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Marcelo Enrique Conti - One of the best experts on this subject based on the ideXlab platform.

  • Implementing the monitoring breakdown structure: native lichens as biomonitors of element deposition in the southern Patagonian forest connected with the Puyehue volcano event in 2011—a 6-year survey (2006–2012)
    Environmental Science and Pollution Research, 2020
    Co-Authors: Marcelo Enrique Conti, Cristina Simone, Raquel Jasan, Maria Grazia Finoia
    Abstract:

    This study aims to investigate the airborne elements’ deposition by using native Usnea barbata lichens as biomonitors in the forested areas of Tierra del Fuego (TdF, southern Patagonia), an apparently Pristine Environment. The present study is linked to the volcanic eruption of the Puyehue-Cordón Caulle which started in north Patagonia in June 2011, which gives rise to long-distance transport of pollutants through the atmosphere at 1700 km from our sampling sites. The monitoring breakdown structure (MBS) was applied to three sampling campaigns in 2006 (baseline) ➔ 2011–2012 (3 and 15 months after the volcanic event, respectively). We have on purpose enhanced the information variety endowment: (i) Seventy-one referenced sites were double sampled; (ii) up to 426 composite lichen samples were collected; (iii) twenty-six elements were measured by neutron activation analysis (As, Ba, Br, Ca, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Na, Rb, Sb, Sc, Se, Sm, Ta, Tb, Th, U, Yb, Zn) for samples of 2011 and 2012 campaigns; (iv) thirteen common elements (As, Ba, Ca, Co, Cr, Cs, Fe, K, Na, Sb, Se, U, Zn) were determined in 2006 for the baseline comparison. The natural contamination by tephras is reflected by lichens more clearly in the 2011 campaign, where Ba, Cr, Na, Ca, Cs, and U showed higher median levels compared with the baseline campaign (2006). Ca, K, and Na were the most accumulated elements after the volcano event and could be associated with the volcanic ashes’ deposition. Rare earth elements (REEs) showed no significant bioaccumulation levels between 2011 and 2012, indicating their association with higher lithogenic inputs than volcanic ashes. Using the Earth’s crust as reference, nine elements (As, Ba, Br, Ca, K, Na, Sb, Se, and Zn) presented moderate/significant mean enrichment factor (EF) values (> 5). The usefulness of Usnea barbata as test species for direct biomonitoring oriented kinetic studies in areas characterized by a low human impact is confirmed. Eventually, our results confirm that TdF is not an actual Pristine Environment as earlier supposed.

  • Atmospheric background trace elements deposition in Tierra del Fuego region (Patagonia, Argentina), using transplanted Usnea barbata lichens
    Environmental monitoring and assessment, 2011
    Co-Authors: Marcelo Enrique Conti, Beatrice Bocca, Alessandro Alimonti, Maria Grazia Finoia, Giustino Mele, Anna Pino
    Abstract:

    Lichen, Usnea barbata, transplants taken from Tierra del Fuego (south Patagonia, Argentina) were tested as potential biomonitors of atmospheric airborne deposition in an apparently Pristine Environment. In 2005, lichens were sampled in a reference site (n = 31) and transplanted in the northern Region of Tierra del Fuego. After, respectively, 1 month and 1 year of exposure, we collected them. The aim of the study was to determine the bioaccumulation of 26 elements in order to evaluate the background levels in the selected area. Samples were analyzed by the sector field inductively coupled plasma mass spectrometry. Discriminant analysis on principal component analysis factors was applied in order to explore the relationship among the different elements as far as time and spatial variation in transplants regards. The analysis was tested by Monte Carlo test based on 999 replicates. The most important contamination source resulted to be the atmospheric soil particle deposition. Furthermore, the results were compared with those obtained from the lichens collected in central and southern Tierra del Fuego. This study confirms the ability of U. barbata to reflect the background levels of the 26 elements in that Environment. Compared with other background sites in the world, we did confirm that Tierra del Fuego lichens have a low content of the studied elements. Tierra del Fuego turned out not to be a Pristine Environment as supposed, but it can be considered as a reference basal ecosystem for useful comparisons among different geographical areas. These findings can be very relevant and useful for Environmental conservation programs.

  • Lichen Usnea barbata as biomonitor of airborne elements deposition in the Province of Tierra del Fuego (southern Patagonia, Argentina).
    Ecotoxicology and environmental safety, 2009
    Co-Authors: Marcelo Enrique Conti, Anna Pino, Francesco Botrè, Beatrice Bocca, Alessandro Alimonti
    Abstract:

    Abstract Lichen Usnea barbata was tested as a possible biomonitor of atmospheric deposition in a supposedly Pristine Environment Tierra del Fuego (Argentina). Lichen samples were collected in 2005 and again in 2006 in 71 sites covering almost the entire region. The aim of the study was to evaluate the bioaccumulation of 26 elements in order to define the background levels in the region. The quantification was carried out by the sector field inductively coupled plasma mass spectrometry. No relevant temporal accumulation patterns between 2005 and 2006 sampling campaigns were observed. Then, the results were submitted to multivariate statistical analysis (cluster and principal component analyses). Cluster analysis produced a dendrogram where the 71 sites were divided into four clusters at (Dlink/Dmax)100 The present study has revealed the good capacity of U. barbata to reflect the baseline levels of elements in the Environment at a regional scale level. The presence of certain level of elements in lichens agrees with the hypothesis that Tierra del Fuego is not a relatively Pristine Environment as occasionally supposed. However, when comparing our results with other countries, Tierra del Fuego lichens have a very low content of the measured elements.

Alessandro Alimonti - One of the best experts on this subject based on the ideXlab platform.

  • Atmospheric background trace elements deposition in Tierra del Fuego region (Patagonia, Argentina), using transplanted Usnea barbata lichens
    Environmental monitoring and assessment, 2011
    Co-Authors: Marcelo Enrique Conti, Beatrice Bocca, Alessandro Alimonti, Maria Grazia Finoia, Giustino Mele, Anna Pino
    Abstract:

    Lichen, Usnea barbata, transplants taken from Tierra del Fuego (south Patagonia, Argentina) were tested as potential biomonitors of atmospheric airborne deposition in an apparently Pristine Environment. In 2005, lichens were sampled in a reference site (n = 31) and transplanted in the northern Region of Tierra del Fuego. After, respectively, 1 month and 1 year of exposure, we collected them. The aim of the study was to determine the bioaccumulation of 26 elements in order to evaluate the background levels in the selected area. Samples were analyzed by the sector field inductively coupled plasma mass spectrometry. Discriminant analysis on principal component analysis factors was applied in order to explore the relationship among the different elements as far as time and spatial variation in transplants regards. The analysis was tested by Monte Carlo test based on 999 replicates. The most important contamination source resulted to be the atmospheric soil particle deposition. Furthermore, the results were compared with those obtained from the lichens collected in central and southern Tierra del Fuego. This study confirms the ability of U. barbata to reflect the background levels of the 26 elements in that Environment. Compared with other background sites in the world, we did confirm that Tierra del Fuego lichens have a low content of the studied elements. Tierra del Fuego turned out not to be a Pristine Environment as supposed, but it can be considered as a reference basal ecosystem for useful comparisons among different geographical areas. These findings can be very relevant and useful for Environmental conservation programs.

  • Lichen Usnea barbata as biomonitor of airborne elements deposition in the Province of Tierra del Fuego (southern Patagonia, Argentina).
    Ecotoxicology and environmental safety, 2009
    Co-Authors: Marcelo Enrique Conti, Anna Pino, Francesco Botrè, Beatrice Bocca, Alessandro Alimonti
    Abstract:

    Abstract Lichen Usnea barbata was tested as a possible biomonitor of atmospheric deposition in a supposedly Pristine Environment Tierra del Fuego (Argentina). Lichen samples were collected in 2005 and again in 2006 in 71 sites covering almost the entire region. The aim of the study was to evaluate the bioaccumulation of 26 elements in order to define the background levels in the region. The quantification was carried out by the sector field inductively coupled plasma mass spectrometry. No relevant temporal accumulation patterns between 2005 and 2006 sampling campaigns were observed. Then, the results were submitted to multivariate statistical analysis (cluster and principal component analyses). Cluster analysis produced a dendrogram where the 71 sites were divided into four clusters at (Dlink/Dmax)100 The present study has revealed the good capacity of U. barbata to reflect the baseline levels of elements in the Environment at a regional scale level. The presence of certain level of elements in lichens agrees with the hypothesis that Tierra del Fuego is not a relatively Pristine Environment as occasionally supposed. However, when comparing our results with other countries, Tierra del Fuego lichens have a very low content of the measured elements.

Oleg V. Borisov - One of the best experts on this subject based on the ideXlab platform.

  • Spontaneous Assembly of Miktoarm Stars into Vesicular Interpolyelectrolyte Complexes
    Macromolecular Rapid Communications, 2013
    Co-Authors: Felix A. Plamper, Arjan P. H. Gelissen, Jan Timper, Andrea Wolf, Heikki Tenhu, Walter Richtering, Alexander B. Zezin, Ulrich Simon, Joachim Mayer, Oleg V. Borisov
    Abstract:

    : Mixing a bis-hydrophilic, cationic miktoarm star polymer with a linear polyanion leads to the formation of unilamellar polymersomes, which consist of an interpolyelectrolyte complex (IPEC) wall sandwiched between poly(ethylene oxide) brushes. The experimental finding of this rare IPEC morphology is rationalized theoretically: the star architecture forces the assembly into a vesicular shape due to the high entropic penalty for stretching of the insoluble arms in non-planar morphologies. The transmission electron microscopy of vitrified samples (cryogenic TEM) is compared with the samples at ambient conditions (in situ TEM), giving one of the first TEM reports on soft matter in its Pristine Environment.

  • Spontaneous Assembly of Miktoarm Stars into Vesicular Interpolyelectrolyte Complexes
    Macromolecular Rapid Communications, 2013
    Co-Authors: Felix A. Plamper, Arjan P. H. Gelissen, Jan Timper, Andrea Wolf, Heikki Tenhu, Walter Richtering, Alexander B. Zezin, Ulrich Simon, Joachim Mayer, Oleg V. Borisov
    Abstract:

    : Mixing a bis-hydrophilic, cationic miktoarm star polymer with a linear polyanion leads to the formation of unilamellar polymersomes, which consist of an interpolyelectrolyte complex (IPEC) wall sandwiched between poly(ethylene oxide) brushes. The experimental finding of this rare IPEC morphology is rationalized theoretically: the star architecture forces the assembly into a vesicular shape due to the high entropic penalty for stretching of the insoluble arms in non-planar morphologies. The transmission electron microscopy of vitrified samples (cryogenic TEM) is compared with the samples at ambient conditions (in situ TEM), giving one of the first TEM reports on soft matter in its Pristine Environment.

Maria Grazia Finoia - One of the best experts on this subject based on the ideXlab platform.

  • Implementing the monitoring breakdown structure: native lichens as biomonitors of element deposition in the southern Patagonian forest connected with the Puyehue volcano event in 2011—a 6-year survey (2006–2012)
    Environmental Science and Pollution Research, 2020
    Co-Authors: Marcelo Enrique Conti, Cristina Simone, Raquel Jasan, Maria Grazia Finoia
    Abstract:

    This study aims to investigate the airborne elements’ deposition by using native Usnea barbata lichens as biomonitors in the forested areas of Tierra del Fuego (TdF, southern Patagonia), an apparently Pristine Environment. The present study is linked to the volcanic eruption of the Puyehue-Cordón Caulle which started in north Patagonia in June 2011, which gives rise to long-distance transport of pollutants through the atmosphere at 1700 km from our sampling sites. The monitoring breakdown structure (MBS) was applied to three sampling campaigns in 2006 (baseline) ➔ 2011–2012 (3 and 15 months after the volcanic event, respectively). We have on purpose enhanced the information variety endowment: (i) Seventy-one referenced sites were double sampled; (ii) up to 426 composite lichen samples were collected; (iii) twenty-six elements were measured by neutron activation analysis (As, Ba, Br, Ca, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Na, Rb, Sb, Sc, Se, Sm, Ta, Tb, Th, U, Yb, Zn) for samples of 2011 and 2012 campaigns; (iv) thirteen common elements (As, Ba, Ca, Co, Cr, Cs, Fe, K, Na, Sb, Se, U, Zn) were determined in 2006 for the baseline comparison. The natural contamination by tephras is reflected by lichens more clearly in the 2011 campaign, where Ba, Cr, Na, Ca, Cs, and U showed higher median levels compared with the baseline campaign (2006). Ca, K, and Na were the most accumulated elements after the volcano event and could be associated with the volcanic ashes’ deposition. Rare earth elements (REEs) showed no significant bioaccumulation levels between 2011 and 2012, indicating their association with higher lithogenic inputs than volcanic ashes. Using the Earth’s crust as reference, nine elements (As, Ba, Br, Ca, K, Na, Sb, Se, and Zn) presented moderate/significant mean enrichment factor (EF) values (> 5). The usefulness of Usnea barbata as test species for direct biomonitoring oriented kinetic studies in areas characterized by a low human impact is confirmed. Eventually, our results confirm that TdF is not an actual Pristine Environment as earlier supposed.

  • Atmospheric background trace elements deposition in Tierra del Fuego region (Patagonia, Argentina), using transplanted Usnea barbata lichens
    Environmental monitoring and assessment, 2011
    Co-Authors: Marcelo Enrique Conti, Beatrice Bocca, Alessandro Alimonti, Maria Grazia Finoia, Giustino Mele, Anna Pino
    Abstract:

    Lichen, Usnea barbata, transplants taken from Tierra del Fuego (south Patagonia, Argentina) were tested as potential biomonitors of atmospheric airborne deposition in an apparently Pristine Environment. In 2005, lichens were sampled in a reference site (n = 31) and transplanted in the northern Region of Tierra del Fuego. After, respectively, 1 month and 1 year of exposure, we collected them. The aim of the study was to determine the bioaccumulation of 26 elements in order to evaluate the background levels in the selected area. Samples were analyzed by the sector field inductively coupled plasma mass spectrometry. Discriminant analysis on principal component analysis factors was applied in order to explore the relationship among the different elements as far as time and spatial variation in transplants regards. The analysis was tested by Monte Carlo test based on 999 replicates. The most important contamination source resulted to be the atmospheric soil particle deposition. Furthermore, the results were compared with those obtained from the lichens collected in central and southern Tierra del Fuego. This study confirms the ability of U. barbata to reflect the background levels of the 26 elements in that Environment. Compared with other background sites in the world, we did confirm that Tierra del Fuego lichens have a low content of the studied elements. Tierra del Fuego turned out not to be a Pristine Environment as supposed, but it can be considered as a reference basal ecosystem for useful comparisons among different geographical areas. These findings can be very relevant and useful for Environmental conservation programs.

Felix A. Plamper - One of the best experts on this subject based on the ideXlab platform.

  • Spontaneous Assembly of Miktoarm Stars into Vesicular Interpolyelectrolyte Complexes
    Macromolecular Rapid Communications, 2013
    Co-Authors: Felix A. Plamper, Arjan P. H. Gelissen, Jan Timper, Andrea Wolf, Heikki Tenhu, Walter Richtering, Alexander B. Zezin, Ulrich Simon, Joachim Mayer, Oleg V. Borisov
    Abstract:

    : Mixing a bis-hydrophilic, cationic miktoarm star polymer with a linear polyanion leads to the formation of unilamellar polymersomes, which consist of an interpolyelectrolyte complex (IPEC) wall sandwiched between poly(ethylene oxide) brushes. The experimental finding of this rare IPEC morphology is rationalized theoretically: the star architecture forces the assembly into a vesicular shape due to the high entropic penalty for stretching of the insoluble arms in non-planar morphologies. The transmission electron microscopy of vitrified samples (cryogenic TEM) is compared with the samples at ambient conditions (in situ TEM), giving one of the first TEM reports on soft matter in its Pristine Environment.

  • Spontaneous Assembly of Miktoarm Stars into Vesicular Interpolyelectrolyte Complexes
    Macromolecular Rapid Communications, 2013
    Co-Authors: Felix A. Plamper, Arjan P. H. Gelissen, Jan Timper, Andrea Wolf, Heikki Tenhu, Walter Richtering, Alexander B. Zezin, Ulrich Simon, Joachim Mayer, Oleg V. Borisov
    Abstract:

    : Mixing a bis-hydrophilic, cationic miktoarm star polymer with a linear polyanion leads to the formation of unilamellar polymersomes, which consist of an interpolyelectrolyte complex (IPEC) wall sandwiched between poly(ethylene oxide) brushes. The experimental finding of this rare IPEC morphology is rationalized theoretically: the star architecture forces the assembly into a vesicular shape due to the high entropic penalty for stretching of the insoluble arms in non-planar morphologies. The transmission electron microscopy of vitrified samples (cryogenic TEM) is compared with the samples at ambient conditions (in situ TEM), giving one of the first TEM reports on soft matter in its Pristine Environment.