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Article ; Online: A wavelet melt detection algorithm applied to enhanced-resolution scatterometer data over Antarctica (2000–2009)

N. Steiner / M. Tedesco

The Cryosphere, Vol 8, Iss 1, Pp 25-

2014 Volume 40

Abstract: Melting is mapped over Antarctica at a high spatial resolution using a novel melt detection algorithm based on wavelets and multiscale analysis. The method is applied to Ku-band (13.4 GHz) normalized backscattering measured by SeaWinds onboard the ... ...

Abstract	Melting is mapped over Antarctica at a high spatial resolution using a novel melt detection algorithm based on wavelets and multiscale analysis. The method is applied to Ku-band (13.4 GHz) normalized backscattering measured by SeaWinds onboard the satellite QuikSCAT and spatially enhanced on a 5 km grid over the operational life of the sensor (1999–2009). Wavelet-based estimates of melt spatial extent and duration are compared with those obtained by means of threshold-based detection methods, where melting is detected when the measured backscattering is 3 dB below the preceding winter mean value. Results from both methods are assessed by means of automatic weather station (AWS) air surface temperature records. The yearly melting index, the product of melted area and melting duration, found using a fixed threshold and wavelet-based melt algorithm are found to have a relative difference within 7% for all years. Most of the difference between melting records determined from QuikSCAT is related to short-duration backscatter changes identified as melting using the threshold methodology but not the wavelet-based method. The ability to classify melting based on relative persistence is a critical aspect of the wavelet-based algorithm. Compared with AWS air-temperature records, both methods show a relative agreement to within 10% based on estimated melt conditions, although the fixed threshold generally finds a greater agreement with AWS. Melting maps obtained with the wavelet-based approach are also compared with those obtained from spaceborne brightness temperatures recorded by the Special Sensor Microwave/Image (SSM/I). With respect to passive microwave records, we find a higher degree of agreement (9% relative difference) for the melting index using the wavelet-based approach than threshold-based methods (11% relative difference).
Keywords	Environmental sciences ; GE1-350 ; Geology ; QE1-996.5
Subject code	612
Language	English
Publishing date	2014-01-01T00:00:00Z
Publisher	Copernicus Publications
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: A wavelet melt detection algorithm applied to enhanced resolution scatterometer data over Antarctica (2000–2009)

N. Steiner / M. Tedesco

The Cryosphere Discussions, Vol 7, Iss 3, Pp 2635-

2013 Volume 2678

Abstract: Melting is mapped over Antarctica at a high spatial resolution using a novel melt-detection algorithm based on wavelets and multi-scale analysis. The method is applied to Ku band (13.4 GHz) normalized backscattering measured by SeaWinds on QuikSCAT and ... ...

Abstract	Melting is mapped over Antarctica at a high spatial resolution using a novel melt-detection algorithm based on wavelets and multi-scale analysis. The method is applied to Ku band (13.4 GHz) normalized backscattering measured by SeaWinds on QuikSCAT and spatially enhanced on a 5 km grid over the operational life of the sensor (1999–2009). Wavelet-based estimates of melt spatial extent and duration are compared with those obtained by means of threshold-based detection methods, where melting is detected when the measured backscattering is 3 dB below the preceding winter mean value. Results from both methods are assessed by means of Automatic Weather Station (AWS) air surface temperature records. The yearly melting index, the product of melted area and melting duration, found using a fixed threshold and wavelet-based melt algorithm are found to have a relative difference within 7% for all years. The majority of the difference between melting records determined from QuikSCAT are related to short-duration backscatter changes identified as melting using the threshold methodology but not the wavelet-based method. Compared with AWS records both methods show a relative accuracy to within 10% based on estimated melt conditions using air temperatures. Melting maps obtained with the wavelet-based approach are also compared with those obtained from spaceborne brightness temperatures recorded by the Special Sensor Microwave/Image (SSMI). With respect to passive microwave records, we find a higher degree of agreement (9% relative difference) for the melting index using the wavelet-based approach than threshold-based methods (11% relative difference). Additionally, linkages between melting variability and the Southern Annular Mode (SAM), an important large-scale climate driver for Antarctica, are suggested by the results using wavelet based methods that are not found using threshold-based methods.
Keywords	Environmental sciences ; GE1-350 ; Geography. Anthropology. Recreation ; G ; DOAJ:Environmental Sciences ; DOAJ:Earth and Environmental Sciences ; Meteorology. Climatology ; QC851-999 ; Physics ; QC1-999 ; Science ; Q ; DOAJ:Meteorology and Climatology ; Geology ; QE1-996.5 ; Petrology ; QE420-499 ; Dynamic and structural geology ; QE500-639.5
Subject code	550
Language	English
Publishing date	2013-06-01T00:00:00Z
Publisher	Copernicus Publications
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Levels of CEACAM6 in Peripheral Blood Are Elevated in Patients with Plasma Cell Disorders

N. Steiner / R. Hajek / D. Nachbaur / B. Borjan / S. Sevcikova / G. Göbel / E. Gunsilius

Disease Markers, Vol

A Potential New Diagnostic Marker and a New Therapeutic Target?

2019 Volume 2019

Abstract: Introduction. The prognosis of multiple myeloma is still unfavorable due to inherent characteristics of the disease and the often-delayed diagnosis due to widespread and unspecific symptoms such as back pain and fatigue. Therefore, a simple diagnostic ... ...

Abstract	Introduction. The prognosis of multiple myeloma is still unfavorable due to inherent characteristics of the disease and the often-delayed diagnosis due to widespread and unspecific symptoms such as back pain and fatigue. Therefore, a simple diagnostic blood test would be helpful to speed up the diagnostic procedure in such patients (pts.). Here, we evaluated the diagnostic value of plasma levels of carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6) in the peripheral blood and bone marrow of pts. with plasma cell disorders and in healthy controls. Materials and Methods. Immunoreactive CEACAM6 was determined in the peripheral blood and bone marrow (n=95/100) of pts. with monoclonal gammopathy of unknown significance (MGUS: 28/37), newly diagnosed multiple myeloma (NDMM: 42/40), and relapsed/refractory multiple myeloma (RRMM: 25/23) by sandwich ELISA. Results. Median CEACAM6 levels in the peripheral blood of pts. with plasma cell disorders were significantly higher than those of healthy controls (healthy controls: 15.2 pg/ml (12.1-17.1); MGUS: 19.0 pg/ml (16.4-22.5); NDMM: 18.0 pg/ml (13.4-21.2); and RRMM: 18.9 pg/ml (15.2-21.5); p<0.001). Plasma levels of CEACAM6 discriminated healthy subjects from MGUS/NDMM pts. (AUC=0.71, 95% CI: 0.6-0.8); i.e., a CEACAM6 level>17.3 pg/ml has an 82% (95% CI: 70-90) predictive probability for the identification of MGUS or NDMM. Moreover, CEACAM6 levels in the bone marrow were significantly higher in RRMM pts. than in NDMM pts. (p=0.04), suggesting a role of this molecule in disease progression. Conclusion. CEACAM6 plasma levels can noninvasively identify pts. with a plasma cell disorder and should be evaluated prospectively as a potential diagnostic marker. Moreover, due to high CEACAM6 levels in the bone marrow in RRMM pts., this adhesion molecule might be a therapeutic target in multiple myeloma pts.
Keywords	Medicine (General) ; R5-920
Subject code	610
Language	English
Publishing date	2019-01-01T00:00:00Z
Publisher	Hindawi Limited
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: In-situ multispectral and bathymetric measurements over a supraglacial lake in western Greenland using a remotely controlled watercraft

M. Tedesco / N. Steiner

The Cryosphere Discussions, Vol 5, Iss 1, Pp 479-

2011 Volume 498

Abstract: We report concurrent in-situ multi-spectral and depth measurements over a supraglacial lake in West Greenland, collected by means of a remotely controlled boat equipped with a GPS, a sonar and a spectrometer. We focus our attention on the analysis of ... ...

Abstract	We report concurrent in-situ multi-spectral and depth measurements over a supraglacial lake in West Greenland, collected by means of a remotely controlled boat equipped with a GPS, a sonar and a spectrometer. We focus our attention on the analysis of some of the key parameters widely used for multispectral spaceborne bathymetry, namely the lake bottom albedo and the water attenuation coefficient. The analysis of in-situ data highlights the exponential trend of the water-leaving reflectance with lake depth. The values of the attenuation factor are obtained from in-situ data and compared with those computed using approaches proposed in the literature. Also, the values of the lake bottom albedo from in-situ measurements are compared with those obtained from the analysis of reflectance of shallow-waters. Finally, we quantify the error between in-situ measured and satellite-estimated lake depth values for the lake under study.
Keywords	Environmental sciences ; GE1-350 ; Geography. Anthropology. Recreation ; G ; DOAJ:Environmental Sciences ; DOAJ:Earth and Environmental Sciences ; Meteorology. Climatology ; QC851-999 ; Physics ; QC1-999 ; Science ; Q ; DOAJ:Meteorology and Climatology ; Geology ; QE1-996.5 ; Petrology ; QE420-499 ; Dynamic and structural geology ; QE500-639.5
Subject code	333
Language	English
Publishing date	2011-02-01T00:00:00Z
Publisher	Copernicus Publications
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: In-situ multispectral and bathymetric measurements over a supraglacial lake in western Greenland using a remotely controlled watercraft

M. Tedesco / N. Steiner

The Cryosphere, Vol 5, Iss 2, Pp 445-

2011 Volume 452

Abstract: Supraglacial lakes form from meltwater on the Greenland ice sheet in topographic depressions on the surface, affecting both surface and sub-glacial processes. As the reflectance in the visible and near-infrared regions of a column of water is modulated ... ...

Abstract	Supraglacial lakes form from meltwater on the Greenland ice sheet in topographic depressions on the surface, affecting both surface and sub-glacial processes. As the reflectance in the visible and near-infrared regions of a column of water is modulated by its height, retrieval techniques using spaceborne remote sensing data (e.g. Landsat, MODIS) have been proposed in the literature for the detection of lakes and estimation of their volume. These techniques require basic assumptions on the spectral properties of the water as well as the bottom of the lake, among other things. In this study, we report results obtained from the analysis of concurrent in-situ multi-spectral and depth measurements collected over a supraglacial lake during early July 2010 in West Greenland (Lake Olivia, 69°36'35" N, 49°29'40" W) and aim to assess some of the underlying hypotheses in remote sensing based bathymetric approaches. In particular, we focus our attention on the analysis of the lake bottom albedo and of the water attenuation coefficient. The analysis of in-situ data (collected by means of a remotely controlled boat equipped with a GPS, a sonar and a spectrometer) highlights the exponential trend of the water-leaving reflectance with lake depth. The values of the attenuation factor obtained from in-situ data are compared with those computed using approaches proposed in the literature. Also, the values of the lake bottom albedo from in-situ measurements are compared with those obtained from the analysis of reflectance of shallow waters. Finally, we quantify the error between in-situ measured and satellite-estimated lake depth values for the lake under study.
Keywords	Environmental sciences ; GE1-350 ; Geology ; QE1-996.5
Subject code	550
Language	English
Publishing date	2011-05-01T00:00:00Z
Publisher	Copernicus Publications
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Implications of sea-ice biogeochemistry for oceanic production and emissions of dimethyl sulfide in the Arctic

H. Hayashida / N. Steiner / A. Monahan / V. Galindo / M. Lizotte / M. Levasseur

Biogeosciences, Vol 14, Pp 3129-

2017 Volume 3155

Abstract: Sea ice represents an additional oceanic source of the climatically active gas dimethyl sulfide (DMS) for the Arctic atmosphere. To what extent this source contributes to the dynamics of summertime Arctic clouds is, however, not known due to scarcity of ... ...

Abstract	Sea ice represents an additional oceanic source of the climatically active gas dimethyl sulfide (DMS) for the Arctic atmosphere. To what extent this source contributes to the dynamics of summertime Arctic clouds is, however, not known due to scarcity of field measurements. In this study, we developed a coupled sea ice–ocean ecosystem–sulfur cycle model to investigate the potential impact of bottom-ice DMS and its precursor dimethylsulfoniopropionate (DMSP) on the oceanic production and emissions of DMS in the Arctic. The results of the 1-D model simulation were compared with field data collected during May and June of 2010 in Resolute Passage. Our results reproduced the accumulation of DMS and DMSP in the bottom ice during the development of an ice algal bloom. The release of these sulfur species took place predominantly during the earlier phase of the melt period, resulting in an increase of DMS and DMSP in the underlying water column prior to the onset of an under-ice phytoplankton bloom. Production and removal rates of processes considered in the model are analyzed to identify the processes dominating the budgets of DMS and DMSP both in the bottom ice and the underlying water column. When openings in the ice were taken into account, the simulated sea–air DMS flux during the melt period was dominated by episodic spikes of up to 8.1 µmol m −2 d −1 . Further model simulations were conducted to assess the effects of the incorporation of sea-ice biogeochemistry on DMS production and emissions, as well as the sensitivity of our results to changes of uncertain model parameters of the sea-ice sulfur cycle. The results highlight the importance of taking into account both the sea-ice sulfur cycle and ecosystem in the flux estimates of oceanic DMS near the ice margins and identify key uncertainties in processes and rates that should be better constrained by new observations.
Keywords	Ecology ; QH540-549.5 ; Life ; QH501-531 ; Geology ; QE1-996.5
Subject code	551
Language	English
Publishing date	2017-06-01T00:00:00Z
Publisher	Copernicus Publications
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Variations in storm-induced bed level dynamics across intertidal flats

P. L. M. de Vet / B. C. van Prooijen / I. Colosimo / N. Steiner / T. Ysebaert / P. M. J. Herman / Z. B. Wang

Scientific Reports, Vol 10, Iss 1, Pp 1-

2020 Volume 15

Abstract: Abstract Hydrodynamic forces on intertidal flats vary over a range of temporal and spatial scales. These spatiotemporal inhomogeneities have implications for intertidal flat morphodynamics and ecology. We determine whether storm events are capable of ... ...

Abstract	Abstract Hydrodynamic forces on intertidal flats vary over a range of temporal and spatial scales. These spatiotemporal inhomogeneities have implications for intertidal flat morphodynamics and ecology. We determine whether storm events are capable of altering the long-term morphological evolution of intertidal flats, and unravel the contributions of tidal flow, wind-driven flow, waves, and water depth on inhomogeneities in bed level dynamics (bed level changes over ~days) across these areas. We complement decades of bed level measurements on eight intertidal flats in two estuaries in the Netherlands with an extensive 1-month field campaign on one of those flats. Across this intertidal flat, the hydrodynamics and morphodynamics of a storm event were captured, including the post-storm recovery. We show that individual events can persistently alter the morphological evolution of intertidal flats; magnitudes of some bed level changes are even comparable to years of continuous evolution. The morphological impacts of events are largely controlled by the relative timing of the forcing processes, and not solely by their magnitudes. Spatiotemporal variations in bed level dynamics of intertidal flats are driven by a combination of: (1) the inhomogeneous distributions of the hydrodynamic forcing processes (including the under-explored role of the wind); and (2) the linear proportionality between bed level dynamics and the local bed slope.
Keywords	Medicine ; R ; Science ; Q
Subject code	551
Language	English
Publishing date	2020-07-01T00:00:00Z
Publisher	Nature Portfolio
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: L-band vegetation optical depth as an indicator of plant water potential in a temperate deciduous forest stand

N. M. Holtzman / L. D. L. Anderegg / S. Kraatz / A. Mavrovic / O. Sonnentag / C. Pappas / M. H. Cosh / A. Langlois / T. Lakhankar / D. Tesser / N. Steiner / A. Colliander / A. Roy / A. G. Konings

Biogeosciences, Vol 18, Pp 739-

2021 Volume 753

Abstract: Vegetation optical depth (VOD) retrieved from microwave radiometry correlates with the total amount of water in vegetation, based on theoretical and empirical evidence. Because the total amount of water in vegetation varies with relative water content ( ... ...

Abstract	Vegetation optical depth (VOD) retrieved from microwave radiometry correlates with the total amount of water in vegetation, based on theoretical and empirical evidence. Because the total amount of water in vegetation varies with relative water content (as well as with biomass), this correlation further suggests a possible relationship between VOD and plant water potential, a quantity that drives plant hydraulic behavior. Previous studies have found evidence for that relationship on the scale of satellite pixels tens of kilometers across, but these comparisons suffer from significant scaling error. Here we used small-scale remote sensing to test the link between remotely sensed VOD and plant water potential. We placed an L-band radiometer on a tower above the canopy looking down at red oak forest stand during the 2019 growing season in central Massachusetts, United States. We measured stem xylem and leaf water potentials of trees within the stand and retrieved VOD with a single-channel algorithm based on continuous radiometer measurements and measured soil moisture. VOD exhibited a diurnal cycle similar to that of leaf and stem water potential, with a peak at approximately 05:00 eastern daylight time (UTC − 4). VOD was also positively correlated with both the measured dielectric constant and water potentials of stem xylem over the growing season. The presence of moisture on the leaves did not affect the observed relationship between VOD and stem water potential. We used our observed VOD–water-potential relationship to estimate stand-level values for a radiative transfer parameter and a plant hydraulic parameter, which compared well with the published literature. Our findings support the use of VOD for plant hydraulic studies in temperate forests.
Keywords	Ecology ; QH540-549.5 ; Life ; QH501-531 ; Geology ; QE1-996.5
Subject code	580
Language	English
Publishing date	2021-02-01T00:00:00Z
Publisher	Copernicus Publications
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article: Comparative study of the effects of salinity and UV radiation on metabolism and morphology of the red macroalga Acanthophora spicifera (Rhodophyta, Ceramiales)

Pereira, D.T / C. Simioni / É. C. Schmidt / F. Chow / F. Ramlov / L. C. Ouriques / M. Maraschin / N. Steiner / Z. L. Bouzon

Photosynthetica. 2018 Sept., v. 56, no. 3

2018

Abstract: Increase of harmful radiation to the Earth’s surface due to ozone depletion results in higher exposure to harmful ultraviolet- B radiation (UV), while fluctuations in seawater salinity may alter water density, ionic concentration, nutrient uptake, and ... ...

Abstract	Increase of harmful radiation to the Earth’s surface due to ozone depletion results in higher exposure to harmful ultraviolet- B radiation (UV), while fluctuations in seawater salinity may alter water density, ionic concentration, nutrient uptake, and osmotic pressure. This study evaluated the effects of salinity and UV on metabolism and morphology of Acanthophora spicifera (M.Vahl) Børgesen. Water with 30 and 37 psu [g(salt) kg–1(sea water)] was used for experiments during 7 d of exposure to UV (3 h per day). We demonstrated that UV treatment predisposed, irrespective of salinity, A. spicifera to a decrease in its growth rate and cell viability, as well as affected its morphological parameters. After exposure to PAR + UVA + UVB (PAB), samples showed structural changes and damage, such as increasing cell wall thickness and chloroplast disruption. Our results indicate that UV led to dramatic metabolic changes and cellular imbalances, but more remarkable changes were seen in samples exposed to high salinity.
Keywords	Acanthophora ; cell viability ; cell walls ; chloroplasts ; macroalgae ; metabolism ; nutrient uptake ; osmotic pressure ; ozone depletion ; photosynthetically active radiation ; salinity ; seawater ; ultraviolet radiation
Language	English
Dates of publication	2018-09
Size	p. 799-810.
Publishing place	The Institute of Experimental Biology of the Czech Academy of Sciences
Document type	Article
ZDB-ID	208837-x
ISSN	1573-9058 ; 0300-3604
ISSN (online)	1573-9058
ISSN	0300-3604
DOI	10.1007/s11099-017-0731-2
Database	NAL-Catalogue (AGRICOLA)

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Article ; Online: Light-mediated discovery of surfaceome nanoscale organization and intercellular receptor interaction networks

Nature Communications, Vol 12, Iss 1, Pp 1-

2021 Volume 17

Abstract: The spatial organization of cell surface receptors is critical for cell signaling and drug action. Here, the authors develop an optoproteomic method for mapping surface protein interactions, revealing cellular responses to antibodies, drugs and viral ... ...

Abstract	The spatial organization of cell surface receptors is critical for cell signaling and drug action. Here, the authors develop an optoproteomic method for mapping surface protein interactions, revealing cellular responses to antibodies, drugs and viral particles as well as immunosynapse signaling events.
Keywords	Science ; Q
Language	English
Publishing date	2021-12-01T00:00:00Z
Publisher	Nature Portfolio
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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