The Experts below are selected from a list of 15051 Experts worldwide ranked by ideXlab platform
Alexandre Buttler - One of the best experts on this subject based on the ideXlab platform.
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hydrological dynamics and fire history of the last 1300 years in western siberia reconstructed from a high resolution ombrotrophic peat archive
Quaternary Research, 2015Co-Authors: Mariusz Lamentowicz, Katarzyna Marcisz, Michal Slowinski, Malgorzata Zielinska, Karolina Kaliszan, E D Lapshina, Daniel Gilbert, Alexandre Buttler, Barbara FialkiewiczkozielAbstract:Siberian peatlands provide records of past changes in the continental climate of Eurasia. We analyzed a core from Mukhrino Mire in western Siberia to reconstruct environmental change in this region over the last 1300 years. The pollen analysis revealed little variation of local pine-birch forests. A testate amoebae transfer function was used to generate a quantitative water-table reconstruction; pollen, plant macrofossils, and charcoal were analyzed to reconstruct changes in vegetation and fire activity. The study revealed that Mukhrino Mire was wet until the Little Ice Age (LIA), when drought was recorded. Dry conditions during the LIA are consistent with other studies from central and eastern Europe, and with the pattern of carbon accumulation across the Northern Hemisphere. A significant increase in fire activity between ca. AD 1975 and 1990 may be associated with the development of the nearby city of Khanty-Mansiysk, as well as with the prevailing positive Arctic Oscillation. (C) 2015 University of Washington. Published by Elsevier Inc. All rights reserved.
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hydrological dynamics and fire history of the last 1300 years in western siberia reconstructed from a high resolution ombrotrophic peat archive
Quaternary Research, 2015Co-Authors: Mariusz Lamentowicz, Katarzyna Marcisz, Michal Slowinski, Malgorzata Zielinska, Karolina Kaliszan, E D Lapshina, Daniel Gilbert, Alexandre ButtlerAbstract:Siberian peatlands provide records of past changes in the continental climate of Eurasia. We analyzed a core from Mukhrino Mire in western Siberia to reconstruct environmental change in this region over the last 1300 years. The pollen analysis revealed little variation of local pine-birch forests. A testate amoebae transfer function was used to generate a quantitative water-table reconstruction; pollen, plant macrofossils, and charcoal were analyzed to reconstruct changes in vegetation and fire activity. The study revealed that Mukhrino Mire was wet until the Little Ice Age (LIA), when drought was recorded. Dry conditions during the LIA are consistent with other studies from central and eastern Europe, and with the pattern of carbon accumulation across the Northern Hemisphere. A significant increase in fire activity between ca. AD 1975 and 1990 may be associated with the development of the nearby city of Khanty-Mansiysk, as well as with the prevailing positive Arctic Oscillation.
Mariusz Lamentowicz - One of the best experts on this subject based on the ideXlab platform.
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hydrological dynamics and fire history of the last 1300 years in western siberia reconstructed from a high resolution ombrotrophic peat archive
Quaternary Research, 2015Co-Authors: Mariusz Lamentowicz, Katarzyna Marcisz, Michal Slowinski, Malgorzata Zielinska, Karolina Kaliszan, E D Lapshina, Daniel Gilbert, Alexandre ButtlerAbstract:Siberian peatlands provide records of past changes in the continental climate of Eurasia. We analyzed a core from Mukhrino Mire in western Siberia to reconstruct environmental change in this region over the last 1300 years. The pollen analysis revealed little variation of local pine-birch forests. A testate amoebae transfer function was used to generate a quantitative water-table reconstruction; pollen, plant macrofossils, and charcoal were analyzed to reconstruct changes in vegetation and fire activity. The study revealed that Mukhrino Mire was wet until the Little Ice Age (LIA), when drought was recorded. Dry conditions during the LIA are consistent with other studies from central and eastern Europe, and with the pattern of carbon accumulation across the Northern Hemisphere. A significant increase in fire activity between ca. AD 1975 and 1990 may be associated with the development of the nearby city of Khanty-Mansiysk, as well as with the prevailing positive Arctic Oscillation.
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hydrological dynamics and fire history of the last 1300 years in western siberia reconstructed from a high resolution ombrotrophic peat archive
Quaternary Research, 2015Co-Authors: Mariusz Lamentowicz, Katarzyna Marcisz, Michal Slowinski, Malgorzata Zielinska, Karolina Kaliszan, E D Lapshina, Daniel Gilbert, Alexandre Buttler, Barbara FialkiewiczkozielAbstract:Siberian peatlands provide records of past changes in the continental climate of Eurasia. We analyzed a core from Mukhrino Mire in western Siberia to reconstruct environmental change in this region over the last 1300 years. The pollen analysis revealed little variation of local pine-birch forests. A testate amoebae transfer function was used to generate a quantitative water-table reconstruction; pollen, plant macrofossils, and charcoal were analyzed to reconstruct changes in vegetation and fire activity. The study revealed that Mukhrino Mire was wet until the Little Ice Age (LIA), when drought was recorded. Dry conditions during the LIA are consistent with other studies from central and eastern Europe, and with the pattern of carbon accumulation across the Northern Hemisphere. A significant increase in fire activity between ca. AD 1975 and 1990 may be associated with the development of the nearby city of Khanty-Mansiysk, as well as with the prevailing positive Arctic Oscillation. (C) 2015 University of Washington. Published by Elsevier Inc. All rights reserved.
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long term hydrological dynamics and fire history over the last 2000 years in ce europe reconstructed from a high resolution peat archive
Quaternary Science Reviews, 2015Co-Authors: Katarzyna Marcisz, Willy Tinner, Daniele Colombaroli, Piotr Kolaczek, Michal Slowinski, Barbara Fialkiewiczkoziel, Edyta łokas, Mariusz LamentowiczAbstract:Abstract Sphagnum peatlands in the oceanic-continental transition zone of Poland are currently influenced by climatic and anthropogenic factors that lead to peat desiccation and susceptibility to fire. Little is known about the response of Sphagnum peatland testate amoebae (TA) to the combined effects of drought and fire. To understand the relationships between hydrology and fire dynamics, we used high-resolution multi-proxy palaeoecological data to reconstruct 2000 years of Mire history in northern Poland. We employed a new approach for Polish peatlands – joint TA-based water table depth and charcoal-inferred fire activity reconstructions. In addition, the response of most abundant TA hydrological indicators to charcoal-inferred fire activity was assessed. The results show four hydrological stages of peatland development: moderately wet (from ∼35 BC to 800 AD), wet (from ∼800 to 1390 AD), dry (from ∼1390 to 1700 AD) and with an instable water table (from ∼1700 to 2012 AD). Fire activity has increased in the last millennium after constant human presence in the Mire surroundings. Higher fire activity caused a rise in the water table, but later an abrupt drought appeared at the onset of the Little Ice Age. This dry phase is characterized by high ash contents and high charcoal-inferred fire activity. Fires preceded hydrological change and the response of TA to fire was indirect. Peatland drying and hydrological instability was connected with TA community changes from wet (dominance of Archerella flavum, Hyalosphenia papilio, Amphitrema wrightianum) to dry (dominance of Cryptodifflugia oviformis, Euglypha rotunda); however, no clear fire indicator species was found. Anthropogenic activities can increase peat fires and cause substantial hydrology changes. Our data suggest that increased human fire activity was one of the main factors that influenced peatland hydrology, though the Mire response through hydrological changes towards drier conditions was delayed in relation to the surrounding vegetation changes.
Katarzyna Marcisz - One of the best experts on this subject based on the ideXlab platform.
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hydrological dynamics and fire history of the last 1300 years in western siberia reconstructed from a high resolution ombrotrophic peat archive
Quaternary Research, 2015Co-Authors: Mariusz Lamentowicz, Katarzyna Marcisz, Michal Slowinski, Malgorzata Zielinska, Karolina Kaliszan, E D Lapshina, Daniel Gilbert, Alexandre ButtlerAbstract:Siberian peatlands provide records of past changes in the continental climate of Eurasia. We analyzed a core from Mukhrino Mire in western Siberia to reconstruct environmental change in this region over the last 1300 years. The pollen analysis revealed little variation of local pine-birch forests. A testate amoebae transfer function was used to generate a quantitative water-table reconstruction; pollen, plant macrofossils, and charcoal were analyzed to reconstruct changes in vegetation and fire activity. The study revealed that Mukhrino Mire was wet until the Little Ice Age (LIA), when drought was recorded. Dry conditions during the LIA are consistent with other studies from central and eastern Europe, and with the pattern of carbon accumulation across the Northern Hemisphere. A significant increase in fire activity between ca. AD 1975 and 1990 may be associated with the development of the nearby city of Khanty-Mansiysk, as well as with the prevailing positive Arctic Oscillation.
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hydrological dynamics and fire history of the last 1300 years in western siberia reconstructed from a high resolution ombrotrophic peat archive
Quaternary Research, 2015Co-Authors: Mariusz Lamentowicz, Katarzyna Marcisz, Michal Slowinski, Malgorzata Zielinska, Karolina Kaliszan, E D Lapshina, Daniel Gilbert, Alexandre Buttler, Barbara FialkiewiczkozielAbstract:Siberian peatlands provide records of past changes in the continental climate of Eurasia. We analyzed a core from Mukhrino Mire in western Siberia to reconstruct environmental change in this region over the last 1300 years. The pollen analysis revealed little variation of local pine-birch forests. A testate amoebae transfer function was used to generate a quantitative water-table reconstruction; pollen, plant macrofossils, and charcoal were analyzed to reconstruct changes in vegetation and fire activity. The study revealed that Mukhrino Mire was wet until the Little Ice Age (LIA), when drought was recorded. Dry conditions during the LIA are consistent with other studies from central and eastern Europe, and with the pattern of carbon accumulation across the Northern Hemisphere. A significant increase in fire activity between ca. AD 1975 and 1990 may be associated with the development of the nearby city of Khanty-Mansiysk, as well as with the prevailing positive Arctic Oscillation. (C) 2015 University of Washington. Published by Elsevier Inc. All rights reserved.
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long term hydrological dynamics and fire history over the last 2000 years in ce europe reconstructed from a high resolution peat archive
Quaternary Science Reviews, 2015Co-Authors: Katarzyna Marcisz, Willy Tinner, Daniele Colombaroli, Piotr Kolaczek, Michal Slowinski, Barbara Fialkiewiczkoziel, Edyta łokas, Mariusz LamentowiczAbstract:Abstract Sphagnum peatlands in the oceanic-continental transition zone of Poland are currently influenced by climatic and anthropogenic factors that lead to peat desiccation and susceptibility to fire. Little is known about the response of Sphagnum peatland testate amoebae (TA) to the combined effects of drought and fire. To understand the relationships between hydrology and fire dynamics, we used high-resolution multi-proxy palaeoecological data to reconstruct 2000 years of Mire history in northern Poland. We employed a new approach for Polish peatlands – joint TA-based water table depth and charcoal-inferred fire activity reconstructions. In addition, the response of most abundant TA hydrological indicators to charcoal-inferred fire activity was assessed. The results show four hydrological stages of peatland development: moderately wet (from ∼35 BC to 800 AD), wet (from ∼800 to 1390 AD), dry (from ∼1390 to 1700 AD) and with an instable water table (from ∼1700 to 2012 AD). Fire activity has increased in the last millennium after constant human presence in the Mire surroundings. Higher fire activity caused a rise in the water table, but later an abrupt drought appeared at the onset of the Little Ice Age. This dry phase is characterized by high ash contents and high charcoal-inferred fire activity. Fires preceded hydrological change and the response of TA to fire was indirect. Peatland drying and hydrological instability was connected with TA community changes from wet (dominance of Archerella flavum, Hyalosphenia papilio, Amphitrema wrightianum) to dry (dominance of Cryptodifflugia oviformis, Euglypha rotunda); however, no clear fire indicator species was found. Anthropogenic activities can increase peat fires and cause substantial hydrology changes. Our data suggest that increased human fire activity was one of the main factors that influenced peatland hydrology, though the Mire response through hydrological changes towards drier conditions was delayed in relation to the surrounding vegetation changes.
Nancy A. Mcnamara - One of the best experts on this subject based on the ideXlab platform.
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Aire-deficient mice provide a model of corneal and lacrimal gland neuropathy in Sjögren's syndrome
2017Co-Authors: Feeling Y. Chen, Albert Lee, Sara Nathan, Sarah M. Knox, Nancy A. McnamaraAbstract:Sjögren’s syndrome (SS) is a chronic, autoimmune exocrinopathy that leads to severe dryness of the mouth and eyes. Exocrine function is highly regulated by neuronal mechanisms but little is known about the link between chronic inflammation, innervation and altered exocrine function in the diseased eyes and exocrine glands of SS patients. To gain a better understanding of neuronal regulation in the immunopathogenesis of autoimmune exocrinopathy, we profiled a mouse model of spontaneous, autoimmune exocrinopathy that possess key characteristics of peripheral neuropathy experienced by SS patients. Mice deficient in the autoimmune regulator (Aire) gene developed spontaneous, CD4+ T cell-mediated exocrinopathy and aqueous-deficient dry eye that were associated with loss of nerves innervating the cornea and lacrimal gland. Changes in innervation and tear secretion were accompanied by increased proliferation of corneal epithelial basal cells, limbal expansion of KRT19-positive progenitor cells, increased vascularization of the peripheral cornea and reduced nerve function in the lacrimal gland. In addition, we found extensive loss of MIST1+ secretory acinar cells in the Aire -/- lacrimal gland suggesting that acinar cells are a primary target of the disease, Finally, topical application of ophthalmic steroid effectively restored corneal innervation in Aire -/- mice thereby functionally linking nerve loss with local inflammation in the aqueous-deficient dry eye. These data provide important insight regarding the relationship between chronic inflammation and neuropathic changes in autoimmune-mediated dry eye. Peripheral neuropathies characteristic of SS appear to be tightly linked with the underlying immunopathological mechanism and Aire -/- mice provide an excellent tool to explore the interplay between SS-associated immunopathology and peripheral neuropathy.
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pax6 downregulation mediates abnormal lineage commitment of the ocular surface epithelium in aqueous deficient dry eye disease
PLOS ONE, 2013Co-Authors: Yingting Chen, Marianne Gallup, Feeling Y. T. Chen, Trinka Vijmasi, Denise Stephens, Nancy A. McnamaraAbstract:Keratinizing squamous metaplasia (SQM) of the ocular surface is a blinding consequence of systemic autoimmune disease and there is no cure. Ocular SQM is traditionally viewed as an adaptive tissue response during chronic keratoconjunctivitis sicca (KCS) that provokes pathological keratinization of the corneal epithelium and fibrosis of the corneal stroma. Recently, we established the autoimmune regulator-knockout (Aire KO) mouse as a model of autoimmune KCS and identified an essential role for autoreactive CD4+ T cells in SQM pathogenesis. In subsequent studies, we noted the down-regulation of paired box gene 6 (Pax6) in both human patients with chronic KCS associated with Sjogren's syndrome and Aire KO mice. Pax6 encodes a pleiotropic transcription factor guiding eye morphogenesis during development. While the postnatal function of Pax6 is largely unknown, we hypothesized that its role in maintaining ocular surface homeostasis was disrupted in the inflamed eye and that loss of Pax6 played a functional role in the initiation and progression of SQM. Adoptive transfer of autoreactive T cells from Aire KO mice to immunodeficient recipients confirmed CD4+ T cells as the principal downstream effectors promoting Pax6 downregulation in Aire KO mice. CD4+ T cells required local signaling via Interleukin-1 receptor (IL-1R1) to provoke Pax6 loss, which prompted a switch from corneal-specific cytokeratin, CK12, to epidermal-specific CK10. The functional role of Pax6 loss in SQM pathogenesis was indicated by the reversal of SQM and restoration of ocular surface homeostasis following forced expression of Pax6 in corneal epithelial cells using adenovirus. Thus, tissue-restricted restoration of Pax6 prevented aberrant epidermal-lineage commitment suggesting adjuvant Pax6 gene therapy may represent a novel therapeutic approach to prevent SQM in patients with chronic inflammatory diseases of the ocular surface.
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Immune profile of squamous metaplasia development in autoimmune regulator-deficient dry eye.
Molecular vision, 2009Co-Authors: Yingting Chen, Karina Nikulina, Travis C. Porco, Marianne Gallup, Nancy A. McnamaraAbstract:Purpose Squamous metaplasia of the ocular surface epithelium in severe Sjogren syndrome (SS) dry eye has been implicated to be associated with chronic engagement of immune-mediated inflammation. While the detailed immunopathological mechanism underlying keratinization of the ocular muco-epithelium in this setting remains unclear, mice deficient in the autoimmune regulator gene (Aire) demonstrate SS-like pathological changes in the exocrine organs and ocular surface including squamous metaplasia. Using this murine model, we sought to determine the specific immune events that predict squamous metaplasia of the cornea in Aire deficiency.
Yingting Chen - One of the best experts on this subject based on the ideXlab platform.
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Pax6 Downregulation Mediates Abnormal Lineage Commitment of the Ocular Surface Epithelium in Aqueous-Deficient Dry Eye
2016Co-Authors: Yingting Chen, Marianne Gallup, Feeling Y. T. Chen, Trinka Vijmasi, Denise N. Stephens, Nancy AAbstract:Keratinizing squamous metaplasia (SQM) of the ocular surface is a blinding consequence of systemic autoimmune disease and there is no cure. Ocular SQM is traditionally viewed as an adaptive tissue response during chronic keratoconjunctivitis sicca (KCS) that provokes pathological keratinization of the corneal epithelium and fibrosis of the corneal stroma. Recently, we established the autoimmune regulator-knockout (Aire KO) mouse as a model of autoimmune KCS and identified an essential role for autoreactive CD4+ T cells in SQM pathogenesis. In subsequent studies, we noted the down-regulation of paired box gene 6 (Pax6) in both human patients with chronic KCS associated with Sjögren’s syndrome and Aire KO mice. Pax6 encodes a pleiotropic transcription factor guiding eye morphogenesis during development. While the postnatal function of Pax6 is largely unknown, we hypothesized that its role in maintaining ocular surface homeostasis was disrupted in the inflamed eye and that loss of Pax6 played a functional role in the initiation and progression of SQM. Adoptive transfer of autoreactive T cells from Aire KO mice to immunodeficient recipients confirmed CD4+ T cells as the principal downstream effectors promoting Pax6 downregulation in Aire KO mice. CD4+ T cells required local signaling via Interleukin-1 receptor (IL-1R1) to provoke Pax6 loss, which prompted a switch from corneal-specific cytokeratin, CK12, to epidermal-specific CK10. The functional role of Pax6 loss in SQM pathogenesis was indicated by the reversal of SQM and restoration of ocula
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pax6 downregulation mediates abnormal lineage commitment of the ocular surface epithelium in aqueous deficient dry eye disease
PLOS ONE, 2013Co-Authors: Yingting Chen, Marianne Gallup, Feeling Y. T. Chen, Trinka Vijmasi, Denise Stephens, Nancy A. McnamaraAbstract:Keratinizing squamous metaplasia (SQM) of the ocular surface is a blinding consequence of systemic autoimmune disease and there is no cure. Ocular SQM is traditionally viewed as an adaptive tissue response during chronic keratoconjunctivitis sicca (KCS) that provokes pathological keratinization of the corneal epithelium and fibrosis of the corneal stroma. Recently, we established the autoimmune regulator-knockout (Aire KO) mouse as a model of autoimmune KCS and identified an essential role for autoreactive CD4+ T cells in SQM pathogenesis. In subsequent studies, we noted the down-regulation of paired box gene 6 (Pax6) in both human patients with chronic KCS associated with Sjogren's syndrome and Aire KO mice. Pax6 encodes a pleiotropic transcription factor guiding eye morphogenesis during development. While the postnatal function of Pax6 is largely unknown, we hypothesized that its role in maintaining ocular surface homeostasis was disrupted in the inflamed eye and that loss of Pax6 played a functional role in the initiation and progression of SQM. Adoptive transfer of autoreactive T cells from Aire KO mice to immunodeficient recipients confirmed CD4+ T cells as the principal downstream effectors promoting Pax6 downregulation in Aire KO mice. CD4+ T cells required local signaling via Interleukin-1 receptor (IL-1R1) to provoke Pax6 loss, which prompted a switch from corneal-specific cytokeratin, CK12, to epidermal-specific CK10. The functional role of Pax6 loss in SQM pathogenesis was indicated by the reversal of SQM and restoration of ocular surface homeostasis following forced expression of Pax6 in corneal epithelial cells using adenovirus. Thus, tissue-restricted restoration of Pax6 prevented aberrant epidermal-lineage commitment suggesting adjuvant Pax6 gene therapy may represent a novel therapeutic approach to prevent SQM in patients with chronic inflammatory diseases of the ocular surface.
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Immune profile of squamous metaplasia development in autoimmune regulator-deficient dry eye.
Molecular vision, 2009Co-Authors: Yingting Chen, Karina Nikulina, Travis C. Porco, Marianne Gallup, Nancy A. McnamaraAbstract:Purpose Squamous metaplasia of the ocular surface epithelium in severe Sjogren syndrome (SS) dry eye has been implicated to be associated with chronic engagement of immune-mediated inflammation. While the detailed immunopathological mechanism underlying keratinization of the ocular muco-epithelium in this setting remains unclear, mice deficient in the autoimmune regulator gene (Aire) demonstrate SS-like pathological changes in the exocrine organs and ocular surface including squamous metaplasia. Using this murine model, we sought to determine the specific immune events that predict squamous metaplasia of the cornea in Aire deficiency.
