The Experts below are selected from a list of 1833 Experts worldwide ranked by ideXlab platform
Eileen M. Mcgowan - One of the best experts on this subject based on the ideXlab platform.
-
spatial distribution of putative water related features in southern acidalia Cydonia mensae mars
Icarus, 2009Co-Authors: Eileen M. McgowanAbstract:Abstract Many putative water-related features exist in the northern lowlands of Mars. These features may provide clues to the abundance and timing of water or ice that existed there in the past. The Cydonia Mensae and Southern Acidalia area was chosen as the study area owing to the abundance of two of these features: giant polygons and pitted cones. In addition a section of the Deuteronilus shoreline is located there. The abundance and close proximity of the features makes this area an excellent place to study the spatial relationships between these landforms, as well as the morphological characteristics of pitted cones. The features were mapped into a GIS for spatial analyses. The highest densities of pitted cones and giant polygons are adjacent but distinctly separated by a knobby ridge that is surrounded by the Deuteronilus putative shoreline. Pitted cones were measured and examined to determine if a classification by morphology is possible, but the results were inconclusive. Statistical tests on pit-to-cone diameter ratios and tests of surface temperatures of cone material suggest, but do not verify, a single cone origin. The various shapes, sizes, and putative ages of pitted cones may be attributed to temporal variation in emplacement and spatial variation in material properties. Among the possible scenarios put forth for pitted cone genesis on Mars two are likely candidates in Cydonia Mensae: (1) the sublimation of a cold-based glacier, and (2) a buried lens of methane and/or CO2 clathrates.
-
Spatial distribution of putative water related features in Southern Acidalia/Cydonia Mensae, Mars
Icarus, 2009Co-Authors: Eileen M. McgowanAbstract:Abstract Many putative water-related features exist in the northern lowlands of Mars. These features may provide clues to the abundance and timing of water or ice that existed there in the past. The Cydonia Mensae and Southern Acidalia area was chosen as the study area owing to the abundance of two of these features: giant polygons and pitted cones. In addition a section of the Deuteronilus shoreline is located there. The abundance and close proximity of the features makes this area an excellent place to study the spatial relationships between these landforms, as well as the morphological characteristics of pitted cones. The features were mapped into a GIS for spatial analyses. The highest densities of pitted cones and giant polygons are adjacent but distinctly separated by a knobby ridge that is surrounded by the Deuteronilus putative shoreline. Pitted cones were measured and examined to determine if a classification by morphology is possible, but the results were inconclusive. Statistical tests on pit-to-cone diameter ratios and tests of surface temperatures of cone material suggest, but do not verify, a single cone origin. The various shapes, sizes, and putative ages of pitted cones may be attributed to temporal variation in emplacement and spatial variation in material properties. Among the possible scenarios put forth for pitted cone genesis on Mars two are likely candidates in Cydonia Mensae: (1) the sublimation of a cold-based glacier, and (2) a buried lens of methane and/or CO2 clathrates.
-
Spatial Correlation of Putative Water Related Features in Cydonia Mensae and Southern Acidalia Planitia
2007Co-Authors: Eileen M. Mcgowan, G. E. McgillAbstract:Introduction: To understand the distribution and timing of water on Mars we are mapping and spatially analyzing the putative water-related features in the northern lowland of Mars. Earlier we examined [1] the distribution of rampart craters vs. all other craters in Utopia Planitia and found that their distribution differed. This study addresses the spatial distribution of pitted cones and the relationship of this distribution to putative shorelines located in the Cydonia Mensae-Southern Acidalia Planitia area [2], which we will call the study area. This area is bounded by 340-355E and 37.5-47.5N. and includes part of the dichotomy boundary that is gradational [3] and characterized by clusters of knobs and mesas. We use a Geographic Information System (GIS) to help visualize and measure the clustering and density of pitted cones and their proximity to inferred shorelines [3, 4, 5]. Pitted cones: Small cones (diameter 800m) were first seen in Viking imagery [6]. These small cone-like features, most with summit pits, are abundant in the northern lowlands. Various origins have been suggested, all of which, except for cinder cones, are related to water or ice. 1. mud volcanoes [7, 8, 9, 10] 2. pingos [11] 3. cinder cones [12] 4. rootless cones (pseudo-craters) [6, 13, 14, 15, 16, 17, 18] A study of pitted cone morphology in the Acidalia/Cydonia region [9] found morphological differences based on latitude. The northern pitted cones located in Acidalia Planitia (centered at 44N, 21W) are larger and dome shaped and have slightly higher thermal inertia then the southern cones. The southern cones located in Cydonia Mensae (centered at 34N, 9W and extending from Acidalia on the west to 0 longitude and from approximately 30N to 40N latitude) are smaller and cone-shaped. The boundary between the northern and southern areas is at ~40.5N. Parts of both are in our study area. Shorelines: Putative shorelines were first identified by Parker et al. [3, 4] from Viking image data. Since the availability of Mars Orbiter Laser Altimeter (MOLA) topography, the validity of these features as shorelines has been tested by determining if they are equipotential. Most of these tests have been inconclusive and the existence of putative shorelines is hotly debated [19, 20, 21, 22, 23, 24] However, Webb [5], using more robust methods, showed that some putative shorelines are at least locally equipotential. In the Cydonia/Acidalia area Webb [5] found two sections of the Deutorenilus shoreline to be equipotential with elevations of 4200m (contact A) and –4000m (contact B). Contact A is contained within our study area. Methods: The distribution of the pitted cones was taken directly from a published geological map [2]. The pitted cone population consists of all cones with resolvable pits in the high resolution (~42m/px) Viking images used to construct the map. This is the highest resolution continuous data set available for the study area. The map was georeferenced in a GIS and the pitted cones were digitized. We used Mars Orbiter Camera (MOC) narrow-angle images and Thermal Emission Imaging System visible images (Themis VIS) to examine pitted cone morphology. Webb’s [5] Contact A was also georeferenced to our data set. The base for georeferencing is a 231m/px topographic model created in the GIS that is used to correlate elevation with features (fig. 1).
H. F. J. Savelkoul - One of the best experts on this subject based on the ideXlab platform.
-
citrus Cydonia comp can restore the immunological balance in seasonal allergic rhinitis related immunological parameters in vitro
Mediators of Inflammation, 2008Co-Authors: E. W. Baars, H. F. J. SavelkoulAbstract:In two in vitro studies, we examined the immunological (pathways of the) effects of Citrus/Cydonia comp. from, respectively, a healthy and an allergic donor; peripheral blood mononuclear cells (PBMCs) were isolated out of peripheral blood and analyzed in vitro after polyclonal stimulation of T-cells. The differentiation capacity and the influence with regard to Th1 (IFN-γ) and Th2 (IL-5) cells were examined. Citrus/Cydonia comp. has a selective effect on the differentiation of T-cells by producing relatively more IL-10 than IL-12. By that, it also seems to have an effect on the induction of regulatory (IL-10 producing) T-cell subsets. It is in vitro capable of neutralizing (to some extent) the changes, characteristic to allergic rhinitis, with regard to the maturation, differentiation, and activity of the immune system. Thus, Citrus/Cydonia comp. can potentially restore the disturbed immune state of rhinitis patients, which essentially could be sufficient to make allergic symptoms disappear permanently.
-
Citrus/Cydonia comp. can restore the immunological balance in seasonal allergic rhinitis-related immunological parameters in vitro.
Mediators of Inflammation, 2008Co-Authors: E. W. Baars, H. F. J. SavelkoulAbstract:In two in vitro studies, we examined the immunological (pathways of the) effects of Citrus/Cydonia comp. from, respectively, a healthy and an allergic donor; peripheral blood mononuclear cells (PBMCs) were isolated out of peripheral blood and analyzed in vitro after polyclonal stimulation of T-cells. The differentiation capacity and the influence with regard to Th1 (IFN-γ) and Th2 (IL-5) cells were examined. Citrus/Cydonia comp. has a selective effect on the differentiation of T-cells by producing relatively more IL-10 than IL-12. By that, it also seems to have an effect on the induction of regulatory (IL-10 producing) T-cell subsets. It is in vitro capable of neutralizing (to some extent) the changes, characteristic to allergic rhinitis, with regard to the maturation, differentiation, and activity of the immune system. Thus, Citrus/Cydonia comp. can potentially restore the disturbed immune state of rhinitis patients, which essentially could be sufficient to make allergic symptoms disappear permanently.
E. W. Baars - One of the best experts on this subject based on the ideXlab platform.
-
citrus Cydonia comp can restore the immunological balance in seasonal allergic rhinitis related immunological parameters in vitro
Mediators of Inflammation, 2008Co-Authors: E. W. Baars, H. F. J. SavelkoulAbstract:In two in vitro studies, we examined the immunological (pathways of the) effects of Citrus/Cydonia comp. from, respectively, a healthy and an allergic donor; peripheral blood mononuclear cells (PBMCs) were isolated out of peripheral blood and analyzed in vitro after polyclonal stimulation of T-cells. The differentiation capacity and the influence with regard to Th1 (IFN-γ) and Th2 (IL-5) cells were examined. Citrus/Cydonia comp. has a selective effect on the differentiation of T-cells by producing relatively more IL-10 than IL-12. By that, it also seems to have an effect on the induction of regulatory (IL-10 producing) T-cell subsets. It is in vitro capable of neutralizing (to some extent) the changes, characteristic to allergic rhinitis, with regard to the maturation, differentiation, and activity of the immune system. Thus, Citrus/Cydonia comp. can potentially restore the disturbed immune state of rhinitis patients, which essentially could be sufficient to make allergic symptoms disappear permanently.
-
Citrus/Cydonia comp. can restore the immunological balance in seasonal allergic rhinitis-related immunological parameters in vitro.
Mediators of Inflammation, 2008Co-Authors: E. W. Baars, H. F. J. SavelkoulAbstract:In two in vitro studies, we examined the immunological (pathways of the) effects of Citrus/Cydonia comp. from, respectively, a healthy and an allergic donor; peripheral blood mononuclear cells (PBMCs) were isolated out of peripheral blood and analyzed in vitro after polyclonal stimulation of T-cells. The differentiation capacity and the influence with regard to Th1 (IFN-γ) and Th2 (IL-5) cells were examined. Citrus/Cydonia comp. has a selective effect on the differentiation of T-cells by producing relatively more IL-10 than IL-12. By that, it also seems to have an effect on the induction of regulatory (IL-10 producing) T-cell subsets. It is in vitro capable of neutralizing (to some extent) the changes, characteristic to allergic rhinitis, with regard to the maturation, differentiation, and activity of the immune system. Thus, Citrus/Cydonia comp. can potentially restore the disturbed immune state of rhinitis patients, which essentially could be sufficient to make allergic symptoms disappear permanently.
L. R. Gaddis - One of the best experts on this subject based on the ideXlab platform.
-
Variability in Morphology and Thermophysical Properties of Pitted Cones in Acidalia Planitia and Cydonia Mensae
2004Co-Authors: W. H. Farrand, L. R. Gaddis, S. BlundellAbstract:The northern plains of Mars contain a number of unique landforms and are unique in terms of their topography and composition . Much of the speculation about the northern plains centers on whether there was ever a northern ocean, and if there was, was it long-lived or ephemeral? The northern plains also hosts the Vastitas Borealis Formation which has been variously interpreted as the residue from a northern ocean , and pre-existing material reworked by cold-weather processes . In this work we examine a set of unusual features resident on the northern plains, the pitted cones originally recognized in Viking data . Our focus is on the pitted cones in Acidalia and Cydonia regions. The pitted cones of the northern plains have been hypothesized as being equivalent to terrestrial cinder cones , rootless cones , pingos , and mud volcanoes . To examine the Acidalia and Cydonia regions, multispectral data from the Mars Odyssey THEMIS, gridded topography from Mars Global Surveyor (MGS) MOLA, images from MGS MOC, and mineralogic and thermal inertia information from MGS TES have been assembled in a Geographic Information System. Analysis of MOC Narrow Angle camera images
-
Analysis of MGS TES Data over Acidalia Planitia and Cydonia Mensae: Compositional Evidence for Hydrovolcanic Activity?
2003Co-Authors: W. H. Farrand, L. R. GaddisAbstract:For this study, Mars Global Surveyor (MGS) Thermal Emission Spectrometer (TES) emissivity data for Acidalia Planitia and Cydonia Mensae (Figure 1) were assembled and used to examine the surface mineralogy of these areas. Analyzing TES data for high latitude locales such as Acidalia presents a challenge since the surface temperatures over these regions is inherently lower than for equatorial locales. In this report, analyses of TES data are described and results are evaluated for potential compositional evidence for hydrovolcanic activity in Acidalia and Cydonia.
-
THEMIS Observations of Pitted Cones in Acidalia Planitia and Cydonia Mensae
2003Co-Authors: W. H. Farrand, L. R. GaddisAbstract:Analysis of Viking imagery revealed the presence of large numbers of pitted or cratered cones in the northern plains of Mars with the highest concentrations occurring in eastern Acidalia Planitia and Cydonia Mensae. Based largely on crater/cone diameter ratio comparisons, these features were hypothesized as being analogous to terrestrial pseudocraters (rootless cones) such as occur in the Lake Myvatn region of Iceland. Doubts remained about this connection given the disparity in mean diameters between these Martian features (mean diameter of approx. 600 m) and the Icelandic rootless cones (mean diameter of approx. 50 m). Recent analysis of MOC Narrow Angle camera images of Elysium Planitia, Amazonis Planitia and elsewhere have revealed another class of features with diameters commensurate with the Icelandic rootless cones. If the features in Acidalia and Cydonia are not rootless cones, what are they? Recent information on the thermophysical properties of these features as provided by the Mars Odyssey THEMIS instrument may help to answer this question.
-
Hydrovolcanic Landforms in Acidalia and Cydonia: Pan-Spectral Analysis with MGS MOC, MOLA, and TES
2002Co-Authors: W. H. Farrand, L. R. Gaddis, S. BlundellAbstract:Landforms resembling tuyas and moberg hills and ridges in Acidalia and Cydonia are examined using MGS MOC, MOLA, and TES data. Using multiple datasets provides additional constraints on the question of whether these landforms are hydrovolcanic in origin. Additional information is contained in the original extended abstract.
W. H. Farrand - One of the best experts on this subject based on the ideXlab platform.
-
Variability in Morphology and Thermophysical Properties of Pitted Cones in Acidalia Planitia and Cydonia Mensae
2004Co-Authors: W. H. Farrand, L. R. Gaddis, S. BlundellAbstract:The northern plains of Mars contain a number of unique landforms and are unique in terms of their topography and composition . Much of the speculation about the northern plains centers on whether there was ever a northern ocean, and if there was, was it long-lived or ephemeral? The northern plains also hosts the Vastitas Borealis Formation which has been variously interpreted as the residue from a northern ocean , and pre-existing material reworked by cold-weather processes . In this work we examine a set of unusual features resident on the northern plains, the pitted cones originally recognized in Viking data . Our focus is on the pitted cones in Acidalia and Cydonia regions. The pitted cones of the northern plains have been hypothesized as being equivalent to terrestrial cinder cones , rootless cones , pingos , and mud volcanoes . To examine the Acidalia and Cydonia regions, multispectral data from the Mars Odyssey THEMIS, gridded topography from Mars Global Surveyor (MGS) MOLA, images from MGS MOC, and mineralogic and thermal inertia information from MGS TES have been assembled in a Geographic Information System. Analysis of MOC Narrow Angle camera images
-
Analysis of MGS TES Data over Acidalia Planitia and Cydonia Mensae: Compositional Evidence for Hydrovolcanic Activity?
2003Co-Authors: W. H. Farrand, L. R. GaddisAbstract:For this study, Mars Global Surveyor (MGS) Thermal Emission Spectrometer (TES) emissivity data for Acidalia Planitia and Cydonia Mensae (Figure 1) were assembled and used to examine the surface mineralogy of these areas. Analyzing TES data for high latitude locales such as Acidalia presents a challenge since the surface temperatures over these regions is inherently lower than for equatorial locales. In this report, analyses of TES data are described and results are evaluated for potential compositional evidence for hydrovolcanic activity in Acidalia and Cydonia.
-
THEMIS Observations of Pitted Cones in Acidalia Planitia and Cydonia Mensae
2003Co-Authors: W. H. Farrand, L. R. GaddisAbstract:Analysis of Viking imagery revealed the presence of large numbers of pitted or cratered cones in the northern plains of Mars with the highest concentrations occurring in eastern Acidalia Planitia and Cydonia Mensae. Based largely on crater/cone diameter ratio comparisons, these features were hypothesized as being analogous to terrestrial pseudocraters (rootless cones) such as occur in the Lake Myvatn region of Iceland. Doubts remained about this connection given the disparity in mean diameters between these Martian features (mean diameter of approx. 600 m) and the Icelandic rootless cones (mean diameter of approx. 50 m). Recent analysis of MOC Narrow Angle camera images of Elysium Planitia, Amazonis Planitia and elsewhere have revealed another class of features with diameters commensurate with the Icelandic rootless cones. If the features in Acidalia and Cydonia are not rootless cones, what are they? Recent information on the thermophysical properties of these features as provided by the Mars Odyssey THEMIS instrument may help to answer this question.
-
Hydrovolcanic Landforms in Acidalia and Cydonia: Pan-Spectral Analysis with MGS MOC, MOLA, and TES
2002Co-Authors: W. H. Farrand, L. R. Gaddis, S. BlundellAbstract:Landforms resembling tuyas and moberg hills and ridges in Acidalia and Cydonia are examined using MGS MOC, MOLA, and TES data. Using multiple datasets provides additional constraints on the question of whether these landforms are hydrovolcanic in origin. Additional information is contained in the original extended abstract.
