrophyte, Justicia americiana, enhances streambed stability and influences associated benthic organisms. Treatments included removal of aboveground stems, removal of stems and rhizomes, and a control. Stone stability and embeddedness were higher within intact patches of Justicia compared with areas where stems and rhizomes were removed. Presence of belowground structures binding stones and higher embeddedness were responsible for differences in stone stability among treatments. Sediment deposition was highly variable among treatments; however, silt and clay deposition was highest in the control when Justicia stems reached maximum biomass. Response of neighboring benthic organisms to Justicia treatments varied with organism mobility and trophic level. Sedentary unionid mussels were more abundant in the control than in the stem and rhizome-removal treatment, whereas abundance of mobile snails (Elimia ucheensis) and sessile plants (Podostemon ceratophyllum and mosses) did not differ among treatments. Justicia appears to modify the stream environment by: (1) increasing stability of streambed sediments, and (2) reducing current velocity, thereby enhancing deposition of fine sediments and organic matter.

  7. Reproductive Ecology of Vallisneria americana Michaux

    Science.gov (United States)

    2006-12-01

    extent to which human activities (e.g., recrea- tional boating, aquatic gardening, and aquarium trade), animals, water movements, and wind each account...plants of the southeastern United States, monocotyle- dons. Athens, GA: The University of Georgia Press. Grace, J. B. 1993. The adaptive significance

  8. The utilization of Vallisneria aethiopica, Brassica oleracea and Pennisetum clandestinum by Tilapia rendalli

    Science.gov (United States)

    Hlophe, S. N.; Moyo, N. A. G.

    A common lawn grass; kikuyu grass, an abundant vegetable; cabbage and vallisneria a common macrophyte were tested for utilisation by two size classes of a herbivorous fish, Tilapia rendalli held in glass aquarium tanks. The test feeds were given to sub-adult T. rendalli for 133 days at 8% body weight and juvenile fish for 84 days at 15% body weight. Sub-adult and juvenile fish fed kikuyu grass attained a higher specific growth rate, higher protein efficiency ratio and better food conversion ratio than those fed cabbage and vallisneria. This is explained by the differences in the protein content, higher levels of lysine and the sulphur-containing amino acid, methionine in kikuyu grass. Palatability studies of the juveniles also showed that kikuyu was most preferred. However, sub-adults preferred vallisneria, kikuyu and cabbage respectively. The possible reasons for the selection are discussed.

  9. Impact of human activities on water level and clarity and underwater light climate of Vallisneria spiralis L. in Poyan Lake, China

    NARCIS (Netherlands)

    Wu, G.

    2008-01-01

    Almost 95% of the world population of Siberian crane (Grus leucogeranus) winter in Poyang Lake, China. Here they forage on the tubers of the submerged aquatic macrophyte Vallisneria spiralis L. The growth and production of V. spiralis are regulated by the local hydrology, which might also be

  10. Impact of human activities on water level and clarity and underwater light climate of Vallisneria spiralis L. in Poyan Lake, China

    NARCIS (Netherlands)

    Wu, G.

    2008-01-01

    Almost 95% of the world population of Siberian crane (Grus leucogeranus) winter in Poyang Lake, China. Here they forage on the tubers of the submerged aquatic macrophyte Vallisneria spiralis L. The growth and production of V. spiralis are regulated by the local hydrology, which might also be influen

  11. Phytotoxicity of four herbicides on Ceratophyllum demersum, Vallisneria natans and Elodea nuttallii

    Institute of Scientific and Technical Information of China (English)

    PAN Huiyun; LI Xiaolu; XU Xiaohua; GAO Shixiang

    2009-01-01

    The physiological effects of 4 herbicides (butachlor, quinclorac, bensulfuron-methyl and atrazine) on 3 submerged macrophytes (Ceratophyllum demersum, Vallisneria natans and Elodea nuttallii) were tested in laboratory conditions. The variables of the relative growth rate and the photosynthetic pigments content showed that all of the tested herbicides affected the growth of the plants obviously. The abnormal growth of the plants was observed in most treatment groups, even at the lowest concentration (0.0001 mg/L). Except for the C. demersum treated with quinclorac at 0.005 and 0.01 mg/L, the relative growth rates of the plants were inhibited significantly (p < 0.05). Statistical analysis of Chl-a content was carried out with both the t-test and one-way ANOVA to determine the difference between the treatment groups and control. The results showed that Chl-a contents of the plants in all treatment groups were affected by herbicides significantly, except for the C. demersum treated with bensulfuron-methyl at 0.0005 mg/L. The decrease content in Chl-a was positively correlated to the dosage of the herbicides in most treatment groups. It was suggested that herbicides in water body might potentially affect the growth of aquatic macrophytes. Since the Chl-a content of submerged macrophytes responded to the stress of herbicides sensitively and directly, it could be used as biomaker in environmental monitoring or in the ecological risk assessment of herbicide contamination.

  12. Alleviating versus stimulating effects of bicarbonate on the growth of Vallisneria natans under ammonia stress.

    Science.gov (United States)

    Dou, Yanyan; Wang, Baozhong; Chen, Liangyan; Yin, Daqiang

    2013-08-01

    Bicarbonate plays a crucial role in limiting the growth of submersed aquatic macrophytes in eutrophic lakes, and high ammonia is often toxic to macrophytes. In order to evaluate the combined effect of HCO3 (-) and total ammonia (i.e., the total of NH3 and NH4 (+)) on submersed macrophytes Vallisneria natans, the growth and physiological response of V. natans in the presence of HCO3 (-) and ammonia were studied. The results showed that with the increase of ammonia, morphological parameters of V. natans declined. In contrast, increased HCO3 (-) concentration stimulated the growth of V. natans, especially when the NH4 (+)-N/NO3 (-)-N ratio was 1:7. High ammonia concentration induced excess free amino acids (FAA) accumulation and soluble carbohydrates (SC) depletion in plant tissues. However, the elevated HCO3 (-) promoted the synthesis of SC and rendered the decrease of FAA/SC ratio. The results also suggested that HCO3 (-) could partially alleviate the stress of ammonia, as evidenced by the decrease of FAA/SC ratio and the growth enhancement of V. natans when the ammonia concentration was 0.58 mg L(-1). Given the fact that HCO3 (-) is probably the dominant available carbon source in most eutrophic lakes, the ability of V. natans to use HCO3 (-) for SC synthesis may explain the alleviating effect of HCO3 (-) on V. natans under ammonia stress.

  13. Effects of sediment and its re-suspension on the growth of Vallisneria asiatica Miki

    Institute of Scientific and Technical Information of China (English)

    LEI Ze-xiang; XIE Yi-fa; XU De-lan; LIU Zheng-wen

    2008-01-01

    Aquatic macrophytic growth and its distribution in eutrophic lakes are described in relation to its sediment type and irradiance. Hence, it is necessary to characterize the response of macrophytic growth to lake sediment and its re-suspension. We conducted two independent experiments to measure the effects of sediment and its re-suspension on the growth of Vallisneria asi-atica Miki. Based on our study, we conclude that the amount of total biomass of V. asiatica is related, in important ways, to the type of sediment and its re-suspension. According to our comparison, plants and biomass cultured on lake sediments are 2.1 times and 1.5 times greater than that on brown clay from nearby places beside Lake Taihu. The number of plants and the amount of biomass in a turbid water column are smaller than those in a clear water column. The results indicate that the nutrient-rich lake sediments have promoted the growth of V. asiatica, while the re-suspension of the sediment leads to a high turbid level and low light penetra-tion which has a negative impact on the growth of V. asiatica.

  14. Responses in root physiological characteristics of Vallisneria natans (Hydrocharitaceae to increasing nutrient loadings

    Directory of Open Access Journals (Sweden)

    Cai X.

    2016-01-01

    Full Text Available We selected the submerged macrophyte Vallisneria natans (Lour. Hara for investigating the effects of nutrient loadings (nitrogen (N-phosphorus (P in mg·L-1: (1 0.5, 0.05; (2 1.0, 0.1; (3 5.0, 0.5; (4 10.0, 1.0 on root physiological characteristics using sand culture during the growth season (June to October. Results showed that the best root growth was in macrophytes exposed to moderate nutrient conditions (N-P 2, in 1.0 and 0.10 mg· L-1, and high nutrient loadings induced declines in root growth. Analysis of root antioxidant enzyme (superoxide dismutase (SOD, peroxidase (POD and catalase (CAT activities, protein content and cell ultrastructure revealed that the root of V. natans was subject to the stress of senescence during the end of the growth season. Moreover, high nutrient loadings increased oxidative stress in aging roots of V. natans, and made the cell ultrastructure of roots vulnerable to damage during senescence. The results for the changes in CAT activity suggest that CAT can serve as an important component of antioxidant defense mechanism in aging roots of V. natans to protect against nutrient loading induced oxidative injury in the early period.

  15. The response of epiphytic bacteria on Vallisneria natans (Lour.) Hara (Hydrocharitaceae) to increasing nutrient loadings.

    Science.gov (United States)

    Cai, Xianlei; Yao, Ling; Gao, Guang; Xie, Yinfeng; Zhang, Yingying; Tang, Xiangming

    2016-06-01

    To investigate the effects of water column nutrient loading on epiphytic bacteria, we determined the abundance and community composition of epiphytic bacteria on the submerged macrophyte Vallisneria natans (Lour.) Hara during the growth season (June-October) under four different nutrient concentrations (nitrogen (N)-phosphorus (P) in mg L(-1) : 0.5-0.05, 1.0-0.1, 5.0-0.5, 10.0-1.0; hereafter NP-1, NP-2, NP-3, NP-4, respectively), using epifluorescence microscopy method and terminal restriction fragment length polymorphism (T-RFLP) analysis, respectively. Relative to low nutrient conditions (NP-1), there was no significant effect on the epiphytic bacterial community, and even a decrease in the number of epiphytic bacteria, which linked to the well growth status of host macrophytes at moderate nutrient conditions (NP-2). However, further nutrient enrichment induced significant increase in the abundance of epiphytic bacteria, and marked changes in the community structures of epiphytic bacteria. Furthermore, at high nutrient conditions, epiphytic bacterial communities varied widely temporally, and were not stable compared with those at the lower nutrient conditions. These results indicated that the effects of nutrient enrichment on epiphytic bacteria were nonlinear and dependent on the nutrient concentrations in the water.

  16. Growth rate, protein:RNA ratio and stoichiometric homeostasis of submerged macrophytes under eutrophication stress

    Directory of Open Access Journals (Sweden)

    Xing W.

    2016-01-01

    Full Text Available Growth rate hypothesis (GRH and stoichiometric homeostasis of photoautotrophs have always been questioned. However, little is known about GRH and stoichiometric homeostasis of aquatic plants, especially submerged macrophytes. Therefore, we aim to test the GRH and explore stoichiometric homeostasis of four freshwater submerged macrophytes under eutrophication stress. At the single species level and the multi-species level, N:P ratios of Potamogeton maackianus, Myriophyllum spicatum, Vallisneria natans and Ceratophyllum demersum had no consistent trends with growth rates. However, protein:RNA ratios of P. maackianus, M. spicatum and V. natans all correlated negatively with growth rates, demonstrating GRH can apply to freshwater submerged macrophytes, even though they are threatening by eutrophication stress. Protein:RNA ratios positively correlated with N:P ratios in culture media and tissues in submerged macrophytes except in P. maackianus (30d, suggesting effects of varying N:P ratios in culture media on protein:RNA ratios are basically in concert with tissue N:P ratios under short-time eutrophication stress. Stoichiometric homeostasis coefficients (HN:P indicated submerged macrophytes have weak homeostasis. Stoichiometric homeostasis of V. natans was stronger than those of P. maackianus, M. spicatum and C. demersum. The differences in GRH and homeostasis of the four submerged macrophytes may be due to species traits.

  17. Response of Vallisneria natans to Increasing Nitrogen Loading Depends on Sediment Nutrient Characteristics

    Directory of Open Access Journals (Sweden)

    Jiao Gu

    2016-11-01

    Full Text Available High nitrogen (N loading may contribute to recession of submerged macrophytes in shallow lakes; yet, its influences vary depending on environmental conditions. In August 2013, we conducted a 28-day factorial-designed field mesocosm experiment in Lake Taihu at the Taihu Laboratory for Lake Ecosystem Research (TLLER to examine the effects of high N loading on the growth of Vallisneria natans in systems with contrasting sediment types. We ran the experiments with two levels of nutrient loading—present-day external nutrient loading (average P: 5 μg·L−1·day−1, N: 130 μg·L−1·day−1 and P: 5 μg·L−1·day−1, and with three times higher N loading (N: 390 μg·L−1·day−1 and used sediment with two contrasting nutrient levels. V. natans growth decreased significantly with increasing N loading, the effect being dependent, however, on the nutrient status of the sediment. In low nutrient sediment, relative growth rates, leaf biomass and root biomass decreased by 11.9%, 18.2% and 23.3%, respectively, at high rather than low N loading, while the decline was larger (44.0%, 32.7% and 41.8%, respectively when using high nutrient sediment. The larger effect in the nutrient-rich sediment may reflect an observed higher shading of phytoplankton and excess nutrient accumulation in plant tissue, though potential toxic effects of the high-nutrient sediment may also have contributed. Our study confirms the occurrence of a negative effect of increasing N loading on submerged plant growth in shallow nutrient-enriched lakes and further shows that this effect is augmented when the plants grow in nutrient-rich sediment. External N control may, therefore, help to protect or restore submerged macrophytes, especially when the sediment is enriched with nutrients and organic matter.

  18. Checklist of the Aquatic Macrophytes

    African Journals Online (AJOL)

    The emergent macrophytes formed 93.3% of the total macrophyte .... accounted for 2.2% while emergent species with. 93.30% of ... proliferation of floating aquatic macrophytes like ..... Geoelectric Evalution of the Groundwater Potential of Parts.

  19. Comparative assessment of Azolla pinnata and Vallisneria spiralis in Hg removal from G.B. Pant Sagar of Singrauli Industrial region, India.

    Science.gov (United States)

    Rai, Prabhat Kumar; Tripathi, B D

    2009-01-01

    The aim of the present work was to monitor the Hg pollution in water and sediments of G.B. Pant Sagar located in Singrauli Industrial Region, India and to suggest the efficient aquatic plants for its phytoremediation. The study assessed the comparative potential of a free floating water fern Azolla pinnata and submerged aquatic macrophyte Vallisneria spiralis to purify waters polluted by Hg. Six days laboratory experiments have been conducted to mark the percentage removal of Hg at initial concentration of 0.1, 0.5, 1.0 and 3.0 mg L(-1). The percentage removal of Hg was higher for A. pinnata (80-94%) than V. spiralis (70-84%). Likewise, the Hg accumulated in dry mass was much higher for A. pinnata and a high correlation (R(2) = 0.91 for A. pinnata and 0.99 for V. spiralis) was obtained between applied Hg doses and accumulated amounts in biomass. A concentration dependent decrease in chlorophyll a, protein, RNA, DNA and nutrients (NO(3-) and PO(4)(3-)) uptake was detected in A. pinnata and V. spiralis due to Hg toxicity. The decrease was more prominent in Azolla than Vallisneria. The results recommended the use of A. pinnata and V. spiralis to ameliorate the industrial effluents (thermal power, chlor-alkali and coal mine effluent) contaminated with Hg.

  20. EFFECTS OF NUTRIENT PRE-EXPOSURE ON ATRAZINE TOXICITY TO VALLISNERIA AMERICANA MICHX. (WILD CELERY)

    Science.gov (United States)

    The importance of aquatic plants as a valued component of coastal environments is receiving increased attention in the public policy and scientific community. Unfortunately, the fact remains that the effects of anthropogenic contaminants on both emergent (marsh) and submerged aq...

  1. Competition Between Hydrilla verticillata and Vallisneria americana Under Different Environmental Conditions

    Science.gov (United States)

    1994-03-01

    interesting that this occurred only under the low fertility condition, since it has been suggested that foliar uptake and translocation of solution K to...ill. ; 28 cm. - (Technical report ; A-94-1 ) Includes bibliographic references. 1. Plant biomass. 2. Plant competition. 3. Fertilization of plants. I...of canopy-forming submersed aquatic plants, provide a habitat that is generally detrimental to fish and other desirable aquatic organisms (Newroth

  2. EFFECTS OF NUTRIENT PRE-EXPOSURE ON ATRAZINE TOXICITY TO VALLISNERIA AMERICANA MICHX. (WILD CELERY)

    Science.gov (United States)

    The importance of aquatic plants as a valued component of coastal environments is receiving increased attention in the public policy and scientific community. Unfortunately, the fact remains that the effects of anthropogenic contaminants on both emergent (marsh) and submerged aq...

  3. Effects of high nitrogen concentrations on the growth of submersed macrophytes at moderate phosphorus concentrations.

    Science.gov (United States)

    Yu, Qing; Wang, Hong-Zhu; Li, Yan; Shao, Jian-Chun; Liang, Xiao-Min; Jeppesen, Erik; Wang, Hai-Jun

    2015-10-15

    Eutrophication of lakes leading to loss of submersed macrophytes and higher turbidity is a worldwide phenomenon, attributed to excessive loading of phosphorus (P). However, recently, the role of nitrogen (N) for macrophyte recession has received increasing attention. Due to the close relationship between N and P loading, disentanglement of the specific effects of these two nutrients is often difficult, and some controversy still exists as to the effects of N. We studied the effects of N on submersed macrophytes represented by Vallisneria natans (Lour.) Hara in pots positioned at three depths (0.4 m, 0.8 m, and 1.2 m to form a gradient of underwater light conditions) in 10 large ponds having moderate concentrations of P (TP 0.03 ± 0.04 mg L(-1)) and five targeted concentrations of total nitrogen (TN) (0.5, 2, 10, 20, and 100 mg L(-1)), there were two ponds for each treatment. To study the potential shading effects of other primary producers, we also measured the biomass of phytoplankton (ChlaPhyt) and periphyton (ChlaPeri) expressed as chlorophyll a. We found that leaf length, leaf mass, and root length of macrophytes declined with increasing concentrations of TN and ammonium, while shoot number and root mass did not. All the measured growth indices of macrophytes declined significantly with ChlaPhyt, while none were significantly related to ChlaPeri. Neither ChlaPhyt nor ChlaPeri were, however, significantly negatively related to the various N concentrations. Our results indicate that shading by phytoplankton unrelated to the variation in N loading and perhaps toxic stress exerted by high nitrogen were responsible for the decline in macrophyte growth.

  4. Epiphytic bacterial communities on two common submerged macrophytes in Taihu Lake: diversity and host-specificity

    Institute of Scientific and Technical Information of China (English)

    HE Dan; REN Lijuan; WU Qinglong

    2012-01-01

    Leaves of terrestrial and aquatic plants are home to a wide diversity of bacterial species.However,the diversity and variability of epiphytic bacteria on their submerged plant hosts remains poorly understood.We investigated the diversity and composition of epiphytic bacteria from two common submerged macrophytes:Vallisneria natans and Hydrilla verticillata in Taihu Lake,Jiangsu,China,using methods of terminal restriction fragment length polymorphisms (T-RFLP) and clone library analyses targeted at bacterial 16S rRNA genes.The results show that:(1) the libraries of the two waterweeds contain wide phylogenetic distribution of bacteria,and that the sequences of the two libraries can be separated into 93 OTUs (at 97% similar value); (2) Betaproteobacteria,including Burkholderiales,was the most abundant bacterial group on both plants.Cyanobacteria and Gammaproteobacteria were the second largest groups on V.natans and H.verticillata,respectively.Both clone libraries included some sequences related to those of methanotrophs and nitrogen-fixing bacteria; (3) Cluster analysis of the T-RFLP profiles showed two distinct clusters corresponding to the two plant populations.Both ANOSIM of the T-RFLPdata and Libshuff analysis of the two clone libraries indicated a significant difference in epiphytic bacterial communities between the two plants.Therefore,the epiphytic bacterial communities on submerged macrophytes appear to be diverse and host-specific,which may aid in understanding the ecological functions of submerged macrophytes in general.

  5. 水体营养水平及附着藻类对苦草生长的影响%Effects of water nutritional condition and epiphytic algae on the growth of Vallisneria natans

    Institute of Scientific and Technical Information of China (English)

    李佩; 谢从新; 何绪刚; 黄海平; 张松

    2012-01-01

    In order to study the effects of different nutritional conditions and epiphytic algae on the growth of submersed macrophyte. A laboratory experiment was carried out over 42 days in four different nutritional conditions with Vallisneria natans. The results showed that the relative growth rate, superoxide dismutase activity, malondialdehyde contents and epiphytic algae biomass of Vallisneria natans in mesotrophic and eutrophic group was significant different with it in oligotrophic and hypertrophic group ( P < 0. 05 ). The total soluble sugar content of Vallisneria natans in oligotrophic group was significant higher than other groups ( P < 0.05 ). The soluble protein, nitrogen and phosphorus content of Vallisneria natans was significant positive correlation with water nutritional condition. The soluble protein, nitrogen and phosphorus content of Vallisneria natans in oligotrophic and mesotrophic group was significant different with it in eutrophic and hypertrophic group ( P < 0.05 ) . The chlorophyll a content of water column in different groups does't exist significant differences. It is therefore concluded that the middle nutritional condition ( TN = 0. 8mg/L, TP = 0. 08 mg/L ) was most suitable for the growth of Vallisneria natans.%为研究不同水体营养水平及附着藻类对沉水植物生长的影响,选择苦草(Vallisneria natans)作为研究对象,在4种水体营养水平下进行42 d的室内试验.结果表明:试验结束时,中营养及富营养处理组苦草的相对生长率、超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量和附着藻类生物量与贫营养及重富营养处理组具有显著性差异(P<0.05);贫营养处理组苦草的可溶性糖含量显著高于其它处理组(P<0.05);苦草氮磷含量及可溶性蛋白含量与水体营养水平呈明显正相关,且贫营养及中营养处理组与富营养及重富营养处理组之间差异显著(P< 0.05);各处理组水体叶绿素a含量差异

  6. A preliminary study of the feasibility of detecting the floating macrophytes by means of digital processing of MSS/LANDSAT data

    Science.gov (United States)

    Valeriano, D. D. (Principal Investigator)

    1984-01-01

    The feasibility of mapping the floating macrophytes (mostly water hyacinth: (Eichornia crassipes) in the Salto Grande reservoir in Americana, SP, by means of digital processing of MSS/LANDSAT data is described. The area occupied by the macrophytes was extracted by exclusion after the merging of two thematic masks representing the area of vegetation free water surface. One of the masks was obtained from a date when the vegetal cover is insignificant, while the other represents a large infestation episode. The utilization of digital processing of MSS/LANDSAT data techniques for the documentation of macrophytes infestation is feasible only when the phenomenon occurs in large areas.

  7. Effects of shading on Vallisneria natans (Lour. H. Hara growth

    Directory of Open Access Journals (Sweden)

    Fox A.D.

    2013-08-01

    Full Text Available Effects of surface shading were measured on above- and below-ground biomass and fruit production of Vallisneria natans (Lour. H. Hara plants grown from seed in replicated microcosm experiments, based on a control (no shading and four treatments (25%, 50%, 75% and 90% shading. Above- and below-ground biomass was significantly reduced at treatments above 50% shading and first pistillate and staminate florescence dates were significantly delayed above 75% and 50% shading, respectively. Ratios of mature to unripe fruits produced (both in number or dry weight did not differ between shading treatments, but dry weight fruit production was significantly reduced at 90% shading. We conclude that above 50% surface shading, V. natans plants suffer reductions in accumulated biomass and investment in sexual reproduction. We contend that recent expansions in the extent of the native floating water chestnut Trapa spp. at seasonally inundated wetlands in the Yangtze River floodplain could, by shading, have contributed to the reduction in annual biomass and seed production of V. natans, contributing to declines in distribution and abundance.

  8. Physiological response of the three submerged macrophytes to the five cadmium concentrations%3种沉水植物对镉的生理特性响应

    Institute of Scientific and Technical Information of China (English)

    易冕; 张饮江; 董悦; 刘晓培; 李岩; 金晶; 段婷; 张乐亭

    2013-01-01

    This research is aimed at providing a theoretical guidance and experimental basis for the application of submerged macrophytes to treat the effects of heavy-metal sewage pollution on the five concentrations of cadmium(Cd) to the biomass, the growth rate, the chlorophyll content, the chlorophyll activities and the soluable protein of Ceratophyllum demersum L. , Elodea nuttallii and Vallisneria natans through imitating the static and shallow water environment. For our research purpose, we have chosen the well grown Ceratophyllum demersum L. , Elodea nuttallii and Vallisneria natans as the material to be tested, with the 1/4 Hoagland liquid as the culture medium on the basis for determinating the Cd test concentration in the preliminary tests. We have conducted our formal tests lasting for 40 days in hoping to find the biomass, relative growth rate, the chlorophyll content and chlorophyll activity of the above said three submerged macro-phytes under different Cd stresses. The results show that the effects for treating turn to be different due to the different concentrations of cadmium (Cd) used and the different sampling times. It was found that the biomass, the relative growth rate and the chlorophyll contents of the three submerged macrophytes prove to noticeably decrease with the increase of cadmium (Cd) concentration, but the chlorophyll activity and the soluble protein content tend to increase first and then decrease. We have also found that the chlorophyll activities and soluble protein content of Ceratophyllum Demersum L. would reach the highest point with the Cd concentration being 10 μg/L and 5 μg/L respectively, but the Elodea nuttallii being the same as Ceratophyllum Demersum L. . Moreover, when the chlorophyll activity and the soluble protein content of Vallisneria natans reached the highest degree with the Cd concentration being 5 μg/L and 10 μg/L respectively, the concentration change of cadmium(Cd) was supposed to affect the growth of the three

  9. Fluoride remediation using floating macrophytes

    Directory of Open Access Journals (Sweden)

    Naba Kumar Mondal

    2014-04-01

    Full Text Available Six aquatic macrophytes, such as Pistia stratiotes, Ceratophyllum demersum, Nymphoides indica, Lemna major, Azolla pinnata,and Eichhornia crassipes were considered for remove fluoride from aqueous solution. Five different concentrations (10, 30, 50, and 100 ppm of fluoride solution were taken in 1 L plastic container. Fixed weight (20 g of macrophytes along with 500 ml fluoride solution was taken in each plastic container for 72 hours observation. Results demonstrated all the macrophytes show highest fluoride removal during 24 h to 48 h, but after 72 h their efficiency reduced drastically. The species N. indica showed better removal efficiency than other experimental macrophytes. In general, pigment measurement data indicated higher concentration at 72 h. However, Pistia sp. showed higher concentration of pigmentation at intermediate time interval (48 h. Higher level of dry weight to fresh weight ratio was recorded for L. major and A. pinnata at all concentrations, excepting at 10 ppm. In addition, all macrophytes showed lower RGR at higher concentration. Isotherm study indicated that macrophyte C. demersum is a good fitted with Freundlich and Langmuir isotherm whereas L. major with Langmuir isotherm during 24 hours.

  10. Agave Americana Leaf Fibers

    Directory of Open Access Journals (Sweden)

    Ashish Hulle

    2015-02-01

    Full Text Available The growing environmental problems, the problem of waste disposal and the depletion of non-renewable resources have stimulated the use of green materials compatible with the environment to reduce environmental impacts. Therefore, there is a need to design products by using natural resources. Natural fibers seem to be a good alternative since they are abundantly available and there are a number of possibilities to use all the components of a fiber-yielding crop; one such fiber-yielding plant is Agave Americana. The leaves of this plant yield fibers and all the parts of this plant can be utilized in many applications. The “zero-waste” utilization of the plant would enable its production and processing to be translated into a viable and sustainable industry. Agave Americana fibers are characterized by low density, high tenacity and high moisture absorbency in comparison with other leaf fibers. These fibers are long and biodegradable. Therefore, we can look this fiber as a sustainable resource for manufacturing and technical applications. Detailed discussion is carried out on extraction, characterization and applications of Agave Americana fiber in this paper.

  11. Blue-light-induced rapid chloroplast de-anchoring in Vallisneria epidermal cells

    Institute of Scientific and Technical Information of China (English)

    Yuuki Sakai; Shin-Ichiro Inoue; Akiko Harada; Ken-Ichiro Shimazaki; Shingo Takagi

    2015-01-01

    In the outer periclinal cytoplasm of leaf epidermal cells of an aquatic angiosperm Vallisneria, blue light induces “chloroplast de‐anchoring”, a rapid decline in the resistance of chloroplasts against centrifugal force. Chloroplast deanchoring is known induced within 1 min of irradiation with high‐fluence‐rate blue light specifically, preceding the commencement of chloroplasts migration toward the anticlinal cytoplasm. However, its regulatory mechanism has remained elusive, although pharmacological analysis suggested that a calcium release from intracellular calcium stores is necessary for the response. In search of the responsible photoreceptors, immunoblotting analysis using antibodies against phototropins demonstrated that cross‐reactive polypeptides of 120‐kDa exist in the plasma‐membrane fraction prepared from the leaves. In vitro phosphorylation analysis revealed that 120‐kDa polypeptides were phosphorylated by exposure to blue light in a fluence‐dependent manner. The blue‐light‐induced phosphorylation activity was sensitive to a Ser/Thr kinase inhibitor, staurosporine, and unusually was retained at a high level for a long time in darkness. Furthermore, phototropin gene homologs (Vallisneria PHOTOTROPIN1 and PHOTOTROPIN2) expressed in leaves were isolated. We propose that calciumregulated chloroplast de‐anchoring, possibly mediated by phototropins, is an initial process of the blue‐light‐induced avoidance response of chloroplasts in Vallisneria.

  12. Differential photosynthetic and morphological adaptations to low light affect depth distribution of two submersed macrophytes in lakes

    Science.gov (United States)

    Chen, Jianfeng; Cao, Te; Zhang, Xiaolin; Xi, Yilong; Ni, Leyi; Jeppesen, Erik

    2016-01-01

    To evaluate the relative importance of photosynthetic versus morphological adaptations of submersed macrophytes to low light intensity in lakes, rapid light curves (RLCs), morphological parameters, relative growth rate (RGR), clonal reproduction and abundance of two submersed macrophytes (Potamogeton maackianus and Vallisneria natans) were examined under 2.8%, 7.1%, 17.1% and 39.5% ambient light in a field and outdoor experimental study. The plants increased their initial slope of RLCs (α) and decreased their minimum saturating irradiance (Ek) and maximum relative electron transport rate (ETRm) of RLCs under low light stress, but V. natans was more sensitive in RLCs than P. maackianus. Accordingly, the RGR, plant height and abundance of P. maackianus were higher in the high light regimes (shallow water) but lower in the low light regimes than those of V. natans. At the 2.8% ambient light, V. natans produced ramets and thus fulfilled its population expansion, in contrast to P. maackianus. The results revealed that P. maackianus as a canopy-former mainly elongated its shoot length towards the water surface to compensate for the low light conditions, however, it became limited in severe low light stress conditions. V. natans as a rosette adapted to low light stress mainly through photosynthetic adjustments and superior to severely low light than shoot elongation. PMID:27694880

  13. Involvement and interaction of microbial communities in the transformation and stabilization of chromium during the composting of tannery effluent treated biomass of Vallisneria spiralis L.

    Science.gov (United States)

    Shukla, O P; Rai, U N; Dubey, Smita

    2009-04-01

    Tannery effluent treated with aquatic macrophyte Vallisneria spiralis L. for 14 d showed significant improvement in physico-chemical properties and reduction in Cr concentration. Accumulation of Cr was found maximum in roots (358 microg g(-1)dw) as compared to shoot (62 microg g(-1)dw) of the plant. A laboratory scale composter was designed with the objectives to investigate the physico-chemical changes and role of microbes in stabilization and transformation of Cr in the composting material. Results revealed that the composting process was quick within 7-21 d as indicated by peak time for various physico-chemical parameters and drop in C/N ratio up to acceptable limit. The profile of microbial communities indicated that population of anaerobic, aerobic and nitrifying bacteria increased quickly at the initial phase, and reached a peak level of 4.2 x 10(6), 9.78 x 10(8) and 9.32 x 10(9) CFU g(-1), respectively at 21 d; while population of actinomycetes and fungi was found maximum i.e. 3.29 x 10(7) and 9.7 x 10(6) CFU g(-1), respectively, after 35 d of composting. Overall bacterial population dominated over the actinomycetes and fungi during the composting process. Cr((VI)) was transformed to Cr((III)) due to the microbial activity during the process. Sequential extraction of Cr fractionation showed its stabilization via changing into organic matter-bound and residual fractions during the composting.

  14. Study of the depuration effect of Vallisneria spiralis and Elodea Canadensis in water sources area of Gong Hu in winter%冬季苦草与伊乐藻对贡湖水源地水质净化效果研究

    Institute of Scientific and Technical Information of China (English)

    王阳阳; 吴海龙; 霍元子; 曲宪成; 陈群芳; 何培民

    2012-01-01

    This paper studied the depuration effect of two kinds of submerged macrophytes Vallisneria spiralis and Elodea Canadensis in winter,after cold acclimation in laboratory.From 5 to 25 November 2009,ten large embankment enclosures were set up in Dong Jing River of the water source area in Gong Hu,Suzhou Vallisneria spiralis and Elodea Canadensis were planted in the enclosures.Experiments were made in 4 groups: Vallisneria spiralis,Elodea Canadensis,Vallisneria spiralis + Elodea Canadensis and control group.Each treatment had three replicates.Sampled once every five days,to test the water quality inside of the enclosure and the outside enclosure.The results showed that:(1) In the enclosures grown submerged macrophytes: concentrations of NH4-N,NO3-N,TN,were significantly lower than those before the experiment(P0.01),and the concentrations in Vallisneria spiralis control,Elodea Canadensis control,Vallisneria spiralis + Elodea Canadensis control are reduced to 78.76%,70.20%,83.42%,81.85%,72.30%,75.55%,88,80%,78.80%,86.21%,respectively,while the control group and the water outside the enclosures have a lesser extent nitrogen concentrations,in which TN concentrations decreased 37.12% and 15.87%;(2)The control of Vallisneria spiralis + Elodea Canadensis have high reduction rate in decreasing the TP and CODMn,which were 86.97% and 76.16%,significantly higher than other controls(P0.05).(3) The effect of purifying water of Vallisneria spiralis and Elodea Canadensis is better in winter,and the purifying effect: Vallisneria spiralis + Elodea CanadensisVallisneria spiralis Elodea Canadensis.This paper provides a theoretical basis for the recovery of submerged plants of lake ecological restoration,species selection and reasonable allocation.%2009年11月5日至25日在苏州太湖贡湖水源地入湖河道东泾河内设置了10个大型路基围隔,栽植较耐寒沉水植物苦草(Vallisneria spiralis)和伊乐藻(Elodeacanadensis),

  15. Production in aquatic macrophyte communities

    DEFF Research Database (Denmark)

    Binzer, Thomas; Sand-Jensen, Kaj

    2002-01-01

    Many terrestrial plant canopies regulate spatial patterns in leaf density and leaf inclination to distribute light evenly between the photosynthetic tissue and to optimize light utilization efficiency. Sessile aquatic macrophytes, however, cannot maintain the same well-defined three......-dimensional structure because of the strong drag and shear forces of moving water. This difference in canopy structure has been suggested to account for the three- to fivefold higher gross production rates in terrestrial than aquatic communities. To evaluate the effect of community structure in aquatic habitats, we...... was markedly enhanced by a vertical orientation of thalli when absorptance and community density were both high. This result implies that aquatic macrophytes of high thallus absorptance and community density exposed to high light are limited in attaining high gross production rates because of their inability...

  16. Production in aquatic macrophyte communities

    DEFF Research Database (Denmark)

    Binzer, Thomas; Sand-Jensen, Kaj

    2002-01-01

    -dimensional structure because of the strong drag and shear forces of moving water. This difference in canopy structure has been suggested to account for the three- to fivefold higher gross production rates in terrestrial than aquatic communities. To evaluate the effect of community structure in aquatic habitats, we...... to distribute photons evenly between the photosynthetic tissues. As scattering and attenuation in the water column increase, the effect of thallus structure on production declines and thin transparent macrophytes are more efficient at utilizing light than thick opaque macrophytes. The results confirm...... combined a simple mechanistic model and empirical measurements on artificially structured macroalgal communities (Ulva lactuca) with varying thallus absorptance and community density. Predicted and measured values corresponded closely and revealed that gross production in high-light environments...

  17. The Comparative Study on Photosynthesis of Hydrilla verticillata and Vallisneria natans in the Different Depth%黑藻与苦草在不同水深下光合作用的比较研究

    Institute of Scientific and Technical Information of China (English)

    经博翰; 袁龙义

    2014-01-01

    Chosen the Wagouzi site with abundant submerged population in the Honghu Lake as a sampling region, the difference of photosynthesis of submerged macrophytes Hydrilla verticillata( L. f. )Royle and vallisneria natans ( Lour. )Hara which are high resistance and obsorption to the dirty water in Honghu Lake was designed to research their response in the 100 cm and 50 cm water depth by Diving-PAM apparatus. The results showed that the value of External Transfer Rate(ETR)of Hydrilla verticillata and vallisneria natans separately approached to 25. 1 μmol· m-2 · s-1 and 10 . 1 μmol · m-2 · s-1 when the value of Photosynthetic Active Radiation( PAR )was stable for 342 μmol·m-2 · s-1 under the condition of 100 cm water depth. With the PAr intensity gradually becoming strong,ETr of Hydrilla verticillata reached its peak 21. 76 μmol·m-2 ·s-1 when the PAr value was 219 μmol· m-2 ·s-1 ,as well as ETr of vallisneria natans reached its peak 12. 65 μmol·m-2 ·s-1 when the PAr value was 515 μmol·m-2 ·s-1 . On the other hand,the value of ETr of Hydrilla verticillata and vallisneria natans separately approached to 26. 2 μmol·m-2 ·s-1 and 11. 9 μmol·m-2 ·s-1 when the value of PAr was stable for 515 μmol· m-2 ·s-1 under the condition of 50 cm water depth. With the PAr intensity gradually becoming strong,ETr of Hydrilla verticillata reached its peak 25. 27 μmol·m-2 ·s-1 when the PAr value was 219 μmol·m-2 ·s-1 ,as well as ETr of vallisneria natans reached its peak 4. 80 μmol·m-2 ·s-1 when the PAr value was 1 042 μmol· m-2 ·s-1 . In summary,no matter in 100 cm or 50 cm water depth condition,photosynthesis intensity of Hydrilla verticillata is stronger than that of vallisneria natans.%以沉水植物较为丰富的洪湖凹沟子作为采样区域,利用水下调制荧光仪研究洪湖常见的2种高耐污、高吸污水鳖科沉水植物黑藻( Hydrilla verticillata( L. f.)Royle)与苦草( vallisneria natans( Lour

  18. Leishmaniose tegumentar americana

    Directory of Open Access Journals (Sweden)

    Gontijo Bernardo

    2003-01-01

    Full Text Available A leishmaniose tegumentar americana permanence endêmica em vastas áreas da América Latina. Os agentes causadores da doença são a L. (Viannia braziliensis, L. (L. mexicana, L. (V. panamensis, e outras espécies relacionadas. A apresentação clínica da doença varia dentro de um espectro amplo, incluindo úlceras cutâneas múltiplas ou única, leishmaniose cutânea difusa e lesões mucosas. Os principais reservatórios da L. (V. braziliensis e da L. (Viannia spp. são os pequenos roedores silvestres. A doença acomete mais freqüentemente os trabalhadores que invadem as florestas tropicais ou moram próximo a elas. O período de incubação varia de duas semanas a vários meses. As lesões cutâneas constituem úlceras rasas, circulares com bordas elevadas e bem definidas e com o assoalho da úlcera de aspecto granular. Nas infecções pela L. (V. braziliensis a linfoadenopatia regional geralmente precede o surgimento das úlcerações por uma a doze semanas. O diagnóstico definitivo depende da identificação de amastigotas em tecido ou promastigotas em meios de cultura. Os anticorpos anti-leishmania podem ser identificados no soro utilizando-se as técnicas de ELISA, imunofluorescência e testes de aglutinação mas os títulos revelam-se baixos na maioria dos casos. A intradermorreação de Montenegro torna-se positiva durante a evolução da doença. Os antimoniais pentavalentes continuam sendo as drogas de escolha no tratamento da leishmaniose. A anfotericina B encontra indicação nos casos mais graves ou nos indivíduos que não respondem ao tratamento com os antimoniais. A imunoterapia e a imunoprofilaxia constituem alternativas promissoras no tratamento e profilaxia da leishmaniose tegumentar americana.

  19. 3种沉水植物对水体重金属镉去除效果的实验研究%Reaserch on phytoremediation of cadmium contaminated water by three submerged macrophytes

    Institute of Scientific and Technical Information of China (English)

    张饮江; 易冕; 王聪; 董悦; 刘晓培; 文晓峰; 李岩

    2012-01-01

    运用植物修复(phytoremediation)技术,选取金鱼藻(Ceratophyllum demersum L.)、伊乐藻(Elodea nuttallii)、苦草(Vallisnerianatans)3种沉水植物,比较研究不同pH与镉浓度对它们生长及去除镉效果的影响。结果表明,3种沉水植物均能耐受一定浓度范围的镉污染,并能不同程度地去除水体中的镉;在实验对照组中,金鱼藻与伊乐藻在pH为8.5、镉浓度为15μg/L的溶液中,去除镉的能力最强,苦草在pH为7.5、镉浓度为10μg/L的溶液中,去除镉的能力最强。在沉水植物活体中,伊乐藻对水体镉的抗性和去除率最大(达92%),金鱼藻次之(达90%),苦草最小(为66%);沉水植物粉对水体镉的去除效果较沉水植物活体显著,去除率表现为伊乐藻粉最大(达95%),金鱼藻粉次之(达93%),苦草最小(为88%),但苦草粉对镉的去除率随溶液镉浓度、pH等条件的变化波动较小,较稳定,为81%~88%。3种沉水植物适应范围广,高效无污染,可用于镉污染废水的植物修复。%The study is about the growth and cadmium′s restoration effect of three submerged macrophytes(Ceratophyllum demersum L.,Elodea nuttallii and Vallisneria natans)in different pH and cadmium.The result shows that,three submerged macrophytes can all tolerate the pollution of cadmium in a certain concentration range,and eliminate cadmium of the water to different degree.Ceratophyllum demersum L.and Elodea nuttallii have strongest elimination ability of cadmium under pH 8.5 or 15 μg/L cadmium.Vallisneria natans has strongest elimination ability of cadmium under pH 7.5 or 10 μg/L cadmium.Among these living submerged macrophytes,Elodea nuttallii has the strongest tolerate and elimination ability of cadmium(up to 92%),then Ceratophyllum demersum L.(up to 90%),and Vallisneria natans(up to 66%).The elimination ability of the 3 submerged macrophytes’ powder is more obvious than its living form,Elodea Canadensis

  20. Macrophytes: Freshwater Forests of Lakes and Rivers.

    Science.gov (United States)

    McDermid, Karla J.; Naiman, Robert J.

    1983-01-01

    Physical, chemical, and biological effects on macrophytes (aquatic plants) on the freshwater ecosystem are discussed. Research questions and issues related to these organisms are also discussed, including adaptations for survival in a wet environment, ecological consequences of large-scale macrophyte eradication, seasonal changes in plant…

  1. The use of aquatic macrophytes in monitoring and in assessment of biological integrity

    Science.gov (United States)

    Stewart, P.M.; Scribailo, R.W.; Simon, T.P.; Gerhardt, A.

    1999-01-01

    Aquatic plant species, populations, and communities should be used as indicators of the aquatic environment, allowing detection of ecosystem response to different stressors. Plant tissues bioaccumulate and concentrate toxin levels higher than what is present in the sediments; and this appears to be related to organic matter content, acidification, and buffering capacity. The majority of toxicity studies, most of these with heavy metals, have been done with several Lemna species and Vallisneria americana. Organic chemicals reviewed include pesticides and herbicides, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and other industrial contaminants. The use of aquatic plant communities as bioindicators of environmental quality was evaluated for specific characteristics and indices that may assess biological integrity. Indices such as the floristic quality index (FQI) and coefficient of conservatism (C) are pioneering efforts to describe the quality of natural areas and protect native biodiversity. Our case study in the Grand Calumet Lagoons found that 'least-impacted' sites had the greatest aquatic plant species richness, highest FQI and C values, and highest relative abundance. Lastly, we introduce the concepts necessary for the development of a plant index of biotic integrity. Development of reference conditions is essential to understanding aquatic plant community structure, function, individual health, condition, and abundance. Information on guild development and tolerance definition are also integral to the development of a multi-metric index.

  2. A macrophyte submodel for aquatic ecosystems

    Science.gov (United States)

    Collins, Carol Desormeau; Wlosinski, Joseph H.

    1989-01-01

    A macrophyte submodel has been incorporated and tested in CE-QUAL-R1, a one-dimensional, vertically averaged model of reservoir water quality. A quasi two-dimensional scheme was necessary to represent the spatial relationship of macrophytes in reservoirs adequately. The macrophyte processes modeled were photosynthesis, dark respiration, excretion and nonpredatory mortality. Process equations for photosynthesis as a function of light and temperature, and dark respiration as a function of temperature were tested using data from laboratory studies. The submodel was field tested, along with other components of CE-QUAL-R1, using data collected at Eau Galle Reservoir, WI, U.S.A.

  3. Community photosynthesis of aquatic macrophytes

    DEFF Research Database (Denmark)

    Binzer, T.; Sand-Jensen, K.; Middelboe, A. L.

    2006-01-01

    We compared 190 photosynthesis-irradiance (P-E) experiments with single- and multispecies communities of macroalgae and vascular plants from freshwater and marine habitats. We found a typical hyperbolic P-E relation in all communities and no sign of photosaturation or photoinhibition of photosynt......We compared 190 photosynthesis-irradiance (P-E) experiments with single- and multispecies communities of macroalgae and vascular plants from freshwater and marine habitats. We found a typical hyperbolic P-E relation in all communities and no sign of photosaturation or photoinhibition...... of photosynthesis at the highest irradiances of about 2,000 mmol m22 s21. Macrophyte communities displayed much higher maximum gross production (GPmax), respiration, and light compensation point than separate phytoelements because of the multilayered structure and extensive self-shading in the communities, whereas...

  4. Community photosynthesis of aquatic macrophytes

    DEFF Research Database (Denmark)

    Binzer, T.; Sand-Jensen, K.; Middelboe, A. L.

    2006-01-01

    We compared 190 photosynthesis-irradiance (P-E) experiments with single- and multispecies communities of macroalgae and vascular plants from freshwater and marine habitats. We found a typical hyperbolic P-E relation in all communities and no sign of photosaturation or photoinhibition of photosynt......We compared 190 photosynthesis-irradiance (P-E) experiments with single- and multispecies communities of macroalgae and vascular plants from freshwater and marine habitats. We found a typical hyperbolic P-E relation in all communities and no sign of photosaturation or photoinhibition...... of photosynthesis at the highest irradiances of about 2,000 mmol m22 s21. Macrophyte communities displayed much higher maximum gross production (GPmax), respiration, and light compensation point than separate phytoelements because of the multilayered structure and extensive self-shading in the communities, whereas...

  5. Effects of shading on Vallisneria natans (Lour.) H. Hara growth

    DEFF Research Database (Denmark)

    Fox, Anthony David; Meng, F; Shen, X

    2013-01-01

    Effects of surface shading were measured on above- and below-ground biomass and fruit production of Vallisneria natans (Lour.) H. Hara plants grown from seed in replicated microcosm experiments, based on a control (no shading) and four treatments (25%, 50%, 75% and 90% shading). Above- and below......-ground biomass was significantly reduced at treatments above 50% shading and first pistillate and staminate florescence dates were significantly delayed above 75% and 50% shading, respectively. Ratios of mature to unripe fruits produced (both in number or dry weight) did not differ between shading treatments......, but dry weight fruit production was significantly reduced at 90% shading. We conclude that above 50% surface shading, V. natans plants suffer reductions in accumulated biomass and investment in sexual reproduction. We contend that recent expansions in the extent of the native floating water chestnut Trapa...

  6. Macrophytes: ecosystem engineers in UK urban rivers

    Science.gov (United States)

    Gibbs, H.; Gurnell, A.; Heppell, K.; Spencer, K.

    2012-04-01

    Macrophytes act as ecosystem engineers within river channels in that they have the ability to cause geomorphological and ecological change. They induce reductions in flow velocity and associated sediment accumulation, and their system of underground roots and rhizomes also reinforces the accumulated sediment reducing sediment erosion and resuspension and creating habitats. As sediments, particularly finer-grained, store contaminants including metals, this engineering means that in the specific context of urban rivers where sediments are more likely to be contaminated, macrophytes trap and hold contaminated sediments creating a potentially important sink of metals. However, depending on the ability for the macrophyte to reinforce the sediment and reduce erosion and resuspension, there is the potential for the sink to turn in to a source and metals to be released in to the overlying water. This research therefore looks at the ecosystem engineering ability of common macrophytes in UK urban rivers by looking at: (i) the effect upon flow velocity and sediment accumulation of Sparganium erectum (branched bur-reed); (ii) the sediment reinforcement ability of both S. erectum, Typha latifolia (bulrush) and Phalaris arundinacea (reed canary grass); and, (iii) the storage of metals within the sediment, overlying water and the macrophytes. Research was undertaken on the River Blackwater, an urban river in Surrey, UK which has extensive macrophyte growth. Flow velocity measurements and fine sediment depths were recorded both within and outside of dense stands of S. erectum. The uprooting resistance (as an indicator of sediment reinforcement) was measured for three species: S. erectum, T. latifolia and P. arundinacea. Additionally, some preliminary sampling was undertaken of the sediment, overlying water and the macrophytes to determine metal storage. Lower flow velocities and greater volumes of fine sediment were recorded within the stands of S. erectum as opposed to the

  7. [Contact dermatitis from Agave americana].

    Science.gov (United States)

    de la Cueva, Pablo; González-Carrascosa, Mateo; Campos, Minia; Leis, Vicente; Suárez, Ricardo; Lázaro, Pablo

    2005-10-01

    Numerous plant species and their derivatives can cause skin reactions through a variety of mechanisms: irritative contact dermatitis, allergic contact dermatitis, contact urticaria and photodermatitis. We present a case of irritative contact dermatitis after exposure to the sap of Agave americana. The skin symptoms in this case have only been described on rare occasions; although this condition usually presents with a papulovesicular rash, in this patient it appeared as purpuric lesions in the contact area.

  8. The effects of different fish species on growth of submerged macrophytes%不同鱼类对沉水植物生长的影响∗

    Institute of Scientific and Technical Information of China (English)

    王晓平; 王玉兵; 杨桂军; 秦伯强; 杨宏伟

    2016-01-01

    Submerged macrophyte is an important component in ecological restoration of eutrophic waters. Fish is one of the impor⁃tant factors affecting the growth of submerged macrophytes. In the present study, the effects of three fish species( Ctenopharyngodon idellus, Parabramis pekinensis and Carassius auratus) on growth of four submerged macrophytes( Vallisneria natans, Ceratophyllum demersum, Elodea nuttalli and Potamogeton malaianus) were studied. Results showed that the decline rates of submerged macro⁃phytes biomass were 19.2%, 82.1% and 16.6% in controls, C. idellus and P. pekinensis, respectively. However, submerged mac⁃rophytes biomass increased 12.5% in the C. auratus treatments. The rate of increase of Ceratophyllum demersum biomss was the highest among the four submerged macrophytes. The rate of increase of C. demersum biomass in controls, P. pekinensis and C. aura⁃tus treatments were 171.1%,113.9% and 265.5%, respectively, but that was -24.4% in C. idellus treatments. Moreover, all the three fish species inhibited the growth of Spirogyra which is one of the competitors of submerged macrophytes. The results of this study could be used for the fish management during the restoration of submerged macrophytes in eutrophic waters.%沉水植物是富营养水体生态修复的重要组成部分,鱼类是影响沉水植物生长的重要因素之一.为了解鱼类对沉水植物生长的影响,研究3种鱼(草鱼( Ctenopharyngodon idellus)、鲫( Carassius auratus)、鳊( Parabramis pekinensis))对4种沉水植物(苦草( Vallisneria natans)、金鱼藻( Ceratophyllum demersum)、伊乐藻( Elodea nuttalli)、马来眼子菜( Potamogeton malaianus))生长的影响.结果显示,对照组、草鱼组和鳊组沉水植物生物量分别下降19.2%、82.1%和16.6%,而鲫组沉水植物生物量却增长12.5%.4种沉水植物中,金鱼藻生物量增长最高,其中对照组、鳊组和鲫组

  9. Ewingella Americana: An Emerging True Pathogen

    Directory of Open Access Journals (Sweden)

    Syed Hassan

    2012-01-01

    Full Text Available Infections caused by Ewingella americana have been rarely reported in the literature. Most of the cases that have been reported were among the immunocompromised patients. We report a case of E. americana causing osteomyelitis and septic arthritis of the shoulder joint in a previous intravenous drug abuser. The causative pathogen was identified by synovial fluid analysis and culture.

  10. Reconstruction and water purification of submerged macrophytes community in eutrophicated Gehu Lake during summer%夏季富营养化滆湖中沉水植物群落重建及水质净化效果

    Institute of Scientific and Technical Information of China (English)

    黄峰; 李勇; 潘继征; 陶花; 赵海光

    2011-01-01

    通过滆湖原位围隔试验分析了不同单种及混种沉水植物群落随环境变化的生长状况及对水质的净化效果.结果表明:(1)夏季,沉水植物生物量的平均值与透明度/水位存在显著线性相关性,进一步表明沉水植物的生长在很大程度上依赖于光强和水深.(2)各植物区(除马来眼子菜区外)的高锰酸盐指数、TN高于空白对照区.(3)对比空白对照区,苦草区、金鱼藻区、金鱼藻—伊乐藻区对NH3-N、TP、叶绿素a的去除率都在25%以上.对比敞水区,金鱼藻—伊乐藻区、苦草—马来眼子菜区、苦草—伊乐藻区对TP的去除率分别为33.5%、20.8%、9.9%;金鱼藻—伊乐藻区对叶绿素a的去除率为41.4%.(4)TP和叶绿素a存在显著线性关系,反映了沉水植物可通过对TP的去除有效控制藻类的生长.(5)苦草、金鱼藻—伊乐藻群落、苦草—马来眼子菜群落对水体中NH3-N、TP、叶绿素a的平均去除速率(V)都符合V-时间(t)回归方程.(6)在沉水植物群落恢复中可优先考虑金鱼藻—伊乐藻、苦草—马来眼子菜群落等有稳定及较高平均去除速率的沉水植物群落重建形式.%In-situ enclosure experiment was conducted in Genu Lake to investigate the effect of environmental change on growth and purification performance of different single and mixture submerged macrophytes community. Results showed that the average biomass of submerged macrophytes was significant linearly correlated with transparency and water level, which indicated that the growth of submerged macrophytes was highly dependent on the light intensity and water depth. The permanganate index and TN in test area were higher than that in control area except for the test area planting Potamogeton malaianus. Compared with control area, planting Vallisneria spiralis, Cera-tophyllum demersum and Ceratophyllum demersum-Elodea nuttallii could removal more than 25% of NH3-N, TP and chlorophyll-a; Compared

  11. Interspecific competition effects on phosphorus accumulation by Hydrilla verticillata and Vallisneria natans

    Institute of Scientific and Technical Information of China (English)

    Xiufeng Zhang; Zhengwen Liu

    2011-01-01

    The competition between submersed plants has been recognized as an important factor influencing the structure of plant communities in shallow lakes.The ability of different species to take up and store nutrients from the surrounding ambience varies,and hence plant community structure might be expected to affect the cycling of nutrients in lake ecosystems.In this study,the uptake of phosphorus by Hydrilla verticillata and Vallisneria natans was studied and compared in monoculture and competitive mixed-culture plantings.Results showed that for both studied species the phosphorus concentrations of different tissues and of whole plants was unaffected by competition.However,the quantity of phosphorus accumulated by whole plants of H.verticillata was significantly higher in mixture culture than in monoculture,while that of V.natans was lower in the mixed culture.The results indicated that H.verticillata has a competitive advantage over V.natant,when the two species are grown in competition,and is able to accumulate a greater quantity of phosphorus.

  12. Polifenoles en Myristicaceae americanas (I Polifenoles en Myristicaceae americanas (I

    Directory of Open Access Journals (Sweden)

    Aguirre Gálviz Luis Enrique

    1988-06-01

    Full Text Available

    The ocurrence and distribution of phenolic acids and flovonoid agIycones in 122 samples from 22 species of American Myristicaceae, other than Colombian, were studied. The samples were obtained from herbarium specimens in order to establish a qualitative comparison against fresh samples, pointing out to the possibility of studying such compounds directly on botanical voucher specimens for the purpose of phytochemical and cbemmotaxonomic discussions.

    Se estudió1a distribución de agliconas de ácidos fenólicos y flavonoides en 122 muestras de 22 especies de Myristicaceae americanas no colombianas. Las muestras eran provenientes de especímenes de herbario, para comparación cualitativa con muestras frescas, indicando la utilidad de estudios de tales compuestos realizados directamente sobre especímenes botánicos en investigaciones quimiotaxonómicas y fotoquímicas.

  13. AMEG: the new SETAC advisory group on aquatic macrophyte ecotoxicology.

    Science.gov (United States)

    Arts, Gertie; Davies, Jo; Dobbs, Michael; Ebke, Peter; Hanson, Mark; Hommen, Udo; Knauer, Katja; Loutseti, Stefania; Maltby, Lorraine; Mohr, Silvia; Poovey, Angela; Poulsen, Véronique

    2010-05-01

    Primary producers play critical structural and functional roles in aquatic ecosystems; therefore, it is imperative that the potential risks of toxicants to aquatic plants are adequately assessed in the risk assessment of chemicals. The standard required macrophyte test species is the floating (non-sediment-rooted) duckweed Lemna spp. This macrophyte species might not be representative of all floating, rooted, emergent, and submerged macrophyte species because of differences in the duration and mode of exposure; sensitivity to the specific toxic mode of action of the chemical; and species-specific traits (e.g., duckweed's very short generation time). These topics were addressed during the workshop entitled "Aquatic Macrophyte Risk Assessment for Pesticides" (AMRAP) where a risk assessment scheme for aquatic macrophytes was proposed. Four working groups evolved from this workshop and were charged with the task of developing Tier 1 and higher-tier aquatic macrophyte risk assessment procedures. Subsequently, a SETAC Advisory Group, the Macrophyte Ecotoxicology Group (AMEG) was formed as an umbrella organization for various macrophyte working groups. The purpose of AMEG is to provide scientifically based guidance in all aspects of aquatic macrophyte testing in the laboratory and field, including prospective as well as retrospective risk assessments for chemicals. As AMEG expands, it will begin to address new topics including bioremediation and sustainable management of aquatic macrophytes in the context of ecosystem services.

  14. AMEG: the new SETAC advisory group on aquatic macrophyte ecotoxicology

    OpenAIRE

    Arts, G.; Davies, J.; Dobbs, M.; Ebke, P.; Hanson, M.; Hommen, U.; Knauer, K.; Loutseti, S.; Maltby, L; Mohr, S; Poovey, A.; Poulsen, V.

    2010-01-01

    \\ud Introduction and background\\ud \\ud Primary producers play critical structural and functional roles in aquatic ecosystems; therefore, it is imperative that the potential risks of toxicants to aquatic plants are adequately assessed in the risk assessment of chemicals. The standard required macrophyte test species is the floating (non-sediment-rooted) duckweed Lemna spp. This macrophyte species might not be representative of all floating, rooted, emergent, and submerged macrophyte species be...

  15. AMEG: the new SETAC advisory group on auqatic macrophyte ecotoxicology

    OpenAIRE

    Arts, G.H.P.; Davies, J.; Dobbs, M.; Ebke, P.; Hanson, M.A.

    2010-01-01

    ntroduction and background Primary producers play critical structural and functional roles in aquatic ecosystems; therefore, it is imperative that the potential risks of toxicants to aquatic plants are adequately assessed in the risk assessment of chemicals. The standard required macrophyte test species is the floating (non-sediment-rooted) duckweed Lemna spp. This macrophyte species might not be representative of all floating, rooted, emergent, and submerged macrophyte species because of dif...

  16. AMEG: the new SETAC advisory group on aquatic macrophyte ecotoxicology

    OpenAIRE

    Arts, G.; Davies, J.; Dobbs, M.; Ebke, P.; Hanson, M; Hommen, U.; Knauer, K; Loutseti, S.; Maltby, L.; Mohr, S.; Poovey, A.; Poulsen, V.

    2010-01-01

    \\ud Introduction and background\\ud \\ud Primary producers play critical structural and functional roles in aquatic ecosystems; therefore, it is imperative that the potential risks of toxicants to aquatic plants are adequately assessed in the risk assessment of chemicals. The standard required macrophyte test species is the floating (non-sediment-rooted) duckweed Lemna spp. This macrophyte species might not be representative of all floating, rooted, emergent, and submerged macrophyte species be...

  17. Stage III Detailed Project Report and Environmental Impact Statement, Conesus Lake, New York.

    Science.gov (United States)

    1981-09-01

    perfoliatus, P. pusillus, P. zosteriformis, P. gramineus , Ranunculus sp., Vallisneria americana, and Utricularia vulgaris. Forest et al. (1978) report the...Potomogeton crispus, P. nodosus, P. pectinatus, P. perfoliatus, P. pusillus, P. zosteriformis, P. gramineus , Ranunculus sp., Vallisneria americana

  18. Dissolved organic carbon release by marine macrophytes

    Directory of Open Access Journals (Sweden)

    C. Barrón

    2012-02-01

    Full Text Available Estimates of dissolved organic carbon (DOC release by marine macrophyte communities (seagrass meadows and macroalgal beds were obtained experimentally using in situ benthic chambers. The effect of light availability on DOC release by macrophyte communities was examined in two communities both by comparing net DOC release under light and dark, and by examining the response of net DOC release to longer-term (days experimental shading of the communities. All most 85% of the seagrass communities and almost all of macroalgal communities examined acted as net sources of DOC. There was a weak tendency for higher DOC fluxes under light than under dark conditions in seagrass meadow. There is no relationship between net DOC fluxes and gross primary production (GPP and net community production (NCP, however, this relationship is positive between net DOC fluxes and community respiration. Net DOC fluxes were not affected by shading of a T. testudinum community in Florida for 5 days, however, shading of a mixed seagrass meadow in the Philippines led to a significant reduction on the net DOC release when shading was maintained for 6 days compared to only 2 days of shading. Based on published and unpublished results we also estimate the global net DOC production by marine macrophytes. The estimated global net DOC flux, and hence export, from marine macrophyte is about 0.197 ± 0.015 Pg C yr−1 or 0.212 ± 0.016 Pg C yr−1 depending if net DOC flux by seagrass meadows was estimated by taking into account the low or high global seagrass area, respectively.

  19. COMPOSTING AQUATIC MACROPHYTES: SALVINIA AURICULATA AND EICHHORNIA

    Directory of Open Access Journals (Sweden)

    Ana Kleiber Pessoa Borges

    2011-07-01

    Full Text Available High population growth and densities in urban areas and the consumerism present in modern societies have pronounced effect on the generation of organic waste, which may become an environmental problem. Aerobic composting is one of the best known alternatives to treating these wastes. This study aimed to evaluate the applicability of composting as an alternative to the disposal of organic wastes from aquatic macrophytes Eichhornia crassipes and Salvinia auriculata collected in the reservoir UHE Luis Eduardo Magalhães, Tocantins, Brazil and also produce an organic compound from different combinations of macrophytes, prunning residues and organic waste generated by the Campus of Palmas of UFT, TO. The study was conducted in an area of 80m² in unprotected environment at the experimental station of the Campus of Palmas. The experiments were done as three replications in the dry season (from 18.09.2008 to 11.21.2008 and rainy season (from 03.09.2009 to 05.04.2009 and the parameters temperature, pH, total nitrogen and carbon, and organic matter were monitored along with counts of microorganisms. It was possible to produce compost from the combinations of organic wastes within 65 days of composting during the dry season and 55 days in the rainy season. The aquatic macrophytes resulted in a good raw material for composting, since there is not a destination for the excess plant materials removed by the cleaning process of the reservoir.

  20. Review of alien marine macrophytes in Tunisia

    Directory of Open Access Journals (Sweden)

    Y. R. SGHAIER

    2014-06-01

    Full Text Available In the present study, the list of alien marine macrophytes introduced into Tunisia was updated in the light of available data and new observations. A total of 27 alien marine macrophytes have been recorded so far from Tunisia: 18 Rhodophyta, 3 Ochrophyta, 5 Chlorophyta and 1 Magnoliophyta. For each species, the locality (-ies, the year (or period and the source of the first observation in Tunisia are given. The distribution and the status (casual, cryptogenic, established or questionable of species in Tunisia were evaluated and, where appropriate, discussed. Among them, Hypnea cornuta is reported for the first time from Tunisia. Fourteen alien marine macrophytes are established, whereas seven cryptogenic and two casual species require further investigation. Eleven species are considered as invasive or potentially invasive in the Mediterranean Sea: Acrothamnion preissii, Asparagopsis armata, A. taxiformis Indo-Pacific lineage, Hypnea cornuta, Lophocladia lallemandii, Womersleyella setacea, Caulerpa chemnitzia, C. cylindracea, C. taxifolia, Codium fragile subsp. fragile and Halophila stipulacea. Finally, the case of four questionable species is also discussed.

  1. Research on Competition of Elodea nuttallii with Myrioph yllum verticillatum , Vallisneria natans and Ceratoph yllum demersum%伊乐藻与狐尾藻、苦草和金鱼藻的竞争研究

    Institute of Scientific and Technical Information of China (English)

    段德龙; 于金金; 杨静; 胡倩如; 马帅; 任韶霞; 马剑敏

    2011-01-01

    在室外2m×2m的水池中同时种植伊乐藻、狐尾藻、苦草和金鱼藻4种沉水植物,观察其周年生长的长势、分布面积等情况,以了解各自竞争力强弱.结果表明.6-8月时,伊乐藻生长最快,扩张能力最强,从最开始的1.08 m2增长至8月份的3.69m2,其数量占4种沉水植物总数量的比例在6月份达到最高,为76.59%.7-9月时,狐尾藻有冠层位置的优势,能够漂浮在水面上充分利用阳光,面积增大至2.34 m2,而其数量所占的比例仍在增加,直到10月份达到最高(48.99%);而此时苦草具有中下层的生长优势,伊乐藻由于不喜高温而退化,处于劣势,面积最低退至1.26 m2.在秋冬至春季,由于伊乐藻较强的耐寒能力,面积增至3.20 m2,使它在时空竞争中更早地显示出优势,直接影响到种间竞争的格局.从整体来看,伊乐藻在与本土种的竞争中占据明显优势,我国北方引种时要慎重.%Four submerged macrophytes,Elodea nuttallii fMyriophyllum verticillatum ,Vallisneria natans and Ceratophyllum demersum ,were planted to observe the growth potentials and competitive abilities in outdoor 2m×2m pools. The areas of every species were 1. 08 m2. Results showed that from June to August, Elodea nuttallii grew fastest and its expansion ability was strongest. Its distribution area was 3. 69 m2 and the quantity proportion reached highest, 76. 59% in June. From July to September, Myriophyllum verticillatum had the advantage of canopy position, and floated on the surface. It could make full use of sunshine and its area reached 2. 34 m2, while its quantity proportion still increased, and reached the highest of 48. 99% in October. At this period, Vallisneria natans grew in the middle and lower layer of the water body, meanwhile Elodea nuttallii degenerated because of heat and the lowest area reduced to 1. 26 m2. In autumn-winter and spring, because Elodea nuttallii had strong chillness-tolerance, its area increased to 3. 20m2

  2. Classifying aquatic macrophytes as indicators of eutrophication in European lakes

    NARCIS (Netherlands)

    Penning, W.E.; Mjelde, M.; Dudley, B.; Hellsten, S.; Hanganu, J.; Kolada, A.; van den Berg, Marcel S.; Poikane, S.; Phillips, G.; Willby, N.; Ecke, F.

    2008-01-01

    Aquatic macrophytes are one of the biological quality elements in the Water Framework Directive (WFD) for which status assessments must be defined. We tested two methods to classify macrophyte species and their response to eutrophication pressure: one based on percentiles of occurrence along a phosp

  3. New Submerged Macrophytes Revegetation Method and Its Impacts on Water Environment%新型沉水植物种植方法及其对水环境的影响研究

    Institute of Scientific and Technical Information of China (English)

    高翔; 周维成; 彭成荣; 李双双; 张凤格; 王高鸿

    2015-01-01

    Restoring submerged macrophytes artificially is one of the effective measures to recover the contaminated water eco-system.In this study a new revegetation method by employing vallisneria natans was established, in which mud or clay used as package material in traditional sinking method was replaced by agar gel.At the same time we monitored the growth of vallisneria natans and water quality of two different planting methods.The research results showed that under the agar gel-sinking method the survival rate of vallisneria natans reached 100% and other measuring parameters such as biomass, optimal/maximal photo-chemical efficiency of PSⅡin the dark, and the growth of F1 plants also have excellent performance.Meanwhile during the exper-iment time with the sharp drop of CODMn value, total nitrogen content, total phosphorus content and discernable increase of dis-solved oxygen value, oxidation-reduction potential value water quality improved significantly.%人工快速种植沉水植物是受污染水体生态修复与沉水植物重建的有效措施之一.研究采用琼脂凝胶取代传统抛栽法的软泥或粘土作为外裹物对苦草进行人工种植,并与传统插栽法进行了对比研究,结果表明:(1)新型琼脂抛栽法种植的苦草成活率达到100%,生物量、光合效率、子株生长情况等指标都表现优良;(2)新型琼脂抛栽法种植苦草过程中水体的CODMn值、TN含量、TP含量都现大幅下降,DO值、ORP值都明显上升,水体水质明显改善.

  4. [Dermatitis from contact with Agave americana].

    Science.gov (United States)

    Golan, H; Landau, M; Goldberg, I; Brenner, S

    2000-10-01

    Various plants induce dermatitis in man. There have been only a few published cases of contact dermatitis caused by Agave americana (AA). We report intentional exposure to AA in a soldier seeking sick leave, and review our previously reported cases. Treatment with oral antihistamines and topical saline compresses resulted in subsidence of the systemic symptoms within 24 h and regression of cutaneous manifestations in 7-10 days. Physicians should be alert to the possibility of self-inflicted contact dermatitis induced by exposure to plants, especially to A. americana. Systemic signs may accompany the cutaneous lesions.

  5. Response of Attached Algae Colonization of Vallisneria natans to Ammonia Nitrogen Supply%氨氮浓度对苦草上附植藻类定植的影响

    Institute of Scientific and Technical Information of China (English)

    杨美玖; 宋玉芝

    2012-01-01

    为了认识水体富营养化过程中附植藻类群落定植演替规律,利用显微计数法,通过室内静态模拟实验,研究了水体中不同氨氮浓度对太湖常见沉水植物苦草上附植藻类的影响.结果表明:采集的样品在以硅藻门中脆杆藻属、直链藻属、桥弯藻属、舟行藻属以及蓝藻门的色球藻属为优势种的样品在放置到不同浓度氨氮的实验组后,最后群落演变成为在低浓度氨氮营养盐下以舟行藻和脆杆藻为优势属,中高浓度的氨氮营养盐下以绿藻门的毛枝藻和硅藻门的小环藻和舟行藻为优势属的附植藻类群落结构;生物量在低浓度范围内与氨氮营养盐呈正相关.表明氨氮营养盐对附植藻类群落结构影响非常明显.%To recognize community succession rules of attached algae in the eutrophic water body, macroscope counting method was used to study the responses of attached algae on Taihu Lake submerged macrophyte Vallisneria natans to ammonia nitrogen (AN)supply by static incubation test. Results showed that Frailaria of Bacillariophyta, Melosira, Cymbella, Navicula, Chroococcus of Cyanophyta were dominant species at the collected sample, then they were evolved into Navicula, Frailaria as dominant species at low AN level and Stigeoclonium of Chlorophyta, Cyclotella, Navicula of Bacillariophyta at high AN level when laid into glass cylinder of tested group of different AN levels. The biomass was positively correlated to low AN level, indicating AN level was important to attached algae.

  6. Biomass production by freshwater and marine macrophytes

    Energy Technology Data Exchange (ETDEWEB)

    North, W.J.; Gerard, V.A.; Kuwabara, J.S.

    1981-01-01

    Research on aquatic macrophytes as producers of biomass has been undertaken at Woods Hole Oceanographic Institution (WHOI) on the east coast and on the west coast by a group of collaborators in a joint effort known as the Marine Biomass Project. Studies at WHOI have focused on estuarine and coastal situations with some attention recently to freshwater plants. The Marine Farm Project has primarily been concerned with oceanic biomass production. A group at WHOI has undertaken a wide variety of studies concerning aquatic macrophytes including nutrient uptake, growth, yields, and environmental factors affecting yields. Aquatic biomass production systems have been surveyed on a worldwide basis and currently the role of carbon as a potential limiting nutrient in biomass culturing is being examined. The Marine Farm Project is presently attempting to grow giant kelp in offshore waters off southern California. Other work related to aquatic biomass production includes an investigation at the University of California, Berkeley, of microalgae in ponds. This paper will emphasize discussion of the kelp production phases of the Marine Farm Project. Activities by the WHOI are briefly summarized.

  7. An optimisation approach for shallow lake restoration through macrophyte management

    Science.gov (United States)

    Xu, Z. H.; Yin, X. A.; Yang, Z. F.

    2014-06-01

    Lake eutrophication is a serious global environmental issue. Phytoremediation is a promising, cost-effective, and environmentally friendly technology for water quality restoration. However, besides nutrient removal, macrophytes also deeply affect the hydrologic cycle of a lake system through evapotranspiration. Changes in hydrologic cycle caused by macrophytes have a great influence on lake water quality restoration. As a result of the two opposite effects of macrophytes on water quality restoration (i.e. an increase in macrophytes can increase nutrient removal and improve water quality while also increasing evapotranspiration, reducing water volume and consequently decreasing water quality), rational macrophyte control through planting and harvest is very important. In this study, a new approach is proposed to optimise the initial planting area and monthly harvest scheme of macrophytes for water quality restoration. The month-by-month effects of macrophyte management on lake water quality are considered. Baiyangdian Lake serves as a case study, using the common reed. It was found that water quality was closest to Grade III on the Chinese water quality scale when the reed planting area was 123 km2 (40% of the lake surface area) and most reeds would be harvested at the end of June. The optimisation approach proposed in this study will be a useful reference for lake restoration.

  8. An optimisation approach for shallow lake restoration through macrophyte management

    Directory of Open Access Journals (Sweden)

    Z. H. Xu

    2014-01-01

    Full Text Available Lake eutrophication is a serious global environmental issue. Phytoremediation is a promising, cost-effective, and environmentally friendly technology for water quality restoration. However, besides nutrient removal, macrophytes also deeply affect the hydrologic cycle of lake system through evapotranspiration. Changes in hydrologic cycle caused by macrophytes have a great influence on lake water quality restoration. As a result of the two opposite effects of macrophytes on water quality restoration (i.e. an increase in macrophytes can increase nutrient removal and improve water quality while also increasing evapotranspiration, reducing water volume and consequently decreasing water quality, rational macrophyte control through planting and harvest is very important. In this study, a new approach is proposed to optimise the initial planting area and monthly harvest scheme of macrophytes for water quality restoration. The month-by-month effects of macrophyte management on lake water quality are considered. Baiyangdian Lake serves as a case study, using the common reed. It was found that water quality was closest to Grade III on the Chinese water quality scale when the reed planting area was 123 km2 (40% of the lake surface area and most reeds would be harvested at the end of June. The optimisation approach proposed in this study will be a useful reference for lake restoration.

  9. Effect of paclobutrazol on three different aquatic macrophytes under ...

    African Journals Online (AJOL)

    admin

    2013-09-25

    Sep 25, 2013 ... macrophytes under in vitro monoculture or polyculture conditions ... provide many beneficial ecological services, but they could also be problematic .... addition, it was also important to remove all the leaves from the explants.

  10. Oligochaeta (Annelida: Clitellata) associated to aquatic macrophytes in Brazil

    OpenAIRE

    Nathalie Aparecida de Oliveira Sanches; Marina Gulo Alcorinte; Lucas Henrique Sahm; Guilherme Rossi Gorni; Maria Lúcia Ribeiro

    2016-01-01

    Oligochaeta are still characterized as a poorly studied group among the aquatic macroinvertebrates and few studies about their ecology were conducted in Brazil. Thus, our study aimed to provide an overview of the association between Oligochaeta and macrophytes, in Brazilian continental aquatic environments, by means of a literature review along with an inventory of species associated to aquatic macrophytes on marginal lagoons in the reservoir Ribeirão das Anhumas (Américo Brasiliense, São Pau...

  11. Aquatic macrophyte diversity of the Pantanal wetland and upper basin

    OpenAIRE

    VJ. Pott; Pott, A; LCP. Lima; SN. Moreira; AKM Oliveira

    2011-01-01

    This is a short review of the state of the art concerning diversity of aquatic macrophytes and the main aquatic vegetation types in the Brazilian Pantanal wetland and upper watershed. There are ca. 280 species of aquatic macrophytes on the Pantanal floodplain, with scarce endemism. On the upper watershed, Cerrado wetlands (veredas) and limestone springs have a distinct flora from the Pantanal, with twice the species richness. As a representative case of aquatic habitats influenced by river fl...

  12. Oligochaeta (Annelida: Clitellata associated to aquatic macrophytes in Brazil

    Directory of Open Access Journals (Sweden)

    Nathalie Aparecida de Oliveira Sanches

    2016-09-01

    Full Text Available Oligochaeta are still characterized as a poorly studied group among the aquatic macroinvertebrates and few studies about their ecology were conducted in Brazil. Thus, our study aimed to provide an overview of the association between Oligochaeta and macrophytes, in Brazilian continental aquatic environments, by means of a literature review along with an inventory of species associated to aquatic macrophytes on marginal lagoons in the reservoir Ribeirão das Anhumas (Américo Brasiliense, São Paulo, Brazil. In the review, we analyzed 10 articles, where we obtained data on 41 species. We also sampled 5 macrophyte genera, Egeria, Salvinia, Utricularia, Eleocharis, and Ceratophyllum, in August and December 2012 and in March and April 2013, in the reservoir Ribeirão das Anhumas. We registered 21 Oligochaeta species associated to these macrophytes. With the data obtained in the review along with the inventory of the reservoir Ribeirão das Anhumas, we found a total of 41 species associated to aquatic macrophytes, with a higher richness of the Naididae family (93.33%, followed by Opistocystidae (4.44%, and Alluroididae (2.22%. Our study inventoried about 48% of the Oligochaeta diversity registered in continental ecosystems in Brazil, thus highlighting the significance of macrophytes as a resource for these invertebrates, mainly for the Naididae family.

  13. Constituents of Agave americana and Agave barbadensis.

    Science.gov (United States)

    Tinto, W F; Simmons-Boyce, J L; McLean, S; Reynolds, W F

    2005-09-01

    An investigation of Agave americana and Agave barbadensis resulted in the isolation of a new homoisoflavanoid, 7-hydroxy-3-(4-methoxybenzyl)-chroman (3), together with known compounds 7-hydroxy-3-(4-methoxybenzyl)-chroman-4-one (1), 5,7-dihydroxy-3-(4-methoxybenzyl)-chroman-4-one (2), cantalasaponin-1 (4), and 2-hydroxy-butanedioic acid-1-methyl ester (5).

  14. Macrophytes shape trophic niche variation among generalist fishes

    Science.gov (United States)

    Vejřík, Lukáš; Šmejkal, Marek; Čech, Martin; Sajdlová, Zuzana; Frouzová, Jaroslava; Kiljunen, Mikko; Peterka, Jiří

    2017-01-01

    Generalist species commonly have a fundamental role in ecosystems as they can integrate spatially distinct habitats and food-web compartments, as well as control the composition, abundance and behavior of organisms at different trophic levels. Generalist populations typically consist of specialized individuals, but the potential for and hence degree of individual niche variation can be largely determined by habitat complexity. We compared individual niche variation within three generalist fishes between two comparable lakes in the Czech Republic differing in macrophyte cover, i.e. macrophyte-rich Milada and macrophyte-poor Most. We tested the hypothesis that large individual niche variation among generalist fishes is facilitated by the presence of macrophytes, which provides niches and predation shelter for fish and their prey items. Based on results from stable nitrogen (δ15N) and carbon (δ13C) isotopic mixing models, perch (Perca fluviatilis L.) and rudd (Scardinius erythrophthalmus (L.)) showed larger individual variation (i.e., variance) in trophic position in Milada as compared to Most, whereas no significant between-lake differences were observed for roach (Rutilus rutilus (L.)). Contrary to our hypothesis, all the three species showed significantly lower individual variation in the relative reliance on littoral food resources in Milada than in Most. Rudd relied significantly more whereas perch and roach relied less on littoral food resources in Milada than in Most, likely due to prevalent herbivory by rudd and prevalent zooplanktivory by perch and roach in the macrophyte-rich Milada as compared to macrophyte-poor Most. Our study demonstrates how the succession of macrophyte vegetation, via its effects on the physical and biological complexity of the littoral zone and on the availability of small prey fish and zooplankton, can strongly influence individual niche variation among generalist fishes with different ontogenetic trajectories, and hence the overall

  15. Opportunities for Phytoremediation and Bioindication of Arsenic Contaminated Water Using a Submerged Aquatic Plant:Vallisneria natans (lour.) Hara.

    Science.gov (United States)

    Chen, Guoliang; Liu, Xingmei; Brookes, Philip C; Xu, Jianming

    2015-01-01

    The identification of plants with high arsenic hyperaccumulating efficiency from water is required to ensure the successful application of phytoremediation technology. Five dominant submerged plant species (Vallisneria natans (Lour.) Hara., Potamageton crispus L., Myriophyllum spicatum L., Ceratophyllum demersum L. and Hydrilla verticillata (L.f.) Royle) in China were used to determine their potential to remove As from contaminated water. V. natans had the highest accumulation of As among them. The characteristics of As accumulation, transformation and the effect of phosphate on As accumulation in V. natans were then further studied. The growth of V. natans was not inhibited even when the As concentration reached 2.0 mg L(-1). After 21 d of As treatment, the bioconcentration factor (BCF) reached 1300. The As concentration in the environment and exposure time are major factors controlling the As concentration in V. natans. After being absorbed, As(V) is efficiently reduced to As(III) in plants. The synthesis of non-enzymic antioxidants may play an important role under As stress and increase As detoxication. In addition, As(V) uptake by V. natans was negatively correlated with phosphate (P) uptake when P was sufficiently supplied. As(V) is probably taken up via P transporters in V. natans.

  16. Investigation of Darwin’s naturalization hypothesis in invaded macrophyte communities

    Science.gov (United States)

    Although native macrophytes are beneficial in aquatic ecosystems, invasive macrophytes can cause significant ecological and economic harm. Numerous studies have attributed invasiveness to species’ characteristics, whereas others attribute invasion to biotic and abiotic characteristics of the invaded...

  17. Assessment of the Potential Biological Activity of Low Molecular Weight Metabolites of Freshwater Macrophytes with QSAR

    National Research Council Canada - National Science Library

    Kurashov, Evgeny A; Fedorova, Elena V; Krylova, Julia V; Mitrukova, Galina G

    2016-01-01

    ... (Prediction of Activity Spectra for Substances) for the major components of three macrophytes widespread in the Holarctic species of freshwater, emergent macrophyte with floating leaves, Nuphar lutea (L.) Sm...

  18. Effect of removal of free-floating macrophytes on zooplankton habitat in shallow wetland

    OpenAIRE

    Choi Jong-Yun; Jeong Kwang-Seuk; La Geung-Hwan; Joo Gea-Jae

    2014-01-01

    Submerged macrophytes improve the structural heterogeneity of microhabitats in aquatic ecosystems, often providing an important habitat for zooplankton. However, excessive development of free-floating macrophytes on the water surface can reduce the biomass of submerged macrophytes and result in a relatively simple habitat structure. We hypothesized that controlling the development of free-floating macrophytes would result in a more complex habitat structure by promoting the development of sub...

  19. Mechanism and control of Genipa americana seed germination

    NARCIS (Netherlands)

    Queiroz, S.E.E.; Silva, da E.A.A.; Davide, A.C.; Jose, A.C.; Silva, A.T.; Fraiz, A.C.R.; Faria, J.M.R.; Hilhorst, H.W.M.

    2012-01-01

    Genipa americana (Rubiaceae) is important for restoration of riparian forest in the Brazilian Cerrado. The objective was to characterize the mechanism and control of germination of G. americana to support uniform seedling production. Morphology and morphometrics of seeds, embryo and endosperm were a

  20. Incidencia de loque americana en mieles

    OpenAIRE

    Alippi, Adriana Mónica; Reynaldi, Francisco José; López, Ana Claudia; De Giusti, Marisa Raquel

    2003-01-01

    La loque americana de las abejas, ocasionada por la bacteria esporulada Paenibacillus larvae subsp. larvae, es la enfermedad más grave que afecta a las larvas de las abejas melíferas. Las esporas bacterianas permanecen viables en miel manteniendo su capacidad infectiva durante tiempo prolongado y de esa forma diseminan la enfermedad aún desde colmenas asintomáticas. Para determinar la incidencia de la enfermedad, se realizó un monitoreo de la distribución de esporas de P. l. larvae en mieles ...

  1. Enfermedad de Chagas o Tripanosomiasis Americana.

    OpenAIRE

    Felipe Guhl

    2000-01-01

    Situación Actual de Colombia.

    La enfermedad de Chagas o tripanosomiasis americana es una enfermedad parasitaria crónica causada por un protozoario flagelado el Trypanosoma cruzi, descrito por primera vez por Carlos Chagas, médico brasileño, a comienzos de este siglo y en su honor se denominó la enfermedad que lleva su nombre.

    Este parásito normalmente se transmite al ser humano a través de insectos triatomíneos estricta...

  2. Infrared thermography applied to rhea (Rhea americana

    Directory of Open Access Journals (Sweden)

    Jânio Lopes Torquato

    2015-04-01

    Full Text Available Infrared thermography is an innovative tool that has been used in several studies involving animal. This tool used to study heat stress, thermoregulation, behavior, disease diagnosis, mainly in the animal production and animal welfare. Wild birds are animals that get tense with the presence of man in his environment, causing changes in its thermal physiology and behavior. In the Brazilian semiarid, high temperatures cause further stress the birds, in studies involving animal welfare and animal production is important to use procedures and tools that do not cause stress to the animal, hence the implementation of infrared thermography. The Rhea americana is a wild bird, native to Brazil, which is gaining market share because of its meat is healthy and other products that are extracted from it. Little is known about the thermal physiology and behavior of this ratita, it is essential to improve poultry facilities in order to provide a pleasant environment and increase production. Birds and other ratites as the ostrich, emu, kiwi and cassowary use some body areas to dissipate body heat, the areas are: legs, beak and neck. All these body areas used by birds to dissipate heat were found using infrared thermography. Being a ratita, Rhea Americana can use the same body regions to reduce heat stress. So, infrared thermography is critical to the thermoregulatory studies of rheas in hot environments.

  3. Implementation and implications of macrophyte reconfiguration in hydraulic river modeling

    Science.gov (United States)

    Verschoren, Veerle; Schoelynck, Jonas; Buis, Kerst; Meire, Dieter; Bal, Kris; Meire, Patrick; Temmerman, Stijn

    2014-05-01

    In lowland rivers, abundant macrophyte growth can often be observed. The aquatic vegetation has an impact on the flow by creating friction which results in increased water levels and decreased flow velocities. At the same time submerged macrophytes are susceptible to hydrodynamic forces of the water. Their morphology is therefore often flexible and streamlined so that it enables reconfiguration (i.e. bending of macrophytes with water flow) and decreases potential damage at high flow velocities. Knowledge of these mutual interactions is crucial in order to model water flow in vegetated rivers. A correct estimation of flow velocity and water height is indispensable for the calculation of hydraulic, ecological and geomorphological parameters. The total resistance to water flow in a river can be described by a Manning coefficient. This value is influenced by river characteristics as well as by the presence of macrophytes. In this study a simple method is developed to quantify the resistance created by macrophytes after reconfiguration of their canopy. In order to achieve this we derive model formulations and plant parameters for three different macrophyte species and compare model simulation with measured flow velocity data for two case studies. Furthermore, the effect of macrophyte reconfiguration is investigated by modeling the same case studies with and without the implementation of macrophyte reconfiguration. It was found that the local resistance created by the vegetation was overestimated when reconfiguration was not considered. This resulted in an overestimation of stream velocity adjacent to the vegetation and an underestimation of the stream velocity within and behind the vegetation. Another effect was a higher water level gradient and consequently a higher Manning coefficient in the scenario without reconfiguration compared to the scenario with reconfiguration. Reconfiguration had also an influence on ecological and geomorphological parameters. It was found

  4. Effect of removal of free-floating macrophytes on zooplankton habitat in shallow wetland

    Directory of Open Access Journals (Sweden)

    Choi Jong-Yun

    2014-01-01

    Full Text Available Submerged macrophytes improve the structural heterogeneity of microhabitats in aquatic ecosystems, often providing an important habitat for zooplankton. However, excessive development of free-floating macrophytes on the water surface can reduce the biomass of submerged macrophytes and result in a relatively simple habitat structure. We hypothesized that controlling the development of free-floating macrophytes would result in a more complex habitat structure by promoting the development of submerged macrophytes. After applying three experimental treatments (NR, no removal; IR, intermediate removal; CR, complete removal of free-floating macrophytes, we found that CR of free-floating macrophytes improved the growth and development of submerged macrophytes and supported a large zooplankton assemblage. However, the largest zooplankton assemblage (in terms of abundance and diversity was recorded after the IR treatment. Although submerged macrophytes were abundant in the CR treatment, the number, abundance, and density of zooplankton species were much lower than those in the IR treatment. Preferential selection of different macrophyte types by zooplankton presumably led to variation in plant utilization of niches, and the simultaneous presence of different macrophyte life forms created a complex microhabitat structure that induced high species diversity and zooplankton density.

  5. Chemical warfare in freshwater. Allelpathic effects of macrophytes on phytoplankton

    NARCIS (Netherlands)

    Mulderij, G.

    2006-01-01

    Aquatic macrophytes can excrete chemical substances into their enviroment and these compounds may inhibit the growth of phytoplankton. This process is defined as allelopathy: one organism has effects on another via the excretion of a (mixture of) chemical substance(s). With laboratory and field expe

  6. AMEG: the new SETAC advisory group on auqatic macrophyte ecotoxicology

    NARCIS (Netherlands)

    Arts, G.H.P.; Davies, J.; Dobbs, M.; Ebke, P.; Hanson, M.A.

    2010-01-01

    ntroduction and background Primary producers play critical structural and functional roles in aquatic ecosystems; therefore, it is imperative that the potential risks of toxicants to aquatic plants are adequately assessed in the risk assessment of chemicals. The standard required macrophyte test

  7. AMEG: the new SETAC advisory group on auqatic macrophyte ecotoxicology

    NARCIS (Netherlands)

    Arts, G.H.P.; Davies, J.; Dobbs, M.; Ebke, P.; Hanson, M.A.

    2010-01-01

    ntroduction and background Primary producers play critical structural and functional roles in aquatic ecosystems; therefore, it is imperative that the potential risks of toxicants to aquatic plants are adequately assessed in the risk assessment of chemicals. The standard required macrophyte test spe

  8. Experiments on growth interactions between two invasive macrophyte species

    NARCIS (Netherlands)

    Barrat-Segretain, M-H.; Elger, A.F.

    2004-01-01

    The success of invasive species has been attributed to the ability to displace other species by direct competition. We studied growth and possible competition between the two macrophyte species Elodea nuttallii and E. canadensis, because the former has been observed to replace the latter in the

  9. Macrophytes in estuarine gradients: flow through flexible vegetation

    NARCIS (Netherlands)

    Dijkstra, J.T.

    2012-01-01

    Aquatic plants –or macrophytes- are an important part of coastal, estuarine and freshwater ecosystems worldwide, both from an ecological and an engineering viewpoint. Their meadows provide a wide range of ecosystem services: forming a physical protection of the shoreline, enhancing water quality and

  10. African Journal of Science and Technology (AJST) MACROPHYTES ...

    African Journals Online (AJOL)

    opiyo

    MACROPHYTES ET GROUPEMENTS VÉGÉTAUX AQUATIQUES. ET AMPHIBIES DE LA ... plaine d'inondation indique que le marnage demeure important et la salinité des terres reste encore élevée. ..... The Journal of Ecology, vol. 54, n° 3 ...

  11. Macrophyte presence and growth form influence macroinvertebrate community structure

    NARCIS (Netherlands)

    Walker, P.D.; Wijnhoven, S.; van der Velde, G.

    2013-01-01

    Multivariate analysis demonstrated that macroinvertebrate assemblages of macrophyte-dominated sub-habitats within a small eutrophic pond differed markedly from those of Bottom substrate and Open water habitats. Certain habitats (e.g. Nymphaea and Phragmites) appeared to be quite similar in their

  12. Herbivory on freshwater and marine macrophytes : A review and perspective

    NARCIS (Netherlands)

    Bakker, Elisabeth S.; Wood, Kevin A.; Pages, Jordi F.; Veen, G. F. (Ciska); Christianen, Marjolijn J. A.; Santamaria, Luis; Nolet, Bart A.; Hilt, Sabine

    2016-01-01

    Until the 1990s, herbivory on aquatic vascular plants was considered to be of minor importance, and the predominant view was that freshwater and marine macrophytes did not take part in the food web: their primary fate was the detritivorous pathway. In the last 25 years, a substantial body of

  13. Herbivory on freshwater and marine macrophytes : A review and perspective

    NARCIS (Netherlands)

    Bakker, Elisabeth S.; Wood, Kevin A.; Pages, Jordi F.; Veen, G. F. (Ciska); Christianen, Marjolijn J. A.; Santamaria, Luis; Nolet, Bart A.; Hilt, Sabine

    2016-01-01

    Until the 1990s, herbivory on aquatic vascular plants was considered to be of minor importance, and the predominant view was that freshwater and marine macrophytes did not take part in the food web: their primary fate was the detritivorous pathway. In the last 25 years, a substantial body of evidenc

  14. Species pool versus site limitations of macrophytes in urban waters

    DEFF Research Database (Denmark)

    Vermonden, K.; Leuven, R.S.E.W.; van der Velde, G.

    2010-01-01

    Biodiversity in urban areas is affected by a multitude of stressors. In addition to physico-chemical stress factors, the native regional species pool can be greatly reduced in highly urbanized landscapes due to area loss and fragmentation. In this study, we investigated how macrophyte composition...

  15. Chemical warfare in freshwater. Allelpathic effects of macrophytes on phytoplankton

    NARCIS (Netherlands)

    Mulderij, G.

    2006-01-01

    Aquatic macrophytes can excrete chemical substances into their enviroment and these compounds may inhibit the growth of phytoplankton. This process is defined as allelopathy: one organism has effects on another via the excretion of a (mixture of) chemical substance(s). With laboratory and field

  16. Systemic infection with Alaria americana (Trematoda).

    Science.gov (United States)

    Fernandes, B. J.; Cooper, J. D.; Cullen, J. B.; Freeman, R. S.; Ritchie, A. C.; Scott, A. A.; Stuart, P. F.

    1976-01-01

    Alaria americana is a trematode, the adult of which is found in mammalian carnivores. The first case of disseminated human infection by the mesocercarial stage of this worm occurred in a 24-year-old man. The infection possibly was acquired by the eating of inadequately cooked frogs, which are intermediate hosts of the worm. The diagnosis was made during life by lung biopsy and confirmed at autopsy. The mesocercariae were present in the stomach wall, lymph nodes, liver, myocardium, pancreas and surrounding adipose tissue, spleen, kidney, lungs, brain and spinal cord. There was no host reaction to the parasites. Granulomas were present in the stomach wall, lymph nodes and liver, but the worms were not identified in them. Hypersensitivity vasculitis and a bleeding diathesis due to disseminated intravascular coagulation and a circulating anticoagulant caused his death 8 days after the onset of his illness. Images FIG. 1 FIG. 2 FIG. 3 FIG. 4 FIG. 5 FIG. 6 PMID:1000445

  17. Final Critical Habitat for the Whooping crane (Grus americana)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — To provide the user with a general idea of areas where the final critical habitat for Whooping crane (Grus americana) occur based on the description provided in the...

  18. Final Critical Habitat for the Whooping crane (Grus americana)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — To provide the user with a general idea of areas where the final critical habitat for Whooping crane (Grus americana) occur based on the description provided in the...

  19. International Recovery Plan : Whooping Crane (Grus americana) : Third Revision

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In the United States, the whooping crane (Grus americana) was listed as threatened with extinction in 1967 and endangered in 1970 – both listings were...

  20. Pronghorn (Antilocapra americana) Reintroduction and Management Plan [DRAFT

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Pronghorn (Antilocapra americana) have been a component of North America’s grasslands for millions of years and have thus created a niche for themselves in remaining...

  1. A New Pregnane Glycoside from Fermented Leaves of Agave americana

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new minor pregnane glycoside was isolated from the fermented leaves of Agave americana. Its structure was elucidated as (20S)-5α-pregnane-3β, 20-diol 20-O-β-D-glucopyrano- side (1) by spectral methods.

  2. Evaluation of Treatments to Reduce Hardness of Agave americana Core

    OpenAIRE

    Ramírez, José A.; Gómez-Ayala, Rocio C.; Cuauhtémoc Jacques-Hernández; Manuel Vázquez

    2006-01-01

    Agave americana contains inulin as storage carbohydrate. Therefore, agave is interesting to be used for the extraction of inulin by pressing. The yield of the process is low due to the high hardness of the core. The objective of this work was to evaluate pretreatments to reduce the hardness in the process of obtaining inulin by pressing. Treatments with water, sulphuric acid 1 % (by mass) or sodium hydroxide 1 % (by mass) were tested and optimized. The pretreatment of the core of A. americana...

  3. Psicologia Latino-Americana: desafios e possibilidades

    Directory of Open Access Journals (Sweden)

    Camilla Veras Pessoa da Silva

    Full Text Available A comemoração dos 50 anos da regulamentação da profissão da Psicologia no Brasil sinaliza o recente e o contínuo esforço das profissionais psicólogas e psicólogos em contextualizar o saber psicológico com a realidade e as condições de vida da população latino-americana. Atualmente, a Psicologia passa por um processo de reformulação crítica que considera as peculiaridades históricas, culturais, políticas, econômicas e sociais na constituição subjetiva dos sujeitos. Dessa forma, propõe o alinhamento epistemológico desse saber com os demais países da América Latina devido às vivências similares de colonização ibérico-católica, de modernização tardia e de exploração dos recursos naturais e humanos do continente. Contudo, a construção de uma psicologia latino-americana enfrenta desafios, a exemplo das diferenças entre os países, da multiplicidade cultural e dos interesses geopolíticos das nações. O objetivo do presente estudo foi compreender o processo de formação e de construção epistemológica da Psicologia histórico-cultural buscando, na literatura analisada, as principais possibilidades e desafios da integração da Psicologia com os demais países latino-americanos. De qualquer forma, observa-se que, ao se dedicar ao atendimento das demandas populacionais e à implicação no processo de transformação social, são oferecidas à Psicologia diversas possibilidades de atuação.

  4. Temporal and habitat distribution of macrophytes in lowland eutrophic reservoir Gruža in Serbia

    OpenAIRE

    Topuzović, Marina; Pavlović, Dragana; Ostojić, Aleksandar

    2016-01-01

    Background and Purpose: The research in this paper are based on the study of the distribution in time and space of macrophytes along the different parts of shoreline of Gruža Reservoir and emphasize the importance of establishing relations between distribution, diversity and mass of macrophytes and the ecological conditions of the environment. Development diversity of macrophytes needs to be constantly monitored and their regulation is necessary for Reservoir conservation, especially because...

  5. Temporal and spatial distribution of macrophytes in the Gruža Reservoir (Serbia)

    OpenAIRE

    Topuzović Marina; Pavlović Dragana; Ostojić A.

    2009-01-01

    A survey of aquatic macrophytes in the Gruža Reservoir (Serbia) was conducted during the period 2007-2008. Detailed data on the actual condition of macrophytes were established and compared between four parts of the reservoir. The distributions of most aquatic macrophytes of the Gruža Reservoir are heterogeneous, with different values of the MMT and MMO indices and low values of the distribution ratio. Quantitative analysis indicates that the greatest diversity and abundance of species can be...

  6. Response of littoral macrophytes to water level fluctuations in a storage reservoir

    OpenAIRE

    Krolová M.; Čížková H.; Hejzlar J.; Poláková S.

    2013-01-01

    Lakes and reservoirs that are used for water supply and/or flow regulations have usually poorly developed littoral macrophyte communities, which impairs ecological potential in terms of the EU Water Framework Directive. The aim of our study was to reveal controlling factors for the growth of littoral macrophytes in a storage reservoir with fluctuating water level (Lipno Reservoir, Czech Republic). Macrophytes occurred in this reservoir only in the eulittoral zone i.e., the shoreline region be...

  7. Macrophytes: Limitations of Using Them to Assess Reservoir Status According to the Water Framework Directive

    OpenAIRE

    Alaoui, Khadija Sossey; Galoux, Daniel; Rosillon, Francis

    2014-01-01

    Macrophytes are among the major groups of organisms that the Water Framework Directive (WFD) recommends should be used in assessing the status of natural lakes. The use of macrophytes in reservoir monitoring is still limited and further studies are needed on their inter-calibration and sources of variation. Many status assessment methods based on macrophyte communities have been defined for lakes. Nevertheless, few of them have been tested for reservoirs. The purpose of the study is to hig...

  8. Response of littoral macrophytes to water level fluctuations in a storage reservoir

    OpenAIRE

    Krolová M.; Čížková H.; Hejzlar J.; Poláková S.

    2013-01-01

    Lakes and reservoirs that are used for water supply and/or flow regulations have usually poorly developed littoral macrophyte communities, which impairs ecological potential in terms of the EU Water Framework Directive. The aim of our study was to reveal controlling factors for the growth of littoral macrophytes in a storage reservoir with fluctuating water level (Lipno Reservoir, Czech Republic). Macrophytes occurred in this reservoir only in the eulittoral zone i.e., the shoreline region be...

  9. Temporal and habitat distribution of macrophytes in lowland eutrophic reservoir Gruža in Serbia

    OpenAIRE

    Topuzović, Marina; Pavlović, Dragana; Ostojić, Aleksandar

    2016-01-01

    Background and Purpose: The research in this paper are based on the study of the distribution in time and space of macrophytes along the different parts of shoreline of Gruža Reservoir and emphasize the importance of establishing relations between distribution, diversity and mass of macrophytes and the ecological conditions of the environment. Development diversity of macrophytes needs to be constantly monitored and their regulation is necessary for Reservoir conservation, especially because ...

  10. Invasive crayfish threaten the development of submerged macrophytes in lake restoration.

    Directory of Open Access Journals (Sweden)

    Jessica E M van der Wal

    Full Text Available Submerged macrophytes enhance water transparency and aquatic biodiversity in shallow water ecosystems. Therefore, the return of submerged macrophytes is the target of many lake restoration projects. However, at present, north-western European aquatic ecosystems are increasingly invaded by omnivorous exotic crayfish. We hypothesize that invasive crayfish pose a novel constraint on the regeneration of submerged macrophytes in restored lakes and may jeopardize restoration efforts. We experimentally investigated whether the invasive crayfish (Procambarus clarkii Girard affects submerged macrophyte development in a Dutch peat lake where these crayfish are expanding rapidly. Seemingly favourable abiotic conditions for macrophyte growth existed in two 0.5 ha lake enclosures, which provided shelter and reduced turbidity, and in one lake enclosure iron was added to reduce internal nutrient loading, but macrophytes did not emerge. We transplanted three submerged macrophyte species in a full factorial exclosure experiment, where we separated the effect of crayfish from large vertebrates using different mesh sizes combined with a caging treatment stocked with crayfish only. The three transplanted macrophytes grew rapidly when protected from grazing in both lake enclosures, demonstrating that abiotic conditions for growth were suitable. Crayfish strongly reduced biomass and survival of all three macrophyte species while waterfowl and fish had no additive effects. Gut contents showed that crayfish were mostly carnivorous, but also consumed macrophytes. We show that P. clarkii strongly inhibit macrophyte development once favourable abiotic conditions for macrophyte growth are restored. Therefore, expansion of invasive crayfish poses a novel threat to the restoration of shallow water bodies in north-western Europe. Prevention of introduction and spread of crayfish is urgent, as management of invasive crayfish populations is very difficult.

  11. Aquatic macrophyte diversity of the Pantanal wetland and upper basin.

    Science.gov (United States)

    Pott, V J; Pott, A; Lima, L C P; Moreira, S N; Oliveira, A K M

    2011-04-01

    This is a short review of the state of the art concerning diversity of aquatic macrophytes and the main aquatic vegetation types in the Brazilian Pantanal wetland and upper watershed. There are ca. 280 species of aquatic macrophytes on the Pantanal floodplain, with scarce endemism. On the upper watershed, Cerrado wetlands (veredas) and limestone springs have a distinct flora from the Pantanal, with twice the species richness. As a representative case of aquatic habitats influenced by river flood, some primary data are presented for the Pantanal Matogrossense National Park and associated Acurizal Preserve, analysing the floristic similarity among aquatic vegetation types. We comment on problems of conservation and observe that Panicum elephantipes Nees is one of the few natives to compete with the invasive Urochloa arrecta (Hack. ex T. Durand & Schinz) Morrone & Zuloaga.

  12. Aquatic macrophyte diversity of the Pantanal wetland and upper basin

    Directory of Open Access Journals (Sweden)

    VJ. Pott

    Full Text Available This is a short review of the state of the art concerning diversity of aquatic macrophytes and the main aquatic vegetation types in the Brazilian Pantanal wetland and upper watershed. There are ca. 280 species of aquatic macrophytes on the Pantanal floodplain, with scarce endemism. On the upper watershed, Cerrado wetlands (veredas and limestone springs have a distinct flora from the Pantanal, with twice the species richness. As a representative case of aquatic habitats influenced by river flood, some primary data are presented for the Pantanal Matogrossense National Park and associated Acurizal Preserve, analysing the floristic similarity among aquatic vegetation types. We comment on problems of conservation and observe that Panicum elephantipes Nees is one of the few natives to compete with the invasive Urochloa arrecta (Hack. ex T. Durand & Schinz Morrone & Zuloaga.

  13. Aquatic macrophyte community varies in urban reservoirs with different degrees of eutrophication

    Directory of Open Access Journals (Sweden)

    Suelen Cristina Alves da Silva

    2014-06-01

    Full Text Available AIM: Investigate spatial and temporal variation in the aquatic macrophyte community in four urban reservoirs located in Curitiba metropolitan region, Brazil. We tested the hypothesis that aquatic macrophyte community differ among reservoirs with different degrees of eutrophication. METHODS: The reservoirs selected ranged from oligotrophic/mesotrophic to eutrophic. Sampling occurred in October 2011, January 2012 and June 2012. Twelve aquatic macrophytes stands were sampled at each reservoir. Species were identified and the relative abundance of aquatic macrophytes was estimated. Differences among reservoirs and over sampling periods were analyzed: i through two‑way ANOVAs considering the stand extent (m and the stand biodiversity - species richness, evenness, Shannon-Wiener index and beta diversity (species variation along the aquatic macrophyte stand; and ii through PERMANOVA considering species composition. Indicator species that were characteristic for each reservoir were also identified. RESULTS: The aquatic macrophyte stand extent varied among reservoirs and over sampling periods. Species richness showed only temporal variation. On the other hand, evenness and Shannon-Wiener index varied only among reservoirs. The beta diversity of macrophyte stands did not vary among reservoirs or over time, meaning that species variability among aquatic macrophyte stands was independent of the stand extent and reservoir eutrophication. Community composition depended on the reservoir and sampling period. CONCLUSIONS: Our results support our initial expectation that reservoirs of different degrees of eutrophication have different aquatic macrophyte communities. As a consequence, each reservoir had particular indicator species. Therefore, monitoring and management efforts must be offered for each reservoir individually.

  14. Patterns of the aquatic macrophyte cover in Cachoeira Dourada Reservoir (GO-MG

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    L. M Bini

    Full Text Available The relationship between the aquatic macrophyte cover in upper segments of tributaries and this cover in these tributaries but near the reservoir's main body was tested. Sixteen taxa belonging to 12 families of aquatic macrophytes were recorded in Cachoeira Dourada Reservoir. The most frequent species were Eichhornia azurea (frequency of occurrence = 92%; n = 37 sites and E. crassipes (44%. Upper segments of the tributaries were the main areas colonized by these aquatic macrophytes. The positive relationship between the aquatic macrophyte cover between the upper and lower segments of tributaries indicates the importance of dispersion in the colonization of the arms and the reservoir's main body.

  15. Patterns of the aquatic macrophyte cover in Cachoeira Dourada Reservoir (GO-MG).

    Science.gov (United States)

    Bini, L M; Oliveira, L G; Souza, D C; Carvalho, P; Pinto, M P

    2005-02-01

    The relationship between the aquatic macrophyte cover in upper segments of tributaries and this cover in these tributaries but near the reservoir's main body was tested. Sixteen taxa belonging to 12 families of aquatic macrophytes were recorded in Cachoeira Dourada Reservoir. The most frequent species were Eichhornia azurea (frequency of occurrence=92%; n=37 sites) and E. crassipes (44%). Upper segments of the tributaries were the main areas colonized by these aquatic macrophytes. The positive relationship between the aquatic macrophyte cover between the upper and lower segments of tributaries indicates the importance of dispersion in the colonization of the arms and the reservoir's main body.

  16. Assimilate partitioning in avocado, Persea americana

    Energy Technology Data Exchange (ETDEWEB)

    Finazzo, S.; Davenport, T.L.

    1986-04-01

    Assimilate partitioning is being studied in avocado, Persea americana cv. Millborrow in relation to fruit set. Single leaves on girdled branches of 10 year old trees were radiolabeled for 1 hr with 13..mu..Ci of /sup 14/CO/sub 2/. The source leaves were sampled during the experiment to measure translocation rates. At harvest the sink tissues were dissected and the incorporated radioactivity was measured. The translocation of /sup 14/C-labelled compounds to other leaves was minimal. Incorporation of label into fruitlets varied with the tissue and the stage of development. Sink (fruitlets) nearest to the labelled leaf and sharing the same phyllotaxy incorporated the most /sup 14/C. Source leaves for single non-abscising fruitlets retained 3X more /sup 14/C-labelled compounds than did source leaves for 2 or more fruitlets at 31 hrs. post-labelling. Export of label decreased appreciably when fruitlets abscised. If fruitlets abscised within 4 days of labeling then the translocation pattern was similar to the pattern for single fruitlets. If the fruitlet abscised later, the translocation pattern was intermediate between the single and double fruitlet pattern.

  17. A Rússia Americana The American Russia

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    João Marcelo Ehlert Maia

    2005-08-01

    Full Text Available Este artigo procura analisar interpretações do Brasil assentadas na idéia de que seríamos uma "Rússia Americana". Para tanto, analiso as contribuições de Gilberto Freyre, Otávio Velho e Vicente Licínio Cardoso, e apresento brevemente o caso russo, a partir das obras clássicas de Franco Venturi e Isaiah Berlin. Argumento ao longo do texto que essa percepção de que o Brasil teria uma geografia social "russa" implica a produção de um americanismo específico, que encontra sua maior expressão no pensamento de Vicente Licínio Cardoso e em suas idéias que conjugam fordismo e arielismo.This article seeks to analyse Brazil's interpretations founded on the idea that we would be an "American Russia". in order to do so, I analyse the contributions of Gilberto Freyre, Otávio Velho and Vicente Licínio Cardoso, and I briefly present the russian case, using the works of Franco Venturi and Isaiah Berlin. I suggest that this perception implies the production of an especific type of americanism, wich finds its greater expression on the unusual combination between fordism and arielism made by Vicente Licínio.

  18. Arsenic rich iron plaque on macrophyte roots - an ecotoxicological risk?

    Energy Technology Data Exchange (ETDEWEB)

    Taggart, M.A. [School of Biological Sciences, University of Aberdeen, Cruickshank Bld, St Machar Drive, Aberdeen, AB24 3UU (United Kingdom); Instituto de Investigacion en Recursos Cinegeticos, IREC (CSIC-UCLM-JCCM), Ronda de Toledo s/n, 13005 Ciudad Real (Spain)], E-mail: mark.taggart@uclm.es; Mateo, R. [Instituto de Investigacion en Recursos Cinegeticos, IREC (CSIC-UCLM-JCCM), Ronda de Toledo s/n, 13005 Ciudad Real (Spain); Charnock, J.M.; Bahrami, F. [Synchrotron Radiation Department, CCLRC Daresbury Laboratory, Warrington, Cheshire, WA4 4AD (United Kingdom); Green, A.J. [Department of Wetland Ecology, Estacion Biologica de Donana, CSIC, Pabellon del Peru, Avenida Maria Luisa s/n, 41013 Seville (Spain); Meharg, A.A. [School of Biological Sciences, University of Aberdeen, Cruickshank Bld, St Machar Drive, Aberdeen, AB24 3UU (United Kingdom)

    2009-03-15

    Arsenic is known to accumulate with iron plaque on macrophyte roots. Three to four years after the Aznalcollar mine spill (Spain), residual arsenic contamination left in seasonal wetland habitats has been identified in this form by scanning electron microscopy. Total digestion has determined arsenic concentrations in thoroughly washed 'root + plaque' material in excess of 1000 mg kg{sup -1}, and further analysis using X-ray absorption spectroscopy suggests arsenic exists as both arsenate and arsenite. Certain herbivorous species feed on rhizomes and bulbs of macrophytes in a wide range of global environments, and the ecotoxicological impact of consuming arsenic rich iron plaque associated with such food items remains to be quantified. Here, greylag geese which feed on Scirpus maritimus rhizome and bulb material in areas affected by the Aznalcollar spill are shown to have elevated levels of arsenic in their feces, which may originate from arsenic rich iron plaque. - Accumulation of metals with iron plaque on macrophyte roots in wetlands poses an ecotoxicological risk to certain herbivores.

  19. Vulnerabilities of macrophytes distribution due to climate change

    Science.gov (United States)

    Hossain, Kaizar; Yadav, Sarita; Quaik, Shlrene; Pant, Gaurav; Maruthi, A. Y.; Ismail, Norli

    2017-08-01

    The rise in the earth's surface and water temperature is part of the effect of climatic change that has been observed for the last decade. The rates of climate change are unprecedented, and biological responses to these changes have also been prominent in all levels of species, communities and ecosystems. Aquatic-terrestrial ecotones are vulnerable to climate change, and degradation of the emergent aquatic macrophyte zone would have contributed severe ecological consequences for freshwater, wetland and terrestrial ecosystems. Most researches on climate change effects on biodiversity are contemplating on the terrestrial realm, and considerable changes in terrestrial biodiversity and species' distributions have been detected in response to climate change. This is unfortunate, given the importance of aquatic systems for providing ecosystem goods and services. Thus, if researchers were able to identify early-warning indicators of anthropogenic environmental changes on aquatic species, communities and ecosystems, it would certainly help to manage and conserve these systems in a sustainable way. One of such early-warning indicators concerns the expansion of emergent macrophytes in aquatic-terrestrial ecotones. Hence, this review highlights the impact of climatic changes towards aquatic macrophytes and their possible environmental implications.

  20. Microphyte and macrophyte-based lagooning in tropical regions.

    Science.gov (United States)

    Noumsi, I M K; Nya, J; Akoa, A; Eteme, R A; Ndikefor, A; Fonkou, T; Brissaud, F

    2005-01-01

    A 720 m2 plant made of 8 ponds in series, set in Yaounde (Cameroon), was successively operated as a macrophyte-based system (type M) from November 1997 to October 98, a microphyte-based system (type m) from October 1999 to September 2000 and a combination of macrophyte and microphyte ponds (type M + m) from May to July 2001. Average applied loads varied over the years; from 420 kg. BOD5 ha(-1)d(-1) on the year 1997/98, the loads reached 510 kg BOD5 ha(-1)d(-1) in 1999/2000 and 500 in 2001. Though the system became more and more overloaded and sludge accumulated rapidly in the first ponds, it provided average removals of SS, BOD5 and COD that were always higher than 90% whatever the type of lagooning. Performances in the removal of SS, organic matter and the abatement of N-NH4+ and PO4(3-) did not significantly differ according to the type of lagooning and the applied load. Macrophyte lagooning did not show any definitive superiority as to nutrient removal when compared to microphyte lagooning. Microphyte lagooning was the most effective process in faecal indicators removal.

  1. Vulnerabilities of macrophytes distribution due to climate change

    Science.gov (United States)

    Hossain, Kaizar; Yadav, Sarita; Quaik, Shlrene; Pant, Gaurav; Maruthi, A. Y.; Ismail, Norli

    2016-06-01

    The rise in the earth's surface and water temperature is part of the effect of climatic change that has been observed for the last decade. The rates of climate change are unprecedented, and biological responses to these changes have also been prominent in all levels of species, communities and ecosystems. Aquatic-terrestrial ecotones are vulnerable to climate change, and degradation of the emergent aquatic macrophyte zone would have contributed severe ecological consequences for freshwater, wetland and terrestrial ecosystems. Most researches on climate change effects on biodiversity are contemplating on the terrestrial realm, and considerable changes in terrestrial biodiversity and species' distributions have been detected in response to climate change. This is unfortunate, given the importance of aquatic systems for providing ecosystem goods and services. Thus, if researchers were able to identify early-warning indicators of anthropogenic environmental changes on aquatic species, communities and ecosystems, it would certainly help to manage and conserve these systems in a sustainable way. One of such early-warning indicators concerns the expansion of emergent macrophytes in aquatic-terrestrial ecotones. Hence, this review highlights the impact of climatic changes towards aquatic macrophytes and their possible environmental implications.

  2. Analysis of sesquiterpene distributions in leaves, branches, and trunks of avocado (Persea americana Mill.)

    Science.gov (United States)

    Avocado is a commercially valuable fruit crop cultivated in tropical and subtropical climates throughout the world. Taxonomists recognize three horticultural races of avocado, consisting of Mexican (Persea americana var. drymifolia), Guatemalan (P. americana var. guatemalensis), and West Indian (P. ...

  3. Historia de la Tripanosomiasis Americana en Colombia

    Directory of Open Access Journals (Sweden)

    Fernando Serpa Florez

    2000-08-01

    Full Text Available

    La Academia Nacional de Medicina de Colombia rinde homenaje a Carlos Chagas, opónimo médico brasileño, nacido en Oliveira en 1879 y fallecido en Río de Janeiro en 1934, con motivo del nonagésimo aniversario del descubrimiento realizado por él del Trypanosoma cruzi, hazaña científica que bautizó en memoria de su maestro Osvaldo Cruz (1872 – 1917, fundador del Instituto de Manquinhos que hoy lleva el nombre de este sanitarista. (1

    Carlos Chagas fue miembro correspondiente de nuestra Corporación, elegido hace ochenta años, durante la presidencia del profesor Miguel Rueda Acosta, lo que hace que celebremos el triunfo de quien, honrosamente, podemos considerar como uno de los nuestros. (2 Chagas encontró en 1909 la relación existente entre la Tripanosomiasis Americana y el agente de esta dolencia descubierto por él, que por ello hoy se llama Enfermedad de Chagas.

    La tripanosomiasis americana o enfermedad de Chagas, es una entidad autóctona de nuestro continente que, como tantas otras, en un principio fue una zoonosis (enfermedad de los animales que se transmite al hombre tal cual la hidrofobia o rabia, la fiebre amarilla, la encefalitis equina, el carbón bacteridiano, la enfermedad de Lyme… para citar unas cuantas.

    La dolencia se extendió a la especie humana cuando ésta irrumpió en la hábitat del huésped intermedio del mal y se ha hecho cada vez más aparente con el aumento de la población y el desequilibrio ecológico que se presenta con la deforestación.

    Recordemos que sus reservorios (es decir los hospederos que le sirven de depósito, son algunos animales domésticos como el perro, el cerdo o el cobayo y peridomésticos y silvestres como las ratas, los murciélagos, los armadillos, monos y zarigüeyas. Al hombre, desde luego, podemos considerarlo como reservorio de esta dolencia. En Colombia los primeros informes científi-cos sobre animales domésticos y silvestres reservorios del Trypanosoma

  4. Evaluation of Treatments to Reduce Hardness of Agave americana Core

    Directory of Open Access Journals (Sweden)

    José A. Ramírez

    2006-01-01

    Full Text Available Agave americana contains inulin as storage carbohydrate. Therefore, agave is interesting to be used for the extraction of inulin by pressing. The yield of the process is low due to the high hardness of the core. The objective of this work was to evaluate pretreatments to reduce the hardness in the process of obtaining inulin by pressing. Treatments with water, sulphuric acid 1 % (by mass or sodium hydroxide 1 % (by mass were tested and optimized. The pretreatment of the core of A. americana with sulphuric acid 1 % allowed the reduction of hardness from 30 000 g to 2000 g of breaking force. The mathematical model obtained predicts an optimum processing at 84 °C during 75 min. The treatment with sulphuric acid 1 % also allows white core of A. americana to be obtained, while the other treatments provide yellow core. These results open a good alternative to obtain value added products from this resource.

  5. Extending one-dimensional models for deep lakes to simulate the impact of submerged macrophytes on water quality

    NARCIS (Netherlands)

    Sachse, R.; Petzoldt, T.; Blumstock, M.; Moreira, S.; Pätzig, M.; Rücker, J.; Janse, J.H.; Mooij, W.M.; Hilt, S.

    2014-01-01

    Submerged macrophytes can stabilise clear water conditions in shallow lakes. However, many existing models for deep lakes neglect their impact. Here, we tested the hypothesis that submerged macrophytes can affect the water clarity in deep lakes. A one-dimensional, vertically resolved macrophyte mode

  6. Restoring macrophyte diversity in shallow temperate lakes: biotic versus abiotic constraints

    NARCIS (Netherlands)

    Bakker, E.S.; Sarneel, J.M.; Gulati, R.D.; Liu, Z.; Van Donk, E.

    2013-01-01

    Although many lake restoration projects have led to decreased nutrient loads and increased water transparency, the establishment or expansion of macrophytes does not immediately follow the improved abiotic conditions and it is often unclear whether vegetation with high macrophyte diversity will retu

  7. Macrophyte-phytoplankton interactions: the relative importance of allelopathy versus other factors

    NARCIS (Netherlands)

    Mulderij, G.; Nes, van E.H.; Donk, van E.

    2007-01-01

    Submerged aquatic macrophytes are important in shallow aquatic ecosystems because they stabilize the macrophyte-dominated state by increasing water transparency in various ways. One of these is the excretion of allelopathic substances inhibitory to phytoplankton, but it is still controversial whethe

  8. Macrophyte-phytoplankton interactions: the relative importance of allelopathy versus other factors

    NARCIS (Netherlands)

    Mulderij, G.; van Nes, E.H.; Van Donk, E.

    2007-01-01

    Abstract Submerged aquatic macrophytes are important in shallow aquatic ecosystems because they stabilize the macrophyte-dominated state by increasing water transparency in various ways. One of these is the excretion of allelopathic substances inhibitory to phytoplankton, but it is still controversi

  9. Competition between free-floating and submerged macrophytes in a future of climate change

    NARCIS (Netherlands)

    Netten, J.J.C.

    2011-01-01


    This research was about the asymmetric competition between free-floating and submerged macrophytes in shallow freshwater ecosystems. I studied the effect of climate change on the dominance of free-floating macrophytes in temperate regions. The research approach was a combination of outdoor me

  10. Competition between free-floating and submerged macrophytes in a future of climate change

    NARCIS (Netherlands)

    Netten, J.J.C.

    2011-01-01


    This research was about the asymmetric competition between free-floating and submerged macrophytes in shallow freshwater ecosystems. I studied the effect of climate change on the dominance of free-floating macrophytes in temperate regions. The research approach was a combination of outdoor

  11. Macrophyte species distribution, indices of biotic integrity and sampling intensity in isolated Florida marshes

    Science.gov (United States)

    This study tested macrophyte condition metrics calculated after decreasing the effort and area of sampling by 33% to 66%, as tested in 74 emergent isolated wetlands. Four belted transects from wetland edge to center were established and rooted macrophytes were identified. The eff...

  12. Invertebrate grazing during the regenerative phase affects the ultimate structure of macrophyte communities

    NARCIS (Netherlands)

    Elger, A.F.; Willby, N.; Cabello-Martinez, M.

    2009-01-01

    1. Although the biomass of freshwater macrophytes consumed by invertebrate herbivores (excluding crayfish) is usually low, there is growing evidence that invertebrates do exert a structuring effect on macrophyte communities. To explain this, we postulated that the effect of invertebrates may be conc

  13. Effects of the herbicide 2,4-D on the growth of nine aquatic macrophytes

    NARCIS (Netherlands)

    Belgers, J.D.M.; Lieverloo, van R.J.; Pas, van der L.J.T.; Brink, van den P.J.

    2007-01-01

    A study was conducted to determine the effect of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) on nine submersed macrophyte species. The first objective of the study was to investigate the sensitivity of various endpoints in macrophyte toxicity tests. A second objective was to investigate the

  14. Experimental Effects of Lime Application on Aquatic Macrophytes: 4. Growth Response of Three Species

    Science.gov (United States)

    2007-04-01

    James PURPOSE: This investigation examined the growth response of three macrophyte species ( Elodea canadensis, Stuckenia pectinata, and Vallisnaria...different macrophyte species. These hypotheses were tested using experimental mesocosms. METHODS: Elodea canadensis, Stuckenia pectinata, and...Snel, P. E. Zanstra, and R. J. Helder. 1982. The mechanism of bicarbonate assimilation by the polar leaves of Potamogeton and Elodea . CO2 concentrations

  15. First steps in the Central-Baltic intercalibration exercise on lake macrophytes: where do we start?

    NARCIS (Netherlands)

    Tóth, L.G.; Poikane, S.; Penning, W.E.; Free, G.; Mäemets, H.; Kolada, A.; Hanganu, J.

    2008-01-01

    The Water Framework Directive (WFD 2000) defines macrophytes as one of the biological groups required for the ecological assessment of European surface waters. Several indices for macrophyte assessment have been proposed or are currently in use by different European states. As a first step towards p

  16. Macrophyte-phytoplankton interactions: the relative importance of allelopathy versus other factors

    NARCIS (Netherlands)

    Mulderij, G.; van Nes, E.H.; Van Donk, E.

    2007-01-01

    Abstract Submerged aquatic macrophytes are important in shallow aquatic ecosystems because they stabilize the macrophyte-dominated state by increasing water transparency in various ways. One of these is the excretion of allelopathic substances inhibitory to phytoplankton, but it is still

  17. Macrophyte-phytoplankton interactions: the relative importance of allelopathy versus other factors

    NARCIS (Netherlands)

    Mulderij, G.; Nes, van E.H.; Donk, van E.

    2007-01-01

    Submerged aquatic macrophytes are important in shallow aquatic ecosystems because they stabilize the macrophyte-dominated state by increasing water transparency in various ways. One of these is the excretion of allelopathic substances inhibitory to phytoplankton, but it is still controversial

  18. Aspectos quimiotaxonómicos en Myristicaceae Americanas Aspectos quimiotaxonómicos en Myristicaceae Americanas

    Directory of Open Access Journals (Sweden)

    Aguirre Gálviz Luis Enrique

    1990-06-01

    Full Text Available

    Se hace un análisis del patrón de distribución de agliconas de flavonoides y ácidos hidroxiaromáticos en 187 muestras de 33 especies de Myristicaceae americanas y, junto con la información morfo1ógica disponible, se presenta un enfoque biosistemático para el conocimiento taxonómico de la familia.

    A survey of the distribution of flavonoid aglycones and related bydroxy-aromatic acids in 187 samples of 33 species of American Myristicaceae is carried out. This survey, together with the available morfological information, provides a biosynthetic approach to the taxonomy of the family.

  19. Carbonic anhydrase levels and internal lacunar CO/sub 2/ concentrations in aquatic macrophytes

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, C.I.

    1979-01-01

    Carbonic anhydrase levels were examined in a variety of aquatic macrophytes from different habitats. In general, carbonic anhydrase levels increased across the habitat gradient such that activities were low in submersed aquatic macrophytes and high in emergent macrophytes with floating-leaved and free-floating plants exhibiting intermediate activities. Internal lacunar CO/sub 2/ concentrations were analyzed in relation to carbonic anhydrase activities. There was no correlation between these two parameters. Internal CO/sub 2/ concentrations ranged from low to high in submersed macrophytes, but were low in floating-leaved and emergent macrophytes. The observed internal CO/sub 2/ concentrations are discussed in relation to the individual morphologies of the plants and the environments in which they occurred.

  20. Effects of altered estuarine submerged macrophyte bed cover on the omnivorous Cape stumpnose Rhabdosargus holubi.

    Science.gov (United States)

    Sheppard, J N; Whitfield, A K; Cowley, P D; Hill, J M

    2012-03-01

    The ecological importance of submerged macrophyte beds to fishes within estuaries was investigated through the example of the ubiquitous Cape stumpnose Rhabdosargus holubi, an omnivorous, vegetation and estuary-dependent species, using stable-isotope techniques and long-term abundance (catch-per-unit-effort) data from the East Kleinemonde Estuary, South Africa. Outputs from a Bayesian mixing model using δ(13) C and δ(15) N signatures indicated that the submerged macrophytes Ruppia cirrhosa and Potamogeton pectinatus were not a primary source of nutrition for R. holubi, confirming previous work that revealed that macrophytes are consumed but not digested. Long-term seine netting data showed reduced abundance of R. holubi during a prolonged period of macrophyte senescence, suggesting that submerged macrophyte habitats provide shelter that reduces mortality (predation risk) and a food-rich foraging area. © 2012 SAIAB. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  1. Role of macrophyte life forms in driving periphytic microalgal assemblages in a Brazilian reservoir

    Directory of Open Access Journals (Sweden)

    Ubirajara L. Fernandes

    2015-08-01

    Full Text Available Macrophytes play several roles in aquatic ecosystems, including the provision of habitat for many aquatic organisms, especially the periphyton. The aims of this study were to characterize the structure of periphytic microalgal assemblages on different aquatic macrophyte life forms in order to establish similarities between assemblages from nearby sampling sites. We hypothesized that i aquatic macrophytes with different life forms and morphological characteristics could differently influence the structure of the periphyton and that ii the greatest similarity in periphyton composition should be observed among macrophytes that occupy the same sampling site. The study was conducted from 2006 to 2008 in the Thomaz Osterne de Alencar reservoir (Crato City, Ceará State, Brazil and involved the taxonomic surveying of microalgae attached to five different macrophytes with the application of structural descriptors (richness, abundance, frequency, diversity and equitability. A total of 127 taxa, of which 44% belonged to the Chlorophyta, were identified. The microalgae assemblages showed high species richness on Salvinia auriculata Aubl., a free-floating macrophyte, and large abundance on Apalanthe granatensis (Humb. & Bonpl. Planch., a submerged anchored macrophyte. ANOVA indicated that periphyton significantly varied among the macrophytes investigated, and nearby sampling sites showed no structural similarities in microalgal assemblages. In general, we can conclude that the structure of periphyton assemblages is influenced by the substrate (i.e., macrophyte organ, as this can not only promote high diversity and equitability but can also be a predictor of dissimilarity in the distribution and frequency of occurrence of microalgae. These results reinforce the findings of other studies that have shown that macrophytes play an important role in structuring the periphyton assemblages.

  2. Submerged macrophytes mitigate direct and indirect insecticide effects in freshwater communities.

    Directory of Open Access Journals (Sweden)

    William R Brogan

    Full Text Available Understanding how ecological interactions mitigate the impacts of perturbations such as pesticides in biological communities is an important basic and applied question for ecologists. In aquatic ecosystems, new evidence from microcosm experiments suggests that submerged macrophytes can buffer cladocerans from pulse exposures to the widely used insecticide malathion, and that mitigation increases with macrophyte density. However, whether these results scale up to more complex aquatic communities where ecological interactions such as competition can alter toxicity is unknown. Further, macrophyte abilities to mitigate different insecticide exposure scenarios (i.e. single versus repeated pulses have never been tested. To address these gaps, we performed a factorial mesocosm experiment examining the influence of four macrophyte treatments (0, 10, 50, or 100 Elodea Canadensis shoots planted per mesocosm crossed with three malathion exposure scenarios (no insecticide, single pulse, repeated pulses on aquatic communities containing zooplankton, phytoplankton, periphyton, two snail species, and larval amphibians. In the absence of macrophytes, single malathion pulses caused short-term declines in cladoceran abundance followed by their rapid recovery, which precluded any indirect effects (i.e. trophic cascades. However, repeated malathion pulses caused cladoceran extinctions, resulting in persistent phytoplankton blooms and reduced abundance of one snail species. In contrast, with macrophytes present, even at low density, malathion had no effect on any taxa. We also discovered novel effects of macrophytes on the benthic food web. In the two highest macrophyte treatments, we observed trends of reduced periphyton biomass, decreased abundance of one snail species, and decreased amphibian time to and mass at metamorphosis. To our knowledge, this is the first evidence of negative submerged macrophyte effects on amphibians, a taxa of global conservation concern

  3. Physical and chemical properties of substrates produced using macrophytes aquatics

    Directory of Open Access Journals (Sweden)

    Walda Monteiro Farias

    2013-12-01

    Full Text Available Aquatic macrophytes are widely used as bioindicators of water quality because their proliferation usually occurs in eutrophic water sources and has hit several parts of Brazil and the world, restricted the multiple uses of aquatic ecosystems. However, this group of plants is able to retain considerable amounts of nutrients, presenting high productivity and high growth rate, thus, a good source of biomass for use in the production of substrates. In order to evaluate the potential of aquatic macrophytes water hyacinth (Eichhornia crassipes Solms., water lettuce (Pistia stratiotes L. and cattail (Typha domingensis Pers. in the production of substrates was performed in this work, the physical and chemical characterization and evaluation of the degree of humification. The treatments were arranged in a 3 × 4 factorial, completely randomized design with three replications. All substrates produced with 100% macrophyte density present within the limits of 400 kg m-3, considered ideal. The composite substrates with water hyacinth and water lettuce are with the electrical conductivity of 0,79 a 2,49 dS m-1 within recommended. organic compounds produced are considered mature and have high levels of nitrogen phosphorus and potassium; The substrate produced with 70% water lettuce +30 % dung and 70% composed of cattail manure +20% +10% topsoil and 70 +30% cattail manure have C/N ratio within the considered ideal; the humification ratio and humification index, except for the four treatments (70 % water lettuce manure +30%, 5 (100% water hyacinth and 8 (70% water hyacinth manure +30% are within the considered ideal, the percentage of humic acids and polymerization rate, except for treatments 1 (100% water lettuce and 12 (100% cattail, are shown below the ideal.

  4. Tratamento da leishmaniose tegumentar americana pelo niridazol

    Directory of Open Access Journals (Sweden)

    Miroslau Constante Baranski

    1970-08-01

    Full Text Available Foi empregue o niridazol um derivado do nitrotiazol, em doze pacientes com leishmaniose tegumentar americana. Em todos êles, o diagnóstico clínico da doença foi confirmado pela biópsia das lesões e em oito dêles também pela positividade da intradetermorreação de Montenegro. Oito pacientes tinham lesões mucosas metastáticas em atividade e lesões cutâneas iniciais cicatrizadas há tempo mais ou menos longo. Dois apresentavam concomitância de lesões cutâneas e mucosas em atividade, e dois tinham lesões cutâneas exclusivas. A duração da doença variou de 2 meses a 32 anos. A posologia diária do niridazol foi uniformememente de 25 mg/kg de pêso corpóreo. O medicamento foi administrado por via oral, em duas tomadas diárias, sempre com o doente internado em hospital. Quando a tolerância o permitia, o paciente recebia cinco séries de tratamento de 10 dias de duração cada, intercaladas por períodos áe suspensão da droga de 10 dias entre uma série e outra. Isso foi possível em 10 dos 12 pacientes. O tratamento foi bem tolerado em 5 doentes e de tolerância regular em 4. Mal tolerado em um paciente pela ocorrência de alucinações e excitação mental e interrompido pela péssima tolerância em dois doentes devido ao aparecimento de convulsões generalizadas com perda da consciência. O tratamento acompanhou-se de grande incidência, de efeitos colaterais. A ocorrência de para-efeitos mais intensos não foi devida às más condições hepáticas. Provas de função hepática. hemogramas, estudos bioquímicos do sangue e exames de urina, realizados antes, durante e após o tratamento, não revelaram alterações significativas. Biópsias hepáticas por punção com agulha em dez doentes, prévias e posteriores ao tratamento, não detectaram lesões hepáticas que pudessem ser atribuídas à medicação. O seguimento dos doentes prolongou-se pelo prazo de dois a 36 meses apos o tratamento. Alterações eletrocardiogr

  5. Hypoglycemic and hypocholesterolemic potential of Persea americana leaf extracts.

    Science.gov (United States)

    Brai, Bartholomew I C; Odetola, A A; Agomo, P U

    2007-06-01

    The effect of aqueous and methanolic leaf extracts of Persea americana on plasma glucose, total cholesterol, low-density lipoprotein cholesterol (LDL-CHOL), and high-density lipoprotein cholesterol (HDL-CHOL) in rats was investigated. Albino rats were fed a diet containing 20% groundnut oil, 0.5% cholesterol, and 0.25% cholic acid to induce hypercholesterolemia. They were then treated daily with aqueous or methanolic extract of P. americana leaf (10 mg/kg of body weight) for 8 weeks. There were no significant (P > .05) differences in the overall body weight gain of the hypercholesterolemic rats compared to normal control. Liver to body weight ratio, plasma glucose, total cholesterol (T-CHOL), and LDL-CHOL levels were significantly (P americana induced reductions in plasma glucose (16% and 11%,respectively), T-CHOL (8% and 5%, respectively), and LDL-CHOL (19% and 20%, respectively) in the treated rats compared to the hypercholesterolemic controls. Also, plasma HDL-CHOL concentrations increased by 85% and 68%, respectively, in the aqueous and methanolic extract-treated rats compared to the hypercholesterolemic controls. These results suggest that aqueous and methanolic leaf extracts of P. americana lower plasma glucose and influence lipid metabolism in hypercholesterolemic rats with consequent lowering of T-CHOL and LDL-CHOL and a restoration of HDL-CHOL levels. This could represent a protective mechanism against the development of atherosclerosis.

  6. Parasites of Periplaneta americana linnaeus "domestic cockroach" from Ica.

    Directory of Open Access Journals (Sweden)

    Mary Fernádez B.

    2014-06-01

    Full Text Available 244 specimens of Periplaneta americana Linnaeus from 13 localities of Ica were studied. Nematodes and protozoa were identified. They are Lophomonas blattarum, Leptomonas sp., Leidynema appendiculatum and Hammerschmidtiella diesingi. Also, parasites of man were found, three of which are pathogenic: Giardia lamblia, Blastocystis hominis and Cryptosporidium sp.

  7. Teaching German-Americana with Assistance from the Web.

    Science.gov (United States)

    Shea, Robert J.; Hoyt, Giles R.

    1998-01-01

    Argues that the World Wide Web can assist in teaching about German-Americana in German-language instruction, and discusses some basic Web page uses to find and organize literary texts, syllabi, course outlines, images and realia, and information about people, organizations, events, and places. Some of the most useful German-American resources are…

  8. Characterization and development mechanism of Apios americana tuber starch

    Science.gov (United States)

    Apios americana is a wild legume-bearing plant with edible tubers. Domestication of Apios is in progress because of the superior nutritional value and health benefits of the tuber. Objectives of this study were to: 1) characterize physicochemical properties of Apios-tuber starch; and 2) understand d...

  9. Three new hecogenin glycosides from fermented leaves of Agave americana.

    Science.gov (United States)

    Jin, Jian-Ming; Liu, Xi-Kui; Yang, Chong-Ren

    2003-06-01

    Eight steroidal compounds, including three new hecogenin glycosides, agamenosides D-F, were isolated from the fermented leaves of Agave americana. The structures of the new steroidal saponins were elucidated by spectroscopic data and chemical methods. The activity of the isolated compounds on deformations of mycelia germinated from conidia of Pyricularia oaryzae P-2b was evaluated.

  10. Plant based phosphorus recovery from wastewater via algae and macrophytes.

    Science.gov (United States)

    Shilton, Andrew N; Powell, Nicola; Guieysse, Benoit

    2012-12-01

    At present, resource recovery by irrigation of wastewater to plants is usually driven by the value of the water resource rather than phosphorus recovery. Expanded irrigation for increased phosphorus recovery may be expected as the scarcity and price of phosphorus increases, but providing the necessary treatment, storage and conveyance comes at significant expense. An alternative to taking the wastewater to the plants is instead to take the plants to the wastewater. Algal ponds and macrophyte wetlands are already in widespread use for wastewater treatment and if harvested, would require less than one-tenth of the area to recover phosphorus compared to terrestrial crops/pastures. This area could be further decreased if the phosphorus content of the macrophytes and algae biomass was tripled from 1% to 3% via luxury uptake. While this and many other opportunities for plant based recovery of phosphorus exist, e.g. offshore cultivation, much of this technology development is still in its infancy. Research that enhances our understanding of how to maximise phosphorus uptake and harvest yields; and further add value to the biomass for reuse would see the recovery of phosphorus via plants become an important solution in the future.

  11. Efficiency of aquatic macrophytes to treat Nile tilapia pond effluents

    Directory of Open Access Journals (Sweden)

    Henry-Silva Gustavo Gonzaga

    2006-01-01

    Full Text Available The effluents from fish farming can increase the quantity of suspended solids and promote the enrichment of nitrogen and phosphorus in aquatic ecosystems. In this context, the aim of this work was to evaluate the efficiency of three species of floating aquatic macrophytes (Eichhornia crassipes, Pistia stratiotes and Salvinia molesta to treat effluents from Nile tilapia culture ponds. The effluent originated from a 1,000-m² pond stocked with 2,000 male Nile tilapia Oreochromis niloticus. The treatment systems consisted of 12 experimental tanks, three tanks for each macrophyte species, and three control tanks (without plants. Water samples were collected from the: (i fish pond source water, (ii effluent from fish pond and (iii effluents from the treatment tanks. The following water variables were evaluated: turbidity, total and dissolved nitrogen, ammoniacal-N, nitrate-N, nitrite-N, total phosphorus and dissolved phosphorus. E. crassipes and P. stratiotes were more efficient in total phosphorus removal (82.0% and 83.3%, respectively and total nitrogen removal (46.1% and 43.9%, respectively than the S. molesta (72.1% total phosphorus and 42.7% total nitrogen and the control (50.3% total phosphorus and 22.8% total nitrogen, indicating that the treated effluents may be reused in the aquaculture activity.

  12. Enfermedad de Chagas o Tripanosomiasis Americana.

    Directory of Open Access Journals (Sweden)

    Felipe Guhl

    2000-08-01

    Full Text Available

    Situación Actual de Colombia.

    La enfermedad de Chagas o tripanosomiasis americana es una enfermedad parasitaria crónica causada por un protozoario flagelado el Trypanosoma cruzi, descrito por primera vez por Carlos Chagas, médico brasileño, a comienzos de este siglo y en su honor se denominó la enfermedad que lleva su nombre.

    Este parásito normalmente se transmite al ser humano a través de insectos triatomíneos estrictamente hematófagos de la familia Reduviidae, en el momento en que perforan la piel para succionar la sangre que los alimenta.

    Sin embargo, no se inocula directamente por intermedio de las estructuras bucales del insecto en el momento de la picadura como en el caso de las tripanosomiasis africanas, si no que se deposita pasivamente en la piel a través de las heces del insecto, penetrando en el cuerpo por la herida que causa la picadura u otras abrasiones de la piel o de la mucosa. El T. cruzi, también puede transmitirse por infección congénita, por transfusión de sangre contaminada o por el transplante de órganos contaminados. El ciclo vital del parásito es largo y complejo y su desarrollo tiene varias etapas, tanto en el vector triatomineo como en el huésped vertebrado .

    La Enfermedad de Chagas constituye una amenaza permanente para casi la cuarta parte de toda la población de América Latina. Si bien la enfermedad se encuentra presente en toda América Central y del Sur, sus manifestaciones y características epidemiológicas son altamente variables entre una y otra zona endémica. Existe una gran diversidad en las tasas de prevalencia, formas de transmisión, características parasitarias, patología clínica, vectores y reservorios.

    Más que cualquier otra enfermedad parasitaria, la enfermedad de Chagas se relaciona con el desarrollo económico y social de la población: los insectos triatomineos y las enfermedades que ellos transmiten existirán mientras en

  13. Monitoring the dynamics of an invasive emergent macrophyte community using operational remote sensing data

    Science.gov (United States)

    Albright, T.P.; Ode, D.J.

    2011-01-01

    Potamogeton crispus L. (curly pondweed) is a cosmopolitan aquatic macrophyte considered invasive in North America and elsewhere. Its range is expanding and, on individual water bodies, its coverage can be dynamic both within and among years. In this study, we evaluate the use of free and low-cost satellite remote sensing data to monitor a problematic emergent macrophyte community dominated by P. crispus. Between 2000 and 2006, we acquired eight satellite images of 24,000-ha Lake Sharpe, South Dakota (USA). During one of the dates for which satellite imagery was acquired, we sampled the lake for P. crispus and other emergent macrophytes using GPS and photography for documentation. We used cluster analysis to assist in classification of the satellite imagery and independently validated results using the field data. Resulting estimates of emergent macrophyte coverage ranged from less than 20 ha in 2002 to 245 ha in 2004. Accuracy assessment indicated 82% of image pixels were correctly classified, with errors being primarily due to failure to identify emergent macrophytes. These results emphasize the dynamic nature of P. crispus-dominated macrophyte communities and show how they can be effectively monitored over large areas using low-cost remote sensing imagery. While results may vary in other systems depending on water quality and local flora, such an approach could be applied elsewhere and for a variety of macrophyte communities. ?? Springer Science+Business Media B.V. 2010.

  14. Responses of aquatic macrophyte cover and productivity to flooding variability on the Amazon floodplain.

    Science.gov (United States)

    Silva, Thiago S F; Melack, John M; Novo, Evlyn M L M

    2013-11-01

    Macrophyte net primary productivity (NPP) is a significant but understudied component of the carbon budget in large Amazonian floodplains. Annual NPP is determined by the interaction between stem elongation (vertical growth) and plant cover changes (horizontal expansion), each affected differently by flood duration and amplitude. Therefore, hydrological changes as predicted for the Amazon basin could result in significant changes in annual macrophyte NPP. This study investigates the responses of macrophyte horizontal expansion and vertical growth to flooding variability, and its possible effects on the contribution of macrophytes to the carbon budget of Amazonian floodplains. Monthly macrophyte cover was estimated using satellite imagery for the 2003-2004 and 2004-2005 hydrological years, and biomass was measured in situ between 2003 and 2004. Regression models between macrophyte variables and river-stage data were used to build a semiempirical model of macrophyte NPP as a function of water level. Historical river-stage records (1970-2011) were used to simulate variations in NPP, as a function of annual flooding. Vertical growth varied by a factor of ca. 2 over the simulated years, whereas minimum and maximum annual cover varied by ca. 3.5 and 1.5, respectively. Results suggest that these processes act in opposite directions to determine macrophyte NPP, with larger sensitivity to changes in vertical growth, and thus maximum flooding levels. Years with uncommonly large flooding amplitude resulted in the highest NPP values, as both horizontal expansion and vertical growth were enhanced under these conditions. Over the simulated period, annual NPP varied by ca. 1.5 (1.06-1.63 TgC yr(-1) ). A small increasing trend in flooding amplitude, and by extension NPP, was observed for the studied period. Variability in growth rates caused by local biotic and abiotic factors, and the lack of knowledge on macrophyte physiological responses to extreme hydrological conditions

  15. Temporal and spatial distribution of macrophytes in the Gruža Reservoir (Serbia

    Directory of Open Access Journals (Sweden)

    Topuzović Marina

    2009-01-01

    Full Text Available A survey of aquatic macrophytes in the Gruža Reservoir (Serbia was conducted during the period 2007-2008. Detailed data on the actual condition of macrophytes were established and compared between four parts of the reservoir. The distributions of most aquatic macrophytes of the Gruža Reservoir are heterogeneous, with different values of the MMT and MMO indices and low values of the distribution ratio. Quantitative analysis indicates that the greatest diversity and abundance of species can be found in those parts of the reservoir with the shallowest water and greatest indentation of the shoreline.

  16. Functional diversity of macrophyte communities within and between Pyrenean lakes

    Directory of Open Access Journals (Sweden)

    Enric BALLESTEROS

    2009-02-01

    Full Text Available Submersed vegetation is a common feature in about 70% Pyrenean high mountain (>1500 m a.s.l. lakes. Isoetids and soft-water elodeids are common elements of this underwater flora and can form distinct vegetation units (i.e. patches of vegetation dominated by different species within complex mosaics of vegetation in shallow waters (<7 m. Since isoetids exert a strong influence on sediment biogeochemistry due to high radial oxygen loss, we examined the small scale characteristics of the lake environment (water and sediment associated to vegetation patches in order to ascertain potential functional differences among them. To do so, we characterised the species composition and biomass of the main vegetation units from 11 lakes, defined plant communities based on biomass data, and then related each community with sediment properties (redox and dissolved nutrient concentration in the pore water and water nutrient concentration within plant canopy. We also characterised lake water and sediment in areas without vegetation as a reference. A total of twenty-one vegetation units were identified, ranging from one to five per lake. A cluster analysis on biomass species composition suggested seven different macrophyte communities that were named after the most dominant species: Nitella sp., Potamogeton praelongus, Myriophyllum alterniflorum, Sparganium angustifolium, Isoetes echinospora, Isoetes lacustris and Carex rostrata. Coupling between macrophyte communities and their immediate environment (overlying water and sediment was manifested mainly as variation in sediment redox conditions and the dominant form of inorganic nitrogen in pore-water. These effects depended on the specific composition of the community, and on the allocation between above- and belowground biomass, and could be predicted with a model relating the average and standard deviation of sediment redox potential from 0 down to -20 cm, across macrophyte communities. Differences in pore

  17. Production of plant virus inhibitor by Phytolacca americana suspension culture.

    Science.gov (United States)

    Misawa, M; Hayashi, M; Tanaka, H

    1975-09-01

    The inhibitory activity of tobacco mosaic virus (TMV) infection was assayed with the extracts of various callus tissues derived from the intact plants. Phytolacca americana callus was selected as a producer of the virus inhibitor and its cultural conditions in suspension were examined for cell growth and the inhibitor production. A modified liquid medium containing twofold concentrations of all components in that of Murashige and Skoog plus2,4-D (1.0 mg/liter) and sucrose (6%), but without any vitamins and glycine was chosen for production of higher levels of the inhibitor. TMV infections in tobacco, bean, and tomato plants were markedly inhibited by the introduction of the disrupted whole broth of suspension cultured P. americana.

  18. Interactions between nitrifying and denitrifying bacteria in gnotobiotic microcosms planted with the emergent macrophyte Glyceria maxima

    NARCIS (Netherlands)

    Bodelier, P.L.E.; Duyts, H.; Blom, C.W.P.M.; Laanbroek, H.J.

    1998-01-01

    The population dynamics of the chemolithoautotrophic nitrifiers Nitrosomonas europaea and Nitrobacter winogradskyi were studied in gnotobiotic microcosms fed with ammonium in response to the presence or absence of the emergent macrophyte Glyceria maxima and the heterotrophic denitrifying bacterium P

  19. Long-term allelopathic control of phytoplankton by the submerged macrophyte Elodea nuttallii

    NARCIS (Netherlands)

    Vanderstukken, M.; Declerck, S.A.J.; Decaestecker, E.; Muylaert, K.

    2014-01-01

    Keywords: allelochemicals; chemical ecology; competition; nutrient limitation; shallow lakes Summary 1.It is well known that submerged macrophytes can suppress phytoplankton blooms in lakes and thus promote water quality and biodiversity. One of the possible mechanisms through which submerged macrop

  20. Studies on heavy metal accumulation in aquatic macrophytes from Sevan (Armenia) and Carambolim (India) lake systems

    Digital Repository Service at National Institute of Oceanography (India)

    Vardanyan, L.G.; Ingole, B.S.

    in root system. The representative macrophytes from two different physiographic locations show similar trends and order in accumulating different metals generally. Of the 14 metals investigated, 9 (Ca, Fe, Al, Cr, Cu, Ba, Ti, Co and Pb) showed higher rates...

  1. Three-Gorge Dam influences wetland macrophytes in middle and lower reaches of Yangtze

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Dongting Lake, located in the middle and lower reaches of Yangtze, is regarded as a lake during the water swelling period and a continent in the ebbing period. The construction of the Three-Gorge Dam has influenced the water level of Dongting Lake and the growth of wetland macrophytes in the area. In this study, the growth of main species of wetland macrophytes, such as Carex and Phragmites at Dongting Lake, was observed, and the hydraulic gradient, one of the main factors dominating the abundance and distribution of wetland macrophytes, was also studied at six stations in Dongting Lake area and the effect of the Three-Gorge Dam construction on the growth of wetland macrophytes was observed.

  2. Closely related freshwater macrophyte species, Ceratophyllum demersum and em>C. submersum, differ in temperature response

    DEFF Research Database (Denmark)

    Hyldgaard, Benita; Sorrell, Brian Keith; Brix, Hans

    2014-01-01

    1. The importance of temperature responses of photosynthesis and respiration in determining species distributions was compared in two closely related freshwater macrophytes, Ceratophyllum demersum and C. submersum. The two species differed significantly in response to temperature in the short and...

  3. PIXE analysis of chromium phytoaccumulation by the aquatic macrophytes Eicchornia crassipes

    Science.gov (United States)

    Espinoza-Quiñones, F. R.; Rizzutto, M. A.; Added, N.; Tabacniks, M. H.; Módenes, A. N.; Palácio, S. M.; Silva, E. A.; Rossi, F. L.; Martin, N.; Szymanski, N.

    2009-04-01

    The uptake of hexavalent chromium in free living floating aquatic macrophytes Eicchornia crassipes cultivated in non-toxic chromium-doped hydroponic solutions is presented. A Cr-uptake bioaccumulation experiment was carried out using healthy macrophytes grown in a temperature controlled greenhouse. Six samples of nutrient media and plants were collected during the 23 day experiment. Roots and leaves were acid digested with the addition of an internal Gallium standard, for thin film sample preparation and quantitative Cr analysis by PIXE method. The Cr 6+ mass uptake by the macrophytes reached up to 70% of the initial concentration, comparable to former results and literature data. The Cr-uptake data were described using a non-structural first order kinetic model. Due to low cost and high removal efficiency, living aquatic macrophytes E. crassipes are a viable biosorbent in an artificial wetland of a water effluent treatment plant.

  4. Effects of litter on substrate conditions and growth of emergent macrophytes

    NARCIS (Netherlands)

    Van der Putten, W.H.; Peters, B.A.M.; Van den Berg, R.S.

    1997-01-01

    Three successive emergent macrophytes (Typha latifolia L., Phragmites australis (Cav.) Steudel and Glyceria maxima (Hartman) Holmbly) were each grown in substrates collected from three different zones of shoreline vegetation development (non- vegetated sediment, the interface between T. latifolia an

  5. PIXE analysis of chromium phytoaccumulation by the aquatic macrophytes Eicchornia crassipes

    Energy Technology Data Exchange (ETDEWEB)

    Espinoza-Quinones, F.R. [Department of Chemical Engineering - Postgraduate Program - NBQ, West Parana State University, Rua da Faculdade, 645, Jardim Santa Maria, 85903-000 Toledo, Parana (Brazil)], E-mail: f.espinoza@terra.com.br; Rizzutto, M.A.; Added, N.; Tabacniks, M.H. [Physics Institute, University of Sao Paulo, Rua do Matao s/n, Travessa R 187, 05508-900 Sao Paulo, SP (Brazil); Modenes, A.N.; Palacio, S.M.; Silva, E.A.; Rossi, F.L.; Martin, N.; Szymanski, N. [Department of Chemical Engineering - Postgraduate Program - NBQ, West Parana State University, Rua da Faculdade, 645, Jardim Santa Maria, 85903-000 Toledo, Parana (Brazil)

    2009-04-15

    The uptake of hexavalent chromium in free living floating aquatic macrophytes Eicchornia crassipes cultivated in non-toxic chromium-doped hydroponic solutions is presented. A Cr-uptake bioaccumulation experiment was carried out using healthy macrophytes grown in a temperature controlled greenhouse. Six samples of nutrient media and plants were collected during the 23 day experiment. Roots and leaves were acid digested with the addition of an internal Gallium standard, for thin film sample preparation and quantitative Cr analysis by PIXE method. The Cr{sup 6+} mass uptake by the macrophytes reached up to 70% of the initial concentration, comparable to former results and literature data. The Cr-uptake data were described using a non-structural first order kinetic model. Due to low cost and high removal efficiency, living aquatic macrophytes E. crassipes are a viable biosorbent in an artificial wetland of a water effluent treatment plant.

  6. Nitrogen or phosphorus limitation in lakes and its impact on phytoplankton biomass and submerged macrophyte cover

    DEFF Research Database (Denmark)

    Søndergaard, Martin; Lauridsen, Torben Linding; Johansson, Liselotte Sander

    2017-01-01

    macrophyte cover. We conclude that P is of key importance for the ecological quality of Danish lakes but that increased N concentrations, particularly in shallow lakes with moderate to high TP, may have significantly adverse effects on lake water quality and ecological status in summer.......We used data on nutrients, chlorophyll a (Chla) and submerged macrophyte cover from up to 817 Danish lakes to elucidate seasonal variations in nitrogen (N) and phosphorus (P) concentrations and to study the impact of N or its role in combination with P. In both deep and shallow lakes, we found...... related more strongly to TP than to TN, but at high TP concentrations TN explained more of the variability in Chla than TP. Macrophyte cover tended to decrease at increasing TN when TP was between 0.1 and 0.4 mg/l. At macrophyte cover above 20%, Chla was considerably lower compared with lakes with low...

  7. Response of littoral macrophytes to water level fluctuations in a storage reservoir

    National Research Council Canada - National Science Library

    Krolová, M; Čížková, H; Hejzlar, J; Poláková, S

    2013-01-01

    Lakes and reservoirs that are used for water supply and/or flow regulations have usually poorly developed littoral macrophyte communities, which impairs ecological potential in terms of the EU Water Framework Directive...

  8. Does mechanical disturbance affect the performance and species composition of submerged macrophyte communities?

    Science.gov (United States)

    Zhang, Qian; Xu, Ying-Shou; Huang, Lin; Xue, Wei; Sun, Gong-Qi; Zhang, Ming-Xiang; Yu, Fei-Hai

    2014-01-01

    Submerged macrophyte communities are frequently subjected to disturbance of various frequency and strength. However, there is still little experimental evidence on how mechanical disturbance affects the performance and species composition of such plant communities. In a greenhouse experiment, we constructed wetland communities consisting of five co-occurring clonal submerged macrophyte species (Hydrilla verticillata, Elodea canadensis, Ceratophyllum demersum, Chara fragilis, and Myriophyllum spicatum) and subjected these communities to three mechanical disturbance regimes (no, moderate and strong disturbance). Strong mechanical disturbance greatly decreased overall biomass, number of shoot nodes and total shoot length, and increased species diversity (evenness) of the total community. It also substantially decreased the growth of the most abundant species (H. verticillata), but did not affect growth of the other four species. Our data reveal that strong disturbance can have different effects on different submerged macrophyte species and thus alters the performance and species composition of submerged macrophyte communities. PMID:24811826

  9. Capabilities of Seven Species of Aquatic Macrophytes for Phytoremediation of Pentachlorophenol Contaminated Sediment

    Science.gov (United States)

    Zhao, Liangyuan; Guo, Weijie; Li, Qingyun; Li, Huan; Zhao, Weihua; Cao, Xiaohuan

    2017-01-01

    Sediments are regarded as the ultimate sink of pentachlorophenol(PCP) in aquatic environment, and capabilities of seven species of aquatic macrophytes for remediating PCP contaminated sediment were investigated. Seven species of aquatic macrophytes could significantly accelerate the degradation of PCP in sediments. Among all, canna indica L., Acorus calamus L. and Iris tectorum Maxim. can be used as efficient alternative plants for remediation of PCP contaminated sediment, which attained 98%, 92% and 88% of PCP removal in sediments, respectively. PCP was detected only in root tissues and the uptake was closely related to the root lipid contents of seven plants. The presence of seven aquatic macrophytes significantly increased microbial populations and the activities of dehydrogenase compared with control sediments, indicating that rhizosphere microorganism played important role in the remediation process. In conclusion, seven species of aquatic macrophytes may act as promising tools for the PCP phytoremediation in aquatic environment, especially Canna indica L., Acorus calamus L. and Iris tectorum Maxim.

  10. Long-term allelopathic control of phytoplankton by the submerged macrophyte Elodea nuttallii

    NARCIS (Netherlands)

    Vanderstukken, M.; Declerck, S.A.J.; Decaestecker, E.; Muylaert, K.

    2014-01-01

    Keywords: allelochemicals; chemical ecology; competition; nutrient limitation; shallow lakes Summary 1.It is well known that submerged macrophytes can suppress phytoplankton blooms in lakes and thus promote water quality and biodiversity. One of the possible mechanisms through which submerged

  11. Aspectos quimiotaxonómicos en myristicaceae americanas

    OpenAIRE

    Aguirre Gálviz, Luis Enrique

    2011-01-01

    Se hace un análisis del patrón de distribución de agliconas de flavonoides y ácidos hidroxiaromáticos en 187 muestras de 33 especies de Myristicaceae americanas y, junto con la información morfo1ógica disponible, se presenta un enfoque biosistemático para el conocimiento taxonómico de la familia.

  12. A new steroidal saponin from the leaves of Agave americana.

    Science.gov (United States)

    Yokosuka, A; Mimaki, Y; Kuroda, M; Sashida, Y

    2000-05-01

    A new bisdesmosidic spirostanol saponin, along with three known saponins, were isolated from Agave americana (Agavaceae). The structure of the new saponin was elucidated as (25R)-3 beta,6 alpha-dihydroxy-5 alpha-spirostan-12-one 3,6-di-O-beta-D-glucopyranoside. Among the isolated saponins, hecogenin tetraglycoside showed cytotoxic activity against HL-60 human promyelocytic leukemia cells with an IC50 value of 4.3 micrograms/mL.

  13. Regulation and role of epiphytic nitrification and denitrification in macrophyte-dominated systems

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Peder G.

    2000-02-01

    This thesis examines mechanisms regulating bacterial nitrification and denitrification in attached microbial communities on surfaces of aquatic macrophytes. It also evaluates the role of epiphytic nitrification and denitrification for the nitrogen turnover in macrophyte-dominated nutrient-rich freshwater. Epiphytic nitrification is promoted in light and epiphytic denitrification occurs mainly in dark, because the metabolic activity of the aquatic macrophyte and its epiphytes induce in light high and in dark low oxygen concentrations in epiphytic communities. Epiphytic nitrification and denitrification are also affected by the physical and chemical characteristics of the aquatic macrophyte. The spatial distribution of nitrification in emergent macrophyte wetlands is related to the species composition of the emergent vegetation, possibly because of a macrophyte species-related release of organic nitrification inhibitors. Contrasting to nitrifying bacteria, which are lithotrophic, denitrifying bacteria use organic substances as an energy source and are therefore stimulated by the release of organic matter from aquatic macrophytes. Epiphytic communities support more denitrification in nutrient-rich than in nutrient-poor environments. In lakes and ponds, epiphytic denitrification is higher at sheltered locations than at locations exposed to wind-induced water movements or currents. In flowing water, epiphytic denitrification occurs mainly at low oxygen concentrations in the surrounding water. However, because aquatic macrophytes impede water flow and induce low oxygen concentrations in dark, epiphytic denitrification can be present within dense vegetation despite of high oxygen concentrations in the surrounding water. Epiphytic nitrification is almost unaffected by flow conditions, and can occur both in light and in dark. In shallow-water systems such as treatment wetlands, aquatic macrophytes often provide most of the accessible surface area for attached nitrifying and

  14. Haloacetic acids in the aquatic environment. Part I: macrophyte toxicity.

    Science.gov (United States)

    Hanson, Mark L; Solomon, Keith R

    2004-08-01

    Haloacetic acids (HAAs) are contaminants of aquatic ecosystems with numerous sources, both anthropogenic and natural. The toxicity of HAAs to aquatic plants is generally uncharacterized. Laboratory tests were conducted with three macrophytes (Lemna gibba, Myriophyllum sibiricum and Myriophyllum spicatum) to assess the toxicity of five HAAs. Myriophyllum spp. has been proposed as required test species for pesticide registration in North America, but few studies have been conducted under standard test conditions. The HAAs in the present experiments were monochloroacetic acid (MCA), dichloroacetic acid (DCA), trichloroacetic acid (TCA), trifluoroacetic acid (TFA) and chlorodifluoroacetic acid (CDFA). MCA was the most toxic to Myriophyllum spp. with EC50 values ranging from 8 to 12.4 mg/l depending on the endpoint, followed by DCA (EC50 range 62-722.5 mg/l), TCA (EC50 range 49.5-1702.6 mg/l), CDFA (EC50 range 105.3 to >10,000 mg/l) and with TFA (EC50 range 222.1 to 10,000 mg/l) the least toxic. Generally, L. gibba was less sensitive to HAA toxicity than Myriophyllum spp., with the difference in toxicity between them approximately threefold. The range of toxicity within Myriophyllum spp. was normally less than twofold. Statistically, plant length and node number were the most sensitive endpoints as they had the lowest observed coefficients of variation, but they were not the most sensitive to HAA toxicity. Toxicological sensitivity of endpoints varied depending on the measure of effect chosen and the HAA, with morphological endpoints usually an order of magnitude more sensitive than pigments for all plant species. Overall, mass and root measures tended to be the most sensitive indicators of HAA toxicity. The data from this paper were subsequently used in an ecological risk assessment for HAAs and aquatic plants. The assessment found HAAs to be of low risk to aquatic macrophytes and the results are described in the second manuscript of this series.

  15. Experimental Effects of Lime Application on Aquatic Macrophytes: 3. Growth Response Versus Exposure Time

    Science.gov (United States)

    2008-01-01

    ERDC/TN APCRP-EA-17 January 2008 Experimental Effects of Lime Application on Aquatic Macrophytes : 3. Growth Response Versus Exposure Time by William...be effective in both suppressing submersed macrophyte growth and changing species composition (Babin et al. 1992; Chambers et al. 2001; Prepas et al...16 cm height) filled with homogenized sediment (obtained from Eau Galle Reservoir , WI; see James et al. (2005) for a description of sediment

  16. The use of macrophytes for heavy metal pollution control in urban wetlands

    OpenAIRE

    Zhang, Tiantian

    1990-01-01

    A literature survey has been undertaken to identify the role and function of aquatic macrophytes in the removal of contaminants from polluted surface waters. The survey focussed primarily on heavy metals, however nitrate, phosphate and hydrocarbon removal are also discussed and the application of aquatic macrophytes in wastewater treatment systems is also described. The objectives of the research are: To determine heavy metal variations in water, sediment and plant tissues in both fiel...

  17. Terpenoid variations within and among half-sibling avocado trees, Persea americana Mill. (Lauraceae)

    National Research Council Canada - National Science Library

    Niogret, Jerome; Epsky, Nancy D; Schnell, Raymond J; Boza, Edward J; Kendra, Paul E; Heath, Robert R

    2013-01-01

    Chemical analyses were conducted to determine the qualitative and quantitative differences in monoterpenes and sesquiterpenes in plant material from avocado trees, Persea americana Mill. (Lauraceae...

  18. A preliminary evaluation of lake morphometric traits influence on the maximum growing depth of macrophytes

    Directory of Open Access Journals (Sweden)

    Mattia M. Azzella

    2014-03-01

    Full Text Available Underwater light regime is widely considered the principal determinant of aquatic plant depth distribution. The majority of previous studies dealing with macrophytes in lakes have singled out Secchi disk transparency (SD values as the key empirical proxy to explain the maximum depth of macrophyte colonization (Zc. Few studies have investigated the role played by lake morphometry in structuring macrophyte beds. Using a balanced dataset including 20 Italian lakes (10 shallow and 10 deep lakes, we analysed transparency and lake morphometric traits to investigate their possible effects on Zc. Our results demonstrate that lake area plays a significant role, and confirm a direct influence of SD values on Zc. Considering lakes with an equal degree of transparency, smaller lakes may yield a lower Zc than larger ones. Morphology has a great influence on lake ecological characteristics especially on water thermal conditions and mixing depth. Based on our data, we argue that the thermal stratification plays a non negligible role in explaining macrophytes zonation, due to its influence on macrophytes life cycles and phytoplankton vertical distribution. Therefore, the present data suggest the need to enhance and refine our knowledge about the relationship between aquatic plants distribution and lake thermal conditions to better model the response of macrophytes to climate change and eutrophication.

  19. The study of aquatic macrophytes in Neotropics: a scientometrical view of the main trends and gaps.

    Science.gov (United States)

    Padial, A A; Bini, L M; Thomaz, S M

    2008-11-01

    Aquatic macrophytes comprises a diverse group of organisms including angiosperms, ferns, mosses, liverworts and some macroalgae that occur in seasonally or permanently wet environments. Among other implications, aquatic macrophytes are highly productive and with an important structuring role on aquatic environments. Ecological studies involving aquatic plants substantially increased in the last years. However, a precise view of researches devoted to aquatic macrophytes in Neotropics is necessary to reach a reliable evaluation of the scientific production. In the current study, we performed a scientometrics analysis of the scientific production devoted to Neotropical macrophytes in an attempt to find the main trends and gaps of researches concerning this group. The publication devoted to macrophytes in Neotropics increased conspicuously in the last two decades. Brazil, Argentina, Mexico and Chile were the most productive among Neotropical countries. Our analyses showed that the studies dealt mostly with the influences of aquatic macrophytes on organisms and abiotic features. Studies with a predictive approach or aiming to test ecological hypothesis are scarce. In addition, researches aiming to describe unknown species are still necessary. This is essential to support conservation efforts and to subsidize further investigations testing ecological hypotheses.

  20. Emergent Macrophytes Support Zooplankton in a Shallow Tropical Lake: A Basis for Wetland Conservation.

    Science.gov (United States)

    Gebrehiwot, Mesfin; Kifle, Demeke; Triest, Ludwig

    2017-09-08

    Understanding the biodiversity value of littoral zones of lakes is a priority for aquatic biodiversity conservation. However, less emphasis has been given to the littoral part of tropical African lakes, with many of the previous researches focusing only on the open water side. The aim of the present study was, therefore, to investigate the impact of the littoral zone of a shallow freshwater tropical lake (Ziway, Ethiopia), dominated by two emergent macrophytes, on zooplankton community structure. We hypothesized that the wetland vegetation serves as a preferred microhabitat for zooplankton communities. A lake with substantial coverage of emergent macrophytes was monitored monthly from January to August, 2016. The monitoring included the measurements of physical, chemical, and biological parameters. Sampling sites were selected to represent areas of the macrophyte vegetation (Typha latifolia and Phragmites australis) and the open water part of the lake. Sites with macrophyte vegetation were found to be the home of more dense and diverse zooplankton community. However, during the period of high vegetation loss, the density of crustacean zooplankton showed significant reduction within the patches of macrophytes. From biodiversity conservation perspective, it was concluded that the preservation of such small areas of macrophytes covering the littoral zone of lakes could be as important as protecting the whole lake. However, the rapid degradation of wetland vegetation by human activities is a real threat to the lake ecosystem. In the not-too-far future, it could displace and evict riparian vegetation and the biota it supports.

  1. Responses of bacterial community structure and denitrifying bacteria in biofilm to submerged macrophytes and nitrate

    Science.gov (United States)

    Zhang, Songhe; Pang, Si; Wang, Peifang; Wang, Chao; Guo, Chuan; Addo, Felix Gyawu; Li, Yi

    2016-10-01

    Submerged macrophytes play important roles in constructed wetlands and natural water bodies, as these organisms remove nutrients and provide large surfaces for biofilms, which are beneficial for nitrogen removal, particularly from submerged macrophyte-dominated water columns. However, information on the responses of biofilms to submerged macrophytes and nitrogen molecules is limited. In the present study, bacterial community structure and denitrifiers were investigated in biofilms on the leaves of four submerged macrophytes and artificial plants exposed to two nitrate concentrations. The biofilm cells were evenly distributed on artificial plants but appeared in microcolonies on the surfaces of submerged macrophytes. Proteobacteria was the most abundant phylum in all samples, accounting for 27.3-64.8% of the high-quality bacterial reads, followed by Chloroflexi (3.7-25.4%), Firmicutes (3.0-20.1%), Acidobacteria (2.7-15.7%), Actinobacteria (2.2-8.7%), Bacteroidetes (0.5-9.7%), and Verrucomicrobia (2.4-5.2%). Cluster analysis showed that bacterial community structure can be significantly different on macrophytes versus from those on artificial plants. Redundancy analysis showed that electrical conductivity and nitrate concentration were positively correlated with Shannon index and operational taxonomic unit (OTU) richness (log10 transformed) but somewhat negatively correlated with microbial density. The relative abundances of five denitrifying genes were positively correlated with nitrate concentration and electrical conductivity but negatively correlated with dissolved oxygen.

  2. A MODIS-Based Novel Method to Distinguish Surface Cyanobacterial Scums and Aquatic Macrophytes in Lake Taihu

    National Research Council Canada - National Science Library

    Liang, Qichun; Zhang, Yuchao; Ma, Ronghua; Loiselle, Steven; Li, Jing; Hu, Minqi

    2017-01-01

      Satellite remote sensing can be an effective alternative for mapping cyanobacterial scums and aquatic macrophyte distribution over large areas compared with traditional ship's site-specific samplings...

  3. Spatial and temporal dynamics of macrophyte cover in a large regulated river.

    Science.gov (United States)

    Tena, A; Vericat, D; Gonzalo, L E; Batalla, R J

    2016-11-24

    The River Ebro basin is extensively dammed. Dams alter the geomorphological functioning of the river by altering its flow regime (e.g. reducing mean and maximum discharges), increasing bed stability (armouring) and decreasing turbidity (water clarity). These effects, together with an increase in nutrient concentrations and water temperature, have generated optimal conditions for the proliferation of aquatic macrophytes. In this paper, we analyse the temporal and spatial changes of macrophyte cover in the lowermost Ebro through a series of field campaigns carried out between 2009 and 2010. Special attention was paid to the spatial distribution of macrophytes in relation to flow hydraulics, channel geometry and bed sedimentology. Temporal changes in macrophyte cover were analysed in relation to the frequency and magnitude of both natural floods and flushing flows (artificial flow releases from dams with generally a magnitude that equates around a2-year flood in the river). Spatially, the proportion of macrophytes along the reaches showed a variable pattern, with a succession of areas with both high and low plant density, coinciding with the alternation of riffles and pools in the channel. The highest values of plant cover (>65%) occurred in riffles and in transition to riffle areas, while the lowest densities (1% or almost negligible) were observed in pools and transition to pool areas. Water depth and the grain-size distribution of the riverbed materials (i.e. D84), are found to be the main factors controlling the degree of plant cover in the lower Ebro. Temporally, the macrophyte proportion varied during the hydrological year, with a clear increment from late spring to early autumn (i.e. vegetation cover reached 40%, on average, of the channel surface). Macrophyte coverage decreases immediately following a flushing flow but in the long term, vegetation re-occupied the area again, even slightly increasing in some sections; overall, the mean percentage of macrophyte

  4. Temporal trends and effects of diversity on occurrence of exotic macrophytes in a large reservoir

    Science.gov (United States)

    Thomaz, Sidinei Magela; Carvalho, Priscilla; Mormul, Roger Paulo; Ferreira, Fernando Alves; Silveira, Márcio José; Michelan, Thaísa Sala

    2009-09-01

    Two exotic invasive macrophyte species (the emergent Urochloa subquadripara - tenner-grass - and the submersed Hydrilla verticillata - hydrilla) were investigated in a large sub-tropical reservoir. We analyzed their occurrences over an extended period and tested the hypothesis that macrophyte richness decreases their invasibility. The alternative hypothesis that the occurrence of these exotics is affected by fetch and underwater radiation (important determinants of macrophyte assemblage composition in this reservoir) was also tested. Incidence data (presence/absence) was obtained over 9.5 years at 235 stations. Logistic regression was applied to test whether the likelihood of occurrence of these two species was affected by macrophyte richness, fetch or underwater radiation. Tenner-grass was recorded at a high frequency and quickly recovered from disturbances caused by water drawdown. In contrast, H. verticillata was first recorded in 3 sites in January 2007, but it spread quickly, reaching 30.5% of the sites 19 months later. The main channel of the Paraná River was the main source of propagules for this species. The likelihood of occurrence of tenner-grass was positively affected by macrophyte richness but negatively affected by fetch. Thus, wave disturbance is probably more important than diversity in preventing invasion by this species. Hydrilla, by contrast, was negatively affected by macrophyte richness and positively affected by fetch and underwater radiation. Although this result might indicate that macrophyte diversity prevents hydrilla invasion, this is probably not true because hydrilla colonized deeper sites where few species of plant exist. Resistance to disturbances caused by water drawdown (tenner-grass) and waves (hydrilla) as well as persistency of tenner-grass and fast spread of hydrilla make these exotic species a cause for concern because of their potential impacts on water uses and maintenance of diversity.

  5. Simple relationships to predict attributes of fish assemblages in patches of submerged macrophytes

    Directory of Open Access Journals (Sweden)

    Fernando Mayer Pelicice

    Full Text Available Submerged macrophytes play an important role in structuring habitats and, therefore, in determining patterns of aquatic biodiversity. Because these plants are widespread in shallow areas of many Neotropical reservoirs, the present work investigated if variables related to habitat structure, measured in patches of submerged macrophytes (Egeria densa and E. najas, can be used to predict fish assemblage attributes (fish density and species richness. Based on patch characteristics at fine spatial extents (macrophyte patches within reservoir arms, we considered plant biomass, volume and proportional volume (i.e. percentage of macrophyte volume in the water column as potential predictors. Fish and macrophytes were sampled with a 1-m² throw trap in littoral habitats of Rosana Reservoir, Paranapanema River, and simple correlation analyses were performed. Fish richness and abundance were highly correlated with all variables (R = 0.53 to 0.90, a relationship consistently observed in all sites. When compared to biomass, plant volume and proportional volume did not yield stronger correlations. We observed stronger correlations when E. densa and E. najas patches were analyzed separately (mono-specificity, probably because particular effects of each macrophyte on habitat structuring were removed (e.g. unnoticed morphological differences or unknown effects on habitat quality. The high R values observed in all pairwise relationships are uncommon in ecological studies, highlighting the predictive potential of variables related to habitat structure. These results suggest that, at small spatial extents, macrophyte biomass may represent an interesting predictor of fish density and richness in reservoirs with extensive colonization of submerged plants.

  6. Monitoring the effects of floods on submerged macrophytes in a large river.

    Science.gov (United States)

    Ibáñez, Carles; Caiola, Nuno; Rovira, Albert; Real, Montserrat

    2012-12-01

    The lower Ebro River (Catalonia, Spain) has recently undergone a regime shift from a phytoplankton to a macrophyte-dominated system. Macrophytes started to spread at the end of the 1990s and since 2002 artificial floods (flushing flows) of short duration (1-2 days) are released from the Riba-roja dam once or twice a year in order to reduce macrophyte density. The aim of this study was to analyse the spatiotemporal trends of the submerged macrophytes in two stretches of the lower Ebro River using high-resolution hydroacoustic methods, in order to elucidate the effects of artificial floods and natural floods on its distribution and abundance. Results showed that the mean cover in the two studied stretches (Móra and Ginestar) was not reduced after a flushing flow (from 36.59% to 55.85% in Móra, and from 21.18% to 21.05% in Ginestar), but it was greatly reduced after the natural flood (down to 9.79% in Móra and 2.04% in Ginestar); surprisingly the cover increased in Móra after the artificial flood. In order to increase the efficiency of floods in controlling macrophyte spreading, the magnitude and frequency of them should largely increase, as well as the suspended sediment load, approaching as much as possible to the original flood pattern before dam construction. Hydroacoustic methods combined with geostatistics and interpolation in GIS can accurately monitor spatiotemporal trends of submerged macrophytes in large rivers. This is the first article to apply this monitoring system to submerged macrophytes in rivers. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Desempenho da tangerineira 'Span Americana' em diferentes porta-enxertos

    Directory of Open Access Journals (Sweden)

    Simone Rodrigues da Silva

    2013-12-01

    Full Text Available Este trabalho objetivou avaliar o crescimento vegetativo, a produção e a qualidade de frutos da tangerina 'Span Americana' em diferentes porta-enxertos, nas condições edafoclimáticas de Bebedouro-SP. O plantio foi realizado em junho de 2003, em espaçamento de 6,0 m x 3,0 m, sendo utilizada irrigação por gotejamento a partir de 2006. Os porta-enxertos avaliados foram: citranges [Citrus sinensis (L. Osbeck × Poncirus trifoliata L. Raf] 'Carrizo' e 'Troyer', tetraploides; trifoliatas (P. trifoliata 'Davis A' e 'Flying Dragon'; limão Volkameriano Catania 2 (C. volkameriana Tenn. et Pasq., HRS 849 [(C. aurantium L. cv. 'Smooth Flat Seville' x P. trifoliata cv. 'Argentina'], tangelo 'Orlando' (C. reticulata Blanco × C. paradisi Macf. e limão 'Cravo' (C. limonia Osbeck. Foram avaliadas a produção acumulada, a eficiência produtiva e a precocidade de entrada em produção, no período de 2007 a 2009. Avaliaram-se, também, as dimensões das plantas e a taxa média de crescimento das plantas no período de 2005 a 2008, além da qualidade dos frutos em 2006 e 2007. Em pomares irrigados de tangerineira 'Span Americana', os porta-enxertos trifoliata 'Davis A' e HRS 849 apresentam desempenho horticultural satisfatório. Para plantio em alta densidade, a melhor performance da tangerineira 'Span Americana' é obtida com a utilização dos porta-enxertos trifoliata 'Flying Dragon' e citranges 'Troyer' e 'Carrizo'.

  8. Nongastrointestinal helminths in marten (Martes americana) from Ontario, Canada.

    Science.gov (United States)

    Seville, R S; Addison, E M

    1995-10-01

    Six species of nongastrointestinal nematodes were recovered from 405 marten, (Martes americana), examined from six areas in Ontario, Canada in 1992 to 1993. Three species (Crenosoma petrowi, Eucoleus aerophilus, Filaroides martis) were found in the respiratory tract, one in the urinary bladder (Pearsonema plica), one in the kidney (Dioctophyme renale), and one in the musculature (Trichinella sp. larvae). This is the first report of F. martis and P. plica from this host. In addition a specimen of Dracunculus insignis collected from a marten pelt was received. Based on our results, martens are primary definitive hosts for few nongastrointestinal nematodes. Animals in more southern areas had greater species richness than those from higher latitudes.

  9. Heterobilharzia americana Infection and Glomerulonephritis in a Dog.

    Science.gov (United States)

    Ruth, Jeffrey

    2010-01-01

    Schistosomiasis is an uncommonly reported disease that usually causes weight loss, anemia, and gastrointestinal signs. A 6-year-old, neutered male dog developed membranoproliferative glomerulonephritis concurrent with infection with the trematode parasite Heterobilharzia americana. At presentation, the dog had proteinuria, hypoalbuminemia, hyperglobulinemia, and anemia. Diagnosis was based upon the histopathological appearance of the kidney. Clinical signs, biochemical and hematological abnormalities, and proteinuria resolved following treatment with fenbendazole and praziquantel. Fecal examination by saline sedimentation, miracidia hatching, or Heterobilharzia polymerase chain reaction assay may be indicated when examining a dog that is presented with unexplained glomerulonephritis and is from an endemic area.

  10. Leishmaniose tegumentar americana associada à AIDS: relato de quatro casos

    OpenAIRE

    Sampaio Raimunda Nonata Ribeiro; Salaro Cristina Paula; Resende Paula; Paula Carmen Déa Ribeiro de

    2002-01-01

    A co-infecção leishmaniose tegumentar americana e AIDS é de relato recente na literatura, observando-se diversidade quanto ao comportamento clínico e imunológico destes pacientes. Relatamos quatro casos acompanhados no Hospital Universitário de Brasília, com diagnóstico de infecção por parasitas do gênero Leishmania e pelo vírus da imunodeficiência humana, ilustrando diferentes apresentações clínicas, evoluções e respostas terapêuticas.

  11. Componentes volátiles de mamey (mammea americana L.)

    OpenAIRE

    Alicia Lucía Morales; William Arguello; Gustavo García; Iván Herrera

    2010-01-01

    Los componentes volátiles del aroma de mamey (Mammea americana L), fueron extraídos utilizando el método de destilación por arrastre con vapor-extracción simultánea con solvente orgánico. El extracto fue prefraccionado por cromatografía en columna en silica gel con gradiente discontinuo Pentano: Éter etílico para obtener tres fracciones que fueron analizadas por CGAR y CGAR-EM. Se detectaron 34 compuestos, de los cuales fueron identificados 22, siendo los componentes mayoritarios: Furfural (7...

  12. Componentes volátiles de mamey (mammea americana l.)

    OpenAIRE

    Morales, Alicia Lucía; Arguello, William; García, Gustavo; Herrera, Iván

    2010-01-01

    Los componentes volátiles del aroma de mamey (Mammea americana L), fueron extraídos utilizando el método de destilación por arrastre con vapor-extracción simultánea con solvente orgánico. El extracto fue prefraccionado por cromatografía en columna en silica gel con gradiente discontinuo Pentano: Éter etílico para obtener tres fracciones que fueron analizadas por CGAR y CGAR-EM. Se detectaron 34 compuestos, de los cuales fueron identificados 22, siendo los componentes mayoritarios: Furfural (7...

  13. Isocoumarins from American cockroach (Periplaneta americana) and their cytotoxic activities.

    Science.gov (United States)

    Luo, Shi-Lin; Huang, Xiao-Jun; Wang, Ying; Jiang, Ren-Wang; Wang, Lei; Bai, Liang-Liang; Peng, Qun-Long; Song, Cai-Lu; Zhang, Dong-Mei; Ye, Wen-Cai

    2014-06-01

    Four new isocoumarins (1-4), along with three known ones (5-7), were isolated from the 70% ethanol extract of the whole body of the traditional Chinese insect medicine, American cockroach (Periplaneta americana). The structures with absolute configurations of new compounds were elucidated by extensive spectroscopic methods in combination with X-ray diffraction experiment and CD analyses. Compounds 3-5 showed significant cytotoxic activities in HepG2 and MCF-7 cells with IC50 values in the ranges 6.41-23.91 μM and 6.67-39.07 μM, respectively.

  14. La esclavitud americana y las Partidas de Alfonso X

    OpenAIRE

    Lucena Salmoral, Manuel

    1995-01-01

    El autor expone de manera sorprendente la relación entre la esclavitud americana en 1808, en los albores de la Independencia y su coincidencia con un conjunto de leyes como fueron las Partidas de Alfonso X, hechas siete siglos antes. Dentro del marco de las Partidas, que fueron el único Código Negro que la América española tuvo en su vida colonial, se centra en la servidumbre del hombre como mal antinatural y la manumisión de los siervos. The author exposes in an amazing way the relationsh...

  15. Purpuric irritant contact dermatitis induced by Agave americana.

    Science.gov (United States)

    Cherpelis, B S; Fenske, N A

    2000-10-01

    The sap of Agave americana, a popular ornamental plant, may cause irritant contact dermatitis. This rare eruption is typically vesiculopapular; however, a new purpuric variant with evidence of leukocytoclastic vasculitis has recently been reported. We report an additional case of a purpuric eruption associated with severe constitutional symptoms further supporting a possible vasculitic component. Both cases resulted from direct exposure to sap propelled by a chainsaw. We speculate that oxalic acid crystals, which are recognized systemic toxins, are embedded in the skin with resulting oxalism, which may result in vascular damage.

  16. Impacts of aquatic macrophytes configuration modes on water quality.

    Science.gov (United States)

    Liu, Jiakai; Liu, Jinglan; Zhang, Rong; Zou, Yuqi; Wang, Huihui; Zhang, Zhenming

    2014-01-01

    Constructed wetland technology is regarded as an important ecological restoration technology and used widely in sewage disposal. In order to give them a wider scope of application and to improve their performance in water restoration, the current experiment was designed. Four aquatic macrophytes (dwarf cattail (TM), yellow-flowered iris (WI), water shallot (ST) and watermifoil (MS)) were picked and planted in artificial floating islands (AFIs) in different configurations (TM + WI, ST + MS and TM + WI + MS) and two patterns, radiation pattern (RP) and annular pattern (AP), for a 60-day experiment. Then, water quality and growth were monitored every 10 days. The results indicate that the different configurations performed diversely on waste water purification. First, a composite plant configuration removed more pollutant than a single one with the same total increment of biomass. Second, the plant configuration of MS + ST was most effective in total nitrogen (TN), total phosphorus (TP) or PO4(3-) removal, and TM + IW + MS was good at chemical oxygen demand (COD) and NO3(-) removal. However, different patterns comprised from the same species had a certain effect on absorption of pollutants. Generally speaking, plant configurations with a RP were better than an AP in purification. Accordingly, these provided the methods for the pollution wetland restoration.

  17. Determination of Algae and Macrophyte Species Distribution in Three Wastewater Stabilization Ponds Using Metagenomics Analysis

    Directory of Open Access Journals (Sweden)

    Jack Wallace

    2015-06-01

    Full Text Available This study involved the evaluation of algae and macrophyte species distributions in three wastewater stabilization ponds (WSPs at a wastewater treatment plant in Ontario, Canada, which has experienced high pH levels at the final effluent and excessive algae growth during the summer since 2003. From samples collected from the system, the relative abundances of specific algae and aquatic plant (macrophyte taxa were assessed and correlated to water chemistry data. A strong shift from the dominance of green algae, chlorophyceae, in WSP#2, to the dominance of aquatic macrophytes, embryophyta, in WSP#4, was observed and corresponded to field observations. Correlation of the abundances to nutrient parameters suggested that the macronutrient rich conditions in WSP#2 allowed floating green algae to proliferate against macrophytes. In WSP#1 and WSP#4, macrophytes competed against algae and thrived, due to their adaptability to lower nutrient conditions. The pH increases occurred primarily in WSP#2 and were not buffered or reduced in WSP#1 and WSP#4. Two alternatives strategies for pH control were recommended for the system: decreasing algae growth in WSP#2 through duckweed seeding or macronutrient loading reduction; or designing and implementing a constructed wetland (CW in WSP#4 with soil and vegetation to buffer pH prior to release.

  18. Integration of geographic information systems and logistic multiple regression for aquatic macrophyte modeling

    Energy Technology Data Exchange (ETDEWEB)

    Narumalani, S. [Nebraska Univ., Lincoln, NE (United States). Dept. of Geography; Jensen, J.R.; Althausen, J.D.; Burkhalter, S. [South Carolina Univ., Columbia, SC (United States). Dept. of Geography; Mackey, H.E. Jr. [Westinghouse Savannah River Co., Aiken, SC (United States)

    1994-06-01

    Since aquatic macrophytes have an important influence on the physical and chemical processes of an ecosystem while simultaneously affecting human activity, it is imperative that they be inventoried and managed wisely. However, mapping wetlands can be a major challenge because they are found in diverse geographic areas ranging from small tributary streams, to shrub or scrub and marsh communities, to open water lacustrian environments. In addition, the type and spatial distribution of wetlands can change dramatically from season to season, especially when nonpersistent species are present. This research, focuses on developing a model for predicting the future growth and distribution of aquatic macrophytes. This model will use a geographic information system (GIS) to analyze some of the biophysical variables that affect aquatic macrophyte growth and distribution. The data will provide scientists information on the future spatial growth and distribution of aquatic macrophytes. This study focuses on the Savannah River Site Par Pond (1,000 ha) and L Lake (400 ha) these are two cooling ponds that have received thermal effluent from nuclear reactor operations. Par Pond was constructed in 1958, and natural invasion of wetland has occurred over its 35-year history, with much of the shoreline having developed extensive beds of persistent and non-persistent aquatic macrophytes.

  19. Vegetative Propagule Pressure and Water Depth Affect Biomass and Evenness of Submerged Macrophyte Communities.

    Science.gov (United States)

    Li, Hong-Li; Wang, Yong-Yang; Zhang, Qian; Wang, Pu; Zhang, Ming-Xiang; Yu, Fei-Hai

    2015-01-01

    Vegetative propagule pressure may affect the establishment and structure of aquatic plant communities that are commonly dominated by plants capable of clonal growth. We experimentally constructed aquatic communities consisting of four submerged macrophytes (Hydrilla verticillata, Ceratophyllum demersum, Elodea nuttallii and Myriophyllum spicatum) with three levels of vegetative propagule pressure (4, 8 and 16 shoot fragments for communities in each pot) and two levels of water depth (30 cm and 70 cm). Increasing vegetative propagule pressure and decreasing water level significantly increased the growth of the submerged macrophyte communities, suggesting that propagule pressure and water depth should be considered when utilizing vegetative propagules to re-establish submerged macrophyte communities in degraded aquatic ecosystems. However, increasing vegetative propagule pressure and decreasing water level significantly decreased evenness of the submerged macrophyte communities because they markedly increased the dominance of H. verticillata and E. nuttallii, but had little impact on that of C. demersum and M. spicatum. Thus, effects of vegetative propagule pressure and water depth are species-specific and increasing vegetative propagule pressure under lower water level can facilitate the establishment success of submerged macrophyte communities.

  20. Towards Deriving Renewable Energy from Aquatic Macrophytes Polluting Water Bodies in Niger Delta Region of Nigeria

    Directory of Open Access Journals (Sweden)

    Badmus Abdurrahman Adeleye

    2013-01-01

    Full Text Available This study was performed to derive methane rich biogas from biomass of harvested water hyacinth polluting water bodies in selected rivers of the Niger delta region of Nigeria. Field visits were undertaken on selected rivers in the Niger Delta region in which aquatic macrophytes were collected and inventorized. Also different types of aquatic macrophytes were surveyed. Control by harvesting macrophytes and deriving energy (methane-rich biogas from biomass of one (water hyacinth was successfully carried out in this study. An initial test was conducted to evaluate methane rich biogas production from water hyacinth collected from the wild. After a successful production of combustible biogas, laboratory experiments aimed at generating biogas from harvested biomass of aquatic mycrophyte (water hyacinth cultivated under eutrophic and oligotrophic conditions were undertaken in the laboratory. The result of the study showed highest biogas yield of 22 L over a 40 day retention time for water hyacinth raised under eutrophic conditions. Biogas yield for water hyacinth raised under oligotrophic conditions recorded the highest yield of 53L over an 11 day retention time. The conversion of the biomass of harvested aquatic macrophyte (water hyacinth from the Niger Delta into renewable energy, that is combustible biogas, demonstrated an inevitable option for the control and management of environmental pollution associated with aquatic macrophytes and their usability for poverty alleviation in the Niger Delta region of Nigeria.

  1. Genetic and nutritional characterization of some macrophytes, inhabiting the Bardawil Lagoon, Sinai, Egypt

    Directory of Open Access Journals (Sweden)

    Hosam E. Elsaied

    2015-12-01

    Full Text Available The ecological and economical significances of macrophytes, inhabiting the Mediterranean Lagoon, Bardawil, northern Sinai, Egypt, are still ambiguous, due to lack of knowledge. This study focused on genetic and nutritional characterization of three dominant macrophyte species at Bardawil Lagoon. Genetic identifications were done through genomic DNA extraction, followed by PCR amplifications and sequencing of 18S rRNA genes of the studied species. Phylogenetic analyses indicated that two of the recorded species showed homologies with the seagrass species, Posidonia oceanica and Halophila ovalis, with nucleotide identities 94.5% and 96.8%, respectively. The third species showed a unique phylogenetic lineage, representing nucleotide identity average, 86.5%, among the brown seaweeds, Heterokontophyta. Nutritional analyses indicated that the recorded seaweed-like macrophyte had the highest recommended nutritional contents, crude protein, 24.67%, with a total amino acid composition of 6.64 g/100 g protein, and carbohydrate, 38.16%, besides a calorific value of 3.063 K cal/g, among the studied macrophytes. To the best of our knowledge, this is the first attempt to characterize macrophyte community in Bardawil Lagoon, using both genetic and biochemical approaches.

  2. Management of fresh water weeds (macrophytes) by vermicomposting using Eisenia fetida.

    Science.gov (United States)

    Najar, Ishtiyaq Ahmed; Khan, Anisa B

    2013-09-01

    In the present study, potential of Eisenia fetida to recycle the different types of fresh water weeds (macrophytes) used as substrate in different reactors (Azolla pinnata reactor, Trapa natans reactor, Ceratophyllum demersum reactor, free-floating macrophytes mixture reactor, and submerged macrophytes mixture reactor) during 2 months experiment is investigated. E. fetida showed significant variation in number and weight among the reactors and during the different fortnights (P weeds) into three clusters-poor vermicompost substrates, moderate vermicompost substrate, and excellent vermicompost substrate. Two principal components (PCs) have been identified by factor analysis with a cumulative variance of 90.43 %. PC1 accounts for 47.17 % of the total variance represents "reproduction factor" and PC2 explaining 43.26 % variance representing "growth factor." Thus, the nature of macrophyte affects the growth and reproduction pattern of E. fetida among the different reactors, further the addition of A. pinnata in other macrophytes reactors can improve their recycling by E. fetida.

  3. How TK-TD and population models for aquatic macrophytes could support the risk assessment for plant protection products

    NARCIS (Netherlands)

    Hommen, U.; Schmitt, W.; Heine, S.; Brock, T.C.M.; Duquesne, S.; Manson, P.; Meregali, G.; Ochoa-Acuna, H.; Vliet, van P.; Arts, G.H.P.

    2016-01-01

    This case study of the SETAC workshop MODELINK demonstrates the potential use of mechanistic effects models for macrophytes to extrapolate from effects of a plant protection product observed in laboratory tests to effects resulting from dynamic exposure on macrophyte populations in edge-of-field wat

  4. Bimodality in stable isotope composition facilitates the tracing of carbon transfer from macrophytes to higher trophic levels

    NARCIS (Netherlands)

    Mendonca, R.; Kosten, S.; Lacerot, G.; Mazzeo, N.; Roland, F.; Ometto, J.P.; Paz, A.; Bueno, O.C.; Gomes, A.C.M.M.; Scheffer, M.

    2013-01-01

    Even though the suitability of macrophytes to act as a carbon source to food webs has been questioned by some studies, some others indicate that macrophyte-derived carbon may play an important role in the trophic transfer of organic matter in the food web of shallow lakes. To evaluate the importance

  5. The phytochemical and pharmacological profile of Persea americana Mill

    Directory of Open Access Journals (Sweden)

    Mohammad Yasir

    2010-01-01

    Full Text Available Over the past decades, herbal medicine has become a thing of global significance with medicinal and economic implications. Wide spread use of herbs throughout the globe has raised serious concerns over its quality, safety, and efficacy. Thus, exact scientific assessment has become a precondition for acceptance of herbal health claims. Persea americana Mill. (avocado is a tree, native to central America, cultivated in tropical and subtropical climates around the world, belonging to the family Lauraceae, is widely used in Ayurveda and evidence-based phototherapy. There are 3 principal races or groups of avocado: Mexican, Guatemalan, and West Indian named for the areas where they were originally cultivated. The plant is used in traditional medicine for the treatment of various ailments, such as monorrhagia, hypertension, stomach ache, bronchitis, diarrhea, and diabetes. Peptone, b-galactoside, glycosylated abscisic acid, alkaloids, cellulose, polygalacto urease, polyuronoids, cytochrome P-450, and volatile oils are reported to be present in this plant. Biotechnologic approaches show that modified MS medium supplemented with 1.0 mg benzyladenine/L, 0-1mg Indole Butyric Acid/L, 0.1 mg Gibberalic Acid 3/L was optimum for adventitious shoot development. In the present review, an effort has been made to study the different aspects of P. americana Mill.

  6. The phytochemical and pharmacological profile of Persea americana Mill.

    Science.gov (United States)

    Yasir, Mohammad; Das, Sattwik; Kharya, M D

    2010-01-01

    Over the past decades, herbal medicine has become a thing of global significance with medicinal and economic implications. Wide spread use of herbs throughout the globe has raised serious concerns over its quality, safety, and efficacy. Thus, exact scientific assessment has become a precondition for acceptance of herbal health claims. Persea americana Mill. (avocado) is a tree, native to central America, cultivated in tropical and subtropical climates around the world, belonging to the family Lauraceae, is widely used in Ayurveda and evidence-based phototherapy. There are 3 principal races or groups of avocado: Mexican, Guatemalan, and West Indian named for the areas where they were originally cultivated. The plant is used in traditional medicine for the treatment of various ailments, such as monorrhagia, hypertension, stomach ache, bronchitis, diarrhea, and diabetes. Peptone, b-galactoside, glycosylated abscisic acid, alkaloids, cellulose, polygalacto urease, polyuronoids, cytochrome P-450, and volatile oils are reported to be present in this plant. Biotechnologic approaches show that modified MS medium supplemented with 1.0 mg benzyladenine/L, 0-1mg Indole Butyric Acid/L, 0.1 mg Gibberalic Acid 3/L was optimum for adventitious shoot development. In the present review, an effort has been made to study the different aspects of P. americana Mill.

  7. Increased nucleotide diversity with transient Y linkage in Drosophila americana.

    Directory of Open Access Journals (Sweden)

    Bryant F McAllister

    Full Text Available Recombination shapes nucleotide variation within genomes. Patterns are thought to arise from the local recombination landscape, influencing the degree to which neutral variation experiences hitchhiking with selected variation. This study examines DNA polymorphism along Chromosome 4 (element B of Drosophila americana to identify effects of hitchhiking arising as a consequence of Y-linked transmission. A centromeric fusion between the X and 4(th chromosomes segregates in natural populations of D. americana. Frequency of the X-4 fusion exhibits a strong positive correlation with latitude, which has explicit consequences for unfused 4(th chromosomes. Unfused Chromosome 4 exists as a non-recombining Y chromosome or as an autosome proportional to the frequency of the X-4 fusion. Furthermore, Y linkage along the unfused 4 is disrupted as a function of the rate of recombination with the centromere. Inter-population and intra-chromosomal patterns of nucleotide diversity were assayed using six regions distributed along unfused 4(th chromosomes derived from populations with different frequencies of the X-4 fusion. No difference in overall level of nucleotide diversity was detected among populations, yet variation along the chromosome exhibits a distinct pattern in relation to the X-4 fusion. Sequence diversity is inflated at loci experiencing the strongest Y linkage. These findings are inconsistent with the expected reduction in nucleotide diversity resulting from hitchhiking due to background selection or selective sweeps. In contrast, excessive polymorphism is accruing in association with transient Y linkage, and furthermore, hitchhiking with sexually antagonistic alleles is potentially responsible.

  8. 'Gloriosa': cultivar de alface americana tropicalizada 'Gloriosa': crisphead tropicalized cultivar

    Directory of Open Access Journals (Sweden)

    Fernando C. Sala

    2008-09-01

    Full Text Available 'Gloriosa' é uma cultivar de alface (Lactuca sativa L. americana tropicalizada e resistente a Thielaviopsis basicola. Foi selecionada a partir de variantes da cultivar Lucy Brown, pelo método genealógico. Progênies S1 a S6 foram selecionadas para resistência a T. basicola, características hortícolas, tolerância ao pendoamento precoce e adaptação ao cultivo de verão. Apresenta ciclo precoce de 40 a 50 dias pós-transplante, pendoamento lento, cabeças grandes e três camadas de folhas externas. Possui tolerância a Xanthomonas campestris pv. vitians e suporta o cultivo nos períodos de elevadas temperaturas e pluviosidade. Trata-se da primeira cultivar de alface americana tropicalizada no Brasil.'Gloriosa' is a tropicalized crisphead lettuce (Lactuca sativa L. resistant to Thielaviopsis basicola. It was derived by selection from cv. Lucy Brown variants by pedigree method. Progenies S1 to S6 were selected for T. basicola resistance, desirable horticulture traits, slowbolting and adaptation for Brazilian summer crop. It presents a precocious cycle within 40 to 50 days of being planted, slowbolting, large head and three layers of frame levels. It is tolerant to Xanthomonas campestris pv. vitians and is able to be grown under high temperature and rainy summer in southern of Brazil. It is the first crisphead lettuce type developed for tropical regions of Brazil.

  9. Ammonia-oxidizing Bacteria and Archaea in the Rhizosphere of Freshwater Macrophytes

    DEFF Research Database (Denmark)

    Herrmann, Martina; Schramm, Andreas

    2007-01-01

    measurements revealed clear differences in ammonia oxidation rates. The diversity of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) was assessed using the ammonia monooxygenase (amoA) gene as functional marker. Both AOA and AOB could be detected in the rhizosphere of all three plant......AMMONIA-OXIDIZING ARCHAEA AND BACTERIA IN THE RHIZOSPHERE OF FRESHWATER MACROPHYTES Martina Herrmann and Andreas Schramm Department of Biological Sciences, Microbiology, University of Aarhus, Denmark Aquatic macrophytes such as Littorella uniflora and Lobelia dortmanna release oxygen from......-specific microbial community distinct from that of unvegetated sediment and (ii) that aquatic macrophytes have an impact on abundance and activity of nitrifying and denitrifying bacteria in freshwater sediment. The goal of this study was to test these hypotheses for the key functional group for coupled nitrification...

  10. Factors involved in spatiotemporal dynamics of submerged macrophytes in a Portuguese coastal lagoon under Mediterranean climate

    Science.gov (United States)

    Antunes, Cristina; Correia, Otília; Marques da Silva, Jorge; Cruces, Anabela; Freitas, Maria da Conceição; Branquinho, Cristina

    2012-09-01

    Submerged macrophytes are key in coastal ecosystems, with important structural and functional roles. Thus, the characterization of the submerged aquatic vegetation dynamics is of prime importance for assessing the ecological status of coastal ecosystems. The main aim of this study was to assess the spatial and temporal dynamics of submerged macrophytes biomass in a temporarily open coastal lagoon in Melides, Portugal, and to evaluate the physiological performance of the dominant macrophyte in the system. This lagoon is subject to several disturbances such as the dramatic changes in water physicochemical parameters over time, since temporarily opens to the sea occur renewing the lagoon water content. Moreover it is under a Mediterranean climate with the inherently high temporal variability of precipitation and high temperatures during the summer. Our study shows that the submerged macrophyte community was dominated initially by Ruppia cirrhosa and then replaced by Potamogeton pectinatus, which showed a marked temporal and spatial pattern with extremely high values of biomass in August and in the inner part of the lagoon. The spatial and temporal biomass patterns in submerged macrophytes were mainly related with water level, salinity, pH and transparency. The physiological performance of R. cirrhosa was lower when there was greater biomass accumulation and in extremely shallow waters, whereas physiological vigor seemed to be greater at moderate temperatures and in areas with higher salinity and dissolved oxygen. The data from this study can be used to predict submerged biomass macrophyte responses to extreme water quality changes and to feed a decision support system for the best period to promote the seasonal artificial breaching of the sandy barrier.

  11. Macrophytes of the Grlište reservoir (Serbia: Fifteen years after its establishment

    Directory of Open Access Journals (Sweden)

    Stanković Ž.

    2009-01-01

    Full Text Available A large number of macrophytes, often in dense populations, have developed on the Grlište Reservoir, Serbia over a period of 15 years. Fast development of vegetation is a consequence of anthropogenic impact in lake management. The methodology used in this research covered 100% of the water body, including all areas with or without aquatic plants. The results indicate that plant communities are still in the early phase of development. This leaves space for future development of competitor macrophyte species (Najas marina, Eleocharis palustris, Typha latifolia, Typha angustifolia, Phragmites australis, etc. capable of endangering stability of the lake, which will tend toward eutrophication.

  12. Ammonia-oxidizing Bacteria and Archaea in the Rhizosphere of Freshwater Macrophytes

    DEFF Research Database (Denmark)

    Herrmann, Martina; Schramm, Andreas

    2007-01-01

    AMMONIA-OXIDIZING ARCHAEA AND BACTERIA IN THE RHIZOSPHERE OF FRESHWATER MACROPHYTES Martina Herrmann and Andreas Schramm Department of Biological Sciences, Microbiology, University of Aarhus, Denmark Aquatic macrophytes such as Littorella uniflora and Lobelia dortmanna release oxygen from...... measurements revealed clear differences in ammonia oxidation rates. The diversity of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) was assessed using the ammonia monooxygenase (amoA) gene as functional marker. Both AOA and AOB could be detected in the rhizosphere of all three plant...

  13. Aquatic macrophyte richness in Danish lakes in relation to alkalinity, transparency, and lake area

    DEFF Research Database (Denmark)

    Vestergaard, Ole Skafte; Sand-Jensen, Kaj

    2000-01-01

    alkalinity but 12.3 in lakes of high alkalinity due to a greater occurrence of the species-rich group of elodeids. Mean species richness per lake also increased significantly with increasing Secchi depth. No significant relationship between species richness and lake surface area was observed among the entire...... group of lakes or a subset of eutrophic lakes, as the growth of submerged macrophytes in large lakes may be restricted by wave action in shallow water and light restriction in deep water. In contrast, macrophyte species richness increased with lake surface area in transparent lakes, presumably due...

  14. Predicting aquatic macrophyte occurrence in soft-water oligotrophic lakes (Pyrenees mountain range

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    Cristina Pulido

    2014-08-01

    Full Text Available Distribution of aquatic macrophytes in lakes is related to geographical, morphological, catchment and water chemistry variables as well as human impacts, which modify the original environment. Here, we aim at building statistical models to establish the ecological niches of 11 aquatic macrophytes (10 different phanerogams and the genus Nitella from oligotrophic soft-water lakes and infer their ecological requirements and environmental constraints at the southernmost limit of their distribution. Macrophyte occurrence and environmental variables were obtained from 86 non-exploited oligotrophic soft-water lakes from the Pyrenees (Southern Europe; 42º50´N, 1º00´E; macrophytes inhabited 55 of these lakes. Optimum ranges and macrophyte occurrence were predicted in relation to 18 geographical, morphological, catchment and water chemistry variables using univariate and multivariate logistic models. Lakes at low altitude, in vegetated catchments and with low water concentration of NO3- and SO4-2, were the most suitable to host macrophytes. In general, individual species of aquatic macrophytes showed clear patterns of segregation along conductivity and pH gradients, although the specific combination of variables selected in the best models explaining their occurrence differed among species.  Based on the species response to pH and conductivity, we found Isoetes lacustris have its optimum in waters with low conductivity and pH (i.e. negative monotonic response. In contrast, Callitriche palustris, Ranunculus aquatilis, Subularia aquatica, Nitella spp., and Myriophyllum alterniflorum showed an optimum at intermediate values (i.e. unimodal response, whereas Potamogeton berchtoldii, Potamogeton alpinus, and Ranunculus trichophyllus as species had their optimum at relatively high water pH and conductivity (i.e. positive monotonic response. This pattern has been observed in other regions for the same species, although with different optima and tolerance

  15. Phenol toxicity to the aquatic macrophyte Lemna paucicostata

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ji-Sook [Division of Life Science, University of Incheon, Incheon 406-840 (Korea, Republic of); Brown, Murray T. [School of Marine Science and Engineering, University of Plymouth, Plymouth, Devon PL4 8AA (United Kingdom); Han, Taejun, E-mail: hanalgae@hanmail.net [Division of Life Science, University of Incheon, Incheon 406-840 (Korea, Republic of); Institute of Green Environmental Research, University of Incheon, Incheon 406-840 (Korea, Republic of)

    2012-01-15

    Phenol is a ubiquitous environmental pollutant and a widely used reference toxicant for many bioassays. However, little information is available regarding the toxic effects of phenol on aquatic macrophytes. Seventy-two hour bioassays, with different end-points, were carried out to assess phenol toxicity in Lemna paucicostata. A concentration-dependent decline in frond multiplication and colony disintegration was observed, with 11.38 and 22.76 {mu}M phenol resulting in browning of fronds and colony disintegration, respectively. Growth of fronds, as measured by changes in surface area, was significantly inhibited with EC{sub 50} value of 2.70 {mu}M. When pulse amplitude modulated chlorophyll a (Chl a) fluorescence imaging (i-PAM) was employed, the maximum quantum yield of PS II (F{sub v}/F{sub m}) significantly declined with increasing phenol concentrations with resultant EC{sub 50} of 1.91 {mu}M and coefficients of variation (CVs) generated for the EC{sub 50} values of less than 4.7%. A gradual increase in fluorescence emissions from chlorophylls a and b and pheophytin up to a concentration of 2.85 {mu}M was found but declined markedly at higher concentrations. The significant correlation between the F{sub v}/F{sub m} and surface growth rate data implies that the former is an appropriate biomarker of whole plant toxicity. Using imaging Chl a fluorescence on L. paucicostata provides a rapid, sensitive and reliable method for assessing the toxic risks posed by phenol to aquatic ecosystems and has practical applications for municipal and industrial waste water management.

  16. Heterobilharzia americana infection and congestive heart failure in a llama (Lama glama).

    Science.gov (United States)

    Corapi, W V; Eden, K B; Edwards, J F; Snowden, K F

    2015-05-01

    The schistosome Heterobilharzia americana infects several mammalian species in the southeastern United States, including horses, but infections have not been reported in camelids. This is a report of H. americana infection in a 6-year-old llama with extensive cardiac pathology and congestive heart failure. Parasite-induced granulomas were widely disseminated and included overwhelming involvement of the lungs and liver. Microscopic lesions in the heart included myofiber degeneration and necrosis, with extensive replacement fibrosis. Polymerase chain reaction amplification and sequencing confirmed the presence of H. americana in the lungs.

  17. Two New Steroidal Glycosides from Fermented Leaves of Agave americana

    Institute of Scientific and Technical Information of China (English)

    JianMingJIN; XiKuiLIU; 等

    2002-01-01

    Two new spirostanol glycosides named agamenoside A and B, ere isolated from the fermented leaves of Agave americana. Their structures were elucidated as (23S,25R)-5α-spirostan-3β,6α,23-triol 3-O-α-L-rhamnopyranosyl-(1→3)-β-D-glucopyranosyl-(1→2)-[β-D-xylopyranosyl-(1→3)]-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside(1) and (25R)-5α-spiro-stan-3β,6α-diol 3-O-β-D-glucopyranosyl-(1→2)-[β-D-xylopyranosyl-(1→3)]-β-D-glucopyra-nosyl-(1→4)-β-D-galactopyranoside(2) by a combination of chemical and spectral methods.

  18. Two New Steroidal Glycosides from Fermented Leaves of Agave americana

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Two new spirostanol glycosides named agamenoside A and B, were isolated from the fcrmcnted leaves of Agave americana. Their structures were elucidated as (23S, 25R)-5α-spirostan-3β, 6α, 23-triol 3-O-α-L-rhamnopyranosyl-(1→3)- β-D-glucopyranosyl-(l→2)-[β-D-xylopyranosyl-( 1 →3)]-β-D-glucopyranosyl-( l →4)-β-D-galactopyranoside (1) and (25R)-5α-spiro stan-3β, 6α-diol 3-O-β-D-glucopyranosyl-(l→2)-[ β-D-xylopyranosyl-(l→3)]- β-D-glucopyra nosyl-(1→4)- β-D-galactopyranoside (2) by a combination of chemical and spectral methods.

  19. Componentes volátiles de mamey (mammea americana L.

    Directory of Open Access Journals (Sweden)

    Alicia Lucía Morales

    2010-07-01

    Full Text Available Los componentes volátiles del aroma de mamey (Mammea americana L, fueron extraídos utilizando el método de destilación por arrastre con vapor-extracción simultánea con solvente orgánico. El extracto fue prefraccionado por cromatografía en columna en silica gel con gradiente discontinuo Pentano: Éter etílico para obtener tres fracciones que fueron analizadas por CGAR y CGAR-EM. Se detectaron 34 compuestos, de los cuales fueron identificados 22, siendo los componentes mayoritarios: Furfural (7281 ^ig/kg y E-Famesol (2145 ng/kg

  20. Pretreatment of Agave americana stalk for enzymatic saccharification.

    Science.gov (United States)

    Yang, Qiang; Pan, Xuejun

    2012-12-01

    Agave americana is one of commonly grown agave species but currently less valuable because its large flower stalk cannot be used for producing alcoholic beverage. In the present study, the stalk was pretreated with dilute acid (DA), sulfite (SPORL), and sodium hydroxide (NaOH) to preliminarily assess its potential as feedstock for bioethanol production. The changes of cell wall components during the pretreatments, enzymatic digestibility of the pretreated stalks, and the adsorption of cellulases on the substrates were investigated. Results indicated that the pretreatments significantly improved the enzymatic digestibility of the agave stalk. SPORL pretreatment gave higher substrate and sugar yields, while NaOH pretreated stalk had better digestibility under the investigated conditions. The better hydrolysability of NaOH-pretreated stalk was attributed to low lignin and hemicellulose content and high affinity to cellulases.

  1. Efficacy of entomopathogenic hypocrealean fungi against Periplaneta americana.

    Science.gov (United States)

    Hubner-Campos, Rayssa Fátima; Leles, Renan Nunes; Rodrigues, Juscelino; Luz, Christian

    2013-12-01

    The American cockroach Periplaneta americana, one of the worlds' most important urban insect pests was tested with entomopathogenic fungi. Most promising Metarhizium anisopliae, Metarhizium robertsii and Beauveria bassiana killed nymphs (≥ 81.7% mortality, 25 days after treatment), and these fungi developed on all dead insects. Other fungi tested were less virulent (Metarhizium frigidum and Purpureocillium lilacinum) or avirulent (Isaria cateniobliqua, Isaria farinosa, Simplicillium lanosoniveum, Sporothrix insectorum and Tolypocladium cylindrosporum). Intrageneric and intraspecific variability of fungal activity was detected. Adults were highly susceptible, and oothecae proved to be more resistant than nymphs and adults to infection with M. anisopliae IP 46. Findings of the study underscore the potential of fungi as biocontrol agents against this pest.

  2. Properties of peroxisomal and mitochondrial citrate synthase from Agave americana.

    Science.gov (United States)

    Segovia, J L; Zafra, M F; Alejandre, M J; García-Peregrín, E

    1982-09-01

    Adenine nucleotides were tested as effectors of peroxisomal and mitochondrial citrate synthase from Agave americana leaves in the presence of different concentrations of acetyl-CoA and oxalacetate substrates. ATP inhibited both enzyme activities but with a different inhibition profile. 1.0-7.5 mM ADP did not inhibit the peroxisomal citrate synthase in the presence of high substrate concentrations, while the mitochondrial enzyme was strongly inhibited by 1.0 mM ADP in the same conditions. Likewise, a different pattern was obtained with AMP on both peroxisomal and mitochondrial activities. The rate of citrate formation as function of acetyl-CoA and oxalacetate concentration was also studied in both fractions. Maximal velocity was highest in the peroxisomal fraction, whether acetyl-CoA or oxalacetate were the variable substrates. These differences indicate that peroxisomal and mitochondrial citrate synthases seem to be two different isoenzymes.

  3. Climate-related differences in the dominance of submerged macrophytes in shallow lakes

    NARCIS (Netherlands)

    Kosten, S.; Kamarainen, A.; Jeppesen, E.; Nes, van E.H.; Peeters, E.T.H.M.; Lacerot, G.; Scheffer, M.

    2009-01-01

    It has been suggested that shallow lakes in warm climates have a higher probability of being turbid, rather than macrophyte dominated, compared with lakes in cooler climates, but little field evidence exists to evaluate this hypothesis. We analyzed data from 782 lake years in different climate zones

  4. Bioprospecting of Marine Macrophytes Using MS-Based Lipidomics as a New Approach

    Directory of Open Access Journals (Sweden)

    Elisabete Maciel

    2016-03-01

    Full Text Available The marine environment supports a remarkable diversity of organisms which are a potential source of natural products with biological activities. These organisms include a wide variety of marine plants (from micro- to macrophytes, which have been used in the food and pharmaceutical industry. However, the biochemistry and biological activities of many of these macrophytes (namely macroalgae and halophytes, including seagrasses are still far from being fully explored. Most popular bioactive components include polysaccharides, peptides, phenolics and fatty acids (FAs. Polar lipids (glycolipids, phospholipids and betaine lipids are emerging as novel value-added bioactive phytochemicals, rich in n-3 FA, with high nutritional value and health beneficial effects for the prevention of chronic diseases. Polar lipids account various combinations of polar groups, fatty acyl chains and backbone structures. The polar lipidome of macrophytes is remarkably diverse, and its screening represents a significant analytical challenge. Modern research platforms, particularly mass spectrometry (MS-based lipidomic approaches, have been recently used to address this challenge and are here reviewed. The application of lipidomics to address lipid composition of marine macrophytes will contribute to the stimulation of further research on this group and foster the exploration of novel applications.

  5. Impact of submerged macrophytes including charophytes on phyto- and zooplankton communities: allelopathy versus other mechanisms

    NARCIS (Netherlands)

    Van Donk, E.; Van de Bund, W.J.

    2002-01-01

    Submerged macrophytes are crucial for the stabilization of the clear water state in shallow, mesotrophic and eutrophic lakes. Especially, charophytes often play an important role because they are typically rapid colonizers and because charophyte meadows are believed to have a particularly strong pos

  6. Archaea Dominate the Ammonia-Oxidizing Community in the Rhizosphere of the Freshwater Macrophyte Littorella uniflora

    DEFF Research Database (Denmark)

    Herrmann, Martina; Saunders, Aaron M.; Schramm, Andreas

    2008-01-01

    Archaeal and bacterial ammonia monooxygenase genes (amoA) had similar low relative abundances in freshwater sediment. In the rhizosphere of the submersed macrophyte Littorella uniflora, archaeal amoA was 500- to >8,000-fold enriched compared to bacterial amoA, suggesting that the enhanced nitrifi...... nitrification activity observed in the rhizosphere was due to ammonia-oxidizing Archaea....

  7. Ambiguous climate impacts on the competition between submerged macrophytes and phytoplankton in shallow lakes

    NARCIS (Netherlands)

    Kosten, S.; Jeppesen, E.; Huszar, V.M.; Mazzeo, N.; Nes, van E.H.; Peeters, E.T.H.M.; Scheffer, M.

    2011-01-01

    1. Shallow lakes may switch from a state dominated by submerged macrophytes to a phytoplankton-dominated state when a critical nutrient concentration is exceeded. We explore how climate change may affect this critical nutrient concentration by linking a graphical model to data from 83 lakes along a

  8. Effect of Hydrologic Alteration on the Community Succession of Macrophytes at Xiangyang Site, Hanjiang River, China

    Directory of Open Access Journals (Sweden)

    Na Yang

    2017-01-01

    Full Text Available With the intensification of human activities over the past three decades in China, adverse effects on river ecosystem become more serious especially in the Hanjiang River. Xiangyang site is an important spawn ground for four domestic fishes in the downstream region of Hanjiang River. Based on the field survey results of macrophytes during 1997–2000 and 2013-2014, community succession of aquatic macrophytes at Xiangyang site was evaluated and discussed. Two-key ecologic-related hydrologic characteristics, flow regime and water level, were identified as the main influence factors. The EFC (environmental flow components parameters were adopted to evaluate the alteration of flow regimes at Xiangyang site during 1941–2013. Evaluation results demonstrate a highly altered flow process after being regulated by reservoir. The flow patterns tend to be an attenuation process with no large floods occurring but a higher monthly low flow. Furthermore, the water level decreased and fluctuation reduced after the dam was built, which caused the decrease of biomass but favored the submerged macrophytes during 1995–2009. However, with the water level increasing after 2010 and gently fluctuating, due to uplift by the hydraulic projects downstream as well as the flow attenuation, the dominant position of submerged macrophytes will be weakened.

  9. Ecotypic differentiation in thermal traits in the tropical to warm-temperate green macrophyte Valonia utricularis

    NARCIS (Netherlands)

    Eggert, A.; Burger, E.M.; Breeman, Arno

    2003-01-01

    Differentiation of thermal traits (i.e. growth, survival and reproduction) was studied in the green macrophyte Valonia utricularis (Roth) C. Agardh, which has a world-wide tropical to warm-temperate distribution. Ecotypic differentiation between northeast Atlantic/Mediterranean and Indo-west Pacific

  10. Bioprospecting of Marine Macrophytes Using MS-Based Lipidomics as a New Approach.

    Science.gov (United States)

    Maciel, Elisabete; Costa Leal, Miguel; Lillebø, Ana Isabel; Domingues, Pedro; Domingues, Maria Rosário; Calado, Ricardo

    2016-03-08

    The marine environment supports a remarkable diversity of organisms which are a potential source of natural products with biological activities. These organisms include a wide variety of marine plants (from micro- to macrophytes), which have been used in the food and pharmaceutical industry. However, the biochemistry and biological activities of many of these macrophytes (namely macroalgae and halophytes, including seagrasses) are still far from being fully explored. Most popular bioactive components include polysaccharides, peptides, phenolics and fatty acids (FAs). Polar lipids (glycolipids, phospholipids and betaine lipids) are emerging as novel value-added bioactive phytochemicals, rich in n-3 FA, with high nutritional value and health beneficial effects for the prevention of chronic diseases. Polar lipids account various combinations of polar groups, fatty acyl chains and backbone structures. The polar lipidome of macrophytes is remarkably diverse, and its screening represents a significant analytical challenge. Modern research platforms, particularly mass spectrometry (MS)-based lipidomic approaches, have been recently used to address this challenge and are here reviewed. The application of lipidomics to address lipid composition of marine macrophytes will contribute to the stimulation of further research on this group and foster the exploration of novel applications.

  11. Mowing Submerged Macrophytes in Shallow Lakes with Alternative Stable States: Battling the Good Guys?

    NARCIS (Netherlands)

    Kuiper, Jan J.; Verhofstad, Michiel J. J. M.; Louwers, Evelien; Bakker, Elisabeth S.; Brederveld, Robert J.; van Gerven, Luuk P. A.; Janssen, Annette B. G.; de Klein, Jeroen J. M.; Mooij, Wolf M.

    2017-01-01

    Submerged macrophytes play an important role in maintaining good water quality in shallow lakes. Yet extensive stands easily interfere with various services provided by these lakes, and harvesting is increasingly applied as a management measure. Because shallow lakes may possess alternative stable

  12. Hydroponic Uptake of Atrazine and Lambda-cyhalothrin in Aquatic Macrophytes

    Science.gov (United States)

    Bouldin, J. L.; Farris, J. L.; Moore, M. T.; Smith, S.; Cooper, C. M.

    2005-05-01

    Phytoremediation encompasses an array of plant-associated processes known to mitigate contaminants from soil, sediment, and water. Modification of pesticides associated with agricultural runoff includes processes directly associated with aquatic macrophytes in addition to soil geochemical modifications and associated rhizospheric degradation. Remediation attributes of two vegetative species common to agricultural drainages in the Mississippi Delta, USA, were assessed using atrazine and lambda-cyhalothrin. Concentrations used in 8-d hydroponic exposures were calculated using recommended field applications and a 5% runoff model from a 0.65-cm rainfall event on a 2.02-ha field. While greater atrazine uptake was measured in Juncus effusus, greater lambda-cyhalothrin uptake occurred in Ludwigia peploides. Maximum pesticide uptake was reached within 48 h for each exposure and subsequent translocation of pesticides to upper plant biomass occurred in macrophytes exposed to atrazine. Sequestration of 98.2% of lambda-cyhalothrin in roots of L. peploides was measured after 8 d. Translocation of lambda-cyhalothrin in J. effusus resulted in 25.4% of pesticide uptake partitioned to upper plant biomass. These individual macrophyte remediation studies measured species- and pesticide-specific uptake rates, indicating that the seasonality of pesticide applications and macrophyte emergence might interact strongly to enhance mitigation capabilities in edge-of-field conveyance structures.

  13. Effects of contrasting omnivorous fish on submerged macrophyte biomass in temperate lakes: a mesocosm experiment

    NARCIS (Netherlands)

    Dorenbosch, M.; Bakker, E.S.

    2012-01-01

    1.Freshwater fish can affect aquatic vegetation directly by consuming macrophytes or indirectly by changing water quality. However, most fish in the temperate climate zone have an omnivorous diet. The impact of fish as aquatic herbivores in temperate climates therefore remains unclear and depends on

  14. Clonal variation in the thermal response of the submerged aquatic macrophyte Potamogeton pectinatus

    NARCIS (Netherlands)

    Pilon, J.; Santamaria, L.

    2002-01-01

    Broadly distributed plants have to cope with dramatic differences across latitude in the prevailing environmental temperature. We investigated the effect of water temperature on plant morphology, biomass accumulation and oxygen-exchange for five clones of the submerged aquatic macrophyte Potamogeton

  15. Diaspore bank of aquatic macrophytes maintaining species diversity in a Neotropical pond

    Directory of Open Access Journals (Sweden)

    Fernando Alves Ferreira

    2016-12-01

    Full Text Available The diaspore bank is an important component of biological diversity acting mainly as storage and source of diaspores, which also indicate dynamics and patterns of maintenance of plant diversity. We tested the hypothesis that the diaspore bank would be the responsible factor for the maintenance of the aquatic plant species, used two techniques to evaluate the diaspore bank: seedling emergence and direct counting of field samples. Density and richness of the diaspore bank were correlated with plant cover of the aquatic macrophyte communities and also with the euphotic zone radiation in different phases of the hydrological cycle. The diaspore bank is a key factor in maintenance of aquatic macrophyte assemblages in this pond. Nymphaea amazonum was one of the dominant species in the pond and presented temporally peaks of plant cover. Furthermore, depth allowed induction of germination of stored diaspores. Therefore, the diaspore bank may predict which species colonizes a site when environmental characteristics are favorable and allows inferring which processes are linked to changes in structure of aquatic macrophyte assemblages. These mechanisms are the means for recovery of macrophyte species under natural disturbances, represented by water level oscillations in floodplains.

  16. Effects of contrasting omnivorous fish on submerged macrophyte biomass in temperate lakes: a mesocosm experiment

    NARCIS (Netherlands)

    Dorenbosch, M.; Bakker, E.S.

    2012-01-01

    1.Freshwater fish can affect aquatic vegetation directly by consuming macrophytes or indirectly by changing water quality. However, most fish in the temperate climate zone have an omnivorous diet. The impact of fish as aquatic herbivores in temperate climates therefore remains unclear and depends on

  17. Interactions between piscivores, zooplanktivores and zooplankton in submerged macrophytes : Preliminary observations from enclosure and pond experiments

    DEFF Research Database (Denmark)

    Jacobsen, Lene; Perrow, M.R.; Landkildehus, F.

    1997-01-01

    behavioural changes of zooplanktivores has received little attention, even though this may be an important mechanism in enhancing the stability of submerged macrophytes in shallow lakes. Preliminary observations from an unreplicated large-scale field enclosure experiment and a replicated pond experiment...

  18. Effect of Hydrologic Alteration on the Community Succession of Macrophytes at Xiangyang Site, Hanjiang River, China

    Science.gov (United States)

    Duan, Kai

    2017-01-01

    With the intensification of human activities over the past three decades in China, adverse effects on river ecosystem become more serious especially in the Hanjiang River. Xiangyang site is an important spawn ground for four domestic fishes in the downstream region of Hanjiang River. Based on the field survey results of macrophytes during 1997–2000 and 2013-2014, community succession of aquatic macrophytes at Xiangyang site was evaluated and discussed. Two-key ecologic-related hydrologic characteristics, flow regime and water level, were identified as the main influence factors. The EFC (environmental flow components) parameters were adopted to evaluate the alteration of flow regimes at Xiangyang site during 1941–2013. Evaluation results demonstrate a highly altered flow process after being regulated by reservoir. The flow patterns tend to be an attenuation process with no large floods occurring but a higher monthly low flow. Furthermore, the water level decreased and fluctuation reduced after the dam was built, which caused the decrease of biomass but favored the submerged macrophytes during 1995–2009. However, with the water level increasing after 2010 and gently fluctuating, due to uplift by the hydraulic projects downstream as well as the flow attenuation, the dominant position of submerged macrophytes will be weakened. PMID:28127493

  19. Response of littoral macrophytes to water level fluctuations in a storage reservoir

    Directory of Open Access Journals (Sweden)

    Krolová M.

    2013-05-01

    Full Text Available Lakes and reservoirs that are used for water supply and/or flow regulations have usually poorly developed littoral macrophyte communities, which impairs ecological potential in terms of the EU Water Framework Directive. The aim of our study was to reveal controlling factors for the growth of littoral macrophytes in a storage reservoir with fluctuating water level (Lipno Reservoir, Czech Republic. Macrophytes occurred in this reservoir only in the eulittoral zone i.e., the shoreline region between the highest and the lowest seasonal water levels. Three eulittoral sub-zones could be distinguished: the upper eulittoral with a stable community of perennial species with high cover, the middle eulittoral with relatively high richness of emergent and amphibious species present at low cover values, and the lower eulittoral devoid of permanent vegetation. Cover and species composition in particular sub-zones were primarily influenced by the duration and timing of flooding, followed by nutrient limitation and strongly reducing conditions in the flooded organic sediment. Our results stress the ecological importance of eulittoral zone in reservoirs with fluctuating water levels where macrophyte growth can be supported by targeted management of water level, thus helping reservoir managers in improving the ecological potential of this type of water bodies.

  20. A microcosm system to evaluate the toxicity of the triazine herbicide simazine on aquatic macrophytes

    Energy Technology Data Exchange (ETDEWEB)

    Vervliet-Scheebaum, Marco, E-mail: marco.vervliet@biologie.uni-freiburg.d [Plant Biotechnology, Faculty of Biology, University of Freiburg, Schaenzlestr. 1, 79104 Freiburg (Germany); Straus, Alain [Plant Biotechnology, Faculty of Biology, University of Freiburg, Schaenzlestr. 1, 79104 Freiburg (Germany); Tremp, Horst [Institute for Environmental Sciences, University Koblenz-Landau, Fortstr. 7, 76829 Landau (Germany); Hamer, Mick [Ecological Sciences, Syngenta Crop Protection AG, Jealott' s Hill International Research Centre, Bracknell, Berkshire RG42 6EY (United Kingdom); Maund, Stephen J. [Ecological Sciences, Syngenta Crop Protection AG, 4002 Basel (Switzerland); Wagner, Edgar [Plant Biotechnology, Faculty of Biology, University of Freiburg, Schaenzlestr. 1, 79104 Freiburg (Germany); Schulz, Ralf [Institute for Environmental Sciences, University Koblenz-Landau, Fortstr. 7, 76829 Landau (Germany)

    2010-02-15

    This study evaluates the effects of the triazine herbicide simazine in an outdoor pond microcosm test system that contained two submerged rooted species (Myriophyllum spicatum and Elodea canadensis) and two emergent rooted species (Persicaria amphibia and Glyceria maxima) over a period of 84 days. Simazine was applied to the microcosms at nominal concentrations of 0.05, 0.5 and 5 mg/L. General biological endpoints and physiological endpoints were used to evaluate herbicide toxicity on macrophytes and the algae developing naturally in the system. Concentration-related responses of macrophytes and algae were obtained for the endpoints selected, resulting in a no observed ecologically adverse effect concentration (NOEAEC) at simazine concentrations of 0.05 mg active ingredient/L after 84 days. E. canadensis was the most negatively affected species based on length increase, which was consistently a very sensitive parameter for all macrophytes. The experimental design presented might constitute a suitable alternative to conventional laboratory single-species testing. - Simazine at concentrations of 0.05 mg/L does not cause long-term negative effects to aquatic macrophytes or algae.

  1. Aquatic macrophyte and macroinvertebrate diversity and conservation in wetlands of the Sinos River basin.

    Science.gov (United States)

    Maltchik, L; Rolon, A S; Stenert, C

    2010-12-01

    Wetlands are important sites for biological conservation because they support rich biodiversity and present high productivity. Species-area relationship is an important tool in conservation planning and it has been extensively used for wetland management. This study had as aims: (1) to analyse macrophyte and macroinvertebrate diversity in the fragmented wetlands of the Sinos River basin; and (2) to investigate whether wetland areas could work as a tool for selecting the important habitats for biodiversity conservation. Throughout the study, 56 species of macrophytes and 57 taxa of macroinvertebrates were identified. Macrophyte richness was related to the wetland area, but macroinvertebrate richness, however, was not related to the wetland area. The macrophyte and macroinvertebrate composition were not related to the wetland area. Species composition varied between the regions of the basin and the difference in the species composition occurred mainly by the distribution of macroinvertebrates. With regard to the biodiversity conservation of the Sinos River basin, the wetland area must not be a priority criterion for choosing the important wetlands for conservation. The environmental policies for biodiversity conservation must include management actions focused also on the protection of small wetlands. Moreover, other criteria should be analysed in further research such as habitat diversity, hydroperiod, geographic distribution and connectivity.

  2. Aquatic Plant Control Research Program. Effects of Organic Amendments to Sediment on Freshwater Macrophyte Growth.

    Science.gov (United States)

    1983-10-01

    The growth of three submersed macrophyte species (Myriophyllum spicatum, Hyjdri11a verticillata, and Elodea canadensis) and three partially emergent... Elodea canadensis Rich. in Michx; and Hydrilla verticillata (L.f.) Caspary. Nomenclature follows Godfrey and Wooten (1979, 1981). The first two species

  3. Effect of lighting conditions of coastal zone of Knyaginya lake on composition of macrophyte biohydrocenoses

    Directory of Open Access Journals (Sweden)

    B. O. Baranovsky

    2005-10-01

    Full Text Available In articlе the stuffs of researches of influence of a mode of illuminating intensity of coastal zone of a different exposition flood-land of lake Knyaginya (valley Samara on composition of highest aqueous green and macrozoobentos macrophytes biogeocenose are submitted.

  4. Interaction between the macrophyte Stratiotes aloides and filamentous algae: does it indicate allelopathy?

    NARCIS (Netherlands)

    Mulderij, G.; Mau, B.; De Senerpont Domis, L.N.; Smolders, A.J.P.; Van Donk, E.

    2009-01-01

    The aquatic macrophyte Stratiotes aloides Linnaeus, which has recently received attention in studies on allelopathy, has been shown to suppress phytoplankton growth. In the Netherlands, S. aloides often co-occurs with floating filamentous algae. However, filamentous algae are generally absent in

  5. Impact of submerged macrophytes including charophytes on phyto- and zooplankton communities: allelopathy versus other mechanisms

    NARCIS (Netherlands)

    Van Donk, E.; Van de Bund, W.J.

    2002-01-01

    Submerged macrophytes are crucial for the stabilization of the clear water state in shallow, mesotrophic and eutrophic lakes. Especially, charophytes often play an important role because they are typically rapid colonizers and because charophyte meadows are believed to have a particularly strong

  6. A simple equation for describing the temperature dependent growth of free-floating macrophytes

    NARCIS (Netherlands)

    Heide, van Tj.; Roijackers, R.M.M.; Nes, van E.H.; Peeters, E.T.H.M.

    2006-01-01

    Temperature is one of the most important factors determining growth rates of free-floating macrophytes in the field. To analyse and predict temperature dependent growth rates of these pleustophytes, modelling may play an important role. Several equations have been published for describing temperatur

  7. Oil biosynthesis in a basal angiosperm: transcriptome analysis of Persea Americana mesocarp

    National Research Council Canada - National Science Library

    Kilaru, Aruna; Cao, Xia; Dabbs, Parker B; Sung, Ha-Jung; Rahman, Md Mahbubur; Thrower, Nicholas; Zynda, Greg; Podicheti, Ram; Ibarra-Laclette, Enrique; Herrera-Estrella, Luis; Mockaitis, Keithanne; Ohlrogge, John B

    2015-01-01

    ...) in tissues other than seeds is not well understood. The comprehension of controls for carbon partitioning and oil accumulation in nonseed tissues is essential to generate oil-rich biomass in perennial bioenergy crops. Persea americana (avocado...

  8. Description of Tingis americana nymphs (Hemiptera: Tingidae), with emphasis on integumentary structures.

    Science.gov (United States)

    Moreira, Daiane C; Guidoti, Marcus; Barcellos, Aline; Redaelli, Luiza R

    2014-04-03

    The five instars of Tingis (Tingis) americana Drake are described and illustrated, with emphasis on the ontogenetic changes of integumentary structures. The study was performed using scanning electron microscopy.

  9. Removal of personal care compounds from sewage sludge in reed bed container (lysimeter) studies - Effects of macrophytes

    DEFF Research Database (Denmark)

    Chen, Xijuan; Pauly, Udo; Rehfus, Stefan

    2009-01-01

    as on the bactericide Triclosan. Additionally, the capacity of different macrophytes species to affect the treatment process was examined. Three different macrophyte species were compared: bulrush (Typha latifolia), reed (Phragmites australis) and reed canary grass (Phalaris arundinacea). They were planted...... into containers (lysimeters) with a size of 1 m × 1 m × 1 m which were filled with 20 cm gravel at the bottom and 50 cm sludge on top, into which the macrophytes were planted. During the twelve months experiment reduction of 20-30% for HHCB and AHTN, 70% for Triclosan and 70% for OTNE were determined under...

  10. A Case of Ventilator-Associated Pneumonia Caused by Ewingella americana : First Report from Turkey

    Directory of Open Access Journals (Sweden)

    Kenan Ecemiş

    2014-09-01

    Full Text Available Ewingella americana is a very rare cause of serious infections, especially in immunocompromised patients. We report a case of ventilator-associated pneumonia (VAP in an intensive care unit patient, who was treated successfully with ceftriaxone. To the best of our knowledge, this is the first case of VAP due to Ewingella americana in the English literature.J Microbiol Infect Dis 2014; 4(3: 118-120

  11. Swimming black-crowned night-herons (Nycticorax nycticorax) Kleptoparasitize American coots (Fulica americana)

    DEFF Research Database (Denmark)

    Graves, Gary R.

    2015-01-01

    I observed black-crowned night-herons (Nycticorax nycticorax) swimming and kleptoparasitizing American coots (Fulica americana) at an artificial lake in Pinal County, Arizona. This appears to be the first record of interspecific kleptoparasitism by a swimming ardeid.......I observed black-crowned night-herons (Nycticorax nycticorax) swimming and kleptoparasitizing American coots (Fulica americana) at an artificial lake in Pinal County, Arizona. This appears to be the first record of interspecific kleptoparasitism by a swimming ardeid....

  12. Modelos de masculinidad en la literatura chino-americana contemporánea

    OpenAIRE

    Soria Somoza, Carolina

    2016-01-01

    [Resumen] Modelos de masculinidad en la literatura chino-americana contemporánea Esta tesis doctoral estudia los modelos de masculinidad presentes en la literatura chino-americana contemporánea. Para ello, analizo las obras de autores tan representativos como Frank Chin, Louis Chu, David Henry Hwang, Gish Jen, Ha Jin y Maxine Hong Kingston. Mi principal objetivo es examinar las diferencias entre aquellos modelos que resulten obsoletos y estereotípicos de aquellos que puedan ...

  13. Use of low-altitude aerial photography to identify submersed aquatic macrophytes

    Science.gov (United States)

    Schloesser, Donald W.; Manny, Bruce A.; Brown, Charles L.; Jaworski, Eugene

    1987-01-01

    The feasibility of using low-altitude aerial photography to identify beds of submersed macrophytes is demonstrated. True color aerial photos and collateral ground survey information for submersed aquatic macrophyte beds at 10 sites in the St.Clair-Detroit River system were obtained in September 1978. Using the photos and collateral ground survey information, a dichotomous key was developed for the identification of six classes - beds of five genera of macrophytes and one substrate type. A test was prepared to determine how accurately photo interpreters could identify the six classes. The test required an interpreter to examine an unlabeled, outlined area on photographs and identify it using the key. Six interpreters were tested. One pair of interpreters was trained in the interpretation of a variety of aerial photos, a second pair had field experience in the collection and identification of submersed macrophytes in the river system, and a third pair had neither training in the interpretation of aerial photos nor field experience. The criteria that we developed were applied equally well by the interpretors, regardless of their training or experience. Overall accuracy (i.e., omission errors) of all six classes combined was 68% correct, whereas, overall accuracy of individual classes ranged from 50 to 100% correct. Mapping accuracy (i.e. omission and commission errors) of individual classes ranged from 36 to 75%. Although the key developed for this study has only limited application outside the context of the data and sites examined in this study, it is concluded that low-altitude aerial photography, together with limited amounts of collateral ground survey information, can be used to economically identify beds of submersed macrophytes in the St. Clair-Detroit River system and other similar water bodies.

  14. Aquatic macrophytes can be used for wastewater polishing but not for purification in constructed wetlands

    Science.gov (United States)

    Tang, Yingying; Harpenslager, Sarah F.; van Kempen, Monique M. L.; Verbaarschot, Evi J. H.; Loeffen, Laury M. J. M.; Roelofs, Jan G. M.; Smolders, Alfons J. P.; Lamers, Leon P. M.

    2017-02-01

    The sequestration of nutrients from surface waters by aquatic macrophytes and sediments provides an important service to both natural and constructed wetlands. While emergent species take up nutrients from the sediment, submerged and floating macrophytes filter nutrients directly from the surface water, which may be more efficient in constructed wetlands. It remains unclear, however, whether their efficiency is sufficient for wastewater purification and how plant species and nutrient loading affects nutrient distribution over plants, water and sediment. We therefore determined nutrient removal efficiencies of different vegetation (Azolla filiculoides, Ceratophyllum demersum and Myriophyllum spicatum) and sediment types (clay, peaty clay and peat) at three nutrient input rates, in a full factorial, outdoor mesocosm experiment. At low loading (0.43 mg P m-2 d-1), plant uptake was the main pathway (100 %) for phosphorus (P) removal, while sediments showed a net P release. A. filiculoides and M. spicatum showed the highest biomass production and could be harvested regularly for nutrient recycling, whereas C. demersum was outcompeted by spontaneously developing macrophytes and algae. Higher nutrient loading only stimulated A. filiculoides growth. At higher rates ( ≥ 21.4 mg P m-2 d-1), 50-90 % of added P ended up in sediments, with peat sediments becoming more easily saturated. For nitrogen (N), 45-90 % was either taken up by the sediment or lost to the atmosphere at loadings ≥ 62 mg N m-2 d-1. This shows that aquatic macrophytes can indeed function as an efficient nutrient filter but only for low loading rates (polishing) and not for high rates (purification). The outcome of this controlled study not only contributes to our understanding of nutrient dynamics in constructed wetlands but also shows the differential effects of wetland sediment types and plant species. Furthermore, the acquired knowledge may benefit the application of macrophyte harvesting to remove

  15. The role of submerged macrophytes and macroalgae in nutrient cycling: A budget approach

    Science.gov (United States)

    Human, Lucienne R. D.; Snow, Gavin C.; Adams, Janine B.; Bate, Guy C.; Yang, Sheng-Chi

    2015-03-01

    This study used a budget approach to determine the effect of submerged macrophytes and macroalgae on the storage of N and P in an estuary. Above and below ground tissue content of nitrogen and phosphorus were determined for the various macrophyte species. The mouth of the estuary was artificially breached in February 2011 with a volume of 0.3 × 106 m3 and closed a week later. A 1:100 year flood with volume close to 3 × 106 m3 breached the mouth naturally in June 2011 flushing water and sediment out of the estuary. In order to track the change in the nutrient acquisition of the submerged macrophytes and macroalgae over a closed-mouth state, the nutrient budget was constructed for the period February 2011 to July 2011, from the time the mouth closed until it opened again. Relative to other inputs the sediment contributed 30% of the TN and 40% TP toward the nutrient budget, while the submerged macrophytes and macroalgae stored 20-30 % TN and 30-38 % TP. The river and precipitation contributed less than 3% of the TN and TP input. It was previously thought that the sediments of South African temporarily open/closed estuaries did not have the necessary organic stock to fuel primary production. However this research showed this to be incorrect. Submerged macrophytes and macroalgae significantly influenced nutrient cycling and this is the first detailed account of incorporating vegetation into a nutrient budget without relying solely on C:N:P ratios.

  16. Recognising macrophyte-vegetated environments in the rock record: a new criterion using 'hooked' forms of crustose coralline red algae

    Science.gov (United States)

    Beavington-Penney, Simon J.; Paul Wright, V.; Woelkerling, Wm. J.

    2004-04-01

    The role of macrophytes (such as seagrasses) in influencing deposition in shallow marine environments has long been understood. They affect sediment textures such that they do not reflect ambient hydrodynamic conditions, and so the recognition of ancient vegetated environments is important for accurate palaeoenvironmental analysis. However, there is little direct fossil evidence of such plants in the rock record, and so the presence of former macrophyte cover generally has to be inferred from indirect evidence based on the characteristics of modern macrophyte-vegetated environments. We present a new criterion for the recognition of vegetated environments in the rock record, based upon a distinctive 'hooked' form of crustose coralline red algae that is definitively indicative of growth on seagrasses (and also on other macrophytes with similarly flattened blades), and has been recognised from both modern (Inhaca Island, Mozambique) and fossil (the Eocene of Oman) seagrass beds.

  17. Macrophyte succession in floodplain lakes : spatio-temporal patterns in relation to river hydrology, lake morphology and management

    NARCIS (Netherlands)

    Geest, van G.J.

    2005-01-01

    Two questions are central to the work in this thesis: 1. What are the factors determining macrophyte composition in floodplain lakes along the Lower Rhine? 2. What advice can be given for design of future water bodies?

  18. Morphometry and retention time as forcing functions to establishment and maintenance of aquatic macrophytes in a tropical reservoir

    OpenAIRE

    M. B. Cunha-Santino; Fushita,A. T.; PERET, A.C.; Bianchini-Junior,I.

    2016-01-01

    Abstract Macrophytes may constitute an important resource for several chemical, physical and biological processes within aquatic ecosystems. This study considers that in tropical reservoirs with low retention time and with low values of shoreline development (DL), the expansion and persistence of aquatic macrophytes are mainly reported to local conditions (e.g., hydrodynamic and wind exposure) rather than trophic status and depth of the euphotic zone. In this context, this study aimed at desc...

  19. Decreasing but still significant facilitation effect of cold-season macrophytes on wetlands purification function during cold winter

    OpenAIRE

    Xiangxu Zou; Hui Zhang; Jie Zuo; Penghe Wang; Dehua Zhao; Shuqing An

    2016-01-01

    To identify the facilitation effect of a cool-season aquatic macrophyte (FEam) for use in effluent purification via constructed floating wetlands (CFWs) and to determine the possible pathways used during a winter period with an average temperature of less than 5??C, pilot-scale CFWs were planted with the cold-season macrophyte Oenanthe clecumbens and were operated as batch systems. Although some leaves withered, the roots retained relatively high levels of activity during the winter, which ha...

  20. 斧头湖水生植物多样性及群落演替研究%DIVERSITY VARIATION AND COMMUNITY SUCCESSION OF AQUATIC MACROPHYTES IN LAKE FUTOU

    Institute of Scientific and Technical Information of China (English)

    李中强; 任慧; 郝孟曦; 张萌; 徐军

    2012-01-01

    Due to extensive human activities, habitat loss and segmentation induce destruction and disappearance of aquatic plants in the shallow lakes. These activities cause secondary extinctions of aquatic animals, leading to loss of biodiversity in lakes and animal reproduction. Lake Futou, locates in southeastern Hubei Province, China, has the same functions, such as irrigation and aquaculture, as other shallow lakes in the middle and lower reaches of the Yangtze River. However, in recent 50 years, human disturbances, including reclamation, damming and over-fishing, have caused accelerated loss of diversity of aquatic plants. This worsened the ecosystem faction and seriously affected the productivity of aquatic resources and the quality of species. Thus, the aims of the this study were to understand the succession of aquatic plants in Lake Futou in recent decades and to comprehend the reasons associated with exploitation and utilization of resources in this lake. In order to investigate the aquatic plant diversity in Lake Futou, the species and community diversity were studied using field investigation in 2009, and the topology were analysed by geographical information system technique with ARC/INFO. Based on the results obtained from field investigation and previous studies, species diversity variations and succession of aquatic macrophytes community in Lake Futou from 1988 to 2009 were investigated and the reasons between the changes and some controlling factors were analyzed. The results showed that there were some variations on the number of species and dominant species of aquatic plants. Some species that were sensitive to disturbances such as Nymphaea stellata disappeared and some dominant species such as Potamogeton maackianus, Vallisneria denseserrulata and Hydrilla verticillata became sub-dominant species or accompanying species from 1988 to 2009. In addition, the introduced species such as Elodea nuttalli occurred in Lake Futou and became dominant species

  1. Aquatic macrophytes in the large, sub-tropical Itaipu Reservoir, Brazil.

    Science.gov (United States)

    Mormul, Roger Paulo; Ferreira, Fernando Alves; Michelan, Thaisa Sala; Carvalho, Priscilla; Silveira, Marcio José; Thomaz, Sidinei Magela

    2010-12-01

    In the last three decades, rapid assessment surveys have become an important approach for measuring aquatic ecosystem biodiversity. These methods can be used to detect anthropogenic impacts and recognize local or global species extinctions. We present a floristic survey of the aquatic macrophytes along the Brazilian margin of the Itaipu Reservoir conducted in 2008 and compare this with a floristic survey conducted ten years earlier. We used ordination analysis to determine whether assemblage composition differed among reservoir arms. Macrophyte species were sampled in each of the 235 sampling stations using a boat, which was positioned inside three places of each macrophyte stand to record species and search for small plants. We also collected submerged plants using a rake with the boat moving at constant velocity for ten minutes. We assigned individual macrophyte species to life form and identified representative species for each life form. A total of 87 macrophyte taxa were identified. The "emergent" life forms contained the highest number of species, followed by "rooted submerged" life forms. The extensive survey of macrophytes undertaken in September 2008 recorded more species than a survey conducted between 1995 and 1998. This could be due to changes in water physico-chemistry, disturbances due to water drawdown and the long period between surveys, which may have allowed natural colonization by other species. Additionally, differences in the classification systems and taxonomic resolution used in the surveys may account for differences in the number of species recorded. Assemblage composition varied among the arms and was affected by underwater radiation (as measured using a Secchi disk) and fetch. Five non-native species were found. Two of these non-native species (Urochloa subquadripara and Hydrilla verticillata) are of special concern because they have a high frequency of occurrence and occupy large marginal areas of the reservoir. Future surveys should be

  2. Remote Sensing supports EULAKES project for mapping submerged macrophytes in Lake Garda

    Science.gov (United States)

    Matta, Erica; Bresciani, Mariano; Giardino, Claudia; Bolpagni, Rossano; Pellegrini, Giovanna; Braga, Federica

    2013-04-01

    Lake bottoms have an important role in the aquatic ecosystem: bathymetry and morphology may affect the hydrodynamic processes in coastal waters, while the presence of aquatic macrophytes helps to preserve the ecology. Within the context of macrophyte monitoring programs, technical advances in remote sensing with higher spatial and spectral resolutions provide opportunities for big scale ecological studies, with the possibility to assess a multitemporal analysis. One of the objectives of the EULAKES project has been to map aquatic vegetation cover inside the Garda Lake from hyperspectral MIVIS (Multispectral Infrared and Visible Imaging Spectrometer) aerial images thanks to the application of a bio-optical model inversion technique (BOMBER: Bio-Optical Model Based tool for Estimating water quality and bottom properties from Remote sensing images). MIVIS images, with a spectral resolution of 102 bands, working between 430 and 1270 nm, were previously corrected for atmospheric, adjacency and glint effects before being processed with the BOMBER tool. One complete MIVIS overflight (12 runs) acquired on June 27th 2011, allowed the retrieval of a macrophyte presence map all around the first 7m deep coastal belt, with a validation error of about 10%, resulting from 89 in situ measures performed during images acquisition. A relevant spatial distribution could be observed, with higher aquatic plants concentration in the Southern part of the lake. A further local cover distribution map localized on the Sirmione Peninsula was integrated with previous results to perform a temporal analysis of macrophyte colonization patterns along this reduced littoral zone for the last 14 years (acquisitions on September 1997, July 2005 and July 2010). Considerable modifications in terms of macrophyte structural complexity and colonized areas were detectable: a drastic reduction of well-established dense communities (more than 70% of cover) and increasing of un-colonized areas were followed by

  3. Reproductive parameters of the southern stingray Dasyatis americana in southern gulf of Mexico Parámetros reproductivos de la raya látigo americana Dasyatis americana en el sur del golfo de México

    Directory of Open Access Journals (Sweden)

    Edith Ramírez-Mosqueda

    2012-07-01

    Full Text Available The southern stingray Dasyatis americana (Hildebrand & Schroeder, 1928 is the most landed elasmobranch by small-scale fleets in southern gulf of Mexico. However, little is known of its life history parameters in this region. In this study, a total of 900 specimens were collected from February 2006 to December 2008 to determine the reproductive parameters needed for population assessments by means of ecological risk assessments or demographic analysis. Results suggested that females of D. americana reproduce annually, with a gestation of 7-8 months. The reproductive cycle of females is asynchronous, with ovulation and parturition occurring throughout the year. Females and males matured at 764 and 517 mm disc width (DW50 respectively. D. americana has one of the highest fecundity among dasyatids, from 2 to 7 embryos, with a sex ratio of embryos of 1:1. A linear relationship between maternal DW and fecundity was estimated, the larger females contain more embryos. The status of the population of D. americana is a cause of concern in the southern gulf of Mexico due to its high frequency of capture in artisanal fisheries and its apparently low biological productivity.La raya látigo americana Dasyatis americana (Hildebrand & Schroeder, 1928, conocida como balá en México, es el elasmobranquio más capturado y desembarcado por flotas artesanales en el sur del golfo de México. Sin embargo, se conoce poco de sus parámetros de historia de vida en esta región. En este estudio, fueron analizados 900 ejemplares entre febrero 2006 y diciembre 2008 para determinar los parámetros reproductivos necesarios para evaluaciones poblacionales por medio de análisis demográficos o evaluaciones de riesgo ecológico. Los resultados sugieren que las hembras de D. americana se reproducen anualmente, con una gestación de 7-8 meses aproximadamente. El ciclo reproductivo de las hembras es asincrónico, con la ovulación y alumbramiento ocurriendo a lo largo de todo el

  4. A narrativa norte-americana e a Segunda Guerra Mundial

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    Tom Burns

    2005-06-01

    Full Text Available Neste artigo são discutidas as narrativas ficcionais e jornalísticas da Segunda Guerra Mundial no contexto de discórdia da sociedade norte-americana, que esteve dividida entre isolacionistas e intervencionistas durante os primeiros anos da guerra. A participação espontânea na guerra e a dúvida sobre uma percepção clara por que os homens lutavam têm sido questionadas por historiadores revisionistas. Era consenso geral, entanto, que a guerra era tanto justa como necessária. As questões políticas e sociais da guerra, como o totalitarismo, o racismo e outras formas de opressão, não são ignoradas pelas narrativas ficcionais sobre os combates. As narrativas jornalísticas e os filmes de Hollywood ocupam-se mais em mostrar o combatente como representante de valores americanos.

  5. Avocado (Persea americana) seed as a source of bioactive phytochemicals.

    Science.gov (United States)

    Dabas, Deepti; Shegog, Rachel M; Ziegler, Gregory R; Lambert, Joshua D

    2013-01-01

    The pulp of avocado (Persea americana, Lauraceae) has been reported to have beneficial cardiovascular health effects. Avocado oil is used for dermatological applications and its unsaponifiable portion is reported to have beneficial effects against osteoarthritis. Although the seed represents a considerable percentage of the total fruit, scientific research on the phytochemistry and biological effects of avocado seeds is in the nascent stages,. Currently, the seed represents an under-utilized resource and a waste issue for avocado processors. There is ethno-pharmacological information on the use of seeds for the treatment of health-related conditions, especially in South American countries where avocados are endemic and currently grown on a large scale. Current research has shown that avocado seeds may improve hypercholesterolemia, and be useful in the treatment of hypertension, inflammatory conditions and diabetes. Seeds have also been found to possess insecticidal, fungicidal, and anti-microbial activities. The avocado seeds and rich in phenolic compounds, and these may play a role in the putative health effects. Historically, extracts of avocado seeds were also used as ink for writing and research in our laboratory has explored the potential colorant properties of a polyphenol oxidase-produced colored avocado seed extract. Here, we review the currently-available data on the bioactivity and other functional properties of avocado seeds. We discuss the strength of the available data, the putative active compounds, and potential directions for future studies.

  6. Why are there few seedlings beneath the myrmecophyte Triplaris americana?

    Science.gov (United States)

    Larrea-Alcázar, Daniel M.; Simonetti, Javier A.

    2007-07-01

    We compared the relative importance of chemical alellopathy, pruning behaviour of resident ants and other non-related agents to ant-plant mutualism for seedling establishment beneath Triplaris americana L. (Polygonaceae), a myrmecophyte plant. We also included a preliminary analysis of effects of fragmentation on these ecological processes. Seeds and seedlings of Theobroma cacao L. (Sterculiaceae) were used as the target species in all experiments. Leaf-tissue extracts of the myrmecophyte plant did not inhibit germination of cacao seeds. Resident Pseudomyrmex triplarinus Weddell (Pseudomyrmecinae) ants did not remove seeds under the canopy of their host plants. The main seed consumer was the leaf-cutting ant Atta sexdens L. (Myrmicinae). Leaves of cacao seedlings were partially or totally pruned by Pseudomyrmex ants mainly in forest fragments studied. We offer evidence pointing to the possibility that the absence of seedlings beneath Triplaris may result from effects of both ant species. We discuss the benefits of pruning behaviour for the resident ant colony and the effects of ant-ant interactions on seedling establishment beneath this ant-plant system.

  7. Pequeno surto de leishmaniose tegumentar americana em Macuco (Cordeiro - RJ

    Directory of Open Access Journals (Sweden)

    Jacqueline A. Menezes

    1974-06-01

    Full Text Available Por ocasião de um pequeno surto de leishmaniose tegumentar americana em localidade do município de Cordeiro (RJ foram documentados 14 casos. Entre os fatos que chamaram a atenção dos autores estão a alta ocorrência em crianças (57%, a freqüência do componente linfangítico (40%, a tendência à cicatrização espontânea e a distribuição peri-domiciliar dos casos. Um inquérito pela intradermoreação de Montenegro na área de maior concentração de casos, realizado numa fazendo e numa escola, mostrou 17% de reações positivas, 17% de duvidosas e 66% de reações negativas, num total de 117 indivíduos testados. Não foram encontrados casos antigos cicatrizados, o que sugere um foco recente. Discute-se o significado das reações duvidosas.

  8. Protoplast-to-plant regeneration of American elm (Ulmus americana).

    Science.gov (United States)

    Jones, A M P; Shukla, M R; Biswas, G C G; Saxena, P K

    2015-05-01

    This study describes a protocol for regeneration of plants from cell suspension-derived protoplasts of American elm (Ulmus americana). Efficient protoplast isolation was achieved from a two-phase culture system through the incorporation of 100 μM 2-aminoindan-2-phosphonic acid, with a yield of approximately 2 × 10(6) protoplasts/ml packed cell volume. Isolated protoplasts failed to survive in liquid or alginate bead culture systems but initiated and continued to divide when embedded in low melting point agarose beads. Protoplast-derived callus proliferated and differentiated into shoot buds in response to 10 or 20 μM thidiazuron. Differentiated buds elongated and continued to proliferate on elm shoot medium supplemented with 3.0 μM GA3. The protoplast-derived shoots rooted and acclimatized to greenhouse conditions and continued to grow. This system provides the first protoplast-to-plant regeneration system for American elm and provides a framework for the development of protoplast fusion or genome editing technologies.

  9. Paul Strand y las paradojas de la modernidad americana

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    Vicente Sánchez Biosca

    2010-06-01

    Full Text Available As contribuições de Strand para o cinema estão estreitamente relacionadas com seus trabalhos fotográficos da época e mesmo com um olhar que, apesar de suas múltiplas diferenças, possui muitos pontos em comum. Se em Manhatta (1920, Strand (em colaboração com Sheeler oferece uma síntese da natureza e da modernidade, em Redes (1934 o que predomina, em contrapartida, é a experiência da arte muralista mexicana e a influência de Eisenstein (em suas andanças por México são os fatores que determinam seus esforços na construção de uma épica dos operários. Mas sem dúvida, o projeto mais ambicioso de Strand (ao mando da produtora Frontier Films foi Native Land, o filme que atendeu às demandas do American Popular Front e as moldou nas palavras dos fundadores da pátria americana.

  10. Primary integumentary allograft reactivity in the American cockroach, Periplaneta americana.

    Science.gov (United States)

    George, J F; Howcroft, T K; Karp, R D

    1987-04-01

    Previous reports have failed to demonstrate integumentary allograft rejection in insects. We realized however, that these studies may not have fully appreciated the structure of the insect exoskeleton. Since the subcuticlar epidermal layer constitutes the only living tissue associated with insect integument, its destruction would indicate that the animal recognized and responded to the foreign tissue. Thus, we investigated allograft reactivity in the American cockroach, Periplaneta americana, by observing the fate of the epidermal portion of the integument. Each animal in a pair received a 3 X 4-mm integumentary allograft from its partner, as well as a 3 X 4-mm control autograft. The transplants were then examined histologically for signs of epidermal destruction at 0, 1, 3, 5, 7, and 10-70 days (in 10-day increments) posttransplantation. The results indicated that significant rejection of the allografts began by day 3, with peak reactivity occurring by day 7 when 92% of the grafts were scored as rejected. At later periods (greater than 20 days), the graft sites showed signs of repopulation by host epidermal cells. The allograft reaction was found to lag behind the xenograft reaction, which showed peak activity after only 1 day posttransplantation. Even so, allograft rejection in this insect occurred quite rapidly (as compared with some other invertebrates), and would appear to be due to a cytotoxic reaction against the epidermal layer.

  11. Study of aquatic macrophytes in the wetlands on the territory of Vrachanski Balkan nature park

    Directory of Open Access Journals (Sweden)

    Valčev Vladimir V.

    2010-01-01

    Full Text Available An overall study of the species composition and abundance of macrophytes in all open water bodies of a large protected territory was made for the first time in Bulgaria. Four high-mountain eutrophic lakes and the upper stretches of three rivers within the boundaries of Vrachanski Balkan Nature Park were investigated. Thirty-nine macrophyte species (higher plants and mosses were identified scattered around, or forming more or less distinct vegetation groups. Three of the lakes are new for the country locations of the species Elatine alsinastrum and Peplis portula. The processes of eutrophication are more advanced in the lakes. The habitats formed around the investigated water bodies have been determined. They are three habitats of European Community interest for Bulgaria. The major threats for the investigated wetlands on the territory of the Park are pointed out.

  12. Cadmium and chromium removal kinetics from solution by two aquatic macrophytes.

    Science.gov (United States)

    Suñe, N; Sánchez, G; Caffaratti, S; Maine, M A

    2007-01-01

    The aim of this work was to determine chromium and cadmium bioaccumulation processes of two free-floating macrophytes commonly used in wetlands for water treatment: Salvinia herzogii and Pistia stratiotes. Metal removal from the solution involves two stages: a fast one and a slow one. The fast stage of the Cd uptake is significantly different for each species, while it is not significantly different in Cr uptake. The most important processes of Cd uptake are biological ones in S. herzogii and adsorption, chelation and ionic exchange are in P. stratiotes. The main processes of Cr uptake in both macrophytes are adsorption, chelation and ion exchange. The slow stage is different for each species and metal. Cr precipitation induced by roots occurs in P. stratiotes. Cr uptake through leaves is probably the main cause of the increase of Cr in the aerial parts of S. herzogii.

  13. Removal of nutrients and veterinary antibiotics from swine wastewater by a constructed macrophyte floating bed system.

    Science.gov (United States)

    Xian, Qiming; Hu, Lixia; Chen, Hancheng; Chang, Zhizhou; Zou, Huixian

    2010-12-01

    The potential of three varieties of Italian ryegrass (Lolium multiflorum Lam.), Dryan, Tachimasari and Waseyutaka, to improve the water quality of swine wastewater was evaluated using a constructed macrophyte floating bed system. With respect to reductions in levels of nutrients, chemical oxygen demand (COD), and sulfonamide antimicrobials (SAs, including sulfadiazine, sulfamethazine, and sulfamethoxazole), Dryan performed better than Tachimasari and Waseyutaka. For Dryan, total N was reduced by 84.0%, total P by 90.4%, COD by 83.4% and sulfonamide antimicrobials by 91.8-99.5%. Similar results were observed for Tachimasari and Waseyutaka. The results indicated that the treatment of swine wastewater using the constructed macrophyte floating bed system was effective in the removal of nutrients and veterinary antibiotics.

  14. Aquatic macrophytes from Danube Delta lagoons Musura Bay and Zatonul Mare

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    Sava D.,

    2016-05-01

    Full Text Available The Romanian Danube Delta, a unique, young and continuing to grow region situated in the eastern part of Europe, is the largest continuous marshland and the second largest delta on the continent, and also a favorable place for developing a unique flora and fauna in Europe, with many rare and protected species. The predominance of the aquatic environment, led to the existence of a particular macrophytic flora. In this context, the purpose of this paper is to contribute to the study of aquatic macrophytes. The present study took place over two years, between 2013-2014, and in each year a number of expeditions were made in the two lagoons (Musura Bay and Zătonul Mare in different seasons, in order to observe the diverse flora, because, due to seasonal variation in water quality, there might be a significantly seasonality of the vegetation also.

  15. Dispersal of invasive Phytolacca americana seeds by birds in an urban garden in China.

    Science.gov (United States)

    Li, Ning; Yang, Wen; Fang, Shubo; Li, Xinhai; Liu, Zhanchen; Leng, Xin; An, Shuqing

    2017-01-01

    Although seed dispersal is a key process determining the regeneration and spread of invasive plant populations, few studies have explicitly addressed the link between dispersal vector behavior and seedling recruitment to gain insight into the invasion process within an urban garden context. We evaluated the role of bird vectors in the dispersal of pokeweed (Phytolacca americana), a North American herb that is invasive in urban gardens in China. Fruiting P. americana attracted both generalist and specialist bird species that fed on and dispersed its seeds. The generalist species Pycnonotus sinensis and Urocissa erythrorhyncha were the most frequent dispersers. Seedling numbers of P. americana were strongly associated with the perching behavior of frugivorous birds. If newly recruited bird species use seedling-safe perching sites, the P. americana will regenerate faster, which would enhance its invasive potential. Based on our observations, we conclude that the 2 main bird vectors, P. sinensis and U. erythrorhyncha, provide potential effective dispersal agents for P. americana. Our results highlight the role of native birds in seed dispersal of invasive plants in urban gardens.

  16. Susceptibility of Porphyromonas gingivalis and Streptococcus mutans to Antibacterial Effect from Mammea americana

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    Alejandra Herrera Herrera

    2014-01-01

    Full Text Available The development of periodontal disease and dental caries is influenced by several factors, such as microorganisms of bacterial biofilm or commensal bacteria in the mouth. These microorganisms trigger inflammatory and immune responses in the host. Currently, medicinal plants are treatment options for these oral diseases. Mammea americana extracts have reported antimicrobial effects against several microorganisms. Nevertheless, this effect is unknown against oral bacteria. Therefore, the aim of this study was to evaluate the antibacterial effect of M. americana extract against Porphyromonas gingivalis and Streptococcus mutans. For this, an experimental study was conducted. Ethanolic extract was obtained from seeds of M. americana (one oil phase and one ethanolic phase. The strains of Porphyromonas gingivalis ATCC 33277 and Streptococcus mutans ATCC 25175 were exposed to this extract to evaluate its antibacterial effect. Antibacterial activity was observed with the two phases of M. americana extract on P. gingivalis and S. mutans with lower MICs (minimum inhibitory concentration. Also, bactericidal and bacteriostatic activity was detected against S. mutans, depending on the concentration of the extract, while on M. americana extract presented only bacteriostatic activity against P. gingivalis. These findings provide important and promising information allowing for further exploration in the future.

  17. Preparation of Eleutherine americana-Alginate Complex Microcapsules and Application in Bifidobacterium longum

    Science.gov (United States)

    Phoem, Atchara N; Chanthachum, Suphitchaya; Voravuthikunchai, Supayang P

    2015-01-01

    Microencapsulation using extrusion and emulsion techniques was prepared for Bifidobacterium longum protection against sequential exposure to simulated gastric and intestinal juices, refrigeration storage and heat treatment. Eleutherine americana was used as the co-encapsulating agent. Hydrolysis of E. americana by gastric and intestinal juices was also determined. E. americana and its oligosaccharide extract demonstrated their resistance to low pH and partial tolerance to human α-amylase. Microencapsulated B. longum with E. americana and oligosaccharide extract prepared by the extrusion technique survived better than that by the emulsion technique under adverse conditions. Survival of microencapsulated cells after exposure to the juices and refrigeration storage was higher than free cells at Weeks 2 and 4. In addition, the viability of microencapsulated cells was better than free cells at 65 °C for 15 min. This work suggested that microencapsulated B. longum with E. americana offers the effective delivery of probiotics to colon and maintains their survival in food products. PMID:25629556

  18. Relationships of bradyrhizobia from the legumes Apios americana and Desmodium glutinosum.

    Science.gov (United States)

    Parker, M A

    1999-11-01

    Multilocus enzyme electrophoresis, partial 23S rRNA sequences, and nearly full-length 16S rRNA sequences all indicated high genetic similarity among root-nodule bacteria associated with Apios americana, Desmodium glutinosum, and Amphicarpaea bracteata, three common herbaceous legumes whose native geographic ranges in eastern North America overlap extensively. A total of 19 distinct multilocus genotypes (electrophoretic types [ETs]) were found among the 35 A. americana and 33 D. glutinosum isolates analyzed. Twelve of these ETs (representing 78% of all isolates) were either identical to ETs previously observed in A. bracteata populations, or differed at only one locus. Within both 23S and 16S rRNA genes, several isolates from A. americana and D. glutinosum were either identical to A. bracteata isolates or showed only single nucleotide differences. Growth rates and nitrogenase activities of A. bracteata plants inoculated with isolates from D. glutinosum were equivalent to levels found with native A. bracteata bacterial isolates, but none of the three A. americana isolates tested had high symbiotic effectiveness on A. bracteata. Phylogenetic analysis of both 23S and 16S rRNA sequences indicated that both A. americana and D. glutinosum harbored rare bacterial genotypes similar to Bradyrhizobium japonicum USDA 110. However, the predominant root nodule bacteria on both legumes were closely related to Bradyrhizobium elkanii.

  19. Polyphenols with algicidal activity in the submerged macrophyte Myriophyllum Spicatum L.

    OpenAIRE

    Gross, Elisabeth; Sütfeld, Rainer

    1994-01-01

    The role of phenols as defence mechanisms in various terrestrial plants is well studied. However, in aquatic environments, they are probably involved also in the chemical interactions between species. A periodic shift from dominance by submerged macrophytes to dominance by phytoplankton and vice versa without apparent change in the external nutrient loading is sometimes observed in shallow eutrophic lakes. Due to the fact that nutrient levels are not usually limiting to phytoplankton growth, ...

  20. Comparability of river quality assessment using macrophytes: a multi-step procedure to overcome biogeographical differences.

    Science.gov (United States)

    Aguiar, F C; Segurado, P; Urbanič, G; Cambra, J; Chauvin, C; Ciadamidaro, S; Dörflinger, G; Ferreira, J; Germ, M; Manolaki, P; Minciardi, M R; Munné, A; Papastergiadou, E; Ferreira, M T

    2014-04-01

    This paper exposes a new methodological approach to solve the problem of intercalibrating river quality national methods when a common metric is lacking and most of the countries share the same Water Framework Directive (WFD) assessment method. We provide recommendations for similar works in future concerning the assessment of ecological accuracy and highlight the importance of a good common ground to make feasible the scientific work beyond the intercalibration. The approach herein presented was applied to highly seasonal rivers of the Mediterranean Geographical Intercalibration Group for the Biological Quality Element Macrophytes. The Mediterranean Group of river macrophytes involved seven countries and two assessment methods with similar acquisition data and assessment concept: the Macrophyte Biological Index for Rivers (IBMR) for Cyprus, France, Greece, Italy, Portugal and Spain, and the River Macrophyte Index (RMI) for Slovenia. Database included 318 sites of which 78 were considered as benchmarks. The boundary harmonization was performed for common WFD-assessment methods (all countries except Slovenia) using the median of the Good/Moderate and High/Good boundaries of all countries. Then, whenever possible, the Slovenian method, RMI was computed for the entire database. The IBMR was also computed for the Slovenian sites and was regressed against RMI in order to check the relatedness of methods (R(2)=0.45; p<0.00001) and to convert RMI boundaries into the IBMR scale. The boundary bias of RMI was computed using direct comparison of classification and the median boundary values following boundary harmonization. The average absolute class differences after harmonization is 26% and the percentage of classifications differing by half of a quality class is also small (16.4%). This multi-step approach to the intercalibration was endorsed by the WFD Regulatory Committee. © 2013 Elsevier B.V. All rights reserved.

  1. Aquiatic macrophytes in Doñana protected area (SW Spain).

    OpenAIRE

    García Murillo, Pablo; Fernández Zamudio, María del Rosario; Cirujano Bracamonte, Santos; Sousa Martín, Arturo

    2006-01-01

    A big portion of the Doñana protected areas corresponds to wetlands; in them aquatic macrophytes are the main primary producers and play also other important ecological functions. Nevertheless, they are inconspicuous organisms and their importance in these ecosystems does not seem to be well reflected in the bibliography about this natural area. This paper reviews the most significant information gathered about this group of organisms in this protected area, provides an updated catal...

  2. Native macrophyte density and richness affect the invasiveness of a tropical poaceae species.

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    Thaisa S Michelan

    Full Text Available The role of the native species richness and density in ecosystem invasibility is a matter of concern for both ecologists and managers. We tested the hypothesis that the invasiveness of Urochloa arrecta (non-native in the Neotropics is negatively affected by the species richness and abundance of native aquatic macrophytes in freshwater ecosystems. We first created four levels of macrophyte richness in a greenhouse (richness experiment, and we then manipulated the densities of the same native species in a second experiment (density experiment. When the native macrophytes were adults, fragments of U. arrecta were added, and their growth was assessed. Our results from the richness experiment corroborated the hypothesis of a negative relationship between the native species richness and the growth of U. arrecta, as measured by sprout length and root biomass. However, the resistance to invasion was not attributed to the presence of a particular native species with a greater competitive ability. In the density experiment, U. arrecta growth decreased significantly with an increased density of all five of the native species. Density strongly affected the performance of the Poaceae in a negative manner, suggesting that patches that are densely colonized by native macrophytes and less subject to disturbances will be more resistant to invasion than those that are poorly colonized and more commonly subjected to disturbances. Our density experiment also showed that some species exhibit a higher competitive ability than others (sampling effect. Although native richness and abundance clearly limit the colonization and establishment of U. arrecta, these factors cannot completely prevent the invasion of aquatic ecosystems by this Poaceae species.

  3. Native macrophyte density and richness affect the invasiveness of a tropical poaceae species.

    Science.gov (United States)

    Michelan, Thaisa S; Thomaz, Sidinei M; Bini, Luis M

    2013-01-01

    The role of the native species richness and density in ecosystem invasibility is a matter of concern for both ecologists and managers. We tested the hypothesis that the invasiveness of Urochloa arrecta (non-native in the Neotropics) is negatively affected by the species richness and abundance of native aquatic macrophytes in freshwater ecosystems. We first created four levels of macrophyte richness in a greenhouse (richness experiment), and we then manipulated the densities of the same native species in a second experiment (density experiment). When the native macrophytes were adults, fragments of U. arrecta were added, and their growth was assessed. Our results from the richness experiment corroborated the hypothesis of a negative relationship between the native species richness and the growth of U. arrecta, as measured by sprout length and root biomass. However, the resistance to invasion was not attributed to the presence of a particular native species with a greater competitive ability. In the density experiment, U. arrecta growth decreased significantly with an increased density of all five of the native species. Density strongly affected the performance of the Poaceae in a negative manner, suggesting that patches that are densely colonized by native macrophytes and less subject to disturbances will be more resistant to invasion than those that are poorly colonized and more commonly subjected to disturbances. Our density experiment also showed that some species exhibit a higher competitive ability than others (sampling effect). Although native richness and abundance clearly limit the colonization and establishment of U. arrecta, these factors cannot completely prevent the invasion of aquatic ecosystems by this Poaceae species.

  4. COMPARISON OF METHODS TO DETECT ALLELOPATHIC EFFECTS OF SUBMERGED MACROPHYTES ON GREEN ALGAE(1).

    Science.gov (United States)

    Hilt Nee Körner, Sabine; Beutler, Eike; Bauer, Nadine

    2012-02-01

    Detecting allelopathic inhibition of phytoplankton by submerged macrophytes in an ecologically meaningful way is not easy. Multiple-approach investigations from a laboratory scale to the ecosystem level have been recommended to overcome the shortcomings of individual methods. Whether results of different methods are qualitatively or quantitatively comparable has not yet been tested. Here, we compare the sensitivity of the green algae Desmodesmus subspicatus (Chodat) E. Hegewald et Ant. Schmidt and Stigeoclonium helveticum Vischer to the allelopathic effect of the submerged macrophyte Myriophyllum verticillatum L. The following three approaches were used: (i) coincubation of algae in dialysis membrane tubes in a lake inside and outside a M. verticillatum stand, (ii) coincubation of algae in dialysis membrane tubes in aquaria with and without M. verticillatum, and (iii) single additions of tannic acid (TA), an allelopathically active polyphenol present in this macrophyte, to the algae cultures. For each method, fluorescence-based (chl a, PSII activity) and particle-based (cell count, biovolume) parameters were compared after 48 h of incubation. Results revealed quantitative and qualitative differences between methods. Algae incubated in dialysis membrane tubes in aquaria showed a strong decrease in all parameters under the influence of macrophytes. In situ measurements were influenced by adverse growth conditions for the test algae and only detected significant reductions for biovolume. Single additions of TA induced a strong reduction of fluorescence-based parameters similar to aquarium results, but an increase in the cell count. Even the qualitative transfer of laboratory results to field conditions thus requires caution and a proper selection of parameters.

  5. Ocean Acidification Differentially Affects the Photosynthesis of Key New England Macrophytes

    Science.gov (United States)

    Fachon, E.; Ets-Hokin, J. M.; Donham, E. M.; Price, N.

    2016-02-01

    While the influence of anthropogenic CO2 emissions on seawater chemistry is detrimental to calcification among CaCO3 reliant organisms such as commercially important shellfish species, non-calcareous macrophytes like seagrasses and seaweeds can experience enhanced growth under elevated pCO2 conditions and may be a substantial, if ephemeral, CO2 sink. Most marine macrophytes rely on enzyme conversion of HCO3- to supply the inorganic carbon necessary for photosynthesis; the ability to down-regulate this energetically expensive carbon acquisition under high pCO2 conditions could determine future species success. We exposed four commercially and ecologically relevant New England macrophytes (Saccharina latissima, Fucus vesiculosus, Ulva lactuca, and Zostera marina) to pre-industrial (280 uatm), present (400 and 520 utam - recorded in Casco Bay) and future (640, 880 and 1120 uatm - as predicted by the IPCC) pCO2 levels in 1.5 hr long respirometry assays after 72 hrs acclimation. CO2 consumption, photosynthetic quotient (Q = CO2 consumed:O2 evolved), and change in carbonate saturation state (Ωcalcite) were calculated for each sample using differences in initial and final carbonate chemistry and dissolved oxygen concentrations. All species experienced increases in rate of CO2 uptake and Q under elevated pCO2 treatments, but response level differed across species. Saccharina latissima had the greatest relative effect on all parameters measured, consuming 4 times more carbon at high pCO2 levels than the lowest performing species. While all macrophytes were able to raise Ωcalcite, the magnitude of change decreased at higher pCO2 levels, suggesting a limitation to the degree to which photosynthesis can locally raise calcification potential for sensitive native or farmed populations of shellfish in the future. The varied responses observed across species have implications for future community structures and for phytoremediation efforts.

  6. Do Amplitudes of Water Level Fluctuations Affect the Growth and Community Structure of Submerged Macrophytes?

    Science.gov (United States)

    Wang, Mo-Zhu; Liu, Zheng-Yuan; Luo, Fang-Li; Lei, Guang-Chun; Li, Hong-Li

    2016-01-01

    Submerged macrophytes are subjected to potential mechanical stresses associated with fluctuating water levels in natural conditions. However, few experimental studies have been conducted to further understand the effects of water level fluctuating amplitude on submerged macrophyte species and their assemblages or communities. We designed a controlled experiment to investigate the responses of three submerged macrophyte species (Hydrilla verticillata, Ceratophyllum demersum and Elodea nuttallii) and their combinations in communities to three amplitudes (static, ± 30 cm, ± 60 cm) of water level fluctuations. Results showed that water level fluctuating amplitude had little effects on the community performance and the three tested species responded differently. H. verticillata exhibited more growth in static water and it was negatively affected by either of the water level fluctuations amplitude, however, growth parameters of H. verticillata in two fluctuating water level treatments (i.e., ± 30 cm, ± 60 cm) were not significantly different. On the other hand, the growth of C. demersum was not significantly correlated with different amplitude treatments. However, it became more abundant when water levels fluctuated. E. nuttallii was inhibited by the two fluctuating water level treatments, and was less in growth parameters compared to the other species especially in water level fluctuating conditions. The inherent differences in the adaptive capabilities of the tested species indicate that C. demersum or other species with similar responses may be dominant species to restore submerged macrophyte communities with great fluctuating water levels. Otherwise, H. verticillata, E. nuttallii or other species with similar responses could be considered for constructing the community in static water conditions.

  7. Toxicity of Zinc on Growth of an Aquatic Macrophyte, Ipomoea Aquatica Forsk

    OpenAIRE

    Laitonjam Bedabati Chanu; Abhik Gupta

    2016-01-01

    The effects of different concentrations of Zn on growth of an aquatic macrophyte, Ipomoea aquatica Forsk. were studied. Fresh weight, dry weight, shoot length, root length, number of nodes, development of leaves, and chlorophyll and carotene contents were the different growth parameters considered. Toxicity symptoms like browning and decaying of roots could be observed in plants treated at 22.7 mg L-1 Zn as early as 3rd day of experiment while yellowing of older leaves appeared during the lat...

  8. Macrophytes of the Grlište reservoir (Serbia): Fifteen years after its establishment

    OpenAIRE

    Stanković Ž.; Borišev M.; Simić Slobodanka; Vučković Milijana; Igić Ružica; Vidović Milka; Miljanović B.

    2009-01-01

    A large number of macrophytes, often in dense populations, have developed on the Grlište Reservoir, Serbia over a period of 15 years. Fast development of vegetation is a consequence of anthropogenic impact in lake management. The methodology used in this research covered 100% of the water body, including all areas with or without aquatic plants. The results indicate that plant communities are still in the early phase of development. This leaves space for future development of competitor macro...

  9. Study on Flowering, Cultivation, and Reproduction of Agave americana Var. Marginata Hort. (Agavaceae)%Study on Flowering, Cultivation, and Reproduction of Agave americana Var. Marginata Hort. (Agavaceae)

    Institute of Scientific and Technical Information of China (English)

    Fangnong LIU; Shicheng PENG; Lianren LIU

    2012-01-01

    Agave americana Var. Marginata Hort. (Agavaceae) is a perennial herb. This paper summarized its classification, distribution, morphological characteristics, habit, flowering and fruiting, cultivation and reproduction, as well as multiple uses in daily life, which provided references for the exploitation and utilization of Agave americana Vat. Marginata Hort. (Agavaceae).

  10. Cellulase and xylanase activity during the decomposition of three aquatic macrophytes in a tropical oxbow lagoon

    Directory of Open Access Journals (Sweden)

    L Sciessere

    2011-09-01

    Full Text Available Due to the connection between enzymatic activity and degradation of different fractions of organic matter, enzyme assays can be used to estimate degradation rates of particulate and dissolved organic carbon in freshwater systems. The aim of this study was to quantify and model the enzymatic degradation involving the decomposition of macrophytes, describing temporal activity of cellulases (EC 3.2.1.4 and EC 3.2.1.91 and xylanase (EC 3.2.1.8 during in situ decomposition of three aquatic macrophytes (Salvinia sp., Eichhornia azurea and Cyperus giganteus on the surface and water-sediment interface (w-s interface of an oxbow lagoon (Óleo lagoon within a natural Brazilian Savanna Reserve. Overall, the enzymatic degradation of aquatic macrophytes in Óleo lagoon occurred during the whole year and was initiated together with leaching. Xylanase production was ca. 5 times higher than cellulase values due to easy access to this compound by cellulolytic microorganisms. Enzymatic production and detritus mass decay were similar on the surface and w-s interface. Salvinia sp. was the most recalcitrant detritus, with low mass decay and enzymatic activity. E. azurea and C. giganteus decomposition rates and enzymatic production were high and similar. Due to the physicochemical homogeneity observed in the Óleo lagoon, the differences between the decay rates of each species are mostly related with detritus chemical quality.

  11. Kinetics of Cr(III) and Cr(VI) removal from water by two floating macrophytes.

    Science.gov (United States)

    Maine, M A; Hadad, H R; Sánchez, G; Caffaratti, S; Pedro, M C

    2016-01-01

    The aim of this work was to compare Cr(III) and Cr(VI) removal kinetics from water by Pistia stratiotes and Salvinia herzogii. The accumulation in plant tissues and the effects of both Cr forms on plant growth were also evaluated. Plants were exposed to 2 and 6 mg L(-1) of Cr(III) or Cr(VI) during 30 days. At the end of the experiment, Cr(VI) removal percentages were significantly lower than those obtained for Cr(III) for both macrophytes. Cr(III) removal kinetics involved a fast and a slow component. The fast component was primarily responsible for Cr(III) removal while Cr(VI) removal kinetics involved only a slow process. Cr accumulated principally in the roots. In the Cr(VI) treatments a higher translocation from roots to aerial parts than in Cr(III) treatments was observed. Both macrophytes demonstrated a high ability to remove Cr(III) but not Cr(VI). Cr(III) inhibited the growth at the highest studied concentration of both macrophytes while Cr(VI) caused senescence. These results have important implications in the use of constructed wetlands for secondary industrial wastewater treatment. Common primary treatments of effluents containing Cr(VI) consists in its reduction to Cr(III). Cr(III) concentrations in these effluents are normally below the highest studied concentrations in this work.

  12. Assessment of the Potential Biological Activity of Low Molecular Weight Metabolites of Freshwater Macrophytes with QSAR

    Directory of Open Access Journals (Sweden)

    Evgeny A. Kurashov

    2016-01-01

    Full Text Available The paper focuses on the assessment of the spectrum of biological activities (antineoplastic, anti-inflammatory, antifungal, and antibacterial with PASS (Prediction of Activity Spectra for Substances for the major components of three macrophytes widespread in the Holarctic species of freshwater, emergent macrophyte with floating leaves, Nuphar lutea (L. Sm., and two species of submergent macrophyte groups, Ceratophyllum demersum L. and Potamogeton obtusifolius (Mert. et Koch, for the discovery of their ecological and pharmacological potential. The predicted probability of anti-inflammatory or antineoplastic activities above 0.8 was observed for twenty compounds. The same compounds were also characterized by high probability of antifungal and antibacterial activity. Six metabolites, namely, hexanal, pentadecanal, tetradecanoic acid, dibutyl phthalate, hexadecanoic acid, and manool, were a part of the major components of all three studied plants, indicating their high ecological significance and a certain universalism in their use by various species of water plants for the implementation of ecological and biochemical functions. This report underlines the role of identified compounds not only as important components in regulation of biochemical and metabolic pathways and processes in aquatic ecological systems, but also as potential pharmacological agents in the fight against different diseases.

  13. Assessment of the Potential Biological Activity of Low Molecular Weight Metabolites of Freshwater Macrophytes with QSAR.

    Science.gov (United States)

    Kurashov, Evgeny A; Fedorova, Elena V; Krylova, Julia V; Mitrukova, Galina G

    2016-01-01

    The paper focuses on the assessment of the spectrum of biological activities (antineoplastic, anti-inflammatory, antifungal, and antibacterial) with PASS (Prediction of Activity Spectra for Substances) for the major components of three macrophytes widespread in the Holarctic species of freshwater, emergent macrophyte with floating leaves, Nuphar lutea (L.) Sm., and two species of submergent macrophyte groups, Ceratophyllum demersum L. and Potamogeton obtusifolius (Mert. et Koch), for the discovery of their ecological and pharmacological potential. The predicted probability of anti-inflammatory or antineoplastic activities above 0.8 was observed for twenty compounds. The same compounds were also characterized by high probability of antifungal and antibacterial activity. Six metabolites, namely, hexanal, pentadecanal, tetradecanoic acid, dibutyl phthalate, hexadecanoic acid, and manool, were a part of the major components of all three studied plants, indicating their high ecological significance and a certain universalism in their use by various species of water plants for the implementation of ecological and biochemical functions. This report underlines the role of identified compounds not only as important components in regulation of biochemical and metabolic pathways and processes in aquatic ecological systems, but also as potential pharmacological agents in the fight against different diseases.

  14. Cadmium and chromium removal kinetics from solution by two aquatic macrophytes

    Energy Technology Data Exchange (ETDEWEB)

    Sune, N. [Quimica Analitica-Facultad de Ingenieria Quimica, Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), U.N.L. Sgo del Estero 2829, 3000 Santa Fe (Argentina); Sanchez, G. [Quimica Analitica-Facultad de Ingenieria Quimica, Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), U.N.L. Sgo del Estero 2829, 3000 Santa Fe (Argentina); Caffaratti, S. [Quimica Analitica-Facultad de Ingenieria Quimica, Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), U.N.L. Sgo del Estero 2829, 3000 Santa Fe (Argentina); Maine, M.A. [Quimica Analitica-Facultad de Ingenieria Quimica, Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), U.N.L. Sgo del Estero 2829, 3000 Santa Fe (Argentina)]. E-mail: amaine@fiqus.unl.edu.ar

    2007-01-15

    The aim of this work was to determine chromium and cadmium bioaccumulation processes of two free-floating macrophytes commonly used in wetlands for water treatment: Salvinia herzogii and Pistia stratiotes. Metal removal from the solution involves two stages: a fast one and a slow one. The fast stage of the Cd uptake is significantly different for each species, while it is not significantly different in Cr uptake. The most important processes of Cd uptake are biological ones in S. herzogii and adsorption, chelation and ionic exchange are in P. stratiotes. The main processes of Cr uptake in both macrophytes are adsorption, chelation and ion exchange. The slow stage is different for each species and metal. Cr precipitation induced by roots occurs in P. stratiotes. Cr uptake through leaves is probably the main cause of the increase of Cr in the aerial parts of S. herzogii. - Cd uptake processes are biological processes in S. herzogii and adsorption, chelation and ionic exchange are in P. stratiotes, whereas Cr uptake processes in both macrophytes are adsorption, chelation and ion exchange.

  15. Assessment of the Potential Biological Activity of Low Molecular Weight Metabolites of Freshwater Macrophytes with QSAR

    Science.gov (United States)

    Fedorova, Elena V.; Krylova, Julia V.

    2016-01-01

    The paper focuses on the assessment of the spectrum of biological activities (antineoplastic, anti-inflammatory, antifungal, and antibacterial) with PASS (Prediction of Activity Spectra for Substances) for the major components of three macrophytes widespread in the Holarctic species of freshwater, emergent macrophyte with floating leaves, Nuphar lutea (L.) Sm., and two species of submergent macrophyte groups, Ceratophyllum demersum L. and Potamogeton obtusifolius (Mert. et Koch), for the discovery of their ecological and pharmacological potential. The predicted probability of anti-inflammatory or antineoplastic activities above 0.8 was observed for twenty compounds. The same compounds were also characterized by high probability of antifungal and antibacterial activity. Six metabolites, namely, hexanal, pentadecanal, tetradecanoic acid, dibutyl phthalate, hexadecanoic acid, and manool, were a part of the major components of all three studied plants, indicating their high ecological significance and a certain universalism in their use by various species of water plants for the implementation of ecological and biochemical functions. This report underlines the role of identified compounds not only as important components in regulation of biochemical and metabolic pathways and processes in aquatic ecological systems, but also as potential pharmacological agents in the fight against different diseases. PMID:27200207

  16. Microbial communities in marine sediments modify success of an invasive macrophyte.

    Science.gov (United States)

    Gribben, Paul E; Nielsen, Shaun; Seymour, Justin R; Bradley, Daniel J; West, Matthew N; Thomas, Torsten

    2017-08-29

    Invasive plants have extensive impacts on ecosystem function and biodiversity globally. Our inability to manage invasive species stems in part from a lack of understanding of the processes that control their successful establishment and spread. To date, studies have largely considered how above-ground processes control native/invasive plant interactions. Emerging research from terrestrial and wetland ecosystems demonstrates that below-ground processes under microbial control can determine the outcome of interactions between native and invasive plants. Whether sediment microbes modify the success of invasive macrophytes in marine ecosystems is untested, despite marine sediment microbes controlling many ecological processes (e.g. nutrient cycling) comparable to those in terrestrial ecosystems. We first show that sediment bacterial communities differ between the native seagrass Zostera capricorni and the invasive alga Caulerpa taxifolia and that those differences relate to functional changes in sulfur cycling between the macrophytes. Second, by experimentally manipulating the microbial communities we show that intact microbial communities in Z. capricorni sediments provide biotic resistance by reducing C. taxifolia fragment growth 119% compared to when they are inactive, and intact microbial communities in C. taxifolia sediments have positive feedbacks by increasing fragment growth 200%. Thus, similar to terrestrial ecosystems, microorganisms appear to indirectly control the success of invasive macrophytes in marine ecosystems.

  17. Habitat selection by three littoral zone fishes: effects of predation pressure, plant density and macrophyte type

    Science.gov (United States)

    Chick, J.H.; McIvor, C.C.

    1997-01-01

    We conducted laboratory experiments which demonstrated that three littoral zone fishes differentially selected among three macrophytes when seeking refuge from predation. In the presence of a predator (a juvenile Micropterus salmoides), mosquitofish (Gambusia holbrooki), sailfin mollies (Poecilia latipinna). and dollar sunfish (Lepomis marginatus) displayed ferential use of four tank areas containing patches of either Hydrilla verticillata, Potamogeton illinoensis, Panicum hemitomon, or no plants. Patterns habitat selection, and the consistency of these patterns among replicates, differed among the three fishes and among three plant-density treatments - natural (each macrophyte presented at its mean field density), equal (all three macrophytes at the same density), and control (no plants). Selection for H. verticillata by mosquitofish was significant for both the equal and natural treatments, and thus was not caused by differences in plant density alone. Sailfin mollies displayed significant selection for H. verticillata only in the natural plant-density treatments. Dollar sunfish showed less consistent habitat selection than either mosquitofish or sailfin mollies. Significant habitat selection was not found in the absence of a predator, and there was no evidence for lection among the tank areas in control treatments. Patterns of habitat selection by the three fishes in our laboratory study corresponded to observed habitat use in Lake Okeechobee.

  18. An invasion risk map for non-native aquatic macrophytes of the Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    Argantonio Rodríguez-Merino

    2017-05-01

    Full Text Available Freshwater systems are particularly susceptible to non-native organisms, owing to their high sensitivity to the impacts that are caused by these organisms. Species distribution models, which are based on both environmental and socio-economic variables, facilitate the identification of the most vulnerable areas for the spread of non-native species. We used MaxEnt to predict the potential distribution of 20 non-native aquatic macrophytes in the Iberian Peninsula. Some selected variables, such as the temperature seasonality and the precipitation in the driest quarter, highlight the importance of the climate on their distribution. Notably, the human influence in the territory appears as a key variable in the distribution of studied species. The model discriminated between favorable and unfavorable areas with high accuracy. We used the model to build an invasion risk map of aquatic macrophytes for the Iberian Peninsula that included results from 20 individual models. It showed that the most vulnerable areas are located near to the sea, the major rivers basins, and the high population density areas. These facts suggest the importance of the human impact on the colonization and distribution of non-native aquatic macrophytes in the Iberian Peninsula, and more precisely agricultural development during the Green Revolution at the end of the 70’s. Our work also emphasizes the utility of species distribution models for the prevention and management of biological invasions.

  19. Leishmaniose tegumentar americana no Estado do Acre, Brasil

    Directory of Open Access Journals (Sweden)

    Silva Natal S da

    1999-01-01

    Full Text Available OBJETIVO: Apresentar levantamento estatístico descritivo da leishmaniose tegumentar americana (LTA no Estado do Acre. MÉTODOS: Os dados obtidos foram extraídos dos formulários da "Campanha Contra a Leishmaniose", no período de janeiro de 1992 a dezembro de 1997. As variáveis estudadas foram submetidas a análise estatística descritiva. RESULTADOS: O total de casos registrados foi de 2.557. Foi adotada a divisão do Acre em meso e microrregiões para apresentação dos resultados. A maior prevalência foi na microrregião de Brasiléia (231,8 casos/10.000 hab.. A forma clínica predominante foi cutânea (84,05%. A maior ocorrência foi no sexo masculino (71,02%. Portadores com idade de até 24 anos corresponderam a 50% dos casos. Há uma predominância nas ocupações rurais. O exame clínico foi usado para diagnosticar 83,97% dos casos. A maior média de tempo de espera para procurar tratamento médico foi registrada na mesorregião do Vale do Juruá (10,37 meses. CONCLUSÃO: Os altos índices de LTA cutâneo e cutâneo-mucosa encontrados sugerem a necessidade de serem feitas pesquisas sobre os reflexos psicossociais e para identificar fatores que influem na demora do tratamento dos casos.

  20. Fecal corticoid monitoring in whooping cranes (Grus americana) undergoing reintroduction

    Science.gov (United States)

    Hartup, Barry K.; Olsen, Glenn H.; Czekala, Nancy M.

    2005-01-01

    We used radioimmunoassay to determine fecal corticoid concentrations and assess potential stress in 10 endangered whooping cranes (Grus americana) undergoing reintroduction to the wild. Fecal samples were collected shortly after hatching at a captive facility in Maryland, during field training in Wisconsin, and throughout a human-led migration to Florida. After a 14-day decline following hatching, fecal corticoid concentrations stabilized at baseline levels for the duration of the captive period, despite exposure to potentially stressful stimuli. Shipment of the cranes to the field training site was correlated with an eight- to 34-fold increase in fecal corticoid concentrations, which returned to baseline levels within 1 week. Increases were positively correlated with age but not body weight at the time of shipping. Fecal corticoid concentrations during the training period increased slightly and exhibited greater variation than levels observed at the captive facility, but were well within expected norms based on previous studies. Fecal corticoid concentrations increased twofold following premigration physical examinations and placement of radiotransmitters, and persisted for up to 4 days before they returned to baseline levels. Though fecal corticoid concentrations and variation during the migration period were similar to training levels, there was an overall decline in fecal corticoid concentrations during the artificial migration. Acute stressors, such as capture, restraint, and severe storms, were associated with stress responses by the cranes that varied in accordance with lasting physical or psychological stimuli. The overall reintroduction process of costume-rearing, ultralight aircraft habituation, training, and artificial migration was not associated with elevations in fecal corticoid concentrations suggestive of chronic stress.

  1. Cardiovascular effects of Persea americana Mill (Lauraceae) (avocado) aqueous leaf extract in experimental animals.

    Science.gov (United States)

    Ojewole, J A O; Kamadyaapa, D R; Gondwe, M M; Moodley, K; Musabayane, C T

    2007-01-01

    The cardiovascular effects of Persea americana Mill (Lauraceae) aqueous leaf extract (PAE) have been investigated in some experimental animal paradigms. The effects of PAE on myocardial contractile performance was evaluated on guinea pig isolated atrial muscle strips, while the vasodilatory effects of the plant extract were examined on isolated portal veins and thoracic aortic rings of healthy normal Wistar rats in vitro. The hypotensive (antihypertensive) effect of the plant extract was examined in healthy normotensive and hypertensive Dahl salt-sensitive rats in vivo. P americana aqueous leaf extract (25-800 mg/ml) produced concentration-dependent, significant (p americana leaf could be used as a natural supplementary remedy in essential hypertension and certain cases of cardiac dysfunctions in some rural Africa communities.

  2. Anticonvulsant effect of Persea americana Mill (Lauraceae) (Avocado) leaf aqueous extract in mice.

    Science.gov (United States)

    Ojewole, John A O; Amabeoku, George J

    2006-08-01

    Various morphological parts of Persea americana Mill (Lauraceae) (avocado) are widely used in African traditional medicines for the treatment, management and/or control of a variety of human ailments, including childhood convulsions and epilepsy. This study examined the anticonvulsant effect of the plant's leaf aqueous extract (PAE, 50-800 mg/kg i.p.) against pentylenetetrazole (PTZ)-, picrotoxin (PCT)- and bicuculline (BCL)-induced seizures in mice. Phenobarbitone and diazepam were used as reference anticonvulsant drugs for comparison. Like the reference anticonvulsant agents used, Persea americana leaf aqueous extract (PAE, 100-800 mg/kg i.p.) significantly (p Persea americana leaf aqueous extract possesses an anticonvulsant property, and thus lends pharmacological credence to the suggested ethnomedical uses of the plant in the management of childhood convulsions and epilepsy.

  3. Orchidaceae Americanae Orchidaceae Americanae

    Directory of Open Access Journals (Sweden)

    Jones H. G.

    1970-09-01

    Full Text Available The following paper continues the series of nomenclatural notes and adjustments commenced under the title "Studies in Neotropical Orchidology" in Acta Botanica Academiae Scientiarum Hungaricae, Vol. 14: pp. 63-70 (1968. As in the previous contribution, the genera considered in the present study are Brassavola R. Br., Schomburgkia Lindl, and HoffmannseggellaH. G. Jones. The notes which comprise this series of studieshave been accumulated during the course of collecting materials for a taxonomic revision of the three genera concerned.The following paper continues the series of nomenclatural notes and adjustments commenced under the title "Studies in Neotropical Orchidology" in Acta Botanica Academiae Scientiarum Hungaricae, Vol. 14: pp. 63-70 (1968. As in the previous contribution, the genera considered in the present study are Brassavola R. Br., Schomburgkia Lindl, and HoffmannseggellaH. G. Jones. The notes which comprise this series of studieshave been accumulated during the course of collecting materials for a taxonomic revision of the three genera concerned.

  4. Trace element concentrations in freshwater mussels and macrophytes as related to those in their environment

    Directory of Open Access Journals (Sweden)

    Gian Maria BEONE

    2003-02-01

    Full Text Available This study was primarily designed to contribute to the debate "Do accumulator species reflect the element contamination level of their environment?" This research was carried out: 1 to know the distribution of 15 trace elements and calcium in shell and soft tissues of three species of freshwater mussels and macrophytes; 2 to compare the accumulation capacity of each trace element by mussels and by eight species of macrophytes and 3 to test the relationships between the metal concentrations in the mussels and macrophytes and those in water and sediments. The variability of element residues in the mussels is the major limit to accumulator monitoring. The most important causes are: seasonal cycle, physical environment and biological factors such as the size, age and growth rate. This research was designed to eliminate the consequence of variability deriving from the season and the environment. To this end the mussels and macrophytes were collected at the same time from the same habitat: Ranco Bay, Lago Maggiore, Northern Italy. In addition, the element concentrations in more size-classes of the most abundant mussel species (Unio pictorum and Dreissena polymorpha were measured. Trace elements were analyzed by Inductive Coupled Plasma-Mass Spectrometry (ICP-MS. By arranging the data in sequences of decreasing element concentrations in the organisms as well as in water and sediments, we were able to compare the accumulating ability of the tested species and evaluate their capacity to reflect environmental availability. Neither the sequences in the shell nor those in the tissues were similar to the sequence in the water. The differences between the sequences of the mussel tissues and those of the sediments were less striking than those between shells and sediments. Similar results were obtained by macrophytes. In conclusion, the results of this study (which mimics the monitoring practice prove that bioaccumulators cannot be used to evaluate the

  5. Biodiversity patterns of macrophyte and macroinvertebrate communities in two lagoons of Western Greece.

    Science.gov (United States)

    Fyttis, G.; Reizopoulou, S.; Papastergiadou, E.

    2012-04-01

    Aquatic macrophytes and benthic macroinvertebrates were studied seasonally (Spring, Autumn, Summer) between the years 2009 - 2011 in two coastal lagoons (Kotychi and Prokopos) located in Peloponnese, Greece, in order to investigate spatial and temporal biodiversity trends related to hydrological processes (degree of confinement, nitrates, phosphates, chl-a, total suspended materials, light irradiance, pH, salinity, temperature and dissolved oxygen). Kotychi lagoon presents a better communication with the sea, while Prokopos has a high degree of confinement. Both ecosystems seasonally receive freshwater input from streams. The submerged aquatic macrophytes constituted a major component of the ecosystems studied. In total, 22 taxa of aquatic macrophytes (angiosperms and macroalgae), 16 taxa for Kotychi (2 Rhodophyta, 8 Chlorophyta, 5 Magnoliophyta, 1 Streptophyta) and 14 taxa for Prokopos (1 Rhodophyta, 5 Chlorophyta, 5 Magnoliophyta, 3 Streptophyta) were found. Ruppia cirrhosa, and Potamogeton pectinatus were dominant in both lagoons. Kotychi lagoon was also dominated by Zostera noltii and Prokopos by Zannichellia pallustris ssp. pedicellata, while the biomass of aquatic species peaked during the summer periods, in both lagoons. The total number of macroinvertebrates found in the lagoons was 28 taxa for Kotychi and 19 for Prokopos. Chironomidae were dominant in both lagoons, while Kotychi was also dominated by Lekanesphaera monodi and Monocorophium insidiosum, and Prokopos by Ostracoda and Lekanesphaera monodi. Benthic diversity ranged from 1.33 to 2.57 in Kotychi and from 0.67 to 2.48 in Prokopos. Species richness, diversity, and abundance of benthic macroinvertebrates were strongly related to aquatic vegetation and to the degree of communication with the marine environment. Moreover, species richness and abundance of both macrophytes and macroinvertebrates were mainly dependent on depth, temperature, pH and concentration of total suspended materials (TSM). Results

  6. Acute Toxicity and Genotoxic Activity of Avocado Seed Extract (Persea americana Mill., c.v. Hass

    Directory of Open Access Journals (Sweden)

    Eduardo Padilla-Camberos

    2013-01-01

    Full Text Available The use of vegetal extracts requires toxicological and genotoxic evaluations to establish and verify safety before being added to human cosmetic, pharmaceutical medicine, or alimentary products. Persea americana seeds have been used in traditional medicine as treatment for several diseases. In this work, the ethanolic seed extract of Persea americana was evaluated with respect to its genotoxic potential through micronucleus assay in rodents. The frequency of micronuclei in groups of animals treated with avocado seed extract showed no differences compared to the negative control (vehicle; therefore, it is considered that the avocado seed extract showed no genotoxic activity in the micronucleus test.

  7. Acute toxicity and genotoxic activity of avocado seed extract (Persea americana Mill., c.v. Hass).

    Science.gov (United States)

    Padilla-Camberos, Eduardo; Martínez-Velázquez, Moisés; Flores-Fernández, José Miguel; Villanueva-Rodríguez, Socorro

    2013-01-01

    The use of vegetal extracts requires toxicological and genotoxic evaluations to establish and verify safety before being added to human cosmetic, pharmaceutical medicine, or alimentary products. Persea americana seeds have been used in traditional medicine as treatment for several diseases. In this work, the ethanolic seed extract of Persea americana was evaluated with respect to its genotoxic potential through micronucleus assay in rodents. The frequency of micronuclei in groups of animals treated with avocado seed extract showed no differences compared to the negative control (vehicle); therefore, it is considered that the avocado seed extract showed no genotoxic activity in the micronucleus test.

  8. Gerenciamento de resultados e remuneração dos executivos nas companhias latino-americanas

    OpenAIRE

    Santana, Alex Fabiano Bertollo

    2015-01-01

    O objetivo deste estudo foi verificar se as formas de remuneração dos executivos das Companhias Latino-Americanas influenciam o gerenciamento de resultados contábeis. Realizou-se uma análise empírica de 48 empresas, de 4 diferentes países latino-americanos em um período de 5 anos (entre 2002 e 2006), perfazendo um total de 240 observações. Para verificar a ocorrência de gerenciamento de resultados nas companhias latino-americanas, foi adotado o modelo Kang e Sivaramakrishnan (1995). Os testes...

  9. Procjena postupaka za smanjenje tvrdoće srčike biljke Agave americana

    OpenAIRE

    Ramírez, José A.; Gómez-Ayala, Rocio C.; Jacques-Hernández, Cuauhtémoc; Vázquez, Manuel

    2006-01-01

    Biljka Agave americana sadrži inulin kao rezervu ugljikohidrata, stoga je zanimljiva za ekstrakciju inulina prešanjem. Prinos je procesa malen zbog velike tvrdoće srčike. Cilj je ovoga rada procjena prethodne obrade radi smanjenja tvrdoće pri prešanju biljke. Ispitana je i optimirana obrada biljke vodom, s 1 % masenog udjela sumporne kiseline ili 1 % masenog udjela natrijeve lužine. Prethodna obrada srčike A. americana s 1 % sumporne kiseline smanjila je tvrdoću s 30000 g na 2000 g (sile kida...

  10. The role of pH in structuring communities of Maine wetland macrophytes and chironomid larvae (Diptera)

    Science.gov (United States)

    Woodcock, T.S.; Longcore, J.R.; McAuley, D.G.; Mingo, T.M.; Bennatti, C.R.; Stromborg, K.L.

    2005-01-01

    Aquatic vascular plants, or macrophytes, are an important habitat component for many wetland organisms, and larvae of chironomid midges are ubiquitous components of wetland fauna. Many chironomids are primary consumers of algae and detritus and form an essential energetic link between allochthonous and autochthonous primary production and higher trophic levels, while others are predators and feed on smaller invertebrates. Live macrophytes serve mostly as habitat, whereas plant detritus serves as both habitat and as a food source. Assemblages of macrophytes and chironomid larvae were surveyed in ten Maine wetlands, five with low pH (5.5), and explained in terms of physical and chemical habitat variables. Macrophyte richness was significantly greater, and richness of chironomid larvae was lower, in low pH wetlands. There was no difference in chironomid abundance related to pH. However, community structure was related to pH, suggesting that competitive dominance of a few taxa was responsible for lower richness in low pH wetlands, whereas competition was weaker in high pH wetlands, making coexistence of more chironomid taxa possible. An examination of individual chironomid taxa by stepwise multiple regression showed that distribution of most taxa was controlled by water chemistry variables and macrophyte habit (i.e., floating, submergent).

  11. Fish assemblage dynamics in a Neotropical floodplain relative to aquatic macrophytes and the homogenizing effect of a flood pulse

    Science.gov (United States)

    Gomes, L.C.; Bulla, C. K.; Agostinho, A. A.; Vasconcelos, L. P.; Miranda, Leandro E.

    2012-01-01

    The presence of aquatic macrophytes is a key factor in the selection of habitats by fish in floodplain lakes because these plants enhance the physical and biological complexities of aquatic habitats. The seasonal flood pulse may influence this interaction, but there is no information in the literature about the effects that flood events may have on macrophytes assemblages and its associated effects on fish assemblages. Thus, this article aimed to investigate whether species richness, evenness and similarities in fish assemblage composition differed between littoral areas vegetated with macrophytes and unvegetated areas, before and after a flood. We sampled three lakes in the floodplain of the upper Paraná River basin. Sampling was conducted before (December 2004 and January 2005) and after (early March, late March and May 2005) a flood event. Overall, species richness and evenness were higher in macrophytes-covered areas. Before the flood, the composition of fish assemblages was distinct when comparing vegetated and unvegetated areas. After the flood, the similarity in fish assemblage composition was higher, indicating a homogenization effect of floods for fish inhabiting littoral areas of floodplain lakes. After the flood, opportunistic species dominated the fish assemblages in aquatic macrophytes, apparently restructuring assemblages in the littoral, restarting a succession process. Thus, the observed homogenization effect of the flood could minimize biological interactions and could induce fish assemblages to begin a new process of structurization.

  12. The ichthyofauna of drifting macrophyte mats in the Ivinhema River, upper Paraná River basin, Brazil

    Directory of Open Access Journals (Sweden)

    Cíntia Karen Bulla

    Full Text Available We describe the fish assemblages associated with drifting macrophyte mats and consider their possible role as dispersal vectors in the Ivinhema River, a major tributary of the upper Paraná River, Brazil. Fish associated with drifting mats were sampled in the main river channel during January and March 2005, when the wind and/or the increased water level were sufficient to transport macrophyte stands. Fish in the drifting mats were sampled with a floating sieve (4 m long x 2 m wide x 0.6 m high, and 2 mm mesh size. In the laboratory, larvae, juvenile, and adult fish were counted and identified to the lowest possible taxonomic level. In four drifting macrophyte mats we captured 218 individuals belonging to at least 28 species, 17 families, and 6 orders. Aphyocharax dentatus, Serrasalmus spp., and Trachelyopterus galeatus were the most abundant taxa associated with the mats, but species richness ranged from 6 to 24 species per mat. In addition, 85% of the total number of individuals caught was larvae and juveniles. Although preliminary and based on limited samples, this study of drifting macrophyte mats was the first one in the last unregulated stretch of the Paraná River remaining inside Brazilian territory, and alerts us to the potential role of macrophytes mats as dispersers of fish species in the region.

  13. The ichthyofauna of drifting macrophyte mats in the Ivinhema River, upper Paraná River basin, Brazil

    Science.gov (United States)

    Bulla, C. K.; Gomes, Luiz Carlos; Miranda, Leandro E.; Agostinho, A. A.

    2011-01-01

    We describe the fish assemblages associated with drifting macrophyte mats and consider their possible role as dispersal vectors in the Ivinhema River, a major tributary of the upper Paraná River, Brazil. Fish associated with drifting mats were sampled in the main river channel during January and March 2005, when the wind and/or the increased water level were sufficient to transport macrophyte stands. Fish in the drifting mats were sampled with a floating sieve (4 m long x 2 m wide x 0.6 m high, and 2 mm mesh size). In the laboratory, larvae, juvenile, and adult fish were counted and identified to the lowest possible taxonomic level. In four drifting macrophyte mats we captured 218 individuals belonging to at least 28 species, 17 families, and 6 orders. Aphyocharax dentatus, Serrasalmus spp., and Trachelyopterus galeatus were the most abundant taxa associated with the mats, but species richness ranged from 6 to 24 species per mat. In addition, 85% of the total number of individuals caught was larvae and juveniles. Although preliminary and based on limited samples, this study of drifting macrophyte mats was the first one in the last unregulated stretch of the Paraná River remaining inside Brazilian territory, and alerts us to the potential role of macrophytes mats as dispersers of fish species in the region.

  14. Structure of the littoral fish assemblage in an impounded tributary: the effects of macrophytes presence (subtropical region, Brazil).

    Science.gov (United States)

    Hermes-Silva, S; Zaniboni-Filho, E

    2012-08-01

    To evaluate the effects of macrophytes presence in the structure of littoral fish assemblages in the littoral zone, monthly samples were collected from September, 2006 to August, 2007 in an impounded tributary of the Itá Reservoir, the Fragosos River, located in the Upper Uruguay River Basin. Fish were collected using a beach seine and sampling was conducted in the littoral zone inside a macrophyte stand and in an area with no macrophytes. A total of 5,191 fish were captured during the study period. Fish assemblage attributes (fish abundance, species richness, and diversity) varied significantly between sampling months and areas. The abundance of Astyanax cf. bimaculatus, Astyanax fasciatus, Geophagus brasiliensis, and Gymnotus carapo also varied significantly between sampling months and areas. Detrended Correspondence Analysis showed a clear spatial segregation at the first axis and a slight temporal segregation at the second axis. These results were confirmed by Multiple Response Permutation Procedure analysis. Apparently, the presence of the aquatic macrophytes is not the only factor influencing the distribution of littoral fish assemblages in the Fragosos River. Littoral fish seem to be taking advantage of low- to medium-sized macrophyte stands, but few species used maximum-sized stands.

  15. Spatial distribution and biomass of aquatic rooted macrophytes and their relevance in the metabolism of a Mediterranean coastal lagoon

    Directory of Open Access Journals (Sweden)

    Biel Obrador

    2007-03-01

    Full Text Available This work aims to characterise the current autotrophic compartment of the Albufera des Grau coastal lagoon (Menorca, Balearic Islands and to assess the relationship between the submerged macrophytes and the limnological parameters of the lagoon. During the study period the submerged vegetation was dominated by the macrophyte Ruppia cirrhosa, which formed dense extensive meadows covering 79% of the surface. Another macrophyte species, Potamogeton pectinatus, was also observed but only forming small stands near the rushing streams. Macroalgae were only occasionally observed. Macrophyte biomass showed a clear seasonal trend, with maximum values in July. The biomass of R. cirrhosa achieved 1760 g DW m-2, the highest biomass ever reported for this species in the literature. The seasonal production-decomposition cycle of the macrophyte meadows appears to drive the nutrient dynamics and carbon fluxes in the lagoon. Despite the significant biomass accumulation and the absence of a washout of nutrients and organic matter to the sea, the lagoon did not experience a dystrophic collapse. These results indicate that internal metabolism is more important than exchange processes in the lagoon.

  16. UVR induce optical changes and phosphorous release of lake water and macrophyte leachates in shallow Andean lakes

    Directory of Open Access Journals (Sweden)

    Beatriz MODENUTTI

    2010-02-01

    Full Text Available We carried out laboratory experiments in order to study the effect of ultraviolet radiation (UVR on optical features and phosphorous release of Dissolved Organic Mater (DOM from lake water and macrophyte leachates. Lake water samples were obtained from lakes Escondido and El Trébol, and macrophytes (Potamogeton linguatus and Schoenoplectus californicus from their littoral zones. After UVR exposure, DOM from lake El Trébol seemed to react more quickly than that from Lake Escondido and this seems to be related with the degree of lability or aromaticity in the DOM bulk of each lake. Leachates from both macrophytes showed different absorbance spectra with differences in photochemical transformations after UVR exposure: S. californicus leachates exhibited the highest photodegradation. A significant Soluble Reactive Phosphorus (SRP release was observed in lake water after UVR exposure. Lake El Trébol showed the highest SRP concentrations, suggesting that the release of orthophosphate was favored by low molecular weight DOM. P. linguatus leachates have more dissolved phosphorus content than S. californicus ones and after UVR exposure, P. linguatus leachate did not react to UVR while S. californicus exhibited a decrease in SRP. However both macrophyte leachates showed the higher P release in darkness. The obtained results indicated that macrophyte leachates could contribute significantly to changes in the optical characteristics and in the nutrient content in shallow Andean lakes. An increasing input of P. linguatus leachates would produce DOM of high molecular size and a higher P release than S. californicus.

  17. Evaluation of a combined macrophyte-epiphyte bioassay for assessing nutrient enrichment in the Portneuf River, Idaho, USA.

    Science.gov (United States)

    Ray, Andrew M; Mebane, Christopher A; Raben, Flint; Irvine, Kathryn M; Marcarelli, Amy M

    2014-07-01

    We describe and evaluate a laboratory bioassay that uses Lemna minor L. and attached epiphytes to characterize the status of ambient and nutrient-enriched water from the Portneuf River, Idaho. Specifically, we measured morphological (number of fronds, longest surface axis, and root length) and population-level (number of plants and dry mass) responses of L. minor and community-level (ash-free dry mass [AFDM] and chlorophyll a [Chl a]) responses of epiphytes to nutrient enrichment. Overall, measures of macrophyte biomass and abundance increased with increasing concentrations of dissolved phosphorus (P) and responded more predictably to nutrient enrichment than morphological measures. Epiphyte AFDM and Chl a were also greatest in P-enriched water; enrichments of N alone produced no measurable epiphytic response. The epiphyte biomass response did not directly mirror macrophyte biomass responses, illustrating the value of a combined macrophyte-epiphyte assay to more fully evaluate nutrient management strategies. Finally, the most P-enriched waters not only supported greater standing stocks of macrophyte and epiphytes but also had significantly higher water column dissolved oxygen and dissolved organic carbon concentrations and a lower pH. Advantages of this macrophyte-epiphyte bioassay over more traditional single-species assays include the use of a more realistic level of biological organization, a relatively short assay schedule (~10 days), and the inclusion of multiple biological response and water-quality measures.

  18. Study on Decomposition Rate and Nutrition Release of Submerged Macrophytes(Vallisneria spiralis) in Winter%冬季苦草分解速率及营养盐释放规律研究

    Institute of Scientific and Technical Information of China (English)

    陈见; 谢从新; 何绪刚; 胡雄; 李佩; 陆诗敏

    2011-01-01

    采用分解网袋法研究了冬季苦草腐败分解速率及其氮、磷损失规律。结果表明:苦草腐败释放的磷大部分被底泥吸附,少量进入水体;释放到水体中的氨氮(NH4+-N)、亚硝态氮(NO2--N)和硝态氮(NO3--N)数量也较少;底泥减缓了苦草干重损失速度,而加快了TN和TP损失速率;苦草分解过程中磷的释放速率比氮快;苦草腐败分解具有阶段性,前36d分解迅速,以后分解速率显著下降。%This paper studied on the rate of decomposition of tape grass(Vallisneria spiralis) as well as the law of the release of nitrogen and phosphorus in the decomposed tape grass in winter using a litter-bag method.The results showed the majority of phosphorus

  19. El Admirarse como forma de enfrentar la nueva realidad americana

    Directory of Open Access Journals (Sweden)

    Álvarez Moreno, Raúl

    2004-12-01

    Full Text Available The article is a study of the use of admiratio to display the new American reality at the end of the fourteenth and into the fifteenth century. After exploring the semantic wealth of the term and defining it, we will present it as the first stage of the cognitive process of the human being, whose object will be Nature, understood as a whole entity in which men are included. The depiction of the admirable thing as a part of the cognitive process will also have its place in this study. But it is under the renovation that proposed the Renaissance, when admiratio turned into a poetic function related to that of movere, solving America as inventio the problem of verisimilitude inherited from the Middle Ages. Then, this concept will be used by our authors, not only to reflect a stage of knowledge, but with a clearly rhetorical function: to create a specific state of mind in the reader in order to obtain something from him.

    El artículo analiza el uso de la admiratio para presentar la nueva realidad americana a finales del siglo XV y durante el XVI. Tras explorar la riqueza semántica del término y definirlo, se parte del mismo, como el primer estadio del proceso cognitivo del ser humano, cuyo objeto será una naturaleza, entendida como totalidad que incluye al hombre. La plasmación de lo admirable como parte del proceso cognitivo tiene también su lugar en el estudio. Pero será la transformación que supone el Renacimiento, la que convertirá a la admiratio en una función poética relacionada con el movere, y a la que América como inventio solucionaba el problema de la verosimilitud heredado de la Edad Media. El concepto será usado por nuestros autores, no ya para reflejar una fase del conocimiento, sino con una función claramente retórica: provocar un estado de ánimo en el lector para conseguir algo de él.

  20. The role of herbivorous water birds in aquatic systems through interactions with aquatic macrophytes, with special reference to the Bewick's Swan - Fennel Pondweed system

    NARCIS (Netherlands)

    Klaassen, M.R.J.; Nolet, B.A.

    2007-01-01

    The role of aquatic macrophytes in stimulating biodiversity and maintaining clear waters is currently undisputed. The management of (eutrophic) shallow waters is therefore often directed at (re-)establishing macrophyte domination. In contrast, the role of water birds has long been considered of

  1. Retrospective assessment of macrophytic communities in southern Lake Garda (Italy from in situ and MIVIS (Multispectral Infrared and Visible Imaging Spectrometer data

    Directory of Open Access Journals (Sweden)

    Claudia Giardino

    2012-01-01

    Full Text Available In situ and hyperspectral MIVIS (Multispectral Infrared and Visible Imaging Spectrometer images acquired over a period of 13 years are used to assess changes in macrophyte colonization patterns in the coastal zones of the Sirmione Peninsula in the southern part of Lake Garda (Italy. In situ data (abundance, cover density and diversity of macrophyte communities and MIVIS-derived maps of colonized substrates are analyzed by considering the variability of the main hydrological and physicochemical variables in order to indicate the main factors that explain the spatiotemporal variability of macrophyte communities. The results show a considerable modification in terms of macrophyte structural complexity and colonized areas. Almost 98% of macrophyte meadows (in particular communities with a density of over 70% are lost and subsequently replaced by moderate to extremely rare communities with density from 10% to 40%. Well-established submerged macrophytes are replaced by de-structured communities characterized by moderate to scarce density: on average lower than 30%. The study indicates that macrophyte distribution along the littoral zone of the Sirmione Peninsula is certainly linked to water transparency and water level fluctuation. The results also indicate that the worsening of eutrophication may be associated with the gradual disappearance of macrophyte meadows, but may also be accelerated by herbivorous aquatic birds grazing there. Lastly, the increasing frequency and number of catamaran tours could be considered a threat for the stability of these valuable communities.

  2. Description of a new coccid (Hemiptera, Coccidae on avocado (Persea americana Mill. from Colombia, South America

    Directory of Open Access Journals (Sweden)

    Takumasa Kondo

    2010-04-01

    Full Text Available A new soft scale insect, Bombacoccus aguacatae Kondo, gen. n. and sp. n. (Hemiptera: Coccidae collected on the branches and twigs of avocado, Persea americana Mill. (Lauraceae in Colombia, is described and illustrated based on the adult female. An updated taxonomic key to closely related genera of the Toumeyella-group is provided.

  3. Molecular Characterization and Genetic Structure in Avocado (Persea americana Mill.) Using Simple Sequence Repeat (SSR) Markers

    Science.gov (United States)

    Avocado (Persea americana Mill.) is an economically important tropical fruit native to Mesoamerica. It belongs to the Lauraceae family and is subdivided in three horticultural races (Guatemalan, Mexican, and West Indian) based primarily on ecological adaptation, botanical and physiological traits. T...

  4. The Scirtothrips perseae species-group (Thysanoptera), with one new species from avocado, Persea americana.

    Science.gov (United States)

    Mound, Laurence A; Hoddle, Mark S

    2016-02-12

    Following recent molecular studies on avocado thrips, a new species is described from Costa Rica, Ecuador, and Colombia from the young leaves of avocado, Persea americana. Scirtothrips hansoni sp.n. is closely related to the Californian pest, S. perseae, and also to S. astrictus from Costa Rica that remains known from a single female. An illustrated key to these three species is provided.

  5. APPLICATION OF PROPICONAZOLE IN MANAGEMENT OF LAUREL WILT DISEASE IN AVOCADO (Persea americana Mill.) TREES

    Science.gov (United States)

    Laurel wilt is a vascular disease of Lauraceous plants caused by a fungus (Raffaelea spp.) that is carried by a recently introduced, nonnative ambrosia beetle (Xyleborus glabratus). The disease is devastating to Persea species including redbay (Persea borbonia) and avocado (Persea americana) trees i...

  6. Chemotaxonomical researches in higher plants XII. Researches concerning the pigments and glucides of Phytolacca Americana L.

    Directory of Open Access Journals (Sweden)

    Gavrila NEAMTU

    1979-08-01

    Full Text Available The paper presents the results of biochemical analyses of Phytolacca Americana plants grown in the Agrobotanical Garden Cluj-Napoca. Carotenoid pigments (neoxanthin, violaxanthin, zeaxanthin, lutein, cryptoxanthin, alpha-carotene and beta-carotene chlorophyll pigments (a,b and glycoside pigments (betalaines, quercetin have been analysed in fruits and leaves respectively.

  7. Effects of Persea americana leaf extracts on body weight and liver ...

    African Journals Online (AJOL)

    GREGO

    2007-04-16

    Apr 16, 2007 ... “western diets” high in saturated fat and sugar and low in ... Table 1. Mean weekly body weights of rats fed with extracts of P. americana. Week. A. B. C. D ... (1957). Liver total cholesterol (T-CHOL), high-density lipoproteins .... Alteration in carbohydrate and lipid metabolism induced by a diet rich in coconut ...

  8. Applications of Microencapsulated Bifidobacterium Longum with Eleutherine Americana in Fresh Milk Tofu and Pineapple Juice

    OpenAIRE

    Atchara N Phoem; Suphitchaya Chanthachum; Supayang P Voravuthikunchai

    2015-01-01

    Bifidobacterium longum was microencapsulated by extrusion technique and added in fresh milk tofu and pineapple juice. Microencapsulation of B. longum with Eleutherine americana extract, oligosaccharides extract, and commercial fructo-oligosaccharides was assessed for the bacterial survival after sequential exposure to simulated gastric and intestinal juices, and refrigeration storage. Microencapsulated B. longum with the extract and oligosaccharides extract in the food products showed better ...

  9. In-situ genetic conservation of white ash (Fraxinus americana) at the Allegheny national forest

    Science.gov (United States)

    Charles E. Flower; Elijah Aubihl; Jeremie Fant; Stephen Forry; Andrea Hille; Kathleen S. Knight; William K. Oldland; Alejandro A. Royo; Richard M. Turcotte

    2017-01-01

    The emerald ash borer (EAB, Agrilus planipennis) is a non-native forest pest that has been sweeping across North America causing widespread mortality of trees in the genus Fraxinus, which includes the economically valuable white ash (F. americana). The rapid spread and lethality of EAB, paired with low levels of natural...

  10. A Vitória Democrata e a Política Externa Americana

    Directory of Open Access Journals (Sweden)

    GUNTHER RUDZIT

    2010-12-01

    Full Text Available O presente artigo busca analisar os impactos que a vitória do partido democrata nas eleições parlamentares de meio de mandato, realizadas em novembro, exercerão sobre a contestada política externa norte-americana levada a cabo pelo presidente Bush.

  11. Race, Interracial Admixture and Genetic Differentiation of Avocado (Persea americana Mill)

    Science.gov (United States)

    Avocado (Persea americana Mill.) is a major tropical fruit crop native to Mesoamerica and domesticated around 8000 to 7000 BC. It is a member of the Laureace family and currently classified into three subspecies or races: Guatemalan (G), Mexican (M) and West Indian (WI) according to their ecological...

  12. Two New Spirostanol Steroidal Sapogenins from Fermented Leaves of Agave americana

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Two new spirostanol sapogenins named agavegenin A and B were isolated from the fermented leaves of Agave americana L.Their structures were elucidated as (23S, 25R)-5α- spirostan-3β, 6α, 11α, 23-tetraol (1) and (23S, 25S)-5α-spirostan-3β, 23, 27-triol (2) by spectral methods.

  13. Isolation and characterization of an utero-active compound from Agave americana.

    Science.gov (United States)

    Basilio, C M; Seyler, L; Bernstein, J; Castro de la Mata, R

    1989-12-01

    Crude extracts of Agave americana contain two utero-active compounds. One of these, tentatively named "Fraction B", has been purified to chromatographic homogeneity. Its pharmacological actions are similar to those of acetylcholine. However its chromatographic and electrophoretic mobilities are different. Some chemical properties of fraction B are compatible with the structure of an acyl derivative of choline different from acetylcholine.

  14. Phytobezoar from the stem ("quiote") of the cactus Agave americana: report of case.

    Science.gov (United States)

    Villarreal, R; Martinez, O; Berumen, U

    1985-11-01

    Agave americana is a cactus growing abundantly in Mexico. Its cooked stem ("quiote") yields by mastication a sweet juice which is swallowed, while the fibers ("bagazo") are spit out. That is the way Mexicans are taught to chew quiote since their early childhood, and it accounts for the rarity of bezoars from this origin. One of such cases is reported herein.

  15. Comparison of the community structures of ammonia-oxidizing bacteria and archaea in rhizoplanes of floating aquatic macrophytes.

    Science.gov (United States)

    Wei, Bo; Yu, Xin; Zhang, Shuting; Gu, Li

    2011-09-20

    Some common floating aquatic macrophytes could remove nutrients, such as nitrogen, from eutrophic water. However, the relationship between these macrophytes and the ammonia-oxidizing microorganisms on their rhizoplanes is still unknown. In this study, we examined communities of ammonia-oxidizing archaea (AOA) and bacteria (AOB) on the rhizoplanes of common floating aquatic macrophytes (Eichhornia crassipes, Pistia stratiotes and Ipomoea aquatic) in a eutrophic reservoir.The results show that AOB were the predominant ammonia-oxidizer on the three rhizoplanes. The principal AOB were Nitrosomonas europaea and Nitrosomonas ureae clades. The principal group of AOA was most similar to the clone from activated sludge. The ratio of AOB amoA gene copies to AOA varied from 1.36 (on E. crassipes) to 41.90 (on P. stratiotes). Diversity of AOA was much lower than that of AOB in most samples, with the exception of P. stratiotes.

  16. Emergent and floating-leaved macrophytes as refuge for zooplankton in a eutrophic temperate lake without submerged vegetation

    DEFF Research Database (Denmark)

    Cazzanelli, Matteo; Perlt, Trine Warming; Christoffersen, Kirsten Seestern

    2008-01-01

    modifications in the predation pressure, refuge availability and concentration of cyanobacteria in the lake. It is suggested that emergent and floating-leaved macrophytes may play an important role in enhancing water clarity due to increased grazing pressure by zooplankton migrating into the plant stands....... As a consequence, especially in turbid lakes, the ecological role of these functional types of vegetation, and not merely that of submerged macrophyte species, should be taken into consideration.......Several studies have shown that submerged macrophytes provide a refuge for zooplankton against fish predation, whereas the role of emergent and floating-leaved species, which are often dominant in eutrophic turbid lakes, is far less investigated. Zooplankton density in open water and amongst...

  17. Developmental ecdysteroid titers and DNA puffs in larvae of two sciarid species, Rhynchosciara americana and Rhynchosciara milleri (Diptera: Sciaridae).

    Science.gov (United States)

    Soares, M A M; Hartfelder, K; Tesserolli de Souza, J M; Stocker, A J

    2015-10-01

    Ecdysteroid titers, developmental landmarks and the presence of prominent amplifying regions (DNA puffs) have been compared during late larval to pupal development in four groups of Rhynchosciara americana larvae and in R. americana and Rhynchosciara milleri. Three prominent DNA puffs (B2, C3 and C8) expand and regress sequentially on the rising phase of the 20-hydroxyecdysone (20E) titer in R. americana as a firm, cellular cocoon is being constructed. A sharp rise in 20E coincides with the regression of these puffs. The shape of the 20E curve is similar in R. milleri, a species that does not construct a massive cocoon, but the behavior of certain DNA puffs and their temporal relationship to the curve differs. Regions corresponding to B2 and C3 can be identified in R. milleri by banding pattern similarity with R. americana chromosomes and, in the case of B2, by hybridization to an R. americana probe. A B2 puff appears in R. milleri as the 20E titer rises but remains small in all gland regions. A puff similar to the R. americana C3 puff occurs in posterior gland cells of R. milleri (C3(Rm)) after the B2 puff, but this site did not hybridize to R. americana C3 probes. C3(Rm) incorporated (3)H-thymidine above background, but showed less post-puff DNA accumulation than C3 of R. americana. R. americana C8 probes hybridized to a more distal region of the R. milleri C chromosome that did not appear to amplify or form a large puff. These differences can be related to developmental differences, in particular differences in cocoon construction between the two species.

  18. Regime shift from phytoplankton to macrophyte dominance in a large river: Top-down versus bottom-up effects

    Energy Technology Data Exchange (ETDEWEB)

    Ibanez, Carles, E-mail: carles.ibanez@irta.cat [IRTA Aquatic Ecosystems, Carretera Poble Nou, Km 5.5, 43540 St. Carles de la Rapita, Catalonia (Spain); Alcaraz, Carles; Caiola, Nuno; Rovira, Albert; Trobajo, Rosa [IRTA Aquatic Ecosystems, Carretera Poble Nou, Km 5.5, 43540 St. Carles de la Rapita, Catalonia (Spain); Alonso, Miguel [United Research Services S.L., Urgell 143, 08036 Barcelona, Catalonia (Spain); Duran, Concha [Confederacion Hidrografica del Ebro, Sagasta 24-26, 50071 Zaragoza, Aragon (Spain); Jimenez, Pere J. [Grup Natura Freixe, Major 56, 43750 Flix, Catalonia (Spain); Munne, Antoni [Agencia Catalana de l' Aigua, Provenca 204-208, 08036 Barcelona, Catalonia (Spain); Prat, Narcis [Departament d' Ecologia, Universitat de Barcelona, Diagonal 645, 08028 Barcelona Catalonia (Spain)

    2012-02-01

    The lower Ebro River (Catalonia, Spain) has recently undergone a regime shift from a phytoplankton-dominated to a macrophyte-dominated system. This shift is well known in shallow lakes but apparently it has never been documented in rivers. Two initial hypotheses to explain the collapse of the phytoplankton were considered: a) the diminution of nutrients (bottom-up); b) the filtering effect due to the colonization of the zebra mussel (top-down). Data on water quality, hydrology and biological communities (phytoplankton, macrophytes and zebra mussel) was obtained both from existing data sets and new surveys. Results clearly indicate that the decrease in phosphorus is the main cause of a dramatic decrease in chlorophyll and large increase in water transparency, triggering the subsequent colonization of macrophytes in the river bed. A Generalized Linear Model analysis showed that the decrease in dissolved phosphorus had a relative importance 14 times higher than the increase in zebra mussel density to explain the variation of total chlorophyll. We suggest that the described changes in the lower Ebro River can be considered a novel ecosystem shift. This shift is triggering remarkable changes in the biological communities beyond the decrease of phytoplankton and the proliferation of macrophytes, such as massive colonization of Simulidae (black fly) and other changes in the benthic invertebrate communities that are currently investigated. - Highlights: Black-Right-Pointing-Pointer We show a regime shift in a large river from phytoplankton to macrophyte dominance. Black-Right-Pointing-Pointer Two main hypotheses are considered: nutrient decrease and zebra mussel grazing. Black-Right-Pointing-Pointer Phosphorus depletion is found to be the main cause of the phytoplankton decline. Black-Right-Pointing-Pointer We conclude that oligotrophication triggered the colonization of macrophytes. Black-Right-Pointing-Pointer This new regime shift in a river is similar to that described

  19. Interactions of gold nanoparticles with freshwater aquatic macrophytes are size and species dependent.

    Science.gov (United States)

    Glenn, J Brad; White, Sarah A; Klaine, Stephen J

    2012-01-01

    The partitioning of 4- and 18-nm gold nanoparticles (AuNPs) to aquatic macrophytes was investigated in vivo with exposure suspension in well water. Three morphologically distinct aquatic macrophytes were studied. Myriophyllum simulans Orch. and Egeria densa Planch. are submerged aquatic vascular plants, whereas Azolla caroliniana Willd. is a free-floating aquatic fern. Because aquatic plants absorb the majority of their nutrients from the water column, it is logical to hypothesize that they may absorb nanomaterials in suspension, potentially facilitating trophic transfer. Each plant was exposed to two different-sized gold nanospheres at a nominal concentration of 250 µg/L AuNPs for 24 h. Macrophytes were harvested at six time points (1, 3, 6, 12, 18, and 24 h), dried, and then analyzed for gold concentration via inductively coupled plasma-mass spectrometry. Concentrations were normalized to whole-plant dry tissue mass. The present study shows that absorption of AuNPs through root uptake was size and species dependent. Electron microscopy revealed that 4- and 18-nm AuNPs adsorbed to the roots of each species. Root tissue was sectioned, and transmission electron microscopy indicated that 4-nm and 18-nm AuNPs were absorbed by A. caroliniana, whereas only 4-nm AuNPs were absorbed by M. simulans. Egeria densa did not absorb AuNPs of either size. Gold nanoparticles were confirmed in tissue by using energy-dispersive X-ray spectroscopy. Absorption of AuNPs by plants may be a function of the salinity tolerance of each species.

  20. Evaluation of metal contamination and phytoremediation potential of aquatic macrophytes of East Kolkata Wetlands, India

    Science.gov (United States)

    2016-01-01

    Objectives The present study analyzes metal contamination in sediment of the East Kolkata Wetlands, a Ramsar site, which is receiving a huge amount of domestic and industrial wastewater from surrounding areas. The subsequent uptake and accumulation of metals in different macrophytes are also examined in regard to their phytoremediation potential. Methods Metals like cadmium (Cd), copper (Cu), manganese (Mn), and lead (Pb) were estimated in sediment, water and different parts of the macrophytes Colocasia esculenta and Scirpus articulatus. Results The concentration of metals in sediment were, from highest to lowest, Mn (205.0±65.5 mg/kg)>Cu (29.9±10.2 mg/kg)>Pb (22.7±10.3 mg/kg)>Cd (3.7±2.2 mg/kg). The phytoaccumulation tendency of these metals showed similar trends in both native aquatic macrophyte species. The rate of accumulation of metals in roots was higher than in shoots. There were strong positive correlations (p<0.001) between soil organic carbon (OC) percentage and Mn (r =0.771), and sediment OC percentage and Pb (r=0.832). Cation exchange capacity (CEC) also showed a positive correlation (p<0.001) with Cu (r=0.721), Mn (r=0.713), and Pb (r=0.788), while correlations between sediment OC percentage and Cu (r=0.628), sediment OC percentage and Cd (r=0.559), and CEC and Cd (r=0.625) were significant at the p<0.05 level. Conclusions Bioaccumulation factor and translocation factors of these two plants revealed that S. articulatus was comparatively more efficient for phytoremediation, whereas phytostabilization potential was higher in C. esculenta. PMID:27669754

  1. Evaluation of Piper aduncum Linn. Essential Oil (Fam:Piperaceae) against Periplaneta americana (L.).

    Science.gov (United States)

    Ling A, I; Sulaiman, S; Othman, H

    2009-01-01

    The efficacy of Piper aduncum essential oil was evaluated against Periplaneta americana adults and nymphs in the laboratory. The plant essential oil at varying concentrations ranging between 10,000 to 80,000 ppm were placed inside glass beakers, rolled horizontally to ensure the essential oil covers all sides of the beakers and exposed to adults and nymphs of P. americana. Resigen (R) 1ppm was used as positive control and distilled water as negative control. The LT50 and LT90 was obtained using Log Probit programme. Exposure of essential oil to females P. americana at concentrations between 10,000 to 80,000 ppm indicated the LT50 and LT90 values between 5.31 h-189.19 h and 14.90 h-2105.31 h, respectively. Treatment with the same concentrations against males P. americana ,the LT50 and LT90 were 2.08 h-181.73 h and 5.4 h-8460.51 h, respectively. Treatment against the nymphal stage with the same range of concentrations indicated the LT50 and LT 90 of 4.68 h-381.02 h and 28.71 h-5313.36 h, respectively.The nymphs and males were more susceptible than the females cockroaches. Treatment with Resigen (R) at 1ppm indicated much lower LT 50 and LT 90 values of 2.54 h-9.47 h for the females, 1.47 h-4.22 h for the males and 4.69 h-8.92 h for the nymphs.The negative control indicated no mortality for all stages of the cockroach. Piper aduncum essential oil can be used as an alternative natural product for controlling the cockroach Peripatetic americana.

  2. Evaluation of Piper aduncum Linn. Essential Oil (Fam:Piperaceae against Periplaneta americana(L.

    Directory of Open Access Journals (Sweden)

    I Ling A

    2009-12-01

    Full Text Available Background: The efficacy of Piper aduncum essential oil was evaluated against Periplaneta americana adults and nymphs in the laboratory.Methods: The plant essential oil at varying concentrations ranging between 10,000 to 80,000 ppm were placed inside glass beakers, rolled horizontally to ensure the essential oil covers all sides of the beakers and exposed to adults and nymphs of P. americana. Resigen (R 1ppm was used as positive control and distilled water as negative control. The LT50 and LT90 was obtained using Log Probit programme.Results: Exposure of essential oil to females P. americana at concentrations between 10,000 to 80,000 ppm indicated the LT50 and LT90 values between 5.31 h-189.19 h and 14.90 h-2105.31 h, respectively. Treatment with the same con­centrations against males P. americana ,the LT50 and LT90 were 2.08 h-181.73 h and 5.4 h-8460.51 h, respectively. Treatment against the nymphal stage with the same range of concentrations indicated the LT50 and LT 90 of 4.68 h-381.02 h and 28.71 h-5313.36 h, respectively.The nymphs and males were more susceptible than the females cock­roaches. Treatment with Resigen (R at 1ppm indicated much lower LT 50 and LT 90 values of 2.54 h-9.47 h for the fe­males, 1.47 h-4.22 h for the males and 4.69 h-8.92 h for the nymphs.The negative control indicated no mortality for all stages of the cockroach.Conclusion: Piper aduncum essential oil can be used as an alternative natural product for controlling the cockroach Peri­patetic americana.

  3. Avaliação da degradação de macrófitas aquáticas descartadas em ambiente protegido Assessment of the degradation of aquatic macrophytes discarded into a protected environment

    Directory of Open Access Journals (Sweden)

    V.R.S. Cezar

    2005-06-01

    Full Text Available Com o intuito de buscar informações sobre a degradação de macrófitas aquáticas descartadas em pilhas, após ações do controle mecânico, foi conduzido um experimento no Departamento de Recursos Naturais - Ciências Ambientais, UNESP, campus de Botucatu-SP. Para atender o objetivo proposto, foram montadas pilhas com volume de 2,25 m³, compostas, principalmente, por três espécies de macrófitas, retiradas do reservatório da UHE Americana/SP. Foram coletadas amostras na montagem das pilhas, aos 15, 30, 60 e 90 dias, para o acompanhamento da temperatura da pilha e do pH do material orgânico durante o processo, além de uma análise química do composto ao final dos 90 dias. Os tratamentos foram: T1 - somente plantas aquáticas e revolvimento da pilha a cada sete dias; T2 - somente plantas aquáticas e revolvimento a cada quatro dias; T3 - plantas aquáticas + permagel, com revolvimento a cada sete dias; e T4 - plantas aquáticas + permagel e revolvimento a cada quatro dias. Utilizou-se o delineamento estatístico inteiramente casualizado, sendo a análise estatística realizada para coleta aos 90 dias, empregando o programa SISVAR. Concluiu-se que os resultados de macro e micronutrientes, temperatura, umidade, pH, relação C/N e redução do volume das pilhas foram semelhantes aos observados quando se procedeu ao descarte em pilhas com volume de 4,5 m³ sobre o solo.An experiment was carried out at the Department of Natural Resources - Environmental Science, UNESP, Botucatu-SP to evaluate the degradation of aquatic macrophytes discarded in stacks, after mechanical control measures. Stacks of 2.25 m³ volume were set up, composed of three species of macrophytes collected from the Americana UHE reservoir in Sao Paulo. Stack samples were collected at 15, 30, 60 and 90 days, for temperature monitoring and organic material pH assessment during the process, besides compound chemical analysis at day 90. The treatments were: T1-only aquatic

  4. [Aquatic macrophytes from a marginal lake of the Embu-mirim river, São Paulo, Brazil].

    Science.gov (United States)

    Beyruth, Z

    1992-08-01

    In the years 1984/1985, limnological surveys were carried out at a marginal pond of the Embu-mirim river belonging to the hydrographic basin of Guarapiranga Reservoir (S. Paulo, Brazil), in order to obtain data for the determination of physical, chemical and biological parameters. Results obtained from the study of the aquatic macrophytes and their relationships with other environmental parameters are analyzed. Eichhornia crassipes (Mart.) Solms, the dominant macrophyte, was observed in several water bodies of that basin, including the river it self, thus favoring an evaluation of its behavior in similar water bodies of the basin.

  5. The cross-ecosystem impact of deer on an endangered submerged macrophyte, Ranunculus nipponicus var. submersus

    Directory of Open Access Journals (Sweden)

    Hino Takafumi

    2015-07-01

    Full Text Available Macrophytes are a critical component of freshwater ecosystems and are often eaten by cervids. However, the impact of cervids on macrophytes is not well known. In this study, we investigated the effect of sika deer (Cervus nippon yesoensis on the endangered macrophyte Ranunculus nipponicus var. submersus in a spring stream in southwestern Hokkaido, Japan. We monitored the frequency of stream habitat use by deer by using sensor cameras in photography mode for four seasons. We also monitored deer feeding behavior on R. nipponicus var. submersus using sensor cameras in movie mode. To quantitatively evaluate the impact of deer on R. nipponicus var. submersus, we conducted a field experiment in which deer were excluded from part of the stream. We selected 10 pairs of adjacent patches of R. nipponicus var. submersus and set up exclosures covering one patch in each pair. We assessed the frequency of deer feeding and trampling on the control patches using the sensor cameras in photography mode and measured the mean macrophyte stem length in the exclosure and control patches every month for four seasons. To compare abiotic conditions between the exclosure and control patches, we investigated canopy openness, water depth, water temperature, electrical conductivity, pH, current velocity, and water quality at each patch during the growing season. The frequency of deer in the stream habitat was higher from spring to summer than in other seasons. Direct evidence of deer feeding behavior on R. nipponicus var. submersus was recorded using the sensor cameras. Deer often fed on and trampled on the control patches, particularly from spring to summer. The R. nipponicus var. submersus stem length was longer in the exclosure patches than in control patches (P 0.189. Stem growth of R. nipponicus var. submersus differed among seasons (P <0.001, and was low from winter to spring. In addition, exclosure and seasonality significantly affected stem length (P <0.001, and the

  6. Identification of two capa cDNA transcripts and detailed peptidomic characterization of their peptide products in Periplaneta americana

    Directory of Open Access Journals (Sweden)

    Susanne Neupert

    2014-06-01

    Full Text Available The first CAPA peptides of insects were identified from Periplaneta americana using extracts of 8000 abdominal perisympathetic organs. The corresponding gene of cockroaches and other basal insects, however, remained undiscovered. Here we identified two capa cDNA transcripts of P. americana. Single cell mass spectrometry of capa neurons in abdominal ganglia yielded a complete coverage of the precursor sequences of both transcripts; with intermediates of precursor processing more prominent in somata than in perisympathetic organs. The processing of the CAPA precursor in P. americana is compared with that in the beetle Tribolium castaneum which was re-evaluated in this study.

  7. Selective Herbivory by an Invasive Cyprinid, the Rudd Scardinius erythrophthalmus

    Energy Technology Data Exchange (ETDEWEB)

    Kapuscinski, Kevin L [SUNY-ESF, SUNY College of Environmental Science and Forestry; John, Farrell M [SUNY-ESF, SUNY College of Environmental Science and Forestry; Stehman, Stephen V [SUNY-ESF, SUNY College of Environmental Science and Forestry; Boyer, Gregory L [SUNY-ESF, SUNY College of Environmental Science and Forestry; Fernando, Danilo D [SUNY-ESF, SUNY College of Environmental Science and Forestry; Teece, Mark A [SUNY-ESF, SUNY College of Environmental Science and Forestry; Tschaplinski, Timothy J [ORNL

    2014-01-01

    1. Herbivory by non-native animals is a problem of growing concern globally, especially for ecosystems where significant native herbivores did not previously exist or have been replaced by non-natives. The rudd (Scardinius erythrophthalmus) is an omnivorous cyprinid that has a nearly global longitudinal distribution due to human translocations, yet it is unknown whether the rudd feeds selectively among aquatic macrophyte species common to North American waters. 2. We tested a null hypothesis of non-selective feeding by rudds using five species of aquatic macrophytes: Ceratophyllum demersum, Elodea canadensis, Najas flexilis, Stuckenia pectinata, and Vallisneria americana. Four rudds were placed in 15 different 890-L tanks and presented with known quantities of each macrophyte species (each tank serving as a block in a randomized complete block design). Each macrophyte bundle was weighed on six dates during a 13 d experiment. Differences in mean percent weight remaining among macrophyte species were tested using repeated measures analysis of variance. We also quantified differences among chemical attributes of the five macrophyte species and qualitatively determined if selective feeding by rudds was related to dry matter content (DMC), percent C by dry weight (%C), percent N by dry weight (%N), and the concentrations of total soluble proteins, two organic acids (aconitic and oxalic acid), total soluble phenolic compounds (<1,000 Da), nine soluble phenolic metabolites, and total phenolic compounds. 3. Selective feeding by rudds was evident, with the order of macrophyte removal (from highest to lowest) being: N. flexilis > E. canadensis > S. pectinata > V. americana > C. demersum. Selection was positively related to %C and atomic C:N, but not DMC, %N, or concentration of total soluble proteins, contrary to the expectation that rudds would select the most nutritious plants available. The concentration of aconitic acid was greatest in N. flexilis, a preferred macrophyte

  8. Use of aquatic macrophytes in substrate composition to produce moringa seedlings

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    Walda Monteiro Farias

    2016-03-01

    Full Text Available The use of aquatic macrophytes in substrate composition to produce seedlings of moringa is a sustainable alternative. Therefore, the objective of this research was to evaluate the development of moringa seedlings using substrates composed with aquatic macrophytes, and to determine concentrations of N, P and K in the seedlings. We used different combinations of weeds (M, manure (E and topsoil (TV to compose the substrates. The experiment was conducted in a 3 × 4 factorial in randomized arrangement with four replications. We evaluated plant height, crown diameter and stem, relative growth rate in height, canopy diameter and in stem, dry matter of aerial part and of roots, root length and root/shoot ratio, besides the content of N, P and K in seedlings. Moringa seedlings showed reduced growth when produced in substrates composed only with cattail. Water lettuce and substrates composed of 60% M + 30%E + 10 % TV and 70% M + 30% E, promoted greater nutrition and growth of moringa seedlings. The substrate 60M +30E +10TV composed by water hyacinth and cattail resulted in greater amount of P in moringa seedlings.

  9. Concurrent removal and accumulation of heavy metals by the three aquatic macrophytes.

    Science.gov (United States)

    Mishra, Virendra Kumar; Tripathi, B D

    2008-10-01

    Under the present investigation effectiveness of three aquatic macrophytes Pistia stratiotes L. (water lettuce), Spirodela polyrrhiza W. Koch (duckweed) and Eichhornia crassipes were tested for the removal of five heavy metals (Fe, Zn, Cu, Cr and Cd). These plants were grown at three different concentrations (1.0, 2.0 and 5.0mgl(-1)) of metals in laboratory experiment. Result revealed high removal (>90%) of different metals during 15 days experiment. Highest removal was observed on 12th day of experiment, thereafter it decreased. Results revealed E. crassipes as the most efficient for the removal of selected heavy metals followed by P. stratiotes and S. polyrrhiza. Results from analysis confirmed the accumulation of different metals within the plant and a corresponding decrease of metals in the water. Significant correlations between metal concentration in final water and macrophytes were obtained. Plants have accumulated heavy metals in its body without the production of any toxicity or reduction in growth. Selected plants shown a wide range of tolerance to all of the selected metals and therefore can be used for large scale removal of heavy metals from waste water.

  10. Variation of nutrient and metal concentrations in aquatic macrophytes along the Rio Cachoeira in Bahia (Brazil).

    Science.gov (United States)

    Klump, Andreas; Bauer, Konrad; Franz-Gerstein, Charis; de Menezes, Max

    2002-07-01

    The use of cuprous fungicides in cocoa production in the southern part of the state of Bahia (Brazil) for decades has caused an accumulation of copper in various components of the cocoa plantations, and a contamination of regional freshwater ecosystems is suspected. Urban and industrial sources are supposed to contribute to water pollution and eutrophication of the Rio Cachoeira, the main river in this region. In order to study the metal contamination and nutritional status of this freshwater ecosystem, samples of the aquatic macrophytes Eichhornia crassipes and Pistia stratiotes were collected at seven sites along the river course. The samples were analysed for their copper, aluminium, chromium, nitrogen and phosphorus concentrations. The levels of heavy metals increased in the downstream direction, particularly in the roots of water hyacinth. A dramatic increase of nitrogen and phosphorus concentrations in water as well as in plant tissues was found in samples collected downstream from the city of Itabuna. Metal input and eutrophication were attributed to agricultural, industrial and urban sources in the region. Biomonitoring of the water quality using aquatic macrophytes as accumulative indicator plants is recommended in addition to chemical water analyses.

  11. Cellulase activity and dissolved organic carbon release from lignocellulose macrophyte-derived in four trophic conditions.

    Science.gov (United States)

    Bottino, Flávia; Cunha-Santino, Marcela Bianchessi; Bianchini, Irineu

    2016-01-01

    Considering the importance of lignocellulose macrophyte-derived for the energy flux in aquatic ecosystems and the nutrient concentrations as a function of force which influences the decomposition process, this study aims to relate the enzymatic activity and lignocellulose hydrolysis in different trophic statuses. Water samples and two macrophyte species were collected from the littoral zone of a subtropical Brazilian Reservoir. A lignocellulosic matrix was obtained using aqueous extraction of dried plant material (≈40°C). Incubations for decomposition of the lignocellulosic matrix were prepared using lignocelluloses, inoculums and filtered water simulating different trophic statuses with the same N:P ratio. The particulate organic carbon and dissolved organic carbon (POC and DOC, respectively) were quantified, the cellulase enzymatic activity was measured by releasing reducing sugars and immobilized carbon was analyzed by filtration. During the cellulose degradation indicated by the cellulase activity, the dissolved organic carbon daily rate and enzyme activity increased. It was related to a fast hydrolysable fraction of cellulose that contributed to short-term carbon immobilization (ca. 10 days). After approximately 20 days, the dissolved organic carbon and enzyme activity were inversely correlated suggesting that the respiration of microorganisms was responsible for carbon mineralization. Cellulose was an important resource in low nutrient conditions (oligotrophic). However, the detritus quality played a major role in the lignocelluloses degradation (i.e., enzyme activity) and carbon release.

  12. Cellulase activity and dissolved organic carbon release from lignocellulose macrophyte-derived in four trophic conditions

    Directory of Open Access Journals (Sweden)

    Flávia Bottino

    2016-06-01

    Full Text Available Abstract Considering the importance of lignocellulose macrophyte-derived for the energy flux in aquatic ecosystems and the nutrient concentrations as a function of force which influences the decomposition process, this study aims to relate the enzymatic activity and lignocellulose hydrolysis in different trophic statuses. Water samples and two macrophyte species were collected from the littoral zone of a subtropical Brazilian Reservoir. A lignocellulosic matrix was obtained using aqueous extraction of dried plant material (≈40 °C. Incubations for decomposition of the lignocellulosic matrix were prepared using lignocelluloses, inoculums and filtered water simulating different trophic statuses with the same N:P ratio. The particulate organic carbon and dissolved organic carbon (POC and DOC, respectively were quantified, the cellulase enzymatic activity was measured by releasing reducing sugars and immobilized carbon was analyzed by filtration. During the cellulose degradation indicated by the cellulase activity, the dissolved organic carbon daily rate and enzyme activity increased. It was related to a fast hydrolysable fraction of cellulose that contributed to short-term carbon immobilization (ca. 10 days. After approximately 20 days, the dissolved organic carbon and enzyme activity were inversely correlated suggesting that the respiration of microorganisms was responsible for carbon mineralization. Cellulose was an important resource in low nutrient conditions (oligotrophic. However, the detritus quality played a major role in the lignocelluloses degradation (i.e., enzyme activity and carbon release.

  13. Persistence and distribution of 4-nonylphenol in water, sediment, macrophytes, and wall material of littoral enclosures

    Energy Technology Data Exchange (ETDEWEB)

    Heinis, L.J.; Tunell, R.; Liber, K. [Univ. of Wisconsin, Superior, WI (United States). Lake Superior Research Inst.; Knuth, M.L. [Environmental Protection Agency, Duluth, MN (United States). Environmental Research Lab.

    1994-12-31

    Eighteen enclosures (5 m x 10 m) were constructed in the littoral zone of a 2-ha pond near Duluth, MN. Each enclosure consisted of 5 m of natural shoreline and three walls of an inert plastic. The enclosures had an average surface area of 31.9 m{sup 2} , an average depth of 0.6 m and an average water volume of 33.1 m{sup 3}. The enclosure waters were treated with the alkyl phenol ethoxylate precursor and degradation product 4-nonylphenol. Application was accomplished by sub-surface injection over a 20-day period with a 2 day frequency. Nominal aqueous concentrations were 0, 3, 30, 100 and 300 {mu}g/L. Concentrations of 4-nonylphenol were monitored during and after application in the water, sediment, macrophytes, and enclosure wall material. Average maximum water concentrations ranged from 96.5% of nominal to 62.0% of nominal and average minimum water concentrations ranged from 33.3% of nominal to 29.5% of nominal during the application period. Water concentrations decreased exponentially after application ended. Sediment concentrations during the application period were constant from 8 to 20 d and peak concentrations occurred 48 d after application began. Macrophyte concentrations peaked 21 d after initial application with a steady decline through 76 d. Enclosure wall material concentrations reached a peak 3 h before the final application. A gradual decline occurred until 34 d after initial application followed by a more rapid dissipation.

  14. Mowing Submerged Macrophytes in Shallow Lakes with Alternative Stable States: Battling the Good Guys?

    Science.gov (United States)

    Kuiper, Jan J.; Verhofstad, Michiel J. J. M.; Louwers, Evelien L. M.; Bakker, Elisabeth S.; Brederveld, Robert J.; van Gerven, Luuk P. A.; Janssen, Annette B. G.; de Klein, Jeroen J. M.; Mooij, Wolf M.

    2017-04-01

    Submerged macrophytes play an important role in maintaining good water quality in shallow lakes. Yet extensive stands easily interfere with various services provided by these lakes, and harvesting is increasingly applied as a management measure. Because shallow lakes may possess alternative stable states over a wide range of environmental conditions, designing a successful mowing strategy is challenging, given the important role of macrophytes in stabilizing the clear water state. In this study, the integrated ecosystem model PCLake is used to explore the consequences of mowing, in terms of reducing nuisance and ecosystem stability, for a wide range of external nutrient loadings, mowing intensities and timings. Elodea is used as a model species. Additionally, we use PCLake to estimate how much phosphorus is removed with the harvested biomass, and evaluate the long-term effect of harvesting. Our model indicates that mowing can temporarily reduce nuisance caused by submerged plants in the first weeks after cutting, particularly when external nutrient loading is fairly low. The risk of instigating a regime shift can be tempered by mowing halfway the growing season when the resilience of the system is highest, as our model showed. Up to half of the phosphorus entering the system can potentially be removed along with the harvested biomass. As a result, prolonged mowing can prevent an oligo—to mesotrophic lake from becoming eutrophic to a certain extent, as our model shows that the critical nutrient loading, where the lake shifts to the turbid phytoplankton-dominated state, can be slightly increased.

  15. Polluting macrophytes Colombian lake Fúquene used as substrate by edible fungus Pleurotus ostreatus.

    Science.gov (United States)

    Martínez-Nieto, Patricia; García-Gómez, Gustavo; Mora-Ortiz, Laura; Robles-Camargo, George

    2014-01-01

    Invasive aquatic plants from Lake Fúquene (Cundinamarca, Colombia), water hyacinth (Eichhornia crassipes C. Mart.) and Brazilian elodea (Egeria densa Planch.) have been removed mechanically from the lake and can be used for edible mushrooms production. The growth of the oyster mushroom (Pleurotus ostreatus) on these aquatic macrophytes was investigated in order to evaluate the possible use of fruiting bodies and spent biomass in food production for human and animal nutrition, respectively. Treatments included: water hyacinth, Brazilian elodea, sawdust, rice hulls and their combinations, inoculated with P. ostreatus at 3%. Water hyacinth mixed with sawdust stimulated significantly fruiting bodies production (P = 3.3 × 10(-7)) with 71% biological efficacy, followed by water hyacinth with rice husk (55%) and elodea with rice husk (48%), all of these have protein contents between 26 and 47%. Loss of lignin (0.9-21.6%), cellulose (3.7-58.3%) and hemicellulose (1.9-53.8%) and increment in vitro digestibility (16.7-139.3%) and reducing sugars (73.4-838.4%) were observed in most treatments. Treatments spent biomass presented Relative Forage Values (RFV) from 46.1 to 232.4%. The results demonstrated the fungus degrading ability and its potential use in aquatic macrophytes conversion biomass into digestible ruminant feed as added value to the fruiting bodies production for human nutrition.

  16. Using phytoplankton and macrophytes to assess the trophic and ecological status of some Italian transitional systems

    Science.gov (United States)

    Sfriso, Adriano; Facca, Chiara; Bon, Daniele; Giovannone, Federico; Buosi, Alessandro

    2014-06-01

    Assessment of aquatic ecosystems and their recovery became mandatory with the enactment of the Water Framework Directive (WFD, 2000/60/EC). In this framework, the socio-economic value of transitional waters and their role as natural heritage are particularly important. To improve our knowledge of the ecological status and ecosystem functioning of transitional waters, investigations were carried out in Italian lagoons in the Po Delta and elsewhere (Marano-Grado, Goro, Comacchio, Pialassa Baiona, Lesina and Orbertello), applying the same procedures in accordance with National and International protocols. Nutrient concentrations were measured in water and top sediments and the taxonomic composition of phytoplankton and macrophytes was determined so that the trophic and ecological status could be described also by applying the Macrophyte Quality Index. Although the nutrient load was, on average, similar to that of other lagoons with better status, the overall conditions of Po Delta lagoons were found to be poor or bad, as highlighted by the absence of seagrasses and sensitive macroalgal species. Comparing all considered lagoons, the main factors affecting ecosystem recovery seem to be episodic high nutrient inputs, resulting from changes in river outflows, and huge sediment resuspensions caused by human activities. The studied transitional ecosystems displayed a wide range of conditions from bad to high, highlighting the possibility of ecosystem recovery especially by favouring nutrient regulation and angiosperm proliferation.

  17. Utilization of macrophyte biofilter in effluent from aquaculture: I. Floating plant

    Directory of Open Access Journals (Sweden)

    SIPAÚBA-TAVARES L. H.

    2002-01-01

    Full Text Available The objective of this work was to manufacture a low-cost biofilter, made of floating macrophyte (Eichhornia crassipes. Limnological studies were conducted 7 days after the macrophytes were placed in the biofilter, and continued over a period of 30 consecutive days. During rainy and dry seasons, and high production period, samples were taken three times a week. The lowest levels of nitrogen compounds were observed in the July/August period, which corresponded to lower fish production and low supply rattion in the culture ponds. During the experimental period, pH values ranged from acid to alkaline and did not oscillate with higher average values during April/May. Alkalinity and bicarbonate dominance in the medium were directly affected by pH. With respect to associated micro-fauna, among phyto-plankton Chlorophyta was the dominant group and among zooplankton, Rotifera. It is recommended that during production peaks, the aquatic plants should be replaced by small buds every 10 days.

  18. Use of native aquatic macrophytes in the reduction of organic matter from dairy effluents.

    Science.gov (United States)

    Queiroz, Rita de Cássia Souza de; Andrade, Rodrigo Santos; Dantas, Isadora Rosário; Ribeiro, Vinícius de Souza; Neto, Luciano Brito Rodrigues; Almeida Neto, José Adolfo de

    2017-08-03

    Considering the diversity and the unexplored potential of regional aquatic flora, this study aimed to identify and analyze the potential of native aquatic macrophytes to reduce the organic matter of dairy wastewater (DW) using experimental constructed wetlands. The dairy wastewater (DW) had an average chemical oxygen demand (COD) of 7414.63 mg/L and then was diluted to 3133.16 mg/L (D1) and to 2506.53 mg/L (D2). Total solids, COD, temperature, and pH analyses were performed, and the biochemical oxygen demand (BOD) was estimated from the COD values. The best performance in the reduction of the organic matter was observed for Polygonum sp. (87.5% COD and 79.6% BOD) and Eichhornia paniculata (90% COD and 83.7% BOD) at dilution D1, on the 8th day of the experiment. However, the highest total solids removal was observed for Polygonum sp. (32.2%), on the 4th day, at dilution D2. The total solid (TS) concentration has also increased starting from the 8th day of the experiment was observed which may have been due to the development of mosquito larvae and their mechanical removal by sieving, thus changing the steady state of the experimental systems. The macrophytes Polygonum sp. and E. paniculata were considered suitable for the reduction of organic matter of DW using constructed wetlands.

  19. Estimating cyclopoid copepod species richness and geographical distribution (Crustacea across a large hydrographical basin: comparing between samples from water column (plankton and macrophyte stands

    Directory of Open Access Journals (Sweden)

    Gilmar Perbiche-Neves

    2014-06-01

    Full Text Available Species richness and geographical distribution of Cyclopoida freshwater copepods were analyzed along the "La Plata" River basin. Ninety-six samples were taken from 24 sampling sites, twelve sites for zooplankton in open waters and twelve sites for zooplankton within macrophyte stands, including reservoirs and lotic stretches. There were, on average, three species per sample in the plankton compared to five per sample in macrophytes. Six species were exclusive to the plankton, 10 to macrophyte stands, and 17 were common to both. Only one species was found in similar proportions in plankton and macrophytes, while five species were widely found in plankton, and thirteen in macrophytes. The distinction between species from open water zooplankton and macrophytes was supported by nonmetric multidimensional analysis. There was no distinct pattern of endemicity within the basin, and double sampling contributes to this result. This lack of sub-regional faunal differentiation is in accordance with other studies that have shown that cyclopoids generally have wide geographical distribution in the Neotropics and that some species there are cosmopolitan. This contrasts with other freshwater copepods such as Calanoida and some Harpacticoida. We conclude that sampling plankton and macrophytes together provided a more accurate estimate of the richness and geographical distribution of these organisms than sampling in either one of those zones alone.

  20. Field evidence of the influence of aquatic macrophytes on water quality in a shallow eutrophic lake over a 13-year period

    Directory of Open Access Journals (Sweden)

    Edélti Faria Albertoni

    2014-06-01

    Full Text Available AIM: The main objective of this work is to describe the changes in water characteristics of a shallow subtropical lake, in periods with and without growing of macrophytes, related to periods of clear-macrophyte dominance and turbid-phytoplankton dominance states. METHODS: The study was conducted in Biguás Lake, in the south coastal plain of Brazil (32° 04' 43" S and 52° 10' 03" W. Samplings were carried out monthly between October 2000 and November 2013. The limnological variables measured in the water column were dissolved oxygen (DO, water temperature, pH, electrical conductivity (EC, chlorophyll-a, total nitrogen (TN, total phosphorous (TP and suspended material (SM. Data were grouped according to periods with macrophyte growth dominance (MD and without macrophytes, with phytoplankton dominance (PD, and applied t- tests among TP, TN, Chlorophyll-a and SM. During macrophyte growth we estimated the coverage (% and biomass variation of plants. RESULTS: Over the 13 years, the lake was well oxygenated, alkaline, and with a temperature variation according to subtropical seasonality. The lower values of all of the limnological variables were verified during periods of macrophyte growth, characterizing periods of clear and turbid waters. CONCLUSIONS: The influence of aquatic macrophytes in improving water quality in this shallow lake during the studied period, reducing nutrient concentrations, chlorophyll-a and suspended material in water, favoring the maintenance of a clear water state, was verified.

  1. Evaluation of Piper aduncum Linn. Essential Oil (Fam:Piperaceae against Periplaneta americana(L.

    Directory of Open Access Journals (Sweden)

    I Ling A

    2009-12-01

    Full Text Available Background: The efficacy of Piper aduncum essential oil was evaluated against Periplaneta americana adults and nymphs in the laboratory."nMethods: The plant essential oil at varying concentrations ranging between 10,000 to 80,000 ppm were placed inside glass beakers, rolled horizontally to ensure the essential oil covers all sides of the beakers and exposed to adults and nymphs of P. americana. Resigen (R 1ppm was used as positive control and distilled water as negative control. The LT50 and LT90 was obtained using Log Probit programme."nResults: Exposure of essential oil to females P. americana at concentrations between 10,000 to 80,000 ppm indicated the LT50 and LT90 values between 5.31 h-189.19 h and 14.90 h-2105.31 h, respectively. Treatment with the same con­centrations against males P. americana ,the LT50 and LT90 were 2.08 h-181.73 h and 5.4 h-8460.51 h, respectively. Treatment against the nymphal stage with the same range of concentrations indicated the LT50 and LT 90 of 4.68 h-381.02 h and 28.71 h-5313.36 h, respectively.The nymphs and males were more susceptible than the females cock­roaches. Treatment with Resigen (R at 1ppm indicated much lower LT 50 and LT 90 values of 2.54 h-9.47 h for the fe­males, 1.47 h-4.22 h for the males and 4.69 h-8.92 h for the nymphs.The negative control indicated no mortality for all stages of the cockroach."nConclusion: Piper aduncum essential oil can be used as an alternative natural product for controlling the cockroach Peri­patetic americana. "nKeywords: Piper aduncum essential oil, Periplaneta americana, Adults, Nymphs

  2. Bioactivity effect of two macrophyte extracts on growth performance of two bloom-forming cyanophytes

    Directory of Open Access Journals (Sweden)

    M.G. Ghobrial

    2015-01-01

    Full Text Available Allelopathy is a biological phenomenon by which an organism produces one or more biochemicals that influence the growth, survival, and reproduction of other organisms. These biochemicals are known as allelochemicals and can have beneficial (positive allelopathy or detrimental (negative allelopathy effects on the target organisms. The current research aims at using selected brackish water adapted submerged aquatic macrophytes allelopathy to combat bloom-forming cyanophytes, in laboratory bioassay experiments. Dry matters of macrophytes were extracted in solvents and the initial cyanophytes inoculum, derived from unialgal culture media, was used. Therefore, aqueous extracts with 50% and 100% acetone and ethanol solvents of two freshwater macrophytes; Potamogeton pectinatus and Ceratophyllum demersum were used to test their growth performance exhibited on two bloom-forming cyanophytes, Microcystis aeruginosa and Oscillatoria tenuis. The results revealed insignificant difference between the overall total average growth performance at treatment with 50% and 100% Ceratophyllum acetone extracts expressed by optical density (OD as well as chlorophyll a (chl a. Results showed, also, stimulation of M. aeruginosa growth. The highest growth increase in 100 μl/100 ml treatment with 50% acetone extract had a percentage rate (R of 94.66. On the contrary, treatment with ethanol extract recorded the highest inhibitory effect, thus in 1.5 μl/100 ml treatment with 50% Ceratophyllum ethanol extract R recorded −87.54, sustaining LC50 value of 1.12 μl/100 ml. The highest stimulating effect in 105 μl/100 ml treatment with 50% Ceratophyllum acetone extracts against O. tenuis was; R, 169.4. The highest inhibition in 1500 μl/100 ml treatment with 50% Ceratophyllum ethanol extracts against O. tenuis was; R −74.32, with LC50 0.830 μl/100 ml. While, the highest inhibition by 50% and 100% Potamogeton acetone or ethanol extracts against M. aeruginosa was

  3. Geochemical Analyses of Macrophytes (Potamogeton sp.) and ancient DNA from Lake Karakul, Tajikistan

    Science.gov (United States)

    Heinecke, Liv; Epp, Laura S.; Mischke, Steffen; Reschke, Maria; Stoof-Leichsenring, Kathleen; Rajabov, Ilhomjon; Herzschuh, Ulrike

    2016-04-01

    Mountain ecosystems are very sensitive towards changes in moisture and temperature and therefore most likely to be affected by climate change. To be able to get a closer insight into the alpine system of the Pamir Mountains, a 11.25 m long core was retrieved from the eastern basin of Lake Karakul (3,929 m asl), Tajikistan, in 2012. In order to gain insights into changes in the paleo-productivity of Lake Karakul over the last 29 cal kyrs BP, we investigate temporal gradients of elemental content (TOC, TN) and stable isotopes (δ13C, δ15N) of macrophyte remains (Potamogeton sp.) and plant communities obtained from ancient sedimentary DNA along the core. For the geochemical analyses we make use of the ability of submerged macrophytes, such as Potamogeton, to use HCO3- for photosynthesis in times of CO2 shortage and implement our results in a transfer function for paleo-productivity inferences. No data are available from 20 to 7 cal kyrs BP as no macrophyte remains are preserved, indicating unfavourable conditions for plant growth at the coring site or poor preservation conditions during this time. Biogeochemical analyses show significant variations from core base until approx. 20 cal kyrs BP with TOCPotamogeton 25-45 %, TNPotamogeton 0.5 % - 1.5 %, δ13CPotamogeton below -9 ‰ and δ15NPotamogeton of below 3.5 ‰ suggesting a cooler climate and reflecting the last glacial maximum. Sediments in the upper 4.5 m (approx. 6.7 cal kyrs BP) are rich in macrophyte remains. TOCPotamogeton and TNPotamogeton values from this part of the core are higher, and an enrichment of heavier isotopes with δ13CPotamogeton up to -7 ‰ and δ15NPotamogeton up to 6 ‰ indicating a higher productivity within the lake due to more favourable conditions for macrophyte growths on the lake floor. We assume shifts towards a warmer climate and changes in lake level as the dominating causes. Ancient sedimentary DNA was extracted from selected sediment slices and a metabarcoding approach (using

  4. Effect of plant growth-promoting bacteria on the growth and fructan production of Agave americana L.

    OpenAIRE

    Neyser De La Torre-Ruiz; Víctor Manuel Ruiz-Valdiviezo; Clara Ivette Rincón-Molina; Martha Rodríguez-Mendiola; Carlos Arias-Castro; Federico Antonio Gutiérrez-Miceli; Héctor Palomeque-Dominguez; Reiner Rincón-Rosales

    2016-01-01

    ABSTRACT The effect of plant growth-promoting bacteria inoculation on plant growth and the sugar content in Agave americana was assessed. The bacterial strains ACO-34A, ACO-40, and ACO-140, isolated from the A. americana rhizosphere, were selected for this study to evaluate their phenotypic and genotypic characteristics. The three bacterial strains were evaluated via plant inoculation assays, and Azospirillum brasilense Cd served as a control strain. Phylogenetic analysis based on the 16S rRN...

  5. The distribution of radionuclides between the sediments and macrophytes in the cooling pond of the Ignalina NPP - The Distribution of Radionuclides in Freshwater Hydro Ecosystem's Bottom Sediments and Macrophytes depending on the Ecological Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Marciulioniene, D.; Jefanova, O.; Mazeika, J. [Nature Research Centre, Akademijos str. 2, LT-08412 Vilnius, Lietuva (Lithuania)

    2014-07-01

    The distribution of {sup 137}Cs, {sup 60}Co, {sup 54}Mn in the aquatory of lake Drukshiai (the monitoring stations), the coastal area of this lake, the industrial drainage systems channel of the Ignalina NPP and the cooling water channel of the Ignalina NPP was analyzed on the basis of long-term (1988-2009) investigations of radionuclides specific activity in bottom sediments and macrophytes, also the ability of radionuclides falling into lake Drukshiai from the Ignalina NPP through effluents channels was assessed. It was established that {sup 137}Cs, {sup 60}Co and {sup 54}Mn in the bottom sediments and the macrophytes were distributed quite differently in the monitoring stations of lake Drukshiai and the coastal area as well as in the industrial drainage systems channel of the Ignalina NPP and the cooling water channel of the Ignalina NPP. The different characteristics of the sediments, various ecological conditions, as well as the existing anthropogenic environmental factors and the different in the ecological groups of the plants could have had impact on the distribution of {sup 137}Cs, {sup 60}Co and {sup 54}Mn in the bottom sediments and the aquatic plants in lake Drukshiai and the effluents channels of the Ignalina NPP. The {sup 137}Cs, {sup 60}Co and {sup 54}Mn specific activity's values were significantly higher in macrophytes from the industrial drainage systems channel of Ignalina NPP than in macrophytes from the cooling water channel. Nevertheless the specific activities level of these radionuclides differed only slightly in the macrophytes from the areas which were impacted by the effluents channels of the Ignalina NPP. This can be explained by the fact that the phyto-remediation (as the form of auto-purification) of these effluents from the radionuclides had been present in the industrial drainage systems channel of Ignalina NPP before entering the water into lake Drukshiai. (authors)

  6. Macrophyte growth module for the SWAT model – impact of climate change and management on stream ecology

    DEFF Research Database (Denmark)

    Lu, Shenglan; Trolle, Dennis; Erfurt, Jytte

    originates from the INCA-P model (Wade et al. 2002) with an addition of nitrogen stress. In addition, a benthic sediment layer and interaction of nutrients between sediment layer and water column were implemented. The new modules were validated against macrophyte biomass measurements in several Danish...

  7. Differences in acclimation potential of photosynthesis in seven isolates of the tropical to warm temperate macrophyte Valonia utricularis (Chlorophyta)

    NARCIS (Netherlands)

    Eggert, Anja; Visser, Ronald J. W.; Van Hasselt, Philip R.; Breeman, Anneke M.

    2006-01-01

    The potential to acclimate photosynthesis to sub- and supra-optimal temperatures was investigated in seven isolates of Valonia utricularis (Roth) C. Agardh, a green macrophyte with a tropical to warm-temperate distribution. Photosynthesis-light response curves were obtained by measuring chlorophyll

  8. Predicting Changes in Macrophyte Community Structure from Functional Traits in a Freshwater Lake: A Test of Maximum Entropy Model.

    Science.gov (United States)

    Fu, Hui; Zhong, Jiayou; Yuan, Guixiang; Guo, Chunjing; Lou, Qian; Zhang, Wei; Xu, Jun; Ni, Leyi; Xie, Ping; Cao, Te

    2015-01-01

    Trait-based approaches have been widely applied to investigate how community dynamics respond to environmental gradients. In this study, we applied a series of maximum entropy (maxent) models incorporating functional traits to unravel the processes governing macrophyte community structure along water depth gradient in a freshwater lake. We sampled 42 plots and 1513 individual plants, and measured 16 functional traits and abundance of 17 macrophyte species. Study results showed that maxent model can be highly robust (99.8%) in predicting the species relative abundance of macrophytes with observed community-weighted mean (CWM) traits as the constraints, while relative low (about 30%) with CWM traits fitted from water depth gradient as the constraints. The measured traits showed notably distinct importance in predicting species abundances, with lowest for perennial growth form and highest for leaf dry mass content. For tuber and leaf nitrogen content, there were significant shifts in their effects on species relative abundance from positive in shallow water to negative in deep water. This result suggests that macrophyte species with tuber organ and greater leaf nitrogen content would become more abundant in shallow water, but would become less abundant in deep water. Our study highlights how functional traits distributed across gradients provide a robust path towards predictive community ecology.

  9. Water quality and communities associated with macrophytes in a shallow water-supply reservoir on an aquaculture farm.

    Science.gov (United States)

    Sipaúba-Tavares, L H; Dias, S G

    2014-05-01

    Plankton communities and macrofauna associated to aquatic macrophyte stands in a shallow water-supply reservoir (21°14'09″S; 48°18'38″W) on an aquaculture farm were compared to evaluate the relationship between organism densities and some abiotic features of the reservoir. Water and communities associated were sampled at two sites, one in an area with the predominance of Eichhornia azurea (Sw.) Kunth and the other with the predominance of Salvinia auriculata Aublet. Communities associated with macrophytes were sampled with floating quadrants (0.5 m2); the macrophytes were washed and plankton and macrofauna were fixated with 4% formalin and 1% lugol iodine; the specimens were then identified and counted. Plankton and macrofauna communities associated with S. auriculata and E. azurea had a similar diversity of species but different (pmacrophytes presence in the shallow reservoir is a strong predictor of favourable conditions to maintain great diversity plankton community and macrofauna associated with plants. The role of macrophytes is important for not only stabilising the clear-water state and maintaining high diversity of organisms associated, but also it seems to be a good alternative to maintaining desirable water-supply quality for aquaculture farms.

  10. Influence of emergent macrophyte (Phragmites australis) density on water turbulence and erosion of organic-rich sediment

    Institute of Scientific and Technical Information of China (English)

    HORPPILA Jukka; KAITARANTA Joni; JOENSUU Laura; NURMINEN Leena

    2013-01-01

    The effects of the emergent macrophyte Phragmites australis on water turbulence,bottom shear velocity and water turbidity were experimentally studied with the stem densities 0 stems/m2-100 stems/m2 and using organic-rich sediment.It is found that the maximum root-mean-square (rms) velocity and shear velocity decrease linearly with increasing stem density.By affecting the height of peak turbulence values,emergent plants can thus lower the frequency of sediment erosion events.Additionally,the slope of the rms turbulence increment decreases with increasing stem density.Thus,also the duration of strong turbulence is affected by the density of emergent macrophytes.The critical shear velocity for sediment resuspension is 0.0035 rn/s-0.0055 rn/s and not affected by the stem density.In the absence of macrophytes,water flow causes a 6.3-fold increment in turbidity,but with macrophytes turbidity values remain lower.The experiments suggest that even relatively low densities of Phragmites can have substantial effects on water turbulence and consequently on water quality.

  11. Forms and lability of phosphorus in algae and aquatic macrophytes characterized by solution 31P NMR coupled with enzymatic hydrolysis

    Science.gov (United States)

    Increased information on forms and lability of phosphorus (P) in aquatic macrophytes and algae is crucial for better understanding of P biogeochemical cycling in eutrophic lakes. In this work, solution 31P nuclear magnetic resonance (NMR) spectroscopy coupled with enzymatic hydrolysis (EH) was used ...

  12. Quantification of the impact of macrophytes on oxygen dynamics and nitrogen retention in a vegetated lowland river

    NARCIS (Netherlands)

    Desmet, N.J.S.; Van Belleghem, S.; Seuntjens, P.; Bouma, T.J.; Buis, K.; Meire, P.

    2011-01-01

    When macrophytes are growing in the river, the vegetation induces substantial changes to the water quality. Some effects are the result of direct interactions, such as photosynthetic activity or nutrient uptake, whereas others may be attributed to indirect effects of the water plants on

  13. Assessing the Legacy of Red Mud Pollution in a Shallow Freshwater Lake: Arsenic Accumulation and Speciation in Macrophytes.

    Science.gov (United States)

    Olszewska, Justyna P; Meharg, Andrew A; Heal, Kate V; Carey, Manus; Gunn, Iain D M; Searle, Kate R; Winfield, Ian J; Spears, Bryan M

    2016-09-06

    Little is known about long-term ecological responses in lakes following red mud pollution. Among red mud contaminants, arsenic (As) is of considerable concern. Determination of the species of As accumulated in aquatic organisms provides important information about the biogeochemical cycling of the element and transfer through the aquatic food-web to higher organisms. We used coupled ion chromatography and inductively coupled plasma mass spectrometry (ICP-MS) to assess As speciation in tissues of five macrophyte taxa in Kinghorn Loch, U.K., 30 years following the diversion of red mud pollution from the lake. Toxic inorganic As was the dominant species in the studied macrophytes, with As species concentrations varying with macrophyte taxon and tissue type. The highest As content measured in roots of Persicaria amphibia (L.) Gray (87.2 mg kg(-1)) greatly exceeded the 3-10 mg kg(-1) range suggested as a potential phytotoxic level. Accumulation of toxic As species by plants suggested toxicological risk to higher organisms known to utilize macrophytes as a food source.

  14. Stable nitrogen isotope ratios of macrophytes and associated periphyton along a nitrate gradient in two subtropical, spring-fed streams

    DEFF Research Database (Denmark)

    De Brabandere, Loreto; Frazer, Thomas K.; Montoya, Joseph P.

    2007-01-01

    , macrophytes and periphyton as a consequence of isotopic fractionation associated with preferential use of 14NO3-. This hypothesis was tested in two spring-fed river systems, the Chassahowitzka and Homosassa rivers, along Florida’s central Gulf of Mexico coast. 3. In general, d15N values of nitrate...

  15. Macrobenthos of Vembanad estuary in relation to the deposition of degraded water fern Salvinia and other macrophytes

    Digital Repository Service at National Institute of Oceanography (India)

    Gopalan, U.K.; Meenakshikunjamma, P.P.; Vengayil, D.T.

    Composition and seasonal abundance of macrobenthos in Vembanad estuary (India) seems to be influenced by the density of decaying macrophytes, especially the water fern Salvinia , deposited at the bottom of the estuary at the rate of 356.76 g/m super...

  16. Contribuição ao estudo da Tripanosomiase Americana

    Directory of Open Access Journals (Sweden)

    Bichat de Almeida Rodrigues

    1942-01-01

    ano (época do estío. 6 Em plena mata, n’uma toca de tamanduá (T. tetradactylus foram encontradas larvas, ninfas e adultos de P. geniculatus. A casa situada mais próximo desse foco, foi a que apresentou maior infestação (22 exemplares e exclusiva para essa espécie. Em uma toca de macaco da noite (P. flavus, foi encontrada uma larva de Triatomídeo. Este foco também ficava próximo à casa acima referida. Em toca de P. flavus foi também achado um exemplar adulto de Panstrongylus refotuberculatus. 7 Amostras de S. cruzi isoladas de animais silvestres, mostraram fraco poder infectante. A amostra isolada do cão, embora infectando facilmente os animais de laboratório, pelos estudos biométricos feito por DIAS e FREITAS, afasta-se das amostras humanas típicas. 8 São discutidos os resultados acima referidos e, pelos hábitos dos transmissores, pela predominância de depositários silvestres do parasito, conclue-se pela natureza silvestre da Tripanosomiase Americana no local estudado. Se bem que não tenham sido verificadas infecções humanas, dado o encontro de um cão parasitado – infecção esta que se pode ter verificado pelo meio normal da transmissão da moléstia – admite-se a possibilidade do aparecimento de casos humanos nessa região. Ressalta-se a confirmação que tais resultados parecem trazer á hipótese de CARLOS CHAGAS, que pensava ser esta doença primitivamente silvestre, com posterior adaptação aos animais domésticos e ao homem.1 The epidemiology of Chagas’ disease was studied for the first time in a systematized work, in a district of the region of the Amazon estuary, whose ecological conditions differ from those encountered in other zones where similar researches have been made. 2 At the place chosen for the studies – Aurá – a locality about 10 kms from Belem (State of Pará, no human infection by S. cruzi has been found, either by blood examination or xenodiagnosis, both having been tried on all the inhabitants (117 people

  17. Morphometry and retention time as forcing functions to establishment and maintenance of aquatic macrophytes in a tropical reservoir

    Directory of Open Access Journals (Sweden)

    M. B. Cunha-Santino

    Full Text Available Abstract Macrophytes may constitute an important resource for several chemical, physical and biological processes within aquatic ecosystems. This study considers that in tropical reservoirs with low retention time and with low values of shoreline development (DL, the expansion and persistence of aquatic macrophytes are mainly reported to local conditions (e.g., hydrodynamic and wind exposure rather than trophic status and depth of the euphotic zone. In this context, this study aimed at describing and comparing the incidence of aquatic macrophytes in a throughflowing, non-dendritic tropical reservoir. During February 2006 to November 2007, eight limnological surveys were performed quarterly within the Ourinhos Reservoir, and in the mouth areas of its tributaries. At the six sampling stations 30 variables were measured. The number of sites with plants varied between 21 and 38 and at the end of the 1st year the total richness was found. The sampling survey outcome the recognition of 18 species of aquatic macrophytes; Cyperaceae (2 genera and 1 species, Pontederiaceae (3 species and Onarograceae (3 genera were the families with higher diversity. Seven species (Typha domingensis Pers., Myriophyllum aquaticum (Vell. Verdec, Salvinia auriculata Aubl., Eichhornia azurea (Sw. Kunth, Eleocharis sp1, Eichhornia crassipes (Mart. Solms, Oxycaryum cubense (Poepp. & Kunth Lye always were present and were more frequent in the sites. The occurrence of emergent species predominated (45.9%, followed by submersed rooted (24.5%, free floating (19.5%, floating rooted (9.7% and free submersed (0.3%. Although limnological variables and the distribution of macrophytes have discriminated the same sampling points, the stepwise multiple linear regressions did not pointed out strong correspondences (or coherence among the most constant and distributed macrophyte species and the selected limnological variables, as well the trophic statuses. Seeing the low relationship among

  18. Morphometry and retention time as forcing functions to establishment and maintenance of aquatic macrophytes in a tropical reservoir.

    Science.gov (United States)

    Cunha-Santino, M B; Fushita, A T; Peret, A C; Bianchini-Junior, I

    2016-05-03

    Macrophytes may constitute an important resource for several chemical, physical and biological processes within aquatic ecosystems. This study considers that in tropical reservoirs with low retention time and with low values of shoreline development (DL), the expansion and persistence of aquatic macrophytes are mainly reported to local conditions (e.g., hydrodynamic and wind exposure) rather than trophic status and depth of the euphotic zone. In this context, this study aimed at describing and comparing the incidence of aquatic macrophytes in a throughflowing, non-dendritic tropical reservoir. During February 2006 to November 2007, eight limnological surveys were performed quarterly within the Ourinhos Reservoir, and in the mouth areas of its tributaries. At the six sampling stations 30 variables were measured. The number of sites with plants varied between 21 and 38 and at the end of the 1st year the total richness was found. The sampling survey outcome the recognition of 18 species of aquatic macrophytes; Cyperaceae (2 genera and 1 species), Pontederiaceae (3 species) and Onarograceae (3 genera) were the families with higher diversity. Seven species (Typha domingensis Pers., Myriophyllum aquaticum (Vell.) Verdec, Salvinia auriculata Aubl., Eichhornia azurea (Sw.) Kunth, Eleocharis sp1, Eichhornia crassipes (Mart.) Solms, Oxycaryum cubense (Poepp. & Kunth) Lye) always were present and were more frequent in the sites. The occurrence of emergent species predominated (45.9%), followed by submersed rooted (24.5%), free floating (19.5%), floating rooted (9.7%) and free submersed (0.3%). Although limnological variables and the distribution of macrophytes have discriminated the same sampling points, the stepwise multiple linear regressions did not pointed out strong correspondences (or coherence) among the most constant and distributed macrophyte species and the selected limnological variables, as well the trophic statuses. Seeing the low relationship among limnological

  19. Co-occurrence between macrophytes and macroinvertebrates: towards a new approach for the running waters quality evaluation?

    Directory of Open Access Journals (Sweden)

    Lorenzo Traversetti

    2014-08-01

    Full Text Available Several studies on concordance between macrophyte and macroinvertebrate communities were carried out for decades while any investigation on co-occurrence of single pair of taxa of these two groups was never addressed. Our main aim was to verify the existence of co-occurrence of single macrophyte–macroinvertebrate pair in a Mediterranean river of central Italy. We compared the co-occurrence frequencies of different plant and animal taxa with those expected by chance through the null model approach. Specifically, we proposed two main co-occurrence patterns of macrophyte and macroinvertebrate taxa in terms of aggregation (when groups co-occur more frequently than expected and segregation (when groups co-occur less frequently than expected. This approach was supported by correlations and analysis of covariance in order to identify the most significant co-occurring pairs. In this study we collected a total of 123 taxa (50 macrophytes + 73 macroinvertebrates in October 2008 and 102 (42+60 in June 2009. We obtained a total of 379 significantly correlating macrophyte-macroinvertebrate pairs. Amongst all these correlating pairs, 83.7% of them correlated in October session while 90.3% in June. All the correlating pairs showed a high relationships with human alterations in both the sampling sessions. Our results confirmed that direct correlations there are between macrophytes and macroinvertebrates, highlighting how these two biological groups co-occur mainly following the aggregative model in both sampling sessions. Therefore, it was possible to observe significant relationships between macrophyte and macroinvertebrate pairs along an entire river ecosystem. It allows us to demonstrate that there are some prospective for trying to increase the knowledge on macrophytes-macroinvertebrates co-occurrence and for suggesting to use only single pair of co-occurring taxa in the monitoring running water quality. Aware that more investigations ought to be

  20. Secondary metabolites from the unripe pulp of Persea americana and their antimycobacterial activities.

    Science.gov (United States)

    Lu, Ying-Chen; Chang, Hsun-Shuo; Peng, Chien-Fang; Lin, Chu-Hung; Chen, Ih-Sheng

    2012-12-15

    The fruits of Persea americana (Avocado) are nowadays used as healthy fruits in the world. Bioassay-guided fractionation of the active ethyl acetate soluble fraction has led to the isolation of five new fatty alcohol derivatives, avocadenols A-D (1-4) and avocadoin (5) from the unripe pulp of P. americana, along with 12 known compounds (6-17). These structures were elucidated by spectroscopic analysis. Among the isolates, avocadenol A (1), avocadenol B (2), (2R,4R)-1,2,4-trihydroxynonadecane (6), and (2R,4R)-1,2,4-trihydroxyheptadec-16-ene (7) showed antimycobacterial activity against Mycobacterium tuberculosis H(37)R(V)in vitro, with MIC values of 24.0, 33.8, 24.9, and 35.7 μg/ml, respectively.

  1. Pathogenicity of Aspergillus westerdijkiae to females and oothecae of Periplaneta Americana

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    Mariah Valente Baggio

    2016-01-01

    Full Text Available ABSTRACT: Cockroach control is performed by the application of chemical insecticides which exert high selective pressure on populations and introduces synthetic substances in the environment, motivating the search for other methods of control such as entomopathogenic fungi. The objectives of this study were to investigate the pathogenicity of the JAB 42 Aspergillus westerdijkiae to females and oothecae of Periplaneta americana and to demonstrate its mechanism of action on oothecae. Suspensions containing 106 to 108 conidia/ml were used to infect females and oothecae. Mortality and other variables such as scanning electron microscopy were used to demonstrate the mechanism of action of the fungus. The isolated JAB 42 A. westerdijkiae is pathogenic to oothecae of P. americana, with low capacity to kill females. Adhesion, germination, penetration and extrusion of the fungus on the cockroach oothecae were observed.

  2. Mariner-like elements in Rhynchosciara americana (Sciaridae) genome: molecular and cytological aspects.

    Science.gov (United States)

    Rezende-Teixeira, Paula; Siviero, Fábio; Andrade, Alexandre; Santelli, Roberto Vicente; Machado-Santelli, Gláucia M

    2008-06-01

    Two mariner-like elements, Ramar1 and Ramar2, are described in the genome of Rhynchosciara americana, whose nucleotide consensus sequences were derived from multiple defective copies containing deletions, frame shifts and stop codons. Ramar1 contains several conserved amino acid blocks which were identified, including a specific D,D(34)D signature motif. Ramar2 is a defective mariner-like element, which contains a deletion overlapping in most of the internal region of the transposase ORF while its extremities remain intact. Predicted transposase sequences demonstrated that Ramar1 and Ramar2 phylogenetically present high identity to mariner-like elements of mauritiana subfamily. Southern blot analysis indicated that Ramar1 is widely represented in the genome of Rhynchosciara americana. In situ hybridizations showed Ramar1 localized in several chromosome regions, mainly in pericentromeric heterochromatin and their boundaries, while Ramar2 appeared as a single band in chromosome A.

  3. Leishmaniose tegumentar americana: apresentação pouco comum American tegumentary leishmaniasis: an unusual presentation

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    Antonio Carlos Martins Guedes

    2008-10-01

    Full Text Available Relata-se caso de leishmaniose tegumentar americana com lesões proeminentes na face. Os critérios diagnósticos incluíram dados clínicos e epidemiológicos, intradermorreação de Montenegro, identificação de Leishmania pela reação em cadeia da polimerase e resposta clínica ao tratamento. A importância do relato se deve ao fato de se tratar de caso incomum de leishmaniose tegumentar americana.We report the case of a patient with American cutaneous leishmaniasis and prominent lesions on the face. Diagnostic criteria included clinical and epidemiological data, Montenegro's skin test, identification of Leishmania by means of polymerase chain reaction and clinical response to treatment. Our report is important to call attention to an unusual presentation of American cutaneous leishmaniasis.

  4. Manganese uptake and interactions with cadmium in the hyperaccumulator-Phytolacca Americana L

    Energy Technology Data Exchange (ETDEWEB)

    Peng Kejian [College of Life Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Hunan Research Academy of Environmental Sciences Changsha 410004 (China); Luo Chunling [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); You Wuxin [College of Life Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Lian Chunlan [Asian Natural Environmental Science Center, University of Tokyo, 1-1-8 Midori-cho, Nishitokyo, Tokyo 188-0002 (Japan); Li Xiangdong [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Shen Zhenguo [College of Life Sciences, Nanjing Agricultural University, Nanjing 210095 (China)], E-mail: zgshen@njau.edu.cn

    2008-06-15

    In the present study, the accumulation of Mn and other metals by Phytolacca Americana L. from contaminated soils in Hunan Province, South China, was investigated. Results showed that the average concentrations of Mn in the leaves and roots reached 2198 and 80.4 mg kg{sup -1} (dry weight), respectively, with a maximum 13,400 mg kg{sup -1} in the leaves. A significant correlation was found between Mn concentrations in the plant leaves and those in the corresponding soils. Hydroponic experiments were also conducted to study the Cd uptake ability and interactions between Mn and Cd in the plant. It was found that P. americana hyperaccumulated not only Mn, but also Cd in the leaves. In the presence of Cd, adding Mn to the solution significantly improved the plant growth and reduced the concentrations of Cd in all organs of the plant.

  5. Applications of Microencapsulated Bifidobacterium Longum with Eleutherine Americana in Fresh Milk Tofu and Pineapple Juice

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    Atchara N. Phoem

    2015-04-01

    Full Text Available Bifidobacterium longum was microencapsulated by extrusion technique and added in fresh milk tofu and pineapple juice. Microencapsulation of B. longum with Eleutherine americana extract, oligosaccharides extract, and commercial fructo-oligosaccharides was assessed for the bacterial survival after sequential exposure to simulated gastric and intestinal juices, and refrigeration storage. Microencapsulated B. longum with the extract and oligosaccharides extract in the food products showed better survival than free cells under adverse conditions. Sensory analysis demonstrated that the products containing co-encapsulated bacterial cells were more acceptable by consumers than free cells. Pineapple juice prepared with co-encapsulated cells had lower values for over acidification, compared with the juice with free cells added. This work suggested that microencapsulated B. longum with E. americana could enhance functional properties of fresh milk tofu and pineapple juice.

  6. Applications of microencapsulated Bifidobacterium longum with Eleutherine americana in fresh milk tofu and pineapple juice.

    Science.gov (United States)

    Phoem, Atchara N; Chanthachum, Suphitchaya; Voravuthikunchai, Supayang P

    2015-04-01

    Bifidobacterium longum was microencapsulated by extrusion technique and added in fresh milk tofu and pineapple juice. Microencapsulation of B. longum with Eleutherine americana extract, oligosaccharides extract, and commercial fructo-oligosaccharides was assessed for the bacterial survival after sequential exposure to simulated gastric and intestinal juices, and refrigeration storage. Microencapsulated B. longum with the extract and oligosaccharides extract in the food products showed better survival than free cells under adverse conditions. Sensory analysis demonstrated that the products containing co-encapsulated bacterial cells were more acceptable by consumers than free cells. Pineapple juice prepared with co-encapsulated cells had lower values for over acidification, compared with the juice with free cells added. This work suggested that microencapsulated B. longum with E. americana could enhance functional properties of fresh milk tofu and pineapple juice.

  7. Water quality and communities associated with macrophytes in a shallow water-supply reservoir on an aquaculture farm

    Directory of Open Access Journals (Sweden)

    LH. Sipaúba-Tavares

    Full Text Available Plankton communities and macrofauna associated to aquatic macrophyte stands in a shallow water-supply reservoir (21°14′09″S; 48°18′38″W on an aquaculture farm were compared to evaluate the relationship between organism densities and some abiotic features of the reservoir. Water and communities associated were sampled at two sites, one in an area with the predominance of Eichhornia azurea (Sw. Kunth and the other with the predominance of Salvinia auriculata Aublet. Communities associated with macrophytes were sampled with floating quadrants (0.5 m2; the macrophytes were washed and plankton and macrofauna were fixated with 4% formalin and 1% lugol iodine; the specimens were then identified and counted. Plankton and macrofauna communities associated with S. auriculata and E. azurea had a similar diversity of species but different (p<0.05 in the abundance of associated organisms. Eichhornia azurea had the highest contents in dry and wet weight, total phosphorus, total nitrogen and organic matter. Planktonic algae were directly correlated with biomass of E. azurea. The taxa with highest densities were Rotifera and Zygnematophyceae. Results showed that the environmental variables associated with macrophytes presence in the shallow reservoir is a strong predictor of favourable conditions to maintain great diversity plankton community and macrofauna associated with plants. The role of macrophytes is important for not only stabilising the clear-water state and maintaining high diversity of organisms associated, but also it seems to be a good alternative to maintaining desirable water-supply quality for aquaculture farms.

  8. How TK-TD and population models for aquatic macrophytes could support the risk assessment for plant protection products.

    Science.gov (United States)

    Hommen, Udo; Schmitt, Walter; Heine, Simon; Brock, Theo Cm; Duquesne, Sabine; Manson, Phil; Meregalli, Giovanna; Ochoa-Acuña, Hugo; van Vliet, Peter; Arts, Gertie

    2016-01-01

    This case study of the Society of Environmental Toxicology and Chemistry (SETAC) workshop MODELINK demonstrates the potential use of mechanistic effects models for macrophytes to extrapolate from effects of a plant protection product observed in laboratory tests to effects resulting from dynamic exposure on macrophyte populations in edge-of-field water bodies. A standard European Union (EU) risk assessment for an example herbicide based on macrophyte laboratory tests indicated risks for several exposure scenarios. Three of these scenarios are further analyzed using effect models for 2 aquatic macrophytes, the free-floating standard test species Lemna sp., and the sediment-rooted submerged additional standard test species Myriophyllum spicatum. Both models include a toxicokinetic (TK) part, describing uptake and elimination of the toxicant, a toxicodynamic (TD) part, describing the internal concentration-response function for growth inhibition, and a description of biomass growth as a function of environmental factors to allow simulating seasonal dynamics. The TK-TD models are calibrated and tested using laboratory tests, whereas the growth models were assumed to be fit for purpose based on comparisons of predictions with typical growth patterns observed in the field. For the risk assessment, biomass dynamics are predicted for the control situation and for several exposure levels. Based on specific protection goals for macrophytes, preliminary example decision criteria are suggested for evaluating the model outputs. The models refined the risk indicated by lower tier testing for 2 exposure scenarios, while confirming the risk associated for the third. Uncertainties related to the experimental and the modeling approaches and their application in the risk assessment are discussed. Based on this case study and the assumption that the models prove suitable for risk assessment once fully evaluated, we recommend that 1) ecological scenarios be developed that are also

  9. Relative importance of P and N in macrophyte and epilithic algae biomass in a wastewater-impacted oligotrophic river.

    Science.gov (United States)

    Taube, Nadine; He, Jianxun; Ryan, M Cathryn; Valeo, Caterina

    2016-08-01

    The role of nutrient loading on biomass growth in wastewater-impacted rivers is important in order to effectively optimize wastewater treatment to avoid excessive biomass growth in the receiving water body. This paper directly relates wastewater treatment plant (WWTP) effluent nutrients (including ammonia (NH3-N), nitrate (NO3-N) and total phosphorus (TP)) to the temporal and spatial distribution of epilithic algae and macrophyte biomass in an oligotrophic river. Annual macrophyte biomass, epilithic algae data and WWTP effluent nutrient data from 1980 to 2012 were statistically analysed. Because discharge can affect aquatic biomass growth, locally weighted scatterplot smoothing (LOWESS) was used to remove the influence of river discharge from the aquatic biomass (macrophytes and algae) data before further analysis was conducted. The results from LOWESS indicated that aquatic biomass did not increase beyond site-specific threshold discharge values in the river. The LOWESS-estimated biomass residuals showed a variable response to different nutrients. Macrophyte biomass residuals showed a decreasing trend concurrent with enhanced nutrient removal at the WWTP and decreased effluent P loading, whereas epilithic algae biomass residuals showed greater response to enhanced N removal. Correlation analysis between effluent nutrient concentrations and the biomass residuals (both epilithic algae and macrophytes) suggested that aquatic biomass is nitrogen limited, especially by NH3-N, at most sampling sites. The response of aquatic biomass residuals to effluent nutrient concentrations did not change with increasing distance to the WWTP but was different for P and N, allowing for additional conclusions about nutrient limitation in specific river reaches. The data further showed that the mixing process between the effluent and the river has an influence on the spatial distribution of biomass growth.

  10. Vasorelaxant action of aqueous extract of the leaves of Persea americana on isolated thoracic rat aorta.

    Science.gov (United States)

    Owolabi, Mbang A; Jaja, Smith I; Coker, Herbert A B

    2005-09-01

    The present study investigated the vasorelaxant action of the aqueous leaves extract of Persea americana on isolated rat aorta. The results showed that the extract produced significant vasorelaxation and that the effect is dependent on the synthesis or release of endothelium-derived relaxing factors (EDRFs) as well as the release of prostanoid. The extract also reduced vasoconstriction probably by inhibiting Ca2+ influx through calcium channels.

  11. Optimization of Insoluble and Soluble Fibres Extraction from Agave americana L. Using Response Surface Methodology

    OpenAIRE

    Amine Bouaziz; Manel Masmoudi; Amel Kamoun; Souhail Besbes

    2014-01-01

    Experimental design methodology was used to determine significant factors affecting the extraction yield of soluble and insoluble fibres from Agave americana L. and in second time to find optimum conditions leading to the highest yield. Results clearly indicated that the temperature, the powder to water (P/W) ratio, and the agitation speed were the most important factors influencing fibres extraction yield which increased with temperature, P/W ratio, and agitation speed. Ionic strength affect...

  12. Phenotypic Variations in the Foliar Chemical Profile of Persea americana Mill. cv. Hass.

    Science.gov (United States)

    García-Rodríguez, Yolanda Magdalena; Torres-Gurrola, Guadalupe; Meléndez-González, Claudio; Espinosa-García, Francisco J

    2016-12-01

    The Hass avocado tree Persea americana cv. Hass was derived from a single hybrid tree of P. americana var. drymifolia and P. americana var. guatemalensis, and it is propagated clonally by grafting. This cultivar is the most widely planted in the world but its profile of secondary metabolites has been studied rarely despite of its importance in plant protection. We illustrate the variability of the volatilome of mature leaves by describing the average chemical composition and the phenotypic variability found in 70 trees. Contrary to the uniformity expected in the Hass cultivar, high variability coefficients were found for most of the 36 detected foliar volatile compounds; furthermore we found six chemotypes grouping the foliar phenotypes of the sampled trees using hierarchical cluster analysis. About 48% of trees were grouped in one chemotype; five chemotypes grouped the remaining trees. The compounds that determined these chemotypes were: estragole, α-farnesene, β-caryophyllene, germacrene D, α-cubebene and eugenol. This striking variation in a cultivar propagated clonally is discussed in terms of somatic mutation.

  13. Pro-apoptotic effect of Persea americana var. Hass (avocado) on Jurkat lymphoblastic leukemia cells.

    Science.gov (United States)

    Bonilla-Porras, Angelica R; Salazar-Ospina, Andrea; Jimenez-Del-Rio, Marlene; Pereañez-Jimenez, Andres; Velez-Pardo, Carlos

    2013-11-05

    Abstract Context: Therapy for leukemia has a limited efficacy. There is a need to search for alternative anti-leukemia therapies. Persea americana Mill var. Hass (Lauraceae) is a tropical fruit (avocado) that might be used against cancer. Objective: To investigate whether P. americana induces death in Jurkat lymphoblastic leukemia cells. Materials and methods: Four ethanol extracts (0.1, 0.5, 1, 2 and 5 mg/mL) from avocado fruit (endocarp, whole seed, seed and leaves) were analyzed against Jurkat cells. Hydrogen peroxide generation by oxidation of 2',7'-dichlorodihydrofluorescein diacetate to the fluorescent compound 2',7'-dichlorfluorescein assay, acridine orange/ethidium bromide staining, flow cytometry analysis of annexin-V/7-amino-actinomycin, mitochondrial membrane potential and immunocytochemistry detection of transcription factor p53, caspase-3 and apoptosis-inducing factor (AIF) were evaluated. Results: Endocarp, seed, whole seed, and leaf (0.1 mg/mL) extracts induced significant apoptosis in Jurkat cells (p americana extracts function as a pro-apoptotic compound. Leukemic cells are eliminated through an oxidative stress mechanism. This study contributes to the understanding of the molecular mechanism of the avocado and its therapeutic action on leukemia.

  14. Plant growth-promoting rhizobacteria affect the growth and nutrient uptake of Fraxinus americana container seedlings.

    Science.gov (United States)

    Liu, Fangchun; Xing, Shangjun; Ma, Hailin; Du, Zhenyu; Ma, Bingyao

    2013-05-01

    Plant growth-promoting rhizobacteria (PGPR) are important catalysts that regulate the functional properties of agricultural systems. However, there is little information on the effect of PGPR inoculation on the growth and nutrient accumulation of forest container seedlings. This study determined the effects of a growth medium inoculated with PGPR on the nutrient uptake, nutrient accumulation, and growth of Fraxinus americana container seedlings. PGPR inoculation with fertilizer increased the dry matter accumulation of the F. americana aerial parts with delayed seedling emergence time. Under fertilized conditions, the accumulation time of phosphorous (P) and potassium (K) in the F. americana aerial parts was 13 days longer due to PGPR inoculation. PGPR increased the maximum daily P and K accumulations in fertilized seedlings by 9.31 and 10.44 %, respectively, but had little impact on unfertilized ones. Regardless of fertilizer application, the root exudates, namely sugars, amino acids, and organic acids significantly increased because of PGPR inoculation. PGPR inoculation with fertilizer increased the root, shoot, and leaf yields by 19.65, 22.94, and 19.44 %, respectively, as well as the P and K contents by 8.33 and 10.60 %, respectively. Consequently, the N, P, and K uptakes increased by 19.85, 31.97, and 33.95 %, respectively. Hence, PGPR inoculation with fertilizer can be used as a bioenhancer for plant growth and nutrient uptake in forest container seedling nurseries.

  15. One pot phytosynthesis of gold nanoparticles using Genipa americana fruit extract and its biological applications

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Brajesh, E-mail: krmbraj@gmail.com [Centro de Nanociencia y Nanotecnologia, Universidad de las Fuerzas Armadas ESPE, Av. Gral. Rumiñahui s/n, Sangolqui, P.O. BOX 171-5-231B (Ecuador); Smita, Kumari; Cumbal, Luis [Centro de Nanociencia y Nanotecnologia, Universidad de las Fuerzas Armadas ESPE, Av. Gral. Rumiñahui s/n, Sangolqui, P.O. BOX 171-5-231B (Ecuador); Camacho, Javier [Centro de Nanociencia y Nanotecnologia, Universidad de las Fuerzas Armadas ESPE, Av. Gral. Rumiñahui s/n, Sangolqui, P.O. BOX 171-5-231B (Ecuador); Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Departamento de Farmacología, C.P. 07360 Mexico City (Mexico); Hernández-Gallegos, Elisabeth; Guadalupe Chávez-López, María de [Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Departamento de Farmacología, C.P. 07360 Mexico City (Mexico); Grijalva, Marcelo; Andrade, Kleber [Centro de Nanociencia y Nanotecnologia, Universidad de las Fuerzas Armadas ESPE, Av. Gral. Rumiñahui s/n, Sangolqui, P.O. BOX 171-5-231B (Ecuador)

    2016-05-01

    In this article, rapid one pot synthesis of gold nanoparticles (GNPs) using an eco-friendly extract of Genipa americana L. fruit is described. Electrospray ionization mass spectrometry (ESI-MS) and Fourier transform infrared (FTIR) spectroscopic studies demonstrated that small molecules such as genipin, genipaol, geniposide and ranolazine can act as reducer as well as stabilizers. The monodispersed, spherical GNPs were further characterized by UV–vis spectroscopy at λ{sub max} = 535 nm, transmission electron microscopy (TEM), dynamic light scattering (DLS) and X-ray diffraction (XRD) analysis. This synthetic approach offers a greener and alternate route to the preparation of GNPs free from toxic chemical components and stable for 6–7 months under room temperature. The green synthesized GNPs showed weak antioxidant efficacy against 1,1-diphenyl-2-picrylhydrazyl and no cytotoxicity against A-549 and HeLa human cancer cell lines, from lung and cervix. This study opens a new industrial scope of G. americana fruit in nanoscience and as surface modified GNPs can be developed into a successful drug carrier for future pharmaceutical products. - Highlights: • Gold nanoparticles can be synthesized by Genipa americana fruit extract. • TEM-DLS analysis confirmed that the average particle size is 30.4 ± 14.9 nm. • Nanoparticles showed weak antioxidant and no cytotoxicity activity.

  16. Detecção de Salmonella Anatum em ema (Rhea americana Detection of Salmonella Anatum in the Greater Rhea (Rhea americana

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    Rosecler Alves Pereira

    2008-06-01

    Full Text Available Para pesquisa de Salmonella spp. foram coletadas amostras de fígado e conteúdo cecal de 70 emas (Rhea americana abatidas no Rio Grande do Sul - Brasil. Uma colônia morfológica e bioquimicamente compatível com Salmonella spp., isolada de uma amostra de fígado, foi sorotipada como Salmonella Anatum. Considerando-se o alto potencial zoonótico deste microrganismo, destaca-se a relevância do controle microbiológico efetivo em frigoríficos que abatem espécies silvestres, assim como no produto final.In aiming to investigate the Salmonella spp. presence in one slaughterhouse in Rio Grande do Sul - Brazil, liver and cecum samples from 70 Greater Rhea (Rhea americana were collected. One Salmonella-like colonie was serologically typed and identified as Salmonella Anatum. Considering the high zoonotical potential of this microorganism, an effective microbiological control of wild animal slaughterhouses and the final product is needed.

  17. Ideas linguisticas de Lenz en los paratextos de su Diccionario etimologico de las voces chilenas derivadas de lenguas indigenas americanas: vigencia y urgencia en el espanol de Chile

    National Research Council Canada - National Science Library

    Chavez Fajardo, Soledad

    2011-01-01

    En el presente estudio se analizaran los componentes lexicograficos paratextuales del Diccionario etimologico de las voces chilenas derivadas de lenguas indigenas americanas de Rodolfo Lenz (1905-1910...

  18. Richness and composition of macrophyte assemblages in four Amazonian lakes - doi: 10.4025/actascibiolsci.v35i3.11602

    Directory of Open Access Journals (Sweden)

    Sidinei Magela Thomaz

    2013-08-01

    Full Text Available Aquatic macrophytes are an important component in the structure of lakes in Neotropical floodplains, for example, because they support a high diversity of invertebrates and vertebrates. In this paper, we tested whether or not the variability of macrophyte assemblages is lower in spatially close quadrats than among quadrats of different lakes. The study was carried in four lakes in a large Amazonian floodplain (Purus river, where floating meadows were investigated. A total of 49 taxa of macrophytes were found. Five species dominated and three species were rare. Taxa richness, composition and beta diversity differed more between than within lakes. Because high beta diversity was found among the lakes, they should be considered individually important for maintaining the gamma diversity of macrophytes within the Purus River floodplain, and this should be considered in plans of lake management.  

  19. Updated records and range expansion of alien marine macrophytes in Greece (2009

    Directory of Open Access Journals (Sweden)

    K. TSIAMIS

    2010-02-01

    Full Text Available In the present study the list of alien marine macrophytes already recorded on Greek coasts has been revised in the light of recent studies and new observations. In comparison  to 2008, the total number consists of 32 taxa, and the classification as established, casual and debatable species has been modified, with a total of 14, 5 and 13 species respectively. An interesting increase in established species from 9 taxa in 2008 to 14 taxa in 2009 is noted. With 23 taxa listed, Rhodobionta is the best represented group, followed by Chlorobionta (4 taxa and Chromobionta (4 taxa, while seagrasses (Streptobionta are represented by only one species. Several new records, one new entry and two putative additions are considered here, while two other taxa previously assumed introduced are excluded from the list of aliens.

  20. Use of macrophyte plants, sand & gravel materials in constructed wetlands for greywater treatment

    Science.gov (United States)

    Qomariyah, S.; Ramelan, AH; Sobriyah; Setyono, P.

    2017-02-01

    Greywater discharged without any treatments into drainage channels or natural water bodies will lead to environmental degradation and health risk. Local macrophyte plants combined with natural materials of sand and gravel have been used in a system of constructed wetland for the treatment of the greywater. This paper presents the results of some studies of the system carried out in Indonesia, Thailand, and Costa Rica. The studies demonstrate the success of the constructed wetland systems in removing some pollutants of BOD, COD, TSS, pathogen, and detergent. The studies resulted in the treated water in a level of treatment that fulfils the requirement of the local standards for wastewater reuse as irrigation water, fishery, or other outdoor needs.

  1. Aquatic macrophytes of Itaipu Reservoir, Brazil: survey of species and ecological considerations

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    Sidinei Magela Thomaz

    1999-01-01

    Full Text Available In a survey of the aquatic macrophytes of the Itaipu Reservoir, we identified 62 taxa in 25 families and 42 genera. The highest number taxa was observed for the emergent macrophytes (40 taxa. Reduced fluctuation in water level, increased light penetration, and sediment enrichment by nutrients and organic matter following the formation of the reservoir favored the appearance of a species-rich community of submerged macrophytes (23% of the taxa identified. The aquatic macrophytes were found mainly near the mouths of the main tributaries of the reservoir, in shallow area of depth less than 2 meters. In addition to the shallow depth, the greater nutrient input from the tributaries and relative protection from wind explained this distribution. Among the species found, Egeria najas merits mention for its occurrence in all localities sampled, with biomass values varying between 98 and 186 gDW/m². Some potential nuisance species such as Eichhornia crassipes, Salvinia auriculata, and Pistia stratiotes also deserve attention, since they were also observed to be covering large areas of Itaipu Reservoir.Em um levantamento de macrófitas aquáticas realizado no reservatório de Itaipu foram identificados 62 táxons pertencentes a 25 famílias e 42 gêneros. O maior número de táxons foi representado pelas macrófitas emergentes (40 táxons. O surgimento de uma rica comunidade de espécies submersas (23% dos táxons identificados parece ter sido favorecido pelas alterações decorrentes da formação dor reservatório, tais como redução da flutuação dos níveis de água, aumento da penetração de luz e enriquecimento do sedimento em nutrientes e matéria orgânica. As macrófitas aquáticas foram registradas principalmente próximo à foz dos tributários do reservatório, em áreas rasas (profundidade inferior a 2 metros. Além da reduzida profundidade, o maior aporte de nutrientes associado à proteção do vento explicam essa distribuição. Entre

  2. Aquatic macrophytes as feeding site for small fishes in the Rosana Reservoir, Paranapanema River, southeastern Brazil.

    Science.gov (United States)

    Casatti, L; Mendes, H F; Ferreira, K M

    2003-05-01

    In the present investigation we studied the feeding habits of the fishes associated with aquatic macrophytes in the Rosana Reservoir, southeastern Brazil. Twenty fish species were collected during four field trips, regularly distributed across the dry and wet seasons. Focal snorkeling observations of the fishes were made over a total of six hours. Nine species were present in abundances of more than 1% and, therefore, had their feeding habits analyzed. Hemigrammus marginatus, Roeboides paranensis, Hyphessobrycon eques, Astyanax altiparanae, Serrasalmus spilopleura, and Bryconamericus stramineus were predominantly invertivores, with predominance of aquatic insects (Diptera, Ephemeroptera, and Trichoptera immatures) among their food items. The predominantly algivores were Apareiodon affinis, Serrapinnus notomelas, and Satanoperca pappaterra, with high frequency of filamentous blue-green algae, diatoms, clorophyts, and periderm. The different microhabitat exploitation plus diet composition suggests partitioning of resources and absence of food competition among the most representative fish species in the studied community, indicating the importance of the naturalistic approach to fish ecology studies.

  3. Comparison of diversity indices applied to macrophyte incidence-based data

    Directory of Open Access Journals (Sweden)

    Heloísa Beatriz Antoniazi Evangelista

    2012-04-01

    Full Text Available In this work, a recently proposed diversity index based on Patil and Taillie parametric diversity measure (or Tsallis entropy, Sq*, was applied to samples (presence-absence data of macrophytes from the Itaipu Reservoir, Brazil. This new index was the value of the family of indices Sq for a specific evenness of a sample. Results demonstrated that the Shannon index and species richness showed expressively high correlation with the Sq*; however, the evenness had low correlation coefficients with the index Sq*, indicating that Sq* was particularly sensitive to rarity and species richness. On the other hand, the weak correlations of this index with evenness demonstrated that it was less sensitive to species relative abundances.

  4. The possibility of using macrophytes in lake Palić sediment remediation

    Directory of Open Access Journals (Sweden)

    Petričević J.

    2012-01-01

    Full Text Available Lake Palić is a typical, shallow Pannonian plain lake, with thick sediment layers and high content of phosphorus and nitrogen. The thick layers are the result of accelerated eutrophication, and cause biodiversity loss and disruption of the ecosystem. Numerous methods can be used to overcome the problem of accelerated eutrophication, (sediment removal, phosphorus inactivation etc.. However, these methods have many deficiencies. Lately, using macrophytes as a way to resolve this problem is becoming more and more popular. The aim of this work was to examine the germination possibilities of white mustard (Sinapis alba L., alfalfa (Medicago sativa L., oats (Avena sativa L. and lettuce (Lactuca sativa L. on Lake Palić’s sediment, as a prescreening test for their suitability for further phytoremediation. The results show that plant species can germinate and grow in early stages in such substrates, so they can be recommended for sediment phytoremediation. [Projekat Ministarstva nauke Republike Srbije, br. TR 31080

  5. Distribution and abundance of submerged aquatic macrophytes in a reactor cooling reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Grace, J.B.

    1977-08-01

    Measurements of ash-free dry weight were used to characterize the effects of a heated effluent on submerged macrophytes in a reactor cooling reservoir. The species which were most abundant during the summers of 1974 and 1975 were Myriophyllum spicatum L. and Eleocharis acicularis (L.) R. and S. Examination of the vertical distribution of the shoot biomass of Myriophyllum revealed that plants in heated areas grew closer to the water surface than plants in unheated areas. The biomass of the second most abundant species, Eleocharis acicularis, was less at 0.5 m depths in heated areas (more than 5C/sup 0/ warmer than unheated areas) than at equal depths in unheated areas. Species diversity was greater at heated locations because of a greater equitability (i.e., evenness of distribution of biomass) among species.

  6. EUTROPHICATION OF WATER RESERVOIRS AND ROLE OF MACROPHYTES IN THIS PROCESS

    Directory of Open Access Journals (Sweden)

    Joanna Jadwiga Sender

    2017-06-01

    Full Text Available The paper presents the problem related with the process of eutrophication, with special emphasis on dam reservoirs. Eutrophication is a global process, threatening the water ecosystem on every continent. It often leads to their degradation. Particularly vulnerable to eutrophication are artificial reservoirs which are dam reservoirs. This paper describes the mechanisms of eutrophication. We also pointed to the importance of aquatic plants in the process of water purification, as well as the possibility of multilateral use. Recently, in the world and in Poland there is a tendency to pay attention to the natural or semi-natural method of water purification (including constructed wetland. On the one hand, the presence of macrophytes in water bodies is a guarantor of good ecological status, on the other hand, the undeniable aesthetic value.

  7. Updated records and range expansion of alien marine macrophytes in Greece (2009

    Directory of Open Access Journals (Sweden)

    K. TSIAMIS

    2012-12-01

    Full Text Available In the present study the list of alien marine macrophytes already recorded on Greek coasts has been revised in the light of recent studies and new observations. In comparison  to 2008, the total number consists of 32 taxa, and the classification as established, casual and debatable species has been modified, with a total of 14, 5 and 13 species respectively. An interesting increase in established species from 9 taxa in 2008 to 14 taxa in 2009 is noted. With 23 taxa listed, Rhodobionta is the best represented group, followed by Chlorobionta (4 taxa and Chromobionta (4 taxa, while seagrasses (Streptobionta are represented by only one species. Several new records, one new entry and two putative additions are considered here, while two other taxa previously assumed introduced are excluded from the list of aliens.

  8. Reproductive Allocation in Three Macrophyte Species from Different Lakes with Variable Eutrophic Conditions

    Science.gov (United States)

    Wan, Tao; Han, Qingxiang; Xian, Ling; Cao, Yu; Andrew, Apudo A.; Pan, Xiaojie; Li, Wei; Liu, Fan

    2016-01-01

    Reproductive allocation is a key process in the plant life cycle and aquatic plants exhibit great diversity in their reproductive systems. In the present study, we conduct a field investigation of three aquatic macrophytes: Stuckenia pectinata, Myriophyllum spicatum, and Potamogeton perfoliatus. Our results showed that widespread species, including S. pectinata and M. spicatum had greater plasticity in their allocation patterns in the form of increased sexual and asexual reproduction, and greater potential to set seeds and increase fitness in more eutrophic environments. P. perfoliatus also exhibited a capacity to adopt varied sexual reproductive strategies such as setting more offspring for the future, although only in clear conditions with low nutrient levels. Our results establish strategies and mechanisms of some species for tolerating and surviving in varied eutrophic lake conditions. PMID:27806122

  9. Iron-induced oxidative stress in a macrophyte: a chemometric approach.

    Science.gov (United States)

    Sinha, Sarita; Basant, Ankita; Malik, Amrita; Singh, Kunwar P

    2009-02-01

    Iron-induced oxidative stress in plants of Bacopa monnieri L., a macrophyte with medicinal value, was investigated using the chemometric approach. Cluster analysis (CA) rendered two distinct clusters of roots and shoots. Discriminant analysis (DA) identified discriminating variables (NP-SH and APX) between the root and shoot tissues. Principal component analysis (PCA) results suggested that protein, superoxide dismutase (SOD), ascorbic acid, proline, and Fe uptake are dominant in root tissues, whereas malondialdehyde (MDA), guaiacol peroxidase (POD), cysteine, and non-protein thiol (NP-SH) in shoot of the stress plant. Discriminant partial-least squares (DPLS) results further confirmed that SOD and ascorbic acid contents dominated in root tissues, while NP-SH, cysteine, POD, ascorbate peroxidase (APX), and MDA in shoot. MDA and NP-SH were identified as most pronounced variables in plant during the highest exposure time. The chemometric approach allowed for the interpretation of the induced biochemical changes in plant tissues exposed to iron.

  10. Foliar uptake of cesium from the water column by aquatic macrophytes.

    Science.gov (United States)

    Pinder, J E; Hinton, T G; Whicker, F W

    2006-01-01

    The probable occurrence and rate of foliar absorption of stable cesium (133Cs) from the water column by aquatic macrophyte species was analyzed following the addition of 133Cs into a small reservoir near Aiken, South Carolina, USA. An uptake parameter u (10(3)Lkg(-1)d(-1)) and a loss rate parameter k (d(-1)) were estimated for each species using time series of 133Cs concentrations in the water and plant tissues. Foliar uptake, as indicated by rapid increases in plant concentrations following the 133Cs addition, occurred in two floating-leaf species, Brasenia schreberi and Nymphaea odorata, and two submerged species, Myriophyllum spicatum and Utricularia inflata. These species had values of u> or =0.75 x 10(3)Lkg(-1)d(-1). Less evidence for foliar uptake was observed in three emergent species, including Typha latifolia. Ratios of u to k for B. schreberi, M. spicatum, N. odorata and U. inflata can be used to estimate concentration ratios (CR) at equilibrium, and these estimates were generally within a factor of 2 of the CR for 137Cs for these species in the same reservoir. This correspondence suggests that foliar uptake of Cs was the principal absorption mechanism for these species. Assessments of: (1) the prevalence of foliar uptake of potassium, rubidium and Cs isotopes by aquatic macrophytes and (2) the possible importance of foliar uptake of Cs in other lentic systems are made from a review of foliar uptake studies and estimation of comparable u and k values from lake studies involving Cs releases.

  11. Foliar uptake of cesium from the water column by aquatic macrophytes

    Energy Technology Data Exchange (ETDEWEB)

    Pinder, J.E. [Savannah River Ecology Laboratory, University of Georgia, Drawer E, Aiken, SC 29801 (United States); Hinton, T.G. [Savannah River Ecology Laboratory, University of Georgia, Drawer E, Aiken, SC 29801 (United States)]. E-mail: thinton@srel.edu; Whicker, F.W. [Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523-1618 (United States)

    2006-07-01

    The probable occurrence and rate of foliar absorption of stable cesium ({sup 133}Cs) from the water column by aquatic macrophyte species was analyzed following the addition of {sup 133}Cs into a small reservoir near Aiken, South Carolina, USA. An uptake parameter u (10{sup 3} L kg{sup -1} d{sup -1}) and a loss rate parameter k (d{sup -1}) were estimated for each species using time series of {sup 133}Cs concentrations in the water and plant tissues. Foliar uptake, as indicated by rapid increases in plant concentrations following the {sup 133}Cs addition, occurred in two floating-leaf species, Brasenia schreberi and Nymphaea odorata, and two submerged species, Myriophyllum spicatum and Utricularia inflata. These species had values of u {>=} 0.75 x 10{sup 3} L kg{sup -1} d{sup -1}. Less evidence for foliar uptake was observed in three emergent species, including Typha latifolia. Ratios of u to k for B. schreberi, M. spicatum, N. odorata and U. inflata can be used to estimate concentration ratios (CR) at equilibrium, and these estimates were generally within a factor of 2 of the CR for {sup 137}Cs for these species in the same reservoir. This correspondence suggests that foliar uptake of Cs was the principal absorption mechanism for these species. Assessments of: (1) the prevalence of foliar uptake of potassium, rubidium and Cs isotopes by aquatic macrophytes and (2) the possible importance of foliar uptake of Cs in other lentic systems are made from a review of foliar uptake studies and estimation of comparable u and k values from lake studies involving Cs releases.

  12. Macrophyte distribution and ecological status of the Turiec River (Slovakia: Changes after seven years

    Directory of Open Access Journals (Sweden)

    Hrivnák R.

    2009-01-01

    Full Text Available Characteristics of diversity, abundance, distribution, and ecological status of aquatic macrophytes were observed in 2000 and 2007 on a circa 4.5 km long section of the Turiec River using Kohler's method. In comparison to 2000, the total number of macrophytes in 2007 increased markedly (from 25 to 35, although only the numbers of amphi­phytes and helophytes were changed substantially. The number of hydrophytes increased from 11 to 12; an invasive, Elodea canadenis, was the only new species. The relative plant mass of hydrophytes represents the bulk of all recorded species (95 and 80% in 2000 and 2007, respectively, and it was changed for most hydrophytes. The most significant changes were detected for Myriophyllum spicatum (decrease, filamentous algae (decrease, and Potamogeton crispus (increase. In 2007, the mean mass total (MMT sum of hydrophytes decreased from 16.46 to 14.5. On the other hand, the MMTsum of amphiphytes and helophytes doubled in value (7.4 and 14.1 in 2000 and 2007, respectively. Within hydrophytes, Batrachium species (including B. aquatile and B. trichophyllum, Myriophyllum spicatum, and Potamogeton crispus were ubiquitous (distribution ratio d > 0.5 in 2000, whereas in 2007 only Batrachium species and Potamogeton crispus were ubiquitous. At all times, Batrachium species were the most frequent species in the study area, and their abundance was relatively high (MMT> 2.5. A poor ecological status (MMP = 0.378 and MMP = 0.333 in 2000 and 2007, respectively of the surveyed river section was found in both years, but a slight decline of quality as determined on the basis of aquatic plants was observed after 7 years.

  13. Selection of wild macrophytes for use in constructed wetlands for phytoremediation of contaminant mixtures.

    Science.gov (United States)

    Guittonny-Philippe, Anna; Petit, Marie-Eléonore; Masotti, Véronique; Monnier, Yogan; Malleret, Laure; Coulomb, Bruno; Combroux, Isabelle; Baumberger, Teddy; Viglione, Julien; Laffont-Schwob, Isabelle

    2015-01-01

    Constructed wetlands (CWs) offer an alternative to traditional industrial wastewater treatment systems that has been proved to be efficient, cost-effective and environmentally friendly. Most of the time, CWs are planted with proliferative species such as Phragmites australis or with plants originating from nurseries, both representing a risk for the natural biodiversity conservation of aquatic ecosystems located downstream of the CWs. For the removal of metals and organic pollutant mixtures present in industrial effluents, it is necessary to select tolerant plant species that are able to produce a high aboveground biomass and to develop a healthy belowground system. Wild plant species growing in aquatic bodies at industrial outfalls could constitute suitable tolerant species to use in CWs for industrial effluent treatment. To test this hypothesis, we assessed, under laboratory conditions (using an experimental design), the tolerance to mixtures of metals (Al, As, Cd, Cu, Cr, Fe, Mn, Ni, Pb, Sn, Zn) or/and organic pollutants (THC, PHE, PYR, LAS) of five European sub-cosmopolitan native macrophytes (Alisma lanceolatum, Carex cuprina, Epilobium hirsutum, Iris pseudacorus and Juncus inflexus) that had been collected in a polluted Mediterranean wetland, after a field study (crossing ecological relevés and analyses of contaminant concentrations in water and sediments). Our results demonstrated that research on phytoremediation of industrial effluents should focus much more on the use of native macrophytes growing at short distances from industrial discharges (such as C. cuprina in this study), and that root/shoot ratio, aerial height and proportion of green leaves are good and cost-effective indicators of plant tolerance to metals and organic pollutant mixtures in laboratory studies. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. pH gradients in the diffusive boundary layer of subarctic macrophytes

    KAUST Repository

    Hendriks, Iris E.

    2017-06-20

    Highly productive macrophytes produce diurnal and seasonal cycles in CO concentrations modulated by metabolic activity, which cause discrepancies between pH in the bulk water and near seaweed blades, especially when entering the diffusion boundary layer (DBL). Calcifying epiphytic organisms living in this environment are therefore exposed to a different pH environment than that of the water column. To evaluate the actual pH environment on blade surfaces, we measured the thickness of the DBL and pH gradients within it for six subarctic macrophytes: Fucus vesiculosus, Ascophyllum nodosum, Ulva lactuca, Zostera marina, Saccharina longicruris, and Agarum clathratum. We measured pH under laboratory conditions at ambient temperatures (2–3 °C) and slow, stable flow over the blade surface at five light intensities (dark, 30, 50, 100 and 200 µmol photons m s). Boundary layer thickness ranged between 511 and 1632 µm, while the maximum difference in pH (∆pH) between the blade surface and the water column ranged between 0.4 ± 0.14 (average ± SE; Zostera) and 1.2 ± 0.13 (average ± SE; Ulva) pH units. These differences in pH are larger than predictions for pH changes in the bulk water by the end of the century. A simple quadratic model best described the relationship between light intensity and maximum ∆pH, pointing at relatively low optimum PAR of between 28 and 139 µmol photons m s to reach maximum ∆pH. Elevated pH at the blade surface may provide chemical “refugia” for calcifying epiphytic organisms, especially during summer at higher latitudes where photoperiods are long.

  15. Diversity and biomass of native macrophytes are negatively related to dominance of an invasive Poaceae in Brazilian sub-tropical streams

    OpenAIRE

    Luiz Felipe Gonçalves Fernandes; Mariana Carolina Teixeira; Sidinei Magela Thomaz

    2013-01-01

    Besides exacerbated exploitation, pollution, flow alteration and habitats degradation, freshwater biodiversity is also threatened by biological invasions. This paper addresses how native aquatic macrophyte communities are affected by the non-native species Urochloa arrecta, a current successful invader in Brazilian freshwater systems. We compared the native macrophytes colonizing patches dominated and non-dominated by this invader species. We surveyed eight streams in Northwest Paraná State (...

  16. Diversity and biomass of native macrophytes are negatively related to dominance of an invasive Poaceae in Brazilian sub-tropical streams

    OpenAIRE

    Luiz Felipe Gonçalves Fernandes; Mariana Carolina Teixeira; Sidinei Magela Thomaz

    2013-01-01

    Besides exacerbated exploitation, pollution, flow alteration and habitats degradation, freshwater biodiversity is also threatened by biological invasions. This paper addresses how native aquatic macrophyte communities are affected by the non-native species Urochloa arrecta, a current successful invader in Brazilian freshwater systems. We compared the native macrophytes colonizing patches dominated and non-dominated by this invader species. We surveyed eight streams in Northwest Paraná State (...

  17. Aquatic macrophytes in the large, sub-tropical Itaipu Reservoir, Brazil

    Directory of Open Access Journals (Sweden)

    Roger Paulo Mormul

    2010-12-01

    Full Text Available In the last three decades, rapid assessment surveys have become an important approach for measuring aquatic ecosystem biodiversity. These methods can be used to detect anthropogenic impacts and recognize local or global species extinctions. We present a floristic survey of the aquatic macrophytes along the Brazilian margin of the Itaipu Reservoir conducted in 2008 and compare this with a floristic survey conducted ten years earlier. We used ordination analysis to determine whether assemblage composition differed among reservoir arms. Macrophyte species were sampled in each of the 235 sampling stations using a boat, which was positioned inside three places of each macrophyte stand to record species and search for small plants. We also collected submerged plants using a rake with the boat moving at constant velocity for ten minutes. We assigned individual macrophyte species to life form and identified representative species for each life form. A total of 87 macrophyte taxa were identified. The "emergent" life forms contained the highest number of species, followed by "rooted submerged" life forms. The extensive survey of macrophytes undertaken in September 2008 recorded more species than a survey conducted between 1995 and 1998. This could be due to changes in water physico-chemistry, disturbances due to water drawdown and the long period between surveys, which may have allowed natural colonization by other species. Additionally, differences in the classification systems and taxonomic resolution used in the surveys may account for differences in the number of species recorded. Assemblage composition varied among the arms and was affected by underwater radiation (as measured using a Secchi disk and fetch. Five non-native species were found. Two of these non-native species (Urochloa subquadripara and Hydrilla verticillata are of special concern because they have a high frequency of occurrence and occupy large marginal areas of the reservoir. Future

  18. Herança e ligação em locos de isoenzimas em Genipa americana L. Inheritance and linkage in isozymes loci of Genipa americana L.

    Directory of Open Access Journals (Sweden)

    Alexandre Magno SEBBENN

    2004-06-01

    Full Text Available A herança e a ligação foram estudadasem quatro locos polimórficos (6pghd-1, Pgi-2,Mdh-1 e Mdh-2 de três sistemas isoenzimáticos deGenipa americana, analisados por eletroforesehorizontal em gel de amido, usando tecidoscoletados de quinze progênies de polinização aberta,procedentes de Moji-Guaçu, Estado de São Paulo.Esses locos segregaram de dois a três alelos.A segregação nesses locos foi homogênea entreárvores. Contudo, existem desvios significativos dasegregação esperada 1:1 para algumas árvores emalguns locos. Desvios significativos da razão desegregação esperada 1:1 foram detectados noslocos Mdh-2 e 6pgdh-1. Não foram detectadasevidências de ligação entre nenhum dos pares delocos avaliados em G. americana e esses podemser utilizados sem restrição para estudos do sistemade reprodução, diversidade e estrutura genética depopulações da espécie.Inheritance and linkage for fourpolymorphic loci (6pghd-1, Pgi-2, Mdh-1 andMdh-2 from three enzyme systems in Genipaamericana were analyzed by horizontal starch gelelectrophoresis using tissues collected from fiftyopen-pollinated families in Moji-Guaçu, São PauloState. These allozyme loci have segregated fromtwo to four alleles per polymorphic locus. Genesegregation on those loci was homogeneous amongtrees. However, there were significant deviationsfrom the expected segregation ratios on some lociand some individual trees. In addition, Mdh-2 and6pgdh-1 loci have shown significant deviationsfrom the 1:1 expected segregation ratio. Linkagedisequilibrium evidences were not detected betweenany two pairs of loci from G. americana and thosecan be used with no restriction to study the matingsystem, genetic diversity, and genetic structure onthe species.

  19. Simple Y-autosomal incompatibilities cause hybrid male sterility in reciprocal crosses between Drosophila virilis and D. americana.

    Science.gov (United States)

    Sweigart, Andrea L

    2010-03-01

    Postzygotic reproductive isolation evolves when hybrid incompatibilities accumulate between diverging populations. Here, I examine the genetic basis of hybrid male sterility between two species of Drosophila, Drosophila virilis and D. americana. From these analyses, I reach several conclusions. First, neither species carries any autosomal dominant hybrid male sterility alleles: reciprocal F(1) hybrid males are perfectly fertile. Second, later generation (backcross and F(2)) hybrid male sterility between D. virilis and D. americana is not polygenic. In fact, I identified only three genetically independent incompatibilities that cause hybrid male sterility. Remarkably, each of these incompatibilities involves the Y chromosome. In one direction of the cross, the D. americana Y is incompatible with recessive D. virilis alleles at loci on chromosomes 2 and 5. In the other direction, the D. virilis Y chromosome causes hybrid male sterility in combination with recessive D. americana alleles at a single QTL on chromosome 5. Finally, in contrast with findings from other Drosophila species pairs, the X chromosome has only a modest effect on hybrid male sterility between D. virilis and D. americana.

  20. Polifenoles en Myristicaceae americanas II. Distribución en especies colombianas Polifenoles en Myristicaceae americanas II. Distribución en especies colombianas

    Directory of Open Access Journals (Sweden)

    Aguirre Gálviz Luis Enrique

    1988-06-01

    Full Text Available

    The distribution of phenolic acids and flavonoid aglycones in 65 samples of 11 species of Colombian Myristicaceae was studied in order to complete the data obtained from other samples of American Myristicaceae. The occurrence and distribution of these compounds could be used for chemotaxonomic discusions of the family.

    Se estudió la distribución de polifenoles en 65 muestras de material de herbario de II especies de Myristicaceae coleccionadas en Colombia, con el objeto de complementar los datos obtenidos en otras muestras de Myristicaceae americanas. El patrón de distribución de estos compuestos podría servir para una discusión quimiotaxonómica de la familia.

  1. Periods and dry environments in the seeds quality of Genipa americana L.Períodos e ambientes de secagem na qualidade de sementes de Genipa americana L.

    Directory of Open Access Journals (Sweden)

    Riselane de Lucena Alcântara Bruno

    2011-07-01

    Full Text Available Genipa americana L. is a tropical tree belonging to Rubiaceae family, providing fruit that are consumed in natura and is being increasingly explored as raw material to liquor, wine, soft drink and also the use of white wood for making various products. The seeds drying this species can be made using natural and or artificial methods. Thus, this study aimed to evaluate the effects of natural drying, in different periods and ambient, in the physiological quality of Genipa americana seeds. Seeds were submitted to the determination of moisture content after processing and drying of each period (0, 24, 48, 72, 96, 120, 144 and 168 hours. To evaluate the effects of ambient (laboratory and greenhouse and drying periods were performed the following tests: emergence in greenhouse, emergence speed index, seedling length and dry weight. Drying seed genipa can be done in a greenhouse (temperature of 33°C with relative humidity of 70% for 24 hours or laboratory environment (temperature of 28°C with relative humidity of 75% for 48 hours without compromising the physiological quality.Genipa americana L. é uma árvore tropical, pertencente à família Rubiaceae, fornece frutos que são consumidos in natura e vem sendo explorada cada vez mais como matéria-prima de licor, vinho, refresco e também o uso da madeira branca para confecção de vários produtos. A secagem de sementes dessa espécie pode ser feita pelo método natural e/ou artificial. Dessa forma, este trabalho teve por objetivo avaliar o efeito da secagem natural, em diferentes ambientes e períodos, na qualidade fisiológica das sementes de Genipa americana. As sementes foram submetidas à determinação do teor de água após o beneficiamento em cada período de secagem (0, 24, 48, 72, 96, 120, 144 e 168 horas. Para a avaliação do efeito dos ambientes (laboratório e ambiente telado e períodos de secagem foram realizados os seguintes testes: emergência em ambiente telado, índice de

  2. Submersed macrophyte communities before and after an episodic ice jam in the St. Clair and Detroit rivers

    Science.gov (United States)

    Nichols, S. Jerrine; Schloesser, Donald W.; Hudson, Patrick L.

    1989-01-01

    We conducted surveys in 1983 and 1984 of submersed macrophyte communities off six islands in the St. Clair and Detroit rivers using low altitude aerial photography and ground-truth collections. Sample collections in 1984 followed one of the coldest winters on record, during which ice up to 4 m thick developed in areas that were normally ice-free. Growth of many of the 20 taxa collected was delayed in the spring of 1984, as compared with the spring of 1983. By September 1984, however, total abundance of all taxa was equal to or greater than that in 1983. The location, size, and shape of plant beds in September 1984 were similar to those in 1983. We concluded that the unusual ice jam in early spring of 1984 had little, if any, permanent effect on submersed macrophytes in the St. Clair and Detroit rivers.

  3. Aquatic macrophytes in cool aseasonal and seasonal streams: a comparison between Ecuadorian highland and Danish lowland streams

    DEFF Research Database (Denmark)

    Jacobsen, Dean; Terneus, Esteban

    2001-01-01

    -forms (submerged, amphibious, semiaquatic) was, however, different as submerged plants were less diverse in the Ecuadorian streams. Further, all submerged plants found in the Ecuadorian streams belonged to cosmopolitan genera with a mainly north-temperate distribution. We suggest that the low number of submerged......The diversity and community structure of aquatic macrophytes in aseasonal streams cool by altitude and seasonal streams cool by latitude was compared using a standardised approach. The aquatic vegetation in 12 small highland streams in the Ecuadorian Andes (3400–4100 m) and in 12 physically...... and chemically similar lowland streams in Denmark was examined. Our study confirmed that aquatic macrophyte communities in the neotropics are not particularly species rich. Total as well as mean species richness per stream were about the same in the two regions. The species richness within different life...

  4. Macrophyte and pH buffering updates to the Klamath River water-quality model upstream of Keno Dam, Oregon

    Science.gov (United States)

    Sullivan, Annett B.; Rounds, Stewart A.; Asbill-Case, Jessica R.; Deas, Michael L.

    2013-01-01

    A hydrodynamic, water temperature, and water-quality model of the Link River to Keno Dam reach of the upper Klamath River was updated to account for macrophytes and enhanced pH buffering from dissolved organic matter, ammonia, and orthophosphorus. Macrophytes had been observed in this reach by field personnel, so macrophyte field data were collected in summer and fall (June-October) 2011 to provide a dataset to guide the inclusion of macrophytes in the model. Three types of macrophytes were most common: pondweed (Potamogeton species), coontail (Ceratophyllum demersum), and common waterweed (Elodea canadensis). Pondweed was found throughout the Link River to Keno Dam reach in early summer with densities declining by mid-summer and fall. Coontail and common waterweed were more common in the lower reach near Keno Dam and were at highest density in summer. All species were most dense in shallow water (less than 2 meters deep) near shore. The highest estimated dry weight biomass for any sample during the study was 202 grams per square meter for coontail in August. Guided by field results, three macrophyte groups were incorporated into the CE-QUAL-W2 model for calendar years 2006-09. The CE-QUAL-W2 model code was adjusted to allow the user to initialize macrophyte populations spatially across the model grid. The default CE-QUAL-W2 model includes pH buffering by carbonates, but does not include pH buffering by organic matter, ammonia, or orthophosphorus. These three constituents, especially dissolved organic matter, are present in the upper Klamath River at concentrations that provide substantial pH buffering capacity. In this study, CE-QUAL-W2 was updated to include this enhanced buffering capacity in the simulation of pH. Acid dissociation constants for ammonium and phosphoric acid were taken from the literature. For dissolved organic matter, the number of organic acid groups and each group's acid dissociation constant (Ka) and site density (moles of sites per mole of

  5. Importance of Macrophyte Quality in Determining Life-History Traits of the Apple Snails Pomacea canaliculata: Implications for Bottom-Up Management of an Invasive Herbivorous Pest in Constructed Wetlands

    National Research Council Canada - National Science Library

    Yam, Rita S W; Fan, Yen-Tzu; Wang, Tzu-Ting

    2016-01-01

    Pomacea canaliculata (Ampullariidae) has extensively invaded most Asian constructed wetlands and its massive herbivory of macrophytes has become a major cause of ecosystem dysfunctioning of these restored habitats...

  6. Preparation, Characterization, and Microbial Degradation of Specifically Radiolabeled [14C]Lignocelluloses from Marine and Freshwater Macrophytes

    OpenAIRE

    1984-01-01

    Specifically radiolabeled [14C-lignin]lignocelluloses were prepared from the aquatic macrophytes Spartina alterniflora, Juncus roemerianus, Rhizophora mangle, and Carex walteriana by using [14C]phenylalanine, [14C]tyrosine, and [14C]cinnamic acid as precursors. Specifically radiolabeled [14C-polysaccharide]lignocelluloses were prepared by using [14C]glucose as precursor. The rates of microbial degradation varied among [14C-lignin]lignocelluloses labeled with different lignin precursors within...

  7. Biophysical interactions in fluvial ecosystems: effects of submerged aquatic macrophytes on hydro-morphological processes and ecosystem functioning

    Science.gov (United States)

    Cornacchia, Loreta; Davies, Grieg; Grabowski, Robert; van der Wal, Daphne; van de Koppel, Johan; Wharton, Geraldene; Bouma, Tjeerd

    2016-04-01

    Strong mutual interactions occur at the interface between biota and physical processes in biogeomorphic ecosystems, possibly resulting in self-organized spatial patterns. While these interactions and feedbacks have been increasingly studied in a wide range of landscapes previously, they are still poorly understood in lower energy fluvial systems. Consequently, their impact on the functioning of aquatic ecosystems is largely unknown. In this study we investigate the role of aquatic macrophytes as biological engineers of flow and sediment in lowland streams dominated by water crowfoot (Ranunculus spp.). Using field measurements from two annual growth cycles, we demonstrate that seasonally-changing macrophyte cover maintains relative constant flow rates, both within and between vegetation, despite temporal changes in channel flow discharge. By means of a mathematical model representing the interaction between hydrodynamics and vegetation dynamics, we reveal that scale-dependent feedbacks between plant growth and flow redistribution explain the influence of macrophytes on stabilizing flow rates. Our analysis reveals important implications for ecosystem functions. The creation of fast-flowing channels allows an adequate conveyance of water throughout the annual cycle; yet, patches also have a significant influence on sediment dynamics leading to heterogeneous habitats, thereby facilitating other species. As a last step we investigate the consequences on stream ecosystem functioning, by exploring the relationship between changes in macrophyte cover and the provision of different ecosystem functions (e.g. water conveyance, sediment trapping). Our results highlight that self-organization promotes the combination of multiple ecosystem functions through its effects on hydrological and morphological processes within biogeomorphic ecosystems.

  8. Distribution et assemblages des macrophytes le long d’un gradient d'hydrodynamisme : application au lac de Lacanau (Gironde)

    OpenAIRE

    F. Grigoletto

    2014-01-01

    The objective of the internship is to study the macrophytes distribution and assemblages on Lacanau lake along a gradient of hydrodynamics, including waves. It is also to characterize this gradient at different spatial scales near the coastal areas. The first method of measuring the gradient of hydrodynamics is based on field data acquired using hydrostatic pressure sensor made for exploratory purposes in 2013. This method is used for observations on a small scale (a few square meters). The r...

  9. Bryophytes and macro-algal growths as a part of macrophyte monitoring in rivers used for ecological assessment

    OpenAIRE

    Baláži P.; Hrivnák R.

    2015-01-01

    Altogether, 62 taxa of macrophytes including 18 bryophytes and 16 macro-algal growths were determined at 87 survey sites (73 rivers) representing the both ecoregions in Slovakia (Pannonian and Carpathian) during the years 2010–2013. Bryophytes represented the dominant community in the Carpathians, while the occurrence of macro-algal growths was relatively balanced in both ecoregions. Ordination analyses (DCA) showed an obvious shift ...

  10. Distribution of aquatic macrophytes in contrasting river systems: a critique of compositional-based assessment of water quality.

    Science.gov (United States)

    Demars, Benoît O L; Edwards, Anthony C

    2009-01-01

    A brief summary of the historical developments relating to plant distribution and aquatic macrophyte-nutrient indices provided a means of assessing the general context and validity of previous assumptions. This has particular current relevance because of the prominent use of bioindicators for defining nutrient enrichment. A survey of 161 sites distributed across two broadly contrasting groups of rivers (circum-neutral versus alkaline) recorded 110 species of aquatic macrophytes and these have been statistically analyzed to (i) rank and separate the individual effects of local environmental conditions and spatial isolation on species distribution in the two contrasting groups of sites; (ii) calculate a macrophyte index based on plant cover and species indicator values (Mean Trophic Rank, MTR); and finally (iii) investigate the implications for biomonitoring. Chemical, physical and hydrological site attributes together with spatial isolation, each explained a significant and at least partially independent influence over plant species distribution. It was extremely difficult, however, to separate the single effects of different site attributes on plant distribution. While some plant species are more restricted to certain environmental conditions, many appeared indifferent to the range of those being tested. The role played by nutrients (nitrogen (N) and phosphorus (P)) were either mostly indistinguishable from other site attributes (e.g., nitrate from conductivity) or subordinate (e.g., soluble reactive phosphorus, ammonium). It is therefore very unlikely that macrophyte species composition could provide a reliable bioindicator of the surrounding nutrient (N, P) status. The calculation of the plant index illustrated this unreliability by showing that strong correlations existed with many environmental variables, not just inorganic N and P.

  11. Does the Lagoa do Peixe sandbar opening influence the macrophyte richness and composition in Southern Brazil wetlands?

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    Ana Silvia Rolon

    2013-03-01

    Full Text Available The Lagoa do Peixe has its connection with the sea artificially opened every year at the end of winter. However, this management has been carried out without the evaluation of the impact of this opening in the aquatic biodiversity. This information is crucial for the management of the natural resources of the Lagoa do Peixe National Park, the unique Ramsar site in Southern Brazil. The following questions were analyzed: (1 Do richness and composition of aquatic macrophytes from Lagoa do Peixe floodplain varies temporarily according to the sandbar opening and closing? (2 Does the variation pattern of the macrophyte community changed according to the sandbar opening and closing? A set of eight sampling sites of 1ha were selected over the Lagoa do Peixe floodplain: four sites not influenced by the artificial sandbar opening and four sites influenced by this event, being two sites closer to the sandbar opening and the two sites distant to the sandbar opening. The samplings were carried out between November 2007 and October 2009. The results show that although the artificial sandbar breaching does not affect the aquatic macrophyte richness at the floodplain, it affects the dynamics of species composition. The hydrological variation related to this management can be the main factor of the continuous change in the species composition in the floodplain, especially in the Southern portion. In order to avoid impacts in the macrophyte conservation, the artificial sandbar opening should be considered carefully, since the area of study is one of the most important conservation units to wetland systems in Southern Brazil.

  12. Does the Lagoa do peixe sandbar opening influence the macrophyte richness and composition in Southern Brazil wetlands?

    Science.gov (United States)

    Rolon, Ana Silvia; Rocha, Odete; Maltchik, Leonardo

    2013-03-01

    The Lagoa do Peixe has its connection with the sea artificially opened every year at the end of winter. However, this management has been carried out without the evaluation of the impact of this opening in the aquatic biodiversity. This information is crucial for the management of the natural resources of the Lagoa do Peixe National Park, the unique Ramsar site in Southern Brazil. The following questions were analyzed: (1) Do richness and composition of aquatic macrophytes from Lagoa do Peixe floodplain varies temporarily according to the sandbar opening and closing? (2) Does the variation pattern of the macrophyte community changed according to the sandbar opening and closing? A set of eight sampling sites of 1ha were selected over the Lagoa do Peixe floodplain: four sites not influenced by the artificial sandbar opening and four sites influenced by this event, being two sites closer to the sandbar opening and the two sites distant to the sandbar opening. The samplings were carried out between November 2007 and October 2009. The results show that although the artificial sandbar breaching does not affect the aquatic macrophyte richness at the floodplain, it affects the dynamics of species composition. The hydrological variation related to this management can be the main factor of the continuous change in the species composition in the floodplain, especially in the Southern portion. In order to avoid impacts in the macrophyte conservation, the artificial sandbar opening should be considered carefully, since the area of study is one of the most important conservation units to wetland systems in Southern Brazil.

  13. Aquatic Plant Control Research Program: Effects of Submersed Aquatic Macrophytes on Physical and Chemical Properties of Surrounding Water

    Science.gov (United States)

    1988-12-01

    period. Potamogeton foliosus Raf., Potamogeton pectinatus L., Heteranthera dubia (Jacquin) MacM., Najas flexilis (Willd.) Rostk. & Schmidt, and Elodea ...by Gons (1982) and in dense Elodea stands in a Colorado alpine lake by Buscemi (1958). Actual mechanisms by which these profiles occur are not...by a cover of Elodea canadensis. Oikos 9:239-245. Carpenter, S. R. 1980. Enrichment of Lake Wingra, Wisconsin, by submersed macrophyte decay. Ecology

  14. Cloning of a chitinase gene from Ewingella americana, a pathogen of the cultivated mushroom, Agaricus bisporus

    Directory of Open Access Journals (Sweden)

    P.W. Inglis

    2000-09-01

    Full Text Available We have isolated a gene encoding a chitinase (EC 3.2.1.14 from Ewingella americana, a recently described pathogen of the mushroom Agaricus bisporus. This gene, designated chiA (EMBL/Genbank/DDBJ accession number X90562, was cloned by expression screening of a plasmid-based E. americana HindIII genomic library in Escherichia coli using remazol brilliant violet-stained carboxymethylated chitin incorporated into selective medium. The chiA gene has a 918-bp ORF, terminated by a TAA codon, with a calculated polypeptide size of 33.2 kDa, likely corresponding to a previously purified and characterised 33-kDa endochitinase from E. americana. The deduced amino acid sequence shares 33% identity with chitinase II from Aeromonas sp. No. 10S-24 and 7.8% identity with a chitinase from Saccharopolyspora erythraeus. Homology to other chitinase sequences was otherwise low. The peptide sequence deduced from chiA lacks a typical N-terminal signal sequence and also lacks the chitin binding and type III fibronectin homology units common to many bacterial chitinases. The possibility that this chitinase is not primarily adapted for the environmental mineralisation of pre-formed chitin, but rather for the breakdown of nascent chitin, is discussed in the context of mushroom disease.O gene que codifica uma quitinase (EC 3.2.1.14 foi isolado de Ewingella americana, recentemente descrita como patógeno do cogumelo Agaricus bisporus. Este gene, denominado chiA (EMBL/Genebank/DDBJ número de acesso X9061, foi clonado e selecionado a partir de livraria genômica construída por digestão do DNA de E. americana com HindIII e ligação em plasmídio de expressão em E. coli, utilizando meio seletivo contendo quitina carboximetilada, corada com "remazol brilliant violet'' para seleção de clones. O gene chiA apresenta uma ORF de 918 bp, código terminador TAA, tendo o tamanho do polipeptídeo sido calculado como 33,2 kDa, o qual corresponde ao tamanho de 33 kDa da endoquitinase

  15. Arsenic levels in the soils and macrophytes of the 'Entremuros' after the Aznalcollar mine spill

    Energy Technology Data Exchange (ETDEWEB)

    Taggart, M.A. [Department of Plant and Soil Science, University of Aberdeen, Cruickshank Building, Aberdeen AB24 3UU (United Kingdom)]. E-mail: mark.taggart@abdn.ac.uk; Carlisle, M. [Department of Geography and Environment, University of Aberdeen, Elphinstone Road, Aberdeen AB24 3UF (United Kingdom); Pain, D.J. [RSPB, The Lodge, Sandy, Bedfordshire SG19 2DL (United Kingdom); Williams, R. [RSPB, The Lodge, Sandy, Bedfordshire SG19 2DL (United Kingdom); Green, D. [Department of Geography and Environment, University of Aberdeen, Elphinstone Road, Aberdeen AB24 3UF (United Kingdom); Osborn, D. [Centre for Ecology and Hydrology, Monks Wood, Abbots Ripton, Huntingdon, Cambridgeshire PE28 2LS (United Kingdom); Meharg, A.A. [Department of Plant and Soil Science, University of Aberdeen, Cruickshank Building, Aberdeen AB24 3UU (United Kingdom)

    2005-01-01

    In April 1998, a holding lagoon containing pyrite ore processing waste rich in arsenic, failed and released 5-6 million m{sup 3} of highly polluting sludge and acidic water. Over 2700 ha of the internationally important Don-tilde ana National and Natural Parks were contaminated. The area of Natural Park to sustain the greatest impact was known as the Entremuros. This paper presents 0-5 cm soil monitoring data from the Entremuros, from sampling campaigns 6 and 18 months after the disaster; as well as macrophyte root, rhizome and stem data from samples taken 18 months after the spill. Results show a clear, decreasing, north-south arsenic soil pollution trend, both 6 and 18 months after the spill, and suggest a small reduction in total soil arsenic levels occurred over time; although a significant increase in extractable arsenic is also noted. The two macrophytes (Typha dominguensis and Scirpus maritimus) studied herein are not accumulating arsenic in stem parts, however, accumulation of arsenic on iron plaque on the roots of these plants may be occurring. Further work is recommended in order to determine the ecotoxicological significance of this process in relation to the avian food-chains of Don-tilde ana, and elsewhere. - Capsule: Arsenic associated with iron plaque on macrophyte roots may pose an ecotoxicological risk to certain herbivores.

  16. Resolving the influence of nitrogen abundances on sediment organic matter in macrophyte-dominated lakes, using fluorescence spectroscopy

    Institute of Scientific and Technical Information of China (English)

    Xin Yao; Shengrui Wang; Lixin Jiao; Caihong Yan; Xiangcan Jin

    2015-01-01

    A controlled experiment was designed to resolve the influence of nitrogen abundance on sediment organic matters in macrophyte-dominated lakes using fluorescence analysis.Macrophyte biomass showed coincident growth trends with time,but different variation rates with nitrogen treatment.All plant growth indexes with nitrogen addition (N,NH4Cl 100,200,400 mg/kg,respectively) were lower than those of the control group.Four humiclike components,two autochthonous tryptophan-like components,and one autochthonous tyrosine-like component were identified using the parallel factor analysis model.The results suggested that the relative component changes of fluorescence in the colonized sediments were in direct relation to the change of root biomass with time.In the experiment,the root formation parameters of the plants studied were significantly affected by adding N in sediments,which may be related to the reason that the root growth was affected by N addition.Adding a low concentration of N to sediments can play a part in supplying nutrients to the plants.However,the intensive uptake of NH~ may result in an increase in the intracellular concentration of ammonia,which is highly toxic to the plant cells.Hence,our experiment results manifested that organic matter cycling in the macrophyte-dominated sediment was influenced by nitrogen enrichment through influencing vegetation and relevant microbial activity.

  17. Tolerance and hyperaccumulation of a mixture of heavy metals (Cu, Pb, Hg, and Zn) by four aquatic macrophytes.

    Science.gov (United States)

    Romero-Hernández, Jorge Alberto; Amaya-Chávez, Araceli; Balderas-Hernández, Patricia; Roa-Morales, Gabriela; González-Rivas, Nelly; Balderas-Plata, Miguel Ángel

    2017-03-04

    In the present investigation, four macrophytes, namely Typha latifolia (L.), Lemna minor (L.), Eichhornia crassipes (Mart.) Solms-Laubach, and Myriophyllum aquaticum (Vell.) Verdc, were evaluated for their heavy metal (Cu, Pb, Hg, and Zn) hyperaccumulation potential under laboratory conditions. Tolerance analyses were performed for 7 days of exposure at five different treatments of the metals mixture (Cu(+2), Hg(+2), Pb(+2), and Zn(+2)). The production of chlorophyll and carotenoids was determined at the end of each treatment. L. minor revealed to be sensitive, because it did not survive in all the tested concentrations after 72 hours of exposure. E. crassipes and M. aquaticum displayed the highest tolerance to the metals mixture. For the most tolerant species of aquatic macrophytes, The removal kinetics of E. crassipes and M. aquaticum was carried out, using the following mixture of metals: Cu (0.5 mg/L) and Hg, Pb, and Zn 0.25 mg/L. The obtained results revealed that E. crassipes can remove 99.80% of Cu, 97.88% of Pb, 99.53% of Hg, and 94.37% of Zn. M. aquaticum withdraws 95.2% of Cu, 94.28% of Pb, 99.19% of Hg, and 91.91% of Zn. The obtained results suggest that these two species of macrophytes could be used for the phytoremediation of this mixture of heavy metals from the polluted water bodies.

  18. THE PAINT FORMULATION IN LAMBDACYHALOTHRIN USAGE AS P. americana COCKROACH CONTROL MEASURES

    Directory of Open Access Journals (Sweden)

    Lulus Susanti

    2014-06-01

    Full Text Available ABSTRAKKecoa adalah salah satu jenis serangga yang dianggap kotor dan merupakan seranggavektor. Scbagian besar kecoa yang ditemukan di sekitar pemukiman adalah Periplanetaamericana, Periplaneta brunea, Periplaneta australisea, Blatella germanica, Supellalongipalpa, Neostylopiga rhombifoUa dan Nauphaeta cinerea. Beberapa kecoa juga dapatmenularkan virus, bakteria, worm, protozoit dan jamur.Pengcndalian kecoa secara fogging dengan menggunakan insektisida masih kurangefektif dan praktis, sehingga dibutuhkan alternatif pengcndali. Dalam rangka untuk mencarimetode alternatif pengcndalian kecoa, maka akan dilakukan percobaan menggunakan cat kayuyang ditambahkan dengan insektisida.Dalam penelitian ini, insektisida cat kayu menggunakan bahan aktif Lambdacyhalothrin10WP. Pertama-tama dibuat beberapa solusi dari cat insektisida dalam dosis banyak. Kemudiancat papan kayu lapis. Setelah kcring sekitar satu hari, kemudian melakukan pengujian bioassayterhadap kecoa {Periplaneta americana . Hasil penelitian ini menunjukkan bahwa kayuinsektisida cat dengan dosis minimal 1,591% efektif untuk membunuh kecoa hingga 95%.Kata kunci: kecoa, cat berinsektisida, lambdacyhalothrinABSTRATCCockroaches are still considered to be disgusting insects and vector. Mostlycockroaches that are found around the resident, such as Periplaneta americana, Periplanetabrunea,Periplaneta australisea, Blatella germanica, Supella longipalpa, NeostylopigarhombifoUa and Nauphaeta cinerea. There are can transmit virus, bakteria, worm, protozoit andfungi.The methods for cocroaches control by using the fogging with insecticide is still lesseffective and practical, so it will need a controlling alternative. In order to find the alternativemethods for control the cockroach, it will conduct an experiments using impregnated paint woodby insecticide.In this research, insecticide paint wood using an active materials Lambdacyhalothrin10WP. For the first, it make some solution from insecticide paint in

  19. Flavonoids from Tilia americana with anxiolytic activity in plus-maze test.

    Science.gov (United States)

    Herrera-Ruiz, Maribel; Román-Ramos, Rubén; Zamilpa, Alejandro; Tortoriello, Jaime; Jiménez-Ferrer, J Enrique

    2008-07-23

    The aerial parts of Tilia americana var. mexicana (Schltdl) Hardin (Tiliaceae) have been widely used in Mexican traditional medicine to relieve sleeplessness, headache, and nervous excitement. The anxiolytic effect of four extracts and several flavonoid fractions from the bracts of Tilia americana subsp.mexicana, var. mexicana (Schltdl) Hardin or Tilia mexicana (Tiliaceae) was studied. Administration of 100mg/kg of n-hexane, ethyl acetate, and aqueous extracts to elevated plus-maze (EPM)-exposed mice displayed no anxiolytic effect; however, identical doses of methanol extract was able to increase the time percentage that mice spent in the EPM's open arms, as well as the percentage of crossings in the EPM's arms. The dose-response curve produced by methanol extract showed anxiolytic activity since 25mg/kg; animals showed no motor activity alteration in the open field test (OFT). Methanol extract was subjected to a bioassay-guided fractionation to obtain four ascendant polarity fractions (F1-F4) which were administrated at 100mg/kg. Data results indicate that F1 displayed the main anxiolytic effect. The purification of F1 produced a rich flavonoid anxiolytic mixture (F1C). This fraction was purified by RP-18 open chromatographic column to obtain four polar descent fractions: F1C(1), F1C(2), F1C(3), and F1C(4), respectively. Tiliroside was the major ingredient from the active fraction. High performance liquid chromatography analysis indicated that F1C was constituted principally of tiliroside, quercetin, quercitrin, kaempherol, and their glycosides. These results supported the use of Tilia americana in Mexican traditional medicine as well as the anxiolytic effect of a rich flavonoid fraction without affect motor activity.

  20. Visual pigments, oil droplets, lens, and cornea characterization in the whooping crane (Grus americana)

    Science.gov (United States)

    Porter, Megan L.; Kingston, Alexandra C. N.; McCready, Robert; Cameron, Evan G.; Hofmann, Christopher M.; Suarez, Lauren; Olsen, Glenn H.; Cronin, Thomas W.; Robinson, Phyllis R.

    2014-01-01

    Vision has been investigated in many species of birds, but few studies have considered the visual systems of large birds and the particular implications of large eyes and long-life spans on visual system capabilities. To address these issues we investigated the visual system of the whooping crane, Grus americana (Gruiformes: Gruidae). G. americana (an endangered species) is one of only two North American crane species and represents a large, long-lived bird where ultraviolet sensitivity may be degraded by chromatic aberrations and entrance of ultraviolet light into the eye could be detrimental to retinal tissues. To investigate the whooping crane visual system we used microspectrophotometry to determine the absorbance spectra of retinal oil droplets and to investigate if the ocular media (i.e., the lens and cornea) absorbs UV light. In vitro expression and reconstitution was used to determine the absorbance spectra of rod and cone visual pigments. The rod visual pigments had wavelengths of peak absorbance (λmax) at 500 nm, while the cone visual pigments λmax values were determined to be 404 nm (SWS1), 450 nm (SWS2), 499 nm (RH2), and 561 nm (LWS), similar to other characterized bird visual pigment absorbance values. The oil droplet cutoff wavelength (λcut) values similarly fell within ranges recorded from other avian species: 576 nm (R-type), 522 nm (Y-type), 506 nm (P-type), and 448 nm (C-type). We confirm that G. americana has a violet-sensitive visual system, although based on the λmax of the SWS1 visual pigment (404 nm) may also have some ability for UV sensitivity.

  1. Midgut Transcriptome of the Cockroach Periplaneta americana and Its Microbiota: Digestion, Detoxification and Oxidative Stress Response.

    Directory of Open Access Journals (Sweden)

    Jianhua Zhang

    Full Text Available The cockroach, Periplaneta americana, is an obnoxious and notorious pest of the world, with a strong ability to adapt to a variety of complex environments. However, the molecular mechanism of this adaptability is mostly unknown. In this study, the genes and microbiota composition associated with the adaptation mechanism were studied by analyzing the transcriptome and 16S rDNA pyrosequencing of the P. americana midgut, respectively. Midgut transcriptome analysis identified 82,905 unigenes, among which 64 genes putatively involved in digestion (11 genes, detoxification (37 genes and oxidative stress response (16 genes were found. Evaluation of gene expression following treatment with cycloxaprid further revealed that the selected genes (CYP6J1, CYP4C1, CYP6K1, Delta GST, alpha-amylase, beta-glucosidase and aminopeptidase were upregulated at least 2.0-fold at the transcriptional level, and four genes were upregulated more than 10.0-fold. An interesting finding was that three digestive enzymes positively responded to cycloxaprid application. Tissue expression profiles further showed that most of the selected genes were midgut-biased, with the exception of CYP6K1. The midgut microbiota composition was obtained via 16S rDNA pyrosequencing and was found to be mainly dominated by organisms from the Firmicutes phylum, among which Clostridiales, Lactobacillales and Burkholderiales were the main orders which might assist the host in the food digestion or detoxification of noxious compounds. The preponderant species, Clostridium cellulovorans, was previously reported to degrade lignocellulose efficiently in insects. The abundance of genes involved in digestion, detoxification and response to oxidative stress, and the diversity of microbiota in the midgut might provide P. americana high capacity to adapt to complex environments.

  2. Comportamiento higroscópico de la madera de persea americana var. guatemalensis mill (hass

    Directory of Open Access Journals (Sweden)

    F. J. Fuentes Talavera

    2002-01-01

    Full Text Available Probetas de madera de Persea americana de 20 x 20 x 10 mm, saturadas de humedad, fueron acondicionadas a humedades relativas del aire de 85, 65, 35, 0 % y posteriormente a inmersión en agua, para determinar sus índices de hinchamiento y contracción, así como de sus principales anisotropías. Otro grupo de estas probetas fue utilizado para determinar curvas de desorción y sorción de humedad, en el rango higroscópico de la madera. El movimiento dimensional de P. americana resultó ser de pequeño a muy pequeño. Su movimiento en servicio, calculado con base al hinchamiento lineal que fue de 1.72 %, que la ubica en la categoría de pequeño. Con base en la anisotropía de la contracción por secado (Aβn = 2.67 se considera que el mayor riesgo de distorsiones por cambio de humedad, puede ocurrir al secar la madera, es decir del PSF al 12 % de C. H., mientras que la anisotropía del hinchamiento (Aq = 2.13 muestra que la madera de Persea americana puede ser considerada como moderadamente estable frente a los cambios de su contenido de humedad que ocurran en el intervalo de 18 a 8 %. Los valores de histéresis fluctuaron de 0.788 a 0.885 resultando un promedio de 0.834, para el intervalo de humedad relativa del aire del 30 al 90 %.

  3. Heterobilharzia americana infection as a cause of hepatic parasitic granulomas in a horse.

    Science.gov (United States)

    Corapi, Wayne V; Birch, Sharla M; Carlson, Kelly L; Chaffin, M Keith; Snowden, Karen F

    2011-10-15

    CASE DESCRIPTION-A 22-year-old American Paint Horse gelding from the Gulf Coast region of Texas was evaluated for regrowth of a perirectal squamous cell carcinoma that had been surgically removed 11 months previously. CLINICAL FINDINGS-A necrotic and ulcerated mass was present below the anus. The horse had paraphimosis and was having difficulty with urination. Histologic examination of the mass revealed that it was squamous cell carcinoma, and the horse was euthanized because of the unlikelihood that the mass could be adequately resected and its close proximity to the urethra. OUTCOME-At necropsy, in addition to the squamous cell carcinoma, hundreds of round, white to pale yellow nodules were disseminated throughout the liver, resulting in a so-called starry-sky appearance. Similar granulomas were seen in the right caudal lung lobe and small intestinal serosa. A single granuloma in the liver, which differed from the others by its larger size, contained a pair of adult schistosomes. Several hepatic granuloma specimens were used for PCR amplification and sequencing. Use of primers specific for a portion of the Heterobilharzia americana small subunit rRNA gene resulted in amplification of a 487-base pair product that had 100% sequence identity with H americana. CLINICAL RELEVANCE-Severe cases of disseminated granulomas in the liver of horses may result in a liver with a grossly abnormal starry-sky pattern. To our knowledge, this is the first report documenting the association of granulomas with H americana infection along with adult schistosomes in the liver of a horse.

  4. Antioxidant and acetylcholinesterase inhibition properties of Amorpha fruticosa L. and Phytolacca americana L.

    Directory of Open Access Journals (Sweden)

    Dimitrina Zh Zheleva-Dimitrova

    2013-01-01

    Full Text Available Background: Amorpha fruticosa L. and Phytolacca americana L. are native plants for North America, but invasive for Central Europe and the Mediterranean areas. Previous investigation reported DPPH radical scavenging activity of A. fruticosa seeds from Mississippi river basin and P. americana berries from Iran. The aim of the present study was to investigate methanol extracts from leaves and fruits of these invasive species growing in Bulgaria for radical scavenging and acetylcholinesterase inhibitory potential. Materials and Methods: Antioxidant activity was investigated using DPPH and ABTS free radicals; FRAP assay and inhibition of lipid peroxidation in linoleic acid system by FTC. Modified Ellman′s colorimetric method was carried out to quantify acetylcholinesterase inhibition potential. In addition, the quantities of total polyphenols, flavonoids, and hydroxycinnamic derivatives were determinated using Folin-Chiocalteu reagent, AlCl 3 , and Na 2 MoO 4 , respectively. Results: The highest concentrations of total polyphenols and flavonoids were found in A. fruticosa leaves (786.70±1.78 mg/g dry extract and 32.19±0.29 mg/g dry extract, respectively. A. fruticosa fruit was found to be the most enriched in total hydroxycinnamic derivatives (153.55±1.11 mg/g dry extract and demonstrated the highest antioxidant activity: DPPH, IC 50 9.83 μg/mL; ABTS, IC 50 2.90 μg/mL; FRAP , 642.95±3.95 μg TE/mg de, and acetylcholinesterase inhibitory activity, 48.86±0.55% (2 mg/mL. Conclusions: Phytolacca americana leaves and Amorpha fruticosa could be useful in therapy of free radical pathologies and neurodegenerative disorders.

  5. Vascular riffle flora of Appalachian streams: the ecology and effects of acid mine drainage on Justificia americana (L. ) Vahl

    Energy Technology Data Exchange (ETDEWEB)

    Koryak, M.; Reilly, R.J.

    1984-06-01

    Justicia americana is a stout-based colonial plant, abundant in most of the larger, low to moderate gradient streams of the upper Ohio River basin. The distribution of J. americana is related to acid drainage from bituminous coal mining operations in the upper Ohio River drainage basin. Possible fluvial and biological consequences of the colonization or absence of Justicia are considered. Luxuriant growths were noted on gravel bars and riffles of larger, unpolluted streams in the basin. Acid mine drainage severely depresses the growth of the plant, leaving gravel shoals and riffles in the acid streams either barren or dominated by other emergent species. Particular among these new species is Elecocharis acicularis. The elimination of J. americana from suitable habitat adversely affects channel morphology, substrate composition, general aesthetic quality and aquatic stream life in the region. 16 references, 2 figures, 3 tables.

  6. Genipa americana: prospecção tecnológica

    Directory of Open Access Journals (Sweden)

    Selma Maria Santos Moura

    2016-10-01

    Full Text Available O jenipapo é uma árvore alta (10 a 15 metros, encontrada em regiões de clima tropical úmido, comum no nordeste brasileiro. Seu nome científico é Genipa americana L., jenipapo vem do Tupi-guarani jandipap, que significa fruto que serve para pintar. Apresenta caule reto, folhas verde-escuras, flores amarelo-ouro e o fruto na forma de baga ovoide, possui polpa marrom clara que envolve sementes no centro. Na alimentação humana, seu fruto é comestível ao natural e no preparo de doces, refrescos e vinho. É rico em ferro, vitaminas B1, B2, B5 e C, cálcio e hidratos de carbono. Na cultura popular têm indicações medicinais para o tratamento de afecções. Quando verde, o fruto fornece um suco azul muito utilizado como corante, transparente a princípio, o qual torna-se preto quando oxida, apresenta consistência do nanquim e no corpo, em contato com a pele, deixa manchas que desaparecem após uma semana ou mais, espontaneamente. O objetivo desta pesquisa foi realizar a prospecção tecnológica com relação à Genipa americana L., para apresentar uma visão geral sobre as tecnologias desenvolvidas relacionadas ao tema. Para isso realizou-se uma busca de patentes nas bases do European Patent Office, World Intellectual Property Organization, United States Patent and Trademark Office e no Instituto Nacional de Propriedade Industrial. Utilizando a palavra-chave Genipa americana L. foram registradas 88 patentes, quando acrescido à especificação corante encontrou-se 5 e nenhuma quando utilizou-se Genipa americana L. e célula. O Brasil registrou um número de patentes inferior ao encontrado nos USA e no Japão, sendo os anos de 2010, 2011 e 2015 os que apresentaram maior número. Ações integradas devem ser realizadas para estimular as instituições de fomento à pesquisa no intuito de viabilizar um ambiente propício à geração de inovações, fazendo do Brasil um país mais competitivo do ponto de vista tecnológico.  

  7. Effects of ripening on rheological properties of avocado pulp (Persea americana mill. Cv. Hass)

    Science.gov (United States)

    Osorio, F.; Roman, A.; Ortiz, J.

    2015-04-01

    Avocado (Persea americana Mill) Hass variety is the most planted in Chile with a greater trade prospect. The aim of this study was to investigate the effect of maturity on rheological properties of Chilean Avocado Hass pulp. Fresh unripe avocados were washed and peeled, cut and stored at 3 different times; a portion was treated at 5°C and the other was treated at 20°C until it reached 2 lb puncture pressure. During maturation changes would develop due to temperature and time, with internal cellular structure changes. Preliminary results of the rheological characteristics of avocado puree show a Bingham plastic behavior.

  8. Synthesis and configuration of the nonadecenetriol isolated from seeds of Persea americana.

    Science.gov (United States)

    Yan, Xin; Zhang, Shao-Min; Wu, Yikang; Gao, Po

    2011-10-07

    In an effort to establish the relative as well as absolute configuration of the trypanocidally active natural nonadec-6-en-1,2,4-triol isolated from Persea americana, the (2S,4R), (2S,4S), and (2R,4R) isomers were synthesized. The stereogenic centers taken from enantiopure chiral epoxy building blocks derived from inexpensive and readily available D-glucolactone. The (2R,4R) isomer gave (1)H and (13)C NMR as well as specific rotation in excellent consistence with those reported for the natural triol.

  9. Chemical composition and fatty acid profile of rhea (Rhea americana) meat

    OpenAIRE

    Romanelli,Pedro Fernando; Trabuco, Elizeu [UNESP; Scriboni, Andreia Borges; Visentainer, Jesui Vergilio; Souza,Nilson Evelazio de

    2008-01-01

    The purpose of this work was to determine the proximate composition and fatty acid profiles of the Gastrocnemius pars interna intramuscular fat (IMF) of rhea (Rhea americana) thighs. The birds were bred in captivity, fed with balanced feed (Nutriavestruz Crescimento - Purina) and kept in a pen with grass ad lib. The birds of both sexes used in the research weighed 23 kg on average and were aged about twelve (12) months old. They were subjected to hydric diet (12 h) before slaughtering by elec...

  10. Literatura marginal americana: do épico confessional ao niilismo erótico

    Directory of Open Access Journals (Sweden)

    Lainister de Oliveira Esteves

    2011-08-01

    Full Text Available O objetivo deste artigo é analisar como a prosa ficcional norte americana do século XX se define a partir de um modelo de herói marginal. Autores como Henry Miller; Jack Kerouac e Charles Bukowski dramatizam um tipo de heroísmo baseado na representação de temas como liberdade e redenção que permite pensar como determinados textos se encontram na configuração de uma suposta linhagem literária.

  11. O REMEMORAR NA NARRATIVA IBERO-AMERICANA CONTEMPORÂNEA: LITERATURA E CINEMA

    OpenAIRE

    Diogo, Rita de Cássia Miranda; Universidade do Estado do Rio de Janeiro

    2013-01-01

    No presente trabalho nos propomos a analisar a narrativaibero-americana contemporânea em suas versões literária e cinematográfica apartir da articulação dos conceitos benjaminianos em torno da noção de “perdada tradição”. Entendemos o pensamento de Walter Benjamin como constelações,cujos diferentes conceitos ao mesmo tempo que gravitam em torno da ideia de“perda da tradição”, remetem-se mutuamente. Como corpus literário, selecionamos uma obra do escritor espanhol JulioLlamazares (1997), A chu...

  12. Mycotoxin-induced disease in captive whooping cranes (Grus americana) and sandhill cranes (Grus canadensis)

    Science.gov (United States)

    Olsen, G.H.; Carpenter, J.W.; Gee, G.F.; Thomas, N.J.; Dein, F.J.

    1995-01-01

    In 1987, an epizootic in cranes at the Patuxent Wildlife Research Center, Laurel, Maryland, USA, caused illness in 80% of 300 captive whooping cranes (Grus americana) and sandhill cranes (Grus canadensis) and death of 15 of these cranes. Gross pathology findings were inconclusive and consisted of dehydration, atrophy of fat, renal insufficiency, and small spleens. Extensive testing resulted in isolation of Fusarium sp. mold from constituents of the grain-based diet. Low levels of two mycotoxins, T2 (1-2 ppm) and deoxynivalenol (0.4 ppm), were isolated from the pelleted feed.

  13. Proyecto de mejoramiento para la estacion de servicio "La Americana S.A.S"

    OpenAIRE

    Ortega Cepeda, Miguel Santiago; Ramírez Hernández, Javier Andrés

    2016-01-01

    La estación de servicio “La Americana S.A.S” ha sido una de las primeras estaciones de servicio ubicada en Bucaramanga, dedicada a la comercialización y distribución tanto de gasolina como de los diferentes repuestos y accesorios para los vehículos, razón por la cual desde su fundación y hasta nuestros días, ha venido prestando un servicio destacado, efectivo y cumpliendo siempre con la demanda del mercado proporcionalmente a su consumo. Del mismo modo dicha experiencia dentro de este sect...

  14. Pollen, Tapetum, and Orbicule Development in Colletia paradoxa and Discaria americana (Rhamnaceae

    Directory of Open Access Journals (Sweden)

    M. Gotelli

    2012-01-01

    Full Text Available Tapetum, orbicule, and pollen grain ontogeny in Colletia paradoxa and Discaria americana were studied with transmission electron microscopy (TEM. The ultrastructural changes observed during the different stages of development in the tapetal cells and related to orbicule and pollen grain formation are described. The proorbicules have the appearance of lipid globule, and their formation is related to the endoplasmic reticulum of rough type (ERr. This is the first report on the presence of orbicules in the family Rhamnaceae. Pollen grains are shed at the bicellular stage.

  15. Preliminar toxicological assesement of Ruta graveolens, Origanum vulgare and Persea americana on the preimplantational mouse embryos

    Directory of Open Access Journals (Sweden)

    V. Benavides

    2014-06-01

    Full Text Available The growing interest in natural medicine makes it necessary to study plant properties as well as their possible secondary effects. In recent years the toxic effects of many medicinal plants on the preimplantational mouse embryo development have been studied. Many of them produce malformations and alterations in the embryonic development. Ruta graveolens "ruda", Origanum vulgare "oregano" and Persea americana "palta" are used in rural areas to menstrual colic and to provoke abortion (estrella, 1995. This study is aimed at assessing "in vivd'the effect of extracts of "oregano", "ruda" and "palta" to 20% on the morphology and growth of preimplantational mouse embryos.

  16. Fauna parasitaria de Periplaneta americana Linnaeus en un distrito de Lima

    OpenAIRE

    José Iannacone; Kenneth Velásquez; Anita Arrascue

    2014-01-01

    Se investigaron algunos aspectos de los componentes comunitarios e infracomunitarios de la parasitofauna de Periplaneta americana en 100 especímenes colectados en buzones del distrito de Pueblo Libre, Lima, Perú, en invierno, entre agosto y setiembre de 1996. De todos los hospederos muestreados 67 fueron machos y 33 hembras; 19 adultos y 81 niñas; luego de las necropsias, se observaron cinco tipos de parásitos con la prevalencia e intensidad de infección respectiva: Cephalobellus tipulae (Nem...

  17. Detection of West Nile virus RNA from the louse fly Icosta americana (Diptera: Hippoboscidae).

    Science.gov (United States)

    Farajollahi, Ary; Crans, Wayne J; Nickerson, Diane; Bryant, Patricia; Wolf, Bruce; Glaser, Amy; Andreadis, Theodore G

    2005-12-01

    West Nile virus (WNV) was detected by Taqman reverse transcription-polymerase chain reaction in 4 of 85 (4.7%) blood-engorged (n = 2) and unengorged (n = 2) Icosta americana (Leach) hippoboscid flies that were collected from wild raptors submitted to a wildlife rehabilitation center in Mercer County, NJ, in 2003. This report represents an additional detection of WNV in a nonculicine arthropod in North America and the first documented detection of the virus in unengorged hippoboscid flies, further suggesting a possible role that this species may play in the transmission of WNV in North America.

  18. Effects of simulated acid rain on leaf anatomy and micromorphology of Genipa americana L. (Rubiaceae

    Directory of Open Access Journals (Sweden)

    Bruno Francisco Sant'Anna-Santos

    2006-03-01

    Full Text Available Experiments were conducted in order to characterize the injuries on leaf structure and micromorphology of G. americana and evaluate the degree of susceptibility of this species to simulated acid rain. Plants were exposed to acid rain (pH 3.0 for ten consecutive days. Control plants were submitted only to distilled water (pH 6.0. Leaf tissue was sampled and fixed for light and scanning electron microscopy. Necrotic interveinal spots on the leaf blade occurred. Epidermis and mesophyll cells collapse, hypertrophy of spongy parenchyma cells, accumulation of phenolic compounds and starch grains were observed in leaves exposed to acid rain. The micromorphological analysis showed, in necrotic areas, plasmolized guard cells and cuticle rupture. Epidermal and mesophyll cells alterations occurred before symptoms were visualized in the leaves. These results showed the importance of anatomical data for precocious diagnosis injury and to determine the sensitivity of G. americana to acid rain.Experimentos foram conduzidos para avaliar o grau de susceptibilidade e determinar as injúrias causadas pela chuva ácida simulada na anatomia e micromorfologia foliar de Genipa americana. Plantas foram expostas à chuva com pH 3,0 durante 10 dias consecutivos. No tratamento controle utilizou-se apenas água destilada (pH 6,0. Amostras foliares foram coletadas e fixadas para microscopia de luz e eletrônica de varredura. Foram observados nas folhas expostas à chuva ácida: necroses pontuais intervenais, colapso das células do mesofilo e da epiderme; hipertrofia do parênquima lacunoso e acúmulo de compostos fenólicos e grãos de amido. A análise micromorfológica evidenciou, nas áreas necrosadas, plasmólise das células-guarda e ruptura da cutícula e da crista estomática. Alterações anatômicas ocorreram antes que sintomas visuais fossem observados nas folhas. Estes resultados comprovam a importância de dados anatômicos na diagnose precoce da injúria e na

  19. Consideraciones sobre el cultivo del aguacate Persea Americana Mill. en Atlixco, Puebla

    Directory of Open Access Journals (Sweden)

    Teresa Reyna Trujillo

    1983-01-01

    Full Text Available The production of avocado Persea americana Mill in our country has been intensified the last years, particularly in some states such as Michoacán, Puebla, Veracruz and others. Specifically in Puebla, there are some counties "municipios", Atlixco among others, where its exploitation represents an important economical fact. Because of this, it is being pretended to increase the surface occupied with that fruit tree. However, its growth and cultivation, has been exposed to a great number of problems, such as the ecologic ones (inadecuate soils, for example and fitopathologic ones mainly, reasons enough to consider the increase of its growth as inadecuate.

  20. Observation on the host parasitoid interaction between Periplaneta americana, the American cockroach and Tetrastichus hagenowii, an oothecal parasitoid

    Directory of Open Access Journals (Sweden)

    R. Srinivasan

    1994-09-01

    Full Text Available Investigations were carried out on the host parasitoid interaction between Periplaneta americana, the American cockroach and Tetrastichus hagenowii, an oothecal parasitoid. This gregarious female parasitoid infected and or oviposited in only one host and caused 100 por cento mortality of the infected host. However, increase in parasitoid density decreased the progeny production and influenced the sex ratio. The progenies produced were male biased. When host preference was tested by offering oothecae of different species of cockroaches, T. hagenowii showed a predilection towards the oothecae of P. americana, suggestings its host specificity.

  1. Observation on the host parasitoid interaction between Periplaneta americana, the American cockroach and Tetrastichus hagenowii, an oothecal parasitoid.

    Science.gov (United States)

    Srinivasan, R; Panicker, K N

    1994-01-01

    Investigations were carried out on the host parasitoid interaction between Periplaneta americana, the American cockroach and Tetrastichus hagenowii, an oothecal parasitoid. This gregarious female parasitoid infected and or oviposited in only one host and caused 100% mortality of the infected host. However, increase in parasitoid density decreased the progeny production and influenced the sex ratio. The progenies produced were male biased. When host preference was tested by offering oothecae of different species of cockroaches. T. hagenowii showed a predilection towards the oothecae of P. americana, suggesting its host specificity.

  2. Effect of submerged, freshwater aquatic macrophytes and littoral sediments on pan evaporation in the Lake Balaton region, Hungary

    Science.gov (United States)

    Anda, A.; Simon, B.; Soos, G.; Teixeira da Silva, J. A.; Kucserka, T.

    2016-11-01

    The evaporation (Ep) of a US Class A pan (C) with submerged, freshwater aquatic macrophytes (Potamogeton perfoliatus, Myriophyllum spicatum and Najas marina), hereafter macrophytes (Ps) and a sediment-covered bottom (S) was measured in Hungary during 2014-2015 using reference E of Shuttleworth (Eo) and Penman-Monteith crop reference evapotranspiration (crop ETo). There were two main climatic controls affecting variation in E: direct (air and water temperature) and indirect (wind-mediated change affecting the penetration of sunlight; precipitation inflow, impacting plant emergence). Lower seasonal mean Ep rates of 2.75 ± 0.89, 2.83 ± 0.91 and 3.06 ± 1.14 mm day-1 were observed in C, S and Ps, respectively, during the wet 2014. In the 2015 season, higher overall daily mean Ep rates for C, S and Ps were 3.76 ± 1.3, 4.19 ± 1.34 and 4.65 ± 1.52 mm day-1, respectively. A comparison of US Class A pan Ep containing macrophytes/sediments with that of a standard US Class A pan showed that pan coefficients (Kap and Kas) might allow for more accurate on-site lake E estimates. In 2014, seasonal mean Kas and Kap were 1.04 ± 0.14 and 1.09 ± 0.18, respectively. Slightly higher Ka values were observed during the warm and dry 2015 (Kas: 1.15 ± 0.22; Kap: 1.26 ± 0.23). A Ka value greater than 1 indicates that the Ep of a US Class A pan containing macrophytes and sediment is always higher than that of C. The calculated Eo overestimated measured Ep of Ps during the course of this study. During the warm-dry growing season, crop ETo was closest to Ep of Ps. Empirical coefficients can be useful for estimating E of lakes with submerged macrophytes more precisely. The accuracy of the estimate of Keszthely Bay's E improved by 9.85% when Ka was determined on site.

  3. Submerged macrophyte communities in the Forsmark area. Building of a GIS application as a tool for biomass estimations

    Energy Technology Data Exchange (ETDEWEB)

    Fredriksson, Ronny [Univ. of Kalmar (Sweden)

    2005-12-15

    The aim of this study was to compile the information from previous studies to produce a GIS application that both illustrates the distribution of different vegetation communities and also makes it possible to estimate the total biomass of the different vegetation communities and its associated fauna. The GIS application was created by means of the software Arc View 3.3 by Environmental Systems Research Institute, Inc. Distribution readings and quantitative data of submerged macrophyte communities and its associated fauna was obtained from studies by Kautsky et al. and by Borgiel. Information about the macrophyte distribution in Laangoersviken, located in the northern parts of Kallrigafjaerden, was obtained from a report by Upplandsstiftelsen. Information about water depth and bottom substrate was available as USGS DEM file, produced by Geological Survey of Sweden. Complementary data of the covering degree of submerged vegetation was obtained from a study using an under water video camera by Tobiasson. Quantitative data on macrophyte and faunal biomass were either obtained from the primary SKB data base SICADA or directly from reports. Samples were compiled and analysed according to dominating vegetation. The work was carried out as follows: Where information about the bottom substrate was available polygons were created by means of the substrate shape file and depth grid from Geological Survey of Sweden. The vegetation community and the covering degree on a certain depth and substrate combination were determined by compiled information from studies by Kautsky and by Borgiel. All observations from a certain bottom substrate were analysed to find the dominating vegetation within different depth ranges. After determining the dominating vegetation, the covering degrees of different macrophyte classes within each depth range were calculated as a mean of all readings. Areas without information about the bottom substrate, but still adjacent to areas included in the

  4. Toxicogenetic study of Persea americana fruit pulp oil and its effect on genomic instability.

    Science.gov (United States)

    Nicolella, Heloiza Diniz; Neto, Francisco Rinaldi; Corrêa, Mariana Beltrame; Lopes, Danillo Henrique; Rondon, Edilaura Nunes; Dos Santos, Luiz Felipe Ribeiro; de Oliveira, Pollyanna Francielli; Damasceno, Jaqueline Lopes; Acésio, Nathália Oliveira; Turatti, Izabel Cristina Casanova; Tozatti, Marcos Gomide; Cunha, Wilson Roberto; Furtado, Ricardo Andrade; Tavares, Denise Crispim

    2017-03-01

    Persea americana Mill., commonly known as avocado, is a tree native to Central America that is widely used as a food source and for the treatment of diseases. This plant has various biological properties such as analgesic, anti-inflammatory and total cholesterol-lowering activity. In view of its pharmacological potential, we conducted a toxicogenetic study of the fruit pulp oil of P. americana (PAO) and investigated its influence on genotoxicity induced by methyl methanesulfonate (MMS) and doxorubicin. V79 cells and Swiss mice were used for the assays. The results showed no genotoxic effects of PAO in the in vitro or in vivo test systems. However, the highest PAO dose tested led to an increase in the levels of aspartate aminotransferase, indicating hepatic/tissue damage. This effect may be related to high concentrations of palmitic acid, the main component of PAO. Furthermore, PAO was effective in reducing the chromosome damage induced by MMS and doxorubicin. These results contribute to the safety assessment of PAO as a medicinal plant for human use.

  5. In vitro antioxidant activity of Polygonium hyrcanicum, Centaurea depressa, Sambucus ebulus, Mentha spicata and Phytolacca americana.

    Science.gov (United States)

    Hosseinimehr, Seyed Jalal; Pourmorad, Fereshteh; Shahabimajd, Naghi; Shahrbandy, Kami; Hosseinzadeh, Rasa

    2007-02-15

    Extracts of five plants were investigated for their total flavonoids, phenol contents and their radical scavenging activity using DPPH assays: Polygonium hyrcanicum, Centaurea depressa, Sambucus ebulus, Mentha spicata and Phytolacca americana. Quercetin and butylated hydroxy toluene were used as standard reference with well-documented antioxidant activity. Total flavonoid content in these plants ranged from 31.6 to 109.5 mg g(-1) and the amount of free phenolic compounds was between 32 and 287.5 mg g(-1) extract powder. Free phenolic compounds content were in the order: P. hyrcanium > M. spicata > S. ebulus > C. depressa > P. americana. It was also observed that all methanolic extract samples of studied plants showed free radical scavenging activity. The highest antioxidant activity was found in P. hyrcanium with an IC 50 equal to 0.036 mg mL(-1) that is higher than BHT (IC 50 = 0.054). A correlation between radical scavenging capacities of extracts with total phenolic compounds content was observed. This result indicates that P. hyrcanium contains high levels of phenolic compounds that may contribute to higher free radical scavenging activity compared to the other extracts of the plants in this study.

  6. Characterization of an Invertebrate-Type Dopamine Receptor of the American Cockroach, Periplaneta americana

    Directory of Open Access Journals (Sweden)

    Britta Troppmann

    2014-01-01

    Full Text Available We have isolated a cDNA coding for a putative invertebrate-type dopamine receptor (Peadop2 from P. americana brain by using a PCR-based strategy. The mRNA is present in samples from brain and salivary glands. We analyzed the distribution of the PeaDOP2 receptor protein with specific affinity-purified polyclonal antibodies. On Western blots, PeaDOP2 was detected in protein samples from brain, subesophageal ganglion, thoracic ganglia, and salivary glands. In immunocytochemical experiments, we detected PeaDOP2 in neurons with their somata being located at the anterior edge of the medulla bilaterally innervating the optic lobes and projecting to the ventro-lateral protocerebrum. In order to determine the functional and pharmacological properties of the cloned receptor, we generated a cell line constitutively expressing PeaDOP2. Activation of PeaDOP2-expressing cells with dopamine induced an increase in intracellular cAMP. In contrast, a C-terminally truncated splice variant of this receptor did not exhibit any functional property by itself. The molecular and pharmacological characterization of the first dopamine receptor from P. americana provides the basis for forthcoming studies focusing on the significance of the dopaminergic system in cockroach behavior and physiology.

  7. De Novo Transcriptome Analysis and Detection of Antimicrobial Peptides of the American Cockroach Periplaneta americana (Linnaeus.

    Directory of Open Access Journals (Sweden)

    In-Woo Kim

    Full Text Available Cockroaches are surrogate hosts for microbes that cause many human diseases. In spite of their generally destructive nature, cockroaches have recently been found to harbor potentially beneficial and medically useful substances such as drugs and allergens. However, genomic information for the American cockroach (Periplaneta americana is currently unavailable; therefore, transcriptome and gene expression profiling is needed as an important resource to better understand the fundamental biological mechanisms of this species, which would be particularly useful for the selection of novel antimicrobial peptides. Thus, we performed de novo transcriptome analysis of P. americana that were or were not immunized with Escherichia coli. Using an Illumina HiSeq sequencer, we generated a total of 9.5 Gb of sequences, which were assembled into 85,984 contigs and functionally annotated using Basic Local Alignment Search Tool (BLAST, Gene Ontology (GO, and Kyoto Encyclopedia of Genes and Genomes (KEGG database terms. Finally, using an in silico antimicrobial peptide prediction method, 86 antimicrobial peptide candidates were predicted from the transcriptome, and 21 of these peptides were experimentally validated for their antimicrobial activity against yeast and gram positive and -negative bacteria by a radial diffusion assay. Notably, 11 peptides showed strong antimicrobial activities against these organisms and displayed little or no cytotoxic effects in the hemolysis and cell viability assay. This work provides prerequisite baseline data for the identification and development of novel antimicrobial peptides, which is expected to provide a better understanding of the phenomenon of innate immunity in similar species.

  8. Effect of Agave americana and Agave salmiana Ripeness on Saponin Content from Aguamiel (Agave Sap).

    Science.gov (United States)

    Leal-Díaz, Ana María; Santos-Zea, Liliana; Martínez-Escobedo, Hilda Cecilia; Guajardo-Flores, Daniel; Gutiérrez-Uribe, Janet Alejandra; Serna-Saldivar, Sergio Othón

    2015-04-22

    Steroidal saponins have shown beneficial health effects. Agave spp. leaves and rhizomes are sources of these compounds, but their presence has not been reported in the aguamiel. Aguamiel is the sweet edible sap from mature agave, and its quality is influenced by the plant ripening stage. The purpose of this research was to identify and quantitate saponins in aguamiel from Agave americana and Agave salmiana at two ripening stages. Saponins and sapogenins were identified with HPLC/ESI-MS/TOF and quantitated with HPLC/ELSD. Results proved the presence of saponins derived from kammogenin, manogenin, gentrogenin, and hecogenin. The saponin content in aguamiel from immature A. salmiana was 2-fold higher (478.3 protodioscin equivalents (PE) μg/g aguamiel (DM)) compared with A. americana (179.0 PE μg/g aguamiel (DM)). In both species, saponin content decreased when plants reached sexual maturity. This should be considered before evaluating the effects of Agave spp. as a source of bioactive saponins.

  9. Fatty acid compositions of seed oils of Haematostaphis barteri and Ximenia americana.

    Science.gov (United States)

    Eromosele, C O; Eromosele, I C

    2002-05-01

    The fatty acid compositions of the seed oils of Haematostaphis barteri (blood plum) and Ximenia americana (Wild olive) plants were determined by the Gas Chromatography Mass Spectroscopy (GC-MS) technique. H. barteri contained six fatty acids with oleic (69.35%) and stearic (15.40%) the most abundant unsaturated and saturated fatty acids, respectively. Unsaturated higher fatty acids, namely Eicosadienoic (6.92%) and Erucic acid (2.74%) were detected and the total unsaturation for the oil was 79.01%. For X. americana, 10 fatty acids were identified of which seven were unsaturated yielding a total unsaturation of 92.42%. The oil contained essential fatty acids that is, Linoleic (1.34%), Linolenic (10.31%), Arachidonic (0.60%) and varying levels of unsaturated higher fatty acids, namely, Eicosatrienoic (3.39%), Erucic (3.46%) and Nervonic (1.23%) acids. The level of Oleic acid (72.09%) in the oil was close to the value for H. barteri.

  10. Pharmacokinetic Study of Biotransformation Products from an Anxiolytic Fraction of Tilia americana.

    Science.gov (United States)

    Juárez Ramírez, Virgilio Alfonso; Jiménez-Beltrán, María Isabel; Zamilpa, Alejandro; Herrera-Ruiz, Maribel; Abarca-Vargas, Rodolfo; Lombardo-Earl, Galia; Tortoriello, Jaime; Jiménez-Ferrer, Enrique

    2017-07-27

    An anxiolytic fraction of Tilia americana standardized in tiliroside, rutin, quercitrin, quercetin glucoside, and kaempferol was obtained. After oral administration of the fraction, the above-mentioned flavonoids were not detected in plasma over 24 h. However, meta and para hydroxyphenylacetic acid and dihydroxyphenylacetic acid (m-HPAA, p-HPAA and DOPAC) were monitored. These are the biotransformation compounds of the aglycones of kaempferol and quercetin; these aglycones are products of the other flavonoids present in the anxiolytic fraction. The analytical methods (HPLC) for flavonoids and the related compounds (m-HPAA, p-HPAA and DOPAC) were validated, determining the parameters of accuracy, precision, specificity or selectivity, limit of detection, quantification range, and robustness. The pharmacokinetic assay was performed with ICR mice strains, which were given 200 mg/kg of the standardized active fraction. The results of validation of the analytical methods were obtained, allowing it to be established in a validated way that no flavonoids present in the anxiolytic fraction of T. americana were detected in plasma. However, detection and follow up was possible for the serum levels of m-HPAA, p-HPAA, and DOPAC. The three compounds follow a two-compartment model with very similar parameters between m-HPAA and p-HPAA, some being different from the ones characterized in the pharmacokinetics of DOPAC.

  11. Evaluation of in vitro antioxidant and anti-inflmmatory activities of Ximenia americana extracts

    Directory of Open Access Journals (Sweden)

    Arun Kashivishwanath Shettar

    2015-11-01

    Full Text Available Objective: To evaluate in vitro antioxidant and anti-inflammatory activity of Ximenia americana extracts. Methods: Herbal extraction was done by Soxhlet extraction method with increasing polarity of solvents viz., chloroform, ethyl acetate, methanol, ethanol and water. Phytochemical analysis was done using different biochemical tests. Antioxidant potential of plant extracts were analyzed by ferric ion reducing antioxidant power, phosphomolybdenum and 2,2-diphenyl-1- picrylhydrazyl, and anti-inflammatory activity by using protein denaturation in vitro bioassay. Total phenolic content of each extract was also determined to assess their corresponding effect on antioxidant capacity of plant. Results: Phytochemical analysis showed that each solvent extract contained broad spectrum of secondary metabolites, phenolic compounds, flavonoids, tannins and glycosides, whereas compared to other solvent extracts, chloroform extract showed negative result for phenolic compounds whereas aqueous extract exhibited the highest phenolic content and the significant antioxidant capacity based on the test performed. Out of all extracts, methanol extract showed high anti-inflammatory activity. Conclusions: The present study revealed that different solvent extracts of Ximenia americana leaves contain broad spectrum of bioactive compounds. Results confirm that aqueous extract exhibited high antioxidant activity and methanol extract exhibited high antiinflammatory activity. Further study requires purification, characterization and structural elucidation of phenolic compounds in both extracts that may help in the development of new phytopharmaceuticals.

  12. Vietnam and the Pax Americana: A Genealogy of the “New World Order”

    Directory of Open Access Journals (Sweden)

    William V. Spanos

    2015-03-01

    Full Text Available William V. Spanos’s chapter “Vietnam and the Pax Americana: A Genealogy of the ‘New World Order’” was originally published in his book-length study entitled America’s Shadow: An Anatomy of Empire (1999 and is here reprinted, courtesy of the University of Minnesota Press. Spanos’s prescient, unrelenting, and wide-ranging analysis of the consequences of the Vietnam War argues that the contemporary moment—including the Gulf War, Operation Hope in Somalia, American interventions in Bosnia and Kosovo, for example—has its “provenance” in the Vietnam War, yet the Vietnam War has essentially been underanalyzed and forgotten under the anesthetic of the American amnesiac condition, which perpetuates, systematically, an interpretation and misrepresentation of American exceptionalism and imperialism. Spanos’s philosophically informed interpretation of Vietnam Era literature, as well as other mediated representations of war, suggests that the Derridean specter haunts the “triumphalist” American representation of the post–Cold War reality, the New World Order or “Pax Americana,” and that the various politically correct theories that predict the decline of the nation-state or that celebrate the rise of American multicultural democracy will have mostly been the blind leading the blind toward a misapprehension of the global phenomenon of American hegemony.

  13. Effect of certain entomopathogenic fungi on oxidative stress and mortality of Periplaneta americana.

    Science.gov (United States)

    Chaurasia, Abhilasha; Lone, Yaqoob; Wani, Owais; Gupta, U S

    2016-02-01

    The present paper reports the effects of Metarhizium anisopliae, Isaria fumosoroseus and Hirsutella thompsonaii on Periplaneta americana. I. fumosoroseus and H. thompsonaii were cultured at 28±1°C on potato carrot agar and M. anisopliae was cultured at 28±1°C on potato dextrose agar for 14days. Conidial suspensions of fungi were given to cockroaches through different routes. M. anisopliae shows high virulence against adult cockroaches and mortality ranges from 38.65% to 78.36% after 48h. I. fumosoroseus and H. thompsonii show less virulence compared to M. anisopliae. We also investigated the effect of these three fungi on the activity of lactate dehydrogenase, lipid peroxidation and catalase in different tissues of the insect to gain an understanding of the different target site. The result suggested that the activity of lactate dehydrogenase, catalase and level of malondialdehyde varies in different organs and through different routes of exposure. Based on mortality percentages, all tested fungi had high potentials for biocontrol agents against P. americana. Our study reveals for the first time that I. fumosoroseus and H. thompsonaii fungal infections initiate oxidative stress in the midgut, fat body, whole body and hemolymph of cockroach thereby suggesting them to be the target organs for oxidative damage.

  14. ECOPHYSIOLOGICAL ANALYSIS OF GENIPA AMERICANA L. SEEDS IN AN INDUCED SOIL SEED BANK

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    Francesca Salla

    2016-03-01

    Full Text Available This work studied the behavior of G. americana L. (Rubiaceae seeds in an induced soil seed bank. This study was conducted in Lavras-MG in a seasonal semideciduous forest of the Federal University of Lavras. Seeds collected in the area were cleaned and analyzed (water content, viability and desiccation tolerance. Soil banks were installed in two distinct areas (top of hill and riparian forest located in the understory of the forest. Seeds were placed in nylon nets and covered with a thin litter layer that was previously removed for this purpose. Monthly assessment of germination, seedling emergence, seed and soil water content, and the characterization of the initial seedling growth was performed. It was observed that G. americana seeds forms a transitory seed bank, with maintenance of its viability until the fourth month after disposal in natural environment. In general, the seed bank located in the riparian forest area showed the best potential for seedling establishment in a natural environment, which supports the ecological behavior of this species.

  15. Transplantation immunity in the American cockroach, Periplaneta americana: the rejection of integumentary grafts from Blatta orientalis.

    Science.gov (United States)

    Karp, R D; Meade, C C

    1993-01-01

    The results from several previous studies have indicated that the American cockroach is able to respond to integumentary xenografts, but doubt remained as to whether cockroaches could effectively discriminate between self and allogeneic differences. This was emphasized by the fact that while one study reported that Periplaneta americana responded to grafts donated by the closely related genus Blatta orientalis, the data reported elsewhere, using a different assay system, found no such reactivity. Since we have subsequently reported, using a direct histological assay, that Periplaneta can in fact recognize and destroy integumentary allografts, we initiated a study to hopefully sort out the enigma presented by previous data using Blatta as a transplant donor. Integument from Blatta orientalis was transplanted orthotopically onto Periplaneta americana, and at various time points post-transplant, scored histologically for the survival of the subcuticular epidermal layer. The results clearly demonstrated that Periplaneta reacted to the Blatta tissue, because approximately 82% of the grafts had the epidermal layer destroyed by day 7 posttransplant. The kinetics of the response to Blatta was more in line with our allograft data, which would be in agreement with other work indicating that the closer the donor and recipient are on the phylogenetic tree, the less intense the reactivity to the foreign transplant.

  16. Anti-inflammatory activity of aqueous extracts and steroidal sapogenins of Agave americana.

    Science.gov (United States)

    Peana, A T; Moretti, M D; Manconi, V; Desole, G; Pippia, P

    1997-06-01

    Lyophilized aqueous extracts obtained from Agave americana L (Agavaceae) collected in the north of Sardinia were characterized with regard to their steroidal sapogenin content. Extracts of A. americana and genins isolated from them were evaluated for anti-inflammatory properties by testing their effects on carrageenin-induced edema. The effect of orally administered genins on gastric mucous membranes was also assessed. Lyophilized extracts administered by the intraperitoneal route at doses equivalent to 200 and 300 mg/kg of fresh plant starting material, showed good anti-inflammatory activity. Doses of genins (total steroidal sapogenins, hecogenin and tigogenin) equivalent to the amount in the lyophilized extracts produced an antiedentatous effect which was much stronger and more efficacious than that obtained with an i.p. administration of 5 mg/kg of indomethacin or dexamethasone 21-phosphate at a dose equivalent to the molar content of hecogenin administered. At the doses used to evaluate the anti-inflammatory activity, the genins did not have any harmful effect on the gastric mucous membranes. Lesions occurred when significantly higher doses of hecogenin were given, but gastric damage was still less than that caused by the drugs used for comparative purposes.

  17. ABORDAGEM BIOGEOGRÁFICA SOBRE A FAUNA SILVESTRE EM ÁREAS ANTROPIZADAS: O SISTEMA ATIBAIA-JAGUARI EM AMERICANA (SP / Biogeographical approach about the wild fauna in altered areas:the Atibaia-Jaguari systen in Americana (SP

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    Roberto Marques Neto

    2006-12-01

    Full Text Available The current article shows a biogeographical study about fauna of the Atibaia-Jaguari systen inAmericana (SP. The research undertake to do the list of the species of reptiles, birds and mammals,as well as the show and discuss facts relationship between fauna with the physical mean and theanthropic exploration of the territory.

  18. Assessment of metal sorption mechanisms by aquatic macrophytes using PIXE analysis

    Energy Technology Data Exchange (ETDEWEB)

    Módenes, A.N., E-mail: anmodenes@yahoo.com.br [Department of Chemical Engineering-Postgraduate Program, West Parana State University, Campus of Toledo, rua da Faculdade 645, Jd. La Salle, 85903-000 Toledo, PR (Brazil); Espinoza-Quiñones, F.R.; Santos, G.H.F.; Borba, C.E. [Department of Chemical Engineering-Postgraduate Program, West Parana State University, Campus of Toledo, rua da Faculdade 645, Jd. La Salle, 85903-000 Toledo, PR (Brazil); Rizzutto, M.A. [Physics Institute, University of São Paulo, Rua do Matão s/n, Travessa R 187, 05508-900 São Paulo, SP (Brazil)

    2013-10-15

    Highlights: • Divalent metal ion removals by Egeria densa biosorbent. • Multielements concentrations in biosorbent samples by PIXE analysis. • Elements mass balance in liquid and solid phase before and after metal removals. • Assessment of the mechanisms involved in Cd{sup 2+} and Zn{sup 2+} removal by biosorbent. • Confirmation of the signature of ion exchange process in metal removal. -- Abstract: In this work, a study of the metal sorption mechanism by dead biomass has been performed. All batch metal biosorption experiments were performed using the aquatic macrophyte Egeria densa as biosorbent. Divalent cadmium and zinc solutions were used to assess the sorption mechanisms involved. Using a suitable equilibrium time of 2 h and a mixture of 300 mg biosorbent and 50 mL metal solution at pH 5, monocomponent sorption experiments were performed. In order to determine the residual amounts of metals in the aqueous solutions and the concentrations of removed metals in the dry biomass, Particle Induced X-ray Emission (PIXE) measurements in thin and thick target samples were carried out. Based on the strong experimental evidence from the mass balance among the major elements participating in the sorption processes, an ion exchange process was identified as the mechanism responsible for metal removal by the dry biomass.

  19. Salinity as a constraint on growth of oligohaline marsh macrophytes. II. Salt pulses and recovery potential

    Science.gov (United States)

    Howard, R.J.; Mendelssohn, I.A.

    1999-01-01

    The ability of common oligohaline marsh macrophytes of the northern Gulf of Mexico coast to recover from pulses of increased salinity was investigated in a greenhouse experiment with Eleocharis palustris, Panicum hemitomon, Sagittaria lancifolia, and Scirpus americanus monocultures. Components of salinity pulses applied were final salinity reached (6 or 12 g/L), salinity influx rate (3 d or 3 wk), and duration of exposure (1, 2, or 3 mo). After each exposure period, we placed plants into freshwater until the end of the 120-d experiment to determine recovery potential. The four species varied in their ability to recover from the salinity pulses. Within a species, recovery varied with final salinity level and duration of exposure, and to a lesser extent with salinity influx rate. Scirpus americanus, growth of which was stimulated by salinity for 3 mo. Ability to recover decreased with increased salinity and increased duration of exposure for the remaining three species. Recovery of specific aspects of growth was also suppressed in these species by a rapid salinity influx rate compared to a slow influx rate. The complex variations in recovery patterns displayed by the different species may lead to changes in species dominance following the short-term salinity pulses that can occur during storm events, which in turn may affect marsh plant community composition and structure.

  20. Growth of common brackish marsh macrophytes under altered hydrology and salinity regimes

    Science.gov (United States)

    Howard, Rebecca J.; Biagas, Janelda M.; Allain, Larry K.

    2016-01-01

    Coastal marsh plants are increasingly subject to physicochemical stressors under rising sea levels, and the maintenance of marsh ecological functions can depend on the ability of individual species and communities to tolerate or adapt to altered conditions. We conducted a greenhouse experiment to identify hydrology and salinity effects on growth of three common brackish marsh macrophytes of coastal Florida, USA: Distichlis spicata, Juncus roemerianus, and Spartina bakeri. The species were potted as monocultures and exposed to three salinities (0, 15, or 28 psu) and two hydrologic conditions (saturated, tidal) over 22 months. Final stem density of J. roemerianus and S. bakeri did not differ among treatments. In D. spicata, however, stem density was lowest at 28 psu and lower in tidal compared to saturated conditions. Mean stem height of all species was lowest at 28 psu. Aboveground biomass of J. roemerianus was not affected by the treatments, but in D. spicata andS. bakeri it was lowest at 28 psu. Results indicated that J. roemerianus was the most adaptable species and may, therefore, be more resilient to climate-change driven stressors. However, plant-plant interactions such as interspecific competition and facilitation can alter the response of individual species to environmental factors.

  1. β-N-methylamino-L-alanine (BMAA) metabolism in the aquatic macrophyte Ceratophyllum demersum.

    Science.gov (United States)

    Downing, Simoné; Esterhuizen-Londt, Maranda; Grant Downing, Timothy

    2015-10-01

    The cyanobacterial neurotoxin, β-N-methylamino-l-alanine (BMAA) bioaccumulates and biomagnifies within the environment. However, most reports on the environmental presence of BMAA focus on the presence of BMAA in animals rather than in plants. Various laboratory studies have reported that this neurotoxin, implicated in neurodegenerative disease, is rapidly taken up by various aquatic and terrestrial plants, including crop plants. In this study the metabolism of BMAA in the aquatic macrophyte, Ceratophyllum demersum, was investigated using stable isotopically labelled BMAA. Data show that the toxin is rapidly removed from the environment by the plant. However, during depuration cellular BMAA concentrations decrease considerably, without excretion of the toxin back into the environment and without catabolism of BMAA, evidenced by the absence of label transfer to other amino acids. This strongly suggests that BMAA is metabolised via covalent modification and sequestered inside the plant as a BMAA-derivative. This modification may be reversed in humans following consumption of BMAA-containing plant material. These data therefore impact on the assessment of the risk of human exposure to this neurotoxin. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Predictors of occurrence of the aquatic macrophyte Podostemum ceratophyllum in a southern Appalachian River

    Science.gov (United States)

    Argentina, Jane E.; Freeman, Mary C.; Freeman, Byron J.

    2010-01-01

    The aquatic macrophyte Podostemum ceratophyllum (Hornleaf Riverweed) commonly provides habitat for invertebrates and fishes in flowing-water portions of Piedmont and Appalachian streams in the eastern US. We quantified variation in percent cover by P. ceratophyllum in a 39-km reach of the Conasauga River, TN and GA, to test the hypothesis that cover decreased with increasing non-forest land use. We estimated percent P. ceratophyllum cover in quadrats (0.09 m2) placed at random coordinates within 20 randomly selected shoals. We then used hierarchical logistic regression, in an information-theoretic framework, to evaluate relative support for models incorporating alternative combinations of microhabitat and shoal-level variables to predict the occurrence of high (≥50%)P. ceratophyllum cover. As expected, bed sediment size and measures of light availability (location in the center of the channel, canopy cover) were included in best-supported models and had similar estimated-effect sizes across models. Podostemum ceratophyllum cover declined with increasing watershed size (included in 8 of 13 models in the confidence set of models); however, this decrease in cover was not well predicted by variation in land use. Focused monitoring of temporal and spatial trends in status of P. ceratophyllum are important due to its biotic importance in fast-flowing waters and its potential sensitivity to landscape-level changes, such as declines in forested land cover and homogenization of benthic habitats.

  3. Anaerobic decomposition of a native and an exotic submersed macrophyte in two tropical reservoirs

    Directory of Open Access Journals (Sweden)

    WA Chiba de Castro

    Full Text Available Some aquatic plants have fast metabolism and growth, even at sub-optimal conditions, and become dominant in lentic environments such as large reservoirs, altering the nutrient cycle and impairing their environmental quality. There is great need in the knowledge impact processes of invasive species in aquatic environments, among the major, those related to the decomposition. This study evaluated the anaerobic decomposition of invasive submerged macrophytes Egeria densa Planch, native, and Hydrilla verticillata (L.f. Royle, exotic in Porto Primavera and Jupiá reservoirs, Paraná basin. We evaluated the decay of organic matter, humification degree of the leached material, electrical conductivity and pH of the decomposition process. Mathematical models were utilised to describe the decomposition patterns over time. Both species showed the same heterogeneous pattern of decay of organic matter and carbon mineralisation. The models of carbon mineralisation, compared with the experimentally obtained data presented were adequate. Both species show no significant differences in the decomposition processes. Incubations of both species presented rapid t ½ for POC mineralisation and low DOC mineralisation.

  4. Competition among marsh macrophytes by means of geomorphological displacement in the intertidal zone

    Science.gov (United States)

    Morris, James T.

    2006-09-01

    Competitive interactions among marsh plant species are mediated by the influence of the vegetation on sediment accretion and modifications of the relative elevation of the marsh surface. A model described here demonstrates some of the feedbacks between physical processes like sediment accretion and biological processes such as those that determine species zonation patterns. Changes in geomorphology, primary productivity and the spatial distribution of plant species are explained by competitive interactions and by interactions among the tides, biomass density, and sediment accretion that regulate the elevation of intertidal wetlands toward an equilibrium with mean sea level (MSL). This equilibrium is affected positively (relative elevation of the marsh surface increases) by the biomass density of emergent, salt marsh macrophytes and negatively by the rate of sea-level rise (SLR). It was demonstrated that a dominant, invading species is able to modify its environment, raising the elevation of the habitat, to exclude competitively inferior species, a process I refer to as geomorphological displacement. However, the outcome depends on a number of variables including the rate of sea-level rise and the distributions of the species across the intertidal gradient. The model predicts that a marsh will evolve toward alternative stable states, depending on the rate of sea-level rise and the species' fundamental and realized distributions within the intertidal zone.

  5. Change of trace elements content in sewage water under the influence of hydrophilic macrophytes

    Science.gov (United States)

    Akhmed-Ogly, K. V.; Savichev, O. G.

    2014-08-01

    According to the researches carried out by authors in 2013, the estimate of the effectiveness of domestic sewage treatment with the help of hydrophilic vegetation was received. It has been shown that if sewage is treated with the help of macrophytes, copper and lead concentration reduces. Thus, if the volume of sewage treated by reed mace is 500 ml and 1 l, lead concentration decreases 5 and 3,5 times, if sewage is treated by reed, lead concentration decreases 2,5 times in both cases; if sewage is treated by reed mace copper concentration decreases 0,9 and 1,8 times (if the volume of sewage is 500 ml and 1 l), if sewage is treated by reed, copper concentration decreases 1,4 and 1,5 times respectively. The conclusion has been drawn: in West Siberia it is possible to use the shallow reservoirs with natural aeration and hydrophilic vegetation for effective sewage treatment from such heavy metals as lead and copper.

  6. Aquatic macrophytes as indicators of heavy metal pollution of water in DTD canal system

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    Pajević Slobodanka P.

    2003-01-01

    Full Text Available The aim of this investigation was to establish the presence or absence of chemical contamination of water and the littoral zone (banks of Danube-Tisza-Danube (DTD canal system. The investigation covered the canal section from Bezdan to Prigrevica. By analyzing the chemical composition of dominant aquatic species in four locations of the section, we defined the species with the highest capacity to accumulate nutrients and heavy metals. Concentrations of P and K as well as of a beneficial element Na in the tissues of the analyzed macrophytes were both species- and site-dependent. The highest accumulation was registered for Ceratophyllum demersum while the species Elodea canadensis showed increased P and K accumulation values in the location Sombor. The lowest concentrations of almost all heavy metals were recorded near Sombor, indicating that this section suffered the lowest chemical pollution. Highest concentrations of all of the analyzed heavy metals were recorded in the tissue of Ceratophyllum demersum from the location Prigrevica, possibly due to the influx of polluted drainage waters from surrounding agricultural areas as well as industrial wastewaters. The obtained results showed that the enforcement of biomonitoring and analyses of other parameters indicative of ecosystem conditions might be useful for improved protection of areas experiencing a strong human impact.

  7. Aquatic macrophytes as feeding site for small fishes in the Rosana Reservoir, Paranapanema River, Southeastern Brazil

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    Casatti L.

    2003-01-01

    Full Text Available In the present investigation we studied the feeding habits of the fishes associated with aquatic macrophytes in the Rosana Reservoir, southeastern Brazil. Twenty fish species were collected during four field trips, regularly distributed across the dry and wet seasons. Focal snorkeling observations of the fishes were made over a total of six hours. Nine species were present in abundances of more than 1% and, therefore, had their feeding habits analyzed. Hemigrammus marginatus, Roeboides paranensis, Hyphessobrycon eques, Astyanax altiparanae, Serrasalmus spilopleura, and Bryconamericus stramineus were predominantly invertivores, with predominance of aquatic insects (Diptera, Ephemeroptera, and Trichoptera immatures among their food items. The predominantly algivores were Apareiodon affinis, Serrapinnus notomelas, and Satanoperca pappaterra, with high frequency of filamentous blue-green algae, diatoms, clorophyts, and periderm. The different microhabitat exploitation plus diet composition suggests partitioning of resources and absence of food competition among the most representative fish species in the studied community, indicating the importance of the naturalistic approach to fish ecology studies.

  8. Tubular immunostimulating complex based on cucumarioside A2-2 and monogalactosyldiacylglycerol from marine macrophytes

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    Vorobyeva Natalia S

    2011-09-01

    Full Text Available Abstract Background There is an urgent need to develop safe and effective adjuvants for the new generation of subunit vaccines. We developed the tubular immunostimulating complex (TI-complex as a new nanoparticulate antigen delivery system. The morphology and composition of TI-complexes principally differ from the known vesicular immunostimulating complexes (ISCOMs. However, methodology for the preparation of TI-complexes has suffered a number of shortcomings. The aim of the present work was to obtain an antigen carrier consisting of triterpene glycosides from Cucumaria japonica, cholesterol, and monogalactosyldiacylglycerol from marine macrophytes with reproducible properties and high adjuvant activity. Results The cucumarioside A2-2 - cholesterol - MGalDG ratio of 6:2:4 (by weight was found to provide the most effective formation of TI-complexes and the minimum hemolytic activity in vitro. Tubules of TI-complexes have an outer diameter of about 16 nm, an inner diameter of 6 nm, and a length of 500 nm. A significant dilution by the buffer gradually destroyed the tubular nanoparticles. The TI-complex was able to increase the immunogenicity of the protein antigens from Yersinia pseudotuberculosis by three to four times. Conclusions We propose an optimized methodology for the preparation of homogeneous TI-complexes containing only tubular particles, which would achieve reproducible immunization results. We suggest that the elaborated TI-complexes apply as a universal delivery system for different subunit antigens within anti-infectious vaccines and enhance their economic efficacy and safety.

  9. Invasive Eichhornia crassipes Affects the Capacity of Submerged Macrophytes to Utilize Nutrients

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    Jian Zhou

    2017-04-01

    Full Text Available Invasion by free-floating species, such as Eichhornia crassipes, is one of the most critical threats to the biodiversity and sustainability of wetland ecosystems, where all plants experience spatial heterogeneity in substrate nutrients. However, few studies have focused on the effects of free-floating invaders on the capacity of submerged plants to utilize substrate nutrients. A 10-week greenhouse experiment was conducted to test the effects of free-floating invasive E. crassipes (presence or absence on the growth of Ceratophyllum demersum and Myriophyllum spicatum, and their capacity to use heterogeneous and homogeneous substrate nutrients. We found that the invasion of E. crassipes could significantly decrease the growth of both submerged C. demersum and M. spicatum and that substrate nutrient heterogeneity increased the growth of C. demersum (approximately 30% in total biomass and 40% in the number of nodes but not of M. spicatum. The two submerged species have different strategies to address invasion by E. crassipes. These results indicate that E. crassipes can prevent the growth of submerged plants even if the submerged plants can effectively use heterogeneous nutrients. For the effective conservation of submerged macrophytes in wetlands, measures should be taken to restrict the spread of invasive free-floating species.

  10. Different strategies of cadmium detoxification in the submerged macrophyte Ceratophyllum demersum L.

    Science.gov (United States)

    Andresen, Elisa; Mattusch, Jürgen; Wellenreuther, Gerd; Thomas, George; Arroyo Abad, Uriel; Küpper, Hendrik

    2013-10-01

    The heavy metal cadmium (Cd) is highly toxic to plants. To understand the mechanisms of tolerance and resistance to Cd, we treated the rootless, submerged macrophyte Ceratophyllum demersum L. with sub-micromolar concentrations of Cd under environmentally relevant conditions. X-ray fluorescence measurements revealed changing distribution patterns of Cd and Zn at non-toxic (0.2 nM, 2 nM), moderately toxic (20 nM) and highly toxic (200 nM) levels of Cd. Increasing Cd concentrations led to enhanced sequestration of Cd into non-photosynthetic tissues like epidermis and vein. At toxic Cd concentrations, Zn was redistributed and mainly found in the vein. Cd treatment induced the synthesis of phytochelatins (PCs) in the plants, with a threshold of induction already at 20 nM Cd for PC3. In comparison, in plants treated with Cu, elevated PC levels were detected only at the highest concentrations (100-200 nM Cu). Our results show that also non-accumulators like C. demersum store toxic metals in tissues where the heavy metal interferes least with metabolic pathways, but remaining toxicity interferes with micronutrient distribution. Furthermore, we found that the induction of phytochelatins is not proportional to metal concentration, but has a distinct threshold, specific for each PC species. Finally we could show that 20 nM Cd, which was previously regarded as non-toxic to most plants, already induces detoxifying mechanisms.

  11. Ecological evaluation of transitional and coastal waters: A marine benthic macrophytes-based model

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    S. ORFANIDIS

    2012-12-01

    Full Text Available A model to estimate the ecological status and identify restoration targets of transitional and coastal waters was developed. Marine benthic macrophytic species (seaweeds, seagrasses were used to indicate shifts in the aquatic ecosystem from the pristine state with late-successional species (Ecological State Group I to the degraded state with opportunistic (ESG II species. The first group comprises species with a thick or calcareous thallus, low growth rates and long life cycles (perennials, whereas the second group includes sheet-like and filamentous species with high growth rates and short life cycles (annuals. Seagrasses were included in the first group, whereas Cyanophyceae and species with a coarsely branched thallus were included in the second group.The evaluation of ecological status into five categories from high to bad includes a cross comparison in a matrix of the ESGs and a numerical scoring system (Ecological Evaluation Index. The model could allow comparisons, ranking and setting of priorities at regional and national levels fulfilling the requirements of the EU Water Frame Directive. A successful application of the model was realized in selected lagoons of the Macedonian and Thrace region (North Greece and in the Saronic Gulf coastal ecosystems (Central Greece.

  12. Utilization of Herbicide Concentration/Exposure Time Relationships for Controlling Submersed Invasive Plants on Lake Gaston, Virginia/North Carolina

    Science.gov (United States)

    2011-06-01

    L-1 stock solution of flumioxazin (formulated as Payload®, Valent USA Corp., Walnut Creek, CA) calculated by percent ai was prepared. From this...treatment, plants were healthy and actively growing. A stock solution of bispyribac-sodium (formulated as Velocity®, Valent USA Corp., Walnut Creek, CA...lake plant community. Other Submersed Macrophytes Vallisneria – Native Species Vallisneria ( wild celery, eel grass) is a native plant and is

  13. Effects of taxonomy, sediment, and water column on C:N:P stoichiometry of submerged macrophytes in Yangtze floodplain shallow lakes, China.

    Science.gov (United States)

    Su, Haojie; Wu, Yao; Xie, Ping; Chen, Jun; Cao, Te; Xia, Wulai

    2016-11-01

    Carbon (C), nitrogen (N) and phosphorus (P) are the three most important essential elements limiting growth of primary producers. Submerged macrophytes generally absorb nutrients from sediments by root uptake. However, the C:N:P stoichiometric signatures of plant tissue are affected by many additional factors such as taxonomy, nutrient availability, and light availability. We first revealed the relative importance of taxonomy, sediment, and water column on plant C:N:P stoichiometry using variance partitioning based on partial redundancy analyses. Results showed that taxonomy was the most important factor in determining C:N:P stoichiometry, then the water column and finally the sediment. In this study, a significant positive relationship was found between community C concentration and macrophyte community biomass, indicating that the local low C availability in macrophytes probably was the main reason why submerged macrophytes declined in Yangtze floodplain shallow lakes. Based on our study, it is suggested that submerged macrophytes in Yangtze floodplain shallow lakes are primarily limited by low light levels rather than nutrient availability.

  14. Contrasting patterns of free-living bacterioplankton diversity in macrophyte-dominated versus phytoplankton blooming regimes in Dianchi Lake, a shallow lake in China

    Science.gov (United States)

    Wang, Yujing; Li, Huabing; Xing, Peng; Wu, Qinglong

    2016-04-01

    Freshwater shallow lakes typically exhibit two alternative stable states under certain nutrient loadings: macrophyte-dominated and phytoplankton-dominated water regimes. An ecosystem regime shift from macrophytes to phytoplankton blooming typically reduces the number of species of invertebrates and fishes and results in the homogenization of communities in freshwater lakes. We investigated how microbial biodiversity has responded to a shift of the ecosystem regime in Dianchi Lake, which was previously fully covered with submerged macrophytes but currently harbors both ecological states. We observed marked divergence in the diversity and community composition of bacterioplankton between the two regimes. Although species richness, estimated as the number of operational taxonomic units and phylogenetic diversity (PD), was higher in the phytoplankton dominated ecosystem after this shift, the dissimilarity of bacterioplankton community across space decreased. This decrease in beta diversity was accompanied by loss of planktonic bacteria unique to the macrophyte-dominated ecosystem. Mantel tests between bacterioplankton community distances and Euclidian distance of environmental parameters indicated that this reduced bacterial community diff erentiation primarily reflected the loss of environmental niches, particularly in the macrophyte regime. The loss of this small-scale heterogeneity in bacterial communities should be considered when assessing long-term biodiversity changes in response to ecosystem regime conversions in freshwater lakes.

  15. Temporal and spatial variation of limnological variables and biomass of different macrophyte species in a Neotropical reservoir (São Paulo - Brazil

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    Flávia Bottino

    2013-12-01

    Full Text Available AIM: This study reports an investigation of limnological characteristics and aquatic macrophyte occurrence in a neotropical reservoir in order to assess the spatio-temporal variation of water and sediment variables and their influence on plant distribution. METHODS: Macrophytes, water and sediment samples were collected from a Brazilian reservoir in different seasons from four main arms of the reservoir. In total sixteen water-sediment variables were analyzed including N:P ratio and Trophic State Index. The plants were collected using a quadrat sampling procedure and the dry weight per sample was measured. MANOVA was performed to evaluate spatial and temporal variation of environmental variables as well as seasonal biomass differences. To assess the relationship among environmental variables and macrophytes an ordination analysis (using Canonical Correspondence Analysis: CCA was carried out. RESULTS: The spatial and temporal variation of limnological variables generated a heterogeneous system which supports the presence of different species of macrophyte. pH, dissolved oxygen and sediment composition were important predictors of Polygonum lapathifolium occurrence while nutrients were associated with Eichhornia crassipes and Pistia stratiotes. Inorganic substances were related to biomass variation of Eichhornia azurea and Myriophyllum aquaticum. CONCLUSIONS: The spatial variation of the environmental variables has caused heterogeneity in the reservoir and it may support the occurrence of different species of macrophyte. Limnological variables highlighted in CCA are important to predict the species occurrence and their control in the study area.

  16. 采煤沉陷区苦草的生物学特性及其竞争机制%Biological traits and competition mechanism of Vallisneria natans in the mining subsidence area

    Institute of Scientific and Technical Information of China (English)

    张玉云; 万阳; 田焕新; 刘靓靓; 周忠泽

    2015-01-01

    采煤活动所致的动态沉陷湿地具有动态性、高潜水位和生态脆弱性等特点,探明此类人工重构湿地的水生植物群落的生物学特性及其竞争机制,有助于为采煤沉陷区湿地水生植物群落修复提供科学依据.本研究以淮南潘集区人工构建的苦草群落(Ass.Vallisneria natans)为倒,采用样方调查法,研究苦草的生物学特性及其与其他水生植物的竞争机制.结果表明,1)沉陷区苦草的生物学特性与浅水湖泊较一致.主要表现在苦草的繁殖方式、传粉方式、生活史方面,但研究区苦草以有性繁殖为主.2)沉陷区苦草能与以种子萌发形成的水烛群丛(Ass.Typha angustifolia)共生,但生物量低;在与形成两年以上的水烛群丛竞争中处于劣势,在水烛群丛盖度达到90%时苦草逐渐消失.3)沉陷区苦草在与浮叶植物莕菜群丛(Ass.Nymphoides peltatum)、苹群丛(Ass.Marsilea quadrifolia)竞争中处于弱势,其盖度、株高、生物量等指标都明显下降.4)沉陷区苦草在与沉水植物竹叶眼子菜群丛(Ass.Potamogeton malaianus)竞争中处于劣势,苦草与沉水植物黑藻群丛(Ass.Hydrilla verticillata)、狐尾藻群丛(Ass.Myrioph yllum verticillatum)、大茨藻群丛(Ass.Najas marina)、金鱼藻群丛(Ass.Ceratophyllum demersum)占据不同水层空间,种间竞争不强烈,能较好地共存.总之,苦草较之于相似生长型的植物具有较明显的竞争优势,对于具有不同生活型,尤其是挺水植物和浮叶植物,处于竞争劣势.

  17. The Complex of Scolytinae Inhabiting Persea borbonia and Persea americana in Florida: Possible Interactions with Other Species

    Science.gov (United States)

    A diverse number of Scolytinae (Coleoptera: Curculionidae) have been found inhabiting Persea borbonia and P. americana in Florida during 2009 and 2010. They include the exotic redbay ambrosia beetle, Xyleborus glabratus, vector of Raffaelea lauricola, X. volvulus, X. ferrugineus, Xylosandrus crassiu...

  18. A Comunidade Sul-Americana de Nações no contexto da política externa do Brasil

    Directory of Open Access Journals (Sweden)

    Carlos Ribeiro Santana

    2011-02-01

    Full Text Available O presente artigo tem como finalidade realizar um balanço sobre o significado da I Reunião de Chefes de Estado da Comunidade Sul-Americana de Nações, no que se refere à política externa.

  19. Prevalence of Ewingella americana in retail fresh cultivated mushrooms (Agaricus bisporus, Lentinula edodes and Pleurotus ostreatus) in Zaragoza (Spain).

    Science.gov (United States)

    Reyes, Juan E; Venturini, María E; Oria, Rosa; Blanco, Domingo

    2004-03-01

    The prevalence and mycopathogenic potential of Enterobacteriaceae (especially Ewingella americana) in cultivated mushrooms were studied. A total of 95 samples of Agaricus bisporus, Lentinula edodes and Pleurotus ostreatus were analyzed to quantify the Enterobacteriaceae and to identify the species isolated. The host pathogenicity test was used to verify their mycopathogenic potential. The genus Pseudomonas was also quantified, since it is the predominant bacterial group in cultivated mushrooms. The counts of Enterobacteriaceae ranged from 2.88 to 3.66 log(10) CFU g(-1), which was significantly lower than the counts of Pseudomonas spp. (4.52-7.80 log(10) CFU g(-1)). Among the 151 strains of Enterobacteriaceae isolated, 112 strains (74.2%) were classified as Ewingella americana by the API 20 E system. Other species identified were Enterobacter amnigenus bgp. 1, Enterobacter cloacae, Klebsiella terrigena, Pantoea spp. bgp. 2 and Serratia rubidaea. Only E. americana showed mycopathogenic effect, causing a browning lesion and necrosis in the center of the A. bisporus stipe. This is the first report of the isolation of E. americana from healthy cultivated button mushroom as well as from other species of cultivated mushrooms different from A. bisporus.

  20. Fusarium symbionts of an ambrosia beetle (Euwallacea sp.) in southern Florida are pathogens of avocado, Persea americana

    Science.gov (United States)

    Fusarium dieback, a destructive disease of avocado (Persea americana), was reported in California and Israel in 2012. It is associated with an ambrosia beetle, Euwallacea sp., and damage caused by an unnamed symbiont of the beetle in Clade 3 of the Fusarium solani species complex (FSSC) designated p...