bluuebunny/crossref_metadata_2025 huggingface dataset:
HIERARCHICAL CLASSIFICATION OF POLARIMETRIC SAR IMAGE BASED ON STATISTICAL REGION MERGING
Authors: Lang F. , Yang J. , Zhao L. , Li D.
Published: October 2012

Abstract. Segmentation and classification of polarimetric SAR (PolSAR) imagery are very important for interpretation of PolSAR data. This paper presents a new object-oriented classification method which is based on Statistical Region Merging (SRM) segmentation algorithm and a two-level hierarchical clustering technique. The proposed method takes full advantage of the polarimetric information contained in the PolSAR data, and takes both effectiveness and efficiency into account according to the characteristic of PolSAR. A modification of over-merging to over-segmentation technique and a post processing of segmentation for SRM is proposed according to the application of classification. And a revised symmetric Wishart distance is derived from the Wishart PDF. Segmentation and classification results of AirSAR L-band PolSAR data over the Flevoland test site is shown to demonstrate the validity of the proposed method.
EVALUATION OF ASTER IMAGES FOR CHARACTERIZATION AND MAPPING OF AMETHYST MINING RESIDUES
Authors: Markoski P. R. , Rolim S. B. A.
Published: October 2012

Abstract. The objective of this work was to evaluate the potential of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), subsystems VNIR (Visible and Near Infrared) and SWIR (Short Wave Infrared) images, for discrimination and mapping of amethyst mining residues (basalt) in the Ametista do Sul Region, Rio Grande do Sul State, Brazil. This region provides the most part of amethyst mining of the World. The basalt is extracted during the mining process and deposited outside the mine. As a result, mounts of residues (basalt) rise up. These mounts are many times smaller than ASTER pixel size (VNIR – 15 meters and SWIR – 30 meters). Thus, the pixel composition becomes a mixing of various materials, hampering its identification and mapping. Trying to solve this problem, multispectral algorithm Maximum Likelihood (MaxVer) and the hyperspectral technique SAM (Spectral Angle Mapper) were used in this work. Images from ASTER subsystems VNIR and SWIR were used to perform the classifications. SAM technique produced better results than MaxVer algorithm. The main error found by the techniques was the mixing between "shadow" and "mining residues/basalt" classes. With the SAM technique the confusion decreased because it employed the basalt spectral curve as a reference, while the multispectral techniques employed pixels groups that could have spectral mixture with other targets. The results showed that in tropical terrains as the study area, ASTER data can be efficacious for the characterization of mining residues.
THE LOW BACKSCATTERING TARGETS CLASSIFICATION IN URBAN AREAS
Authors: Shi L.
Published: October 2012

Abstract. The Polarimetric and Interferometric Synthetic Aperture Radar (POLINSAR) is widely used in urban area nowadays. Because of the physical and geometric sensitivity, the POLINSAR is suitable for the city classification, power-lines detection, building extraction, etc. As the new X-band POLINSAR radar, the china prototype airborne system, XSAR works with high spatial resolution in azimuth (0.1 m) and slant range (0.4 m). In land applications, SAR image classification is a useful tool to distinguish the interesting area and obtain the target information. The bare soil, the cement road, the water and the building shadow are common scenes in the urban area. As it always exists low backscattering sign objects (LBO) with the similar scattering mechanism (all odd bounce except for shadow) in the XSAR images, classes are usually confused in Wishart-H-Alpha and Freeman-Durden methods. It is very hard to distinguish those targets only using the general information. To overcome the shortage, this paper explores an improved algorithm for LBO refined classification based on the Pre-Classification in urban areas. Firstly, the Pre-Classification is applied in the polarimetric datum and the mixture class is marked which contains LBO. Then, the polarimetric covariance matrix C3 is re-estimated on the Pre-Classification results to get more reliable results. Finally, the occurrence space which combining the entropy and the phase-diff standard deviation between HH and VV channel is used to refine the Pre-Classification results. The XSAR airborne experiments show the improved method is potential to distinguish the mixture classes in the low backscattering objects.
ADAPTIVE MULTI-OBJECTIVE SUB-PIXEL MAPPING FRAMEWORK BASED ON MEMETIC ALGORITHM FOR HYPERSPECTRAL REMOTE SENSING IMAGERY
Authors: Zhong Y. , Zhang L.
Published: October 2012

Abstract. Sub-pixel mapping technique can specify the location of each class within the pixels based on the assumption of spatial dependence. Traditional sub-pixel mapping algorithms only consider the spatial dependence at the pixel level. The spatial dependence of each sub-pixel is ignored and sub-pixel spatial relation is lost. In this paper, a novel multi-objective sub-pixel mapping framework based on memetic algorithm, namely MSMF, is proposed. In MSMF, the sub-pixel mapping is transformed to a multi-objective optimization problem, which maximizing the spatial dependence index (SDI) and Moran's I, synchronously. Memetic algorithm is utilized to solve the multi-objective problem, which combines global search strategies with local search heuristics. In this framework, the sub-pixel mapping problem can be solved using different evolutionary algorithms and local algorithms. In this paper, memetic algorithm based on clonal selection algorithm (CSA) and random swapping as an example is designed and applied simultaneously in the proposed MSMF. In MSMF, CSA inherits the biologic properties of human immune systems, i.e. clone, mutation, memory, to search the possible sub-pixel mapping solution in the global space. After the exploration based on CSA, the local search based on random swapping is employed to dynamically decide which neighbourhood should be selected to stress exploitation in each generation. In addition, a solution set is used in MSMF to hold and update the obtained non-dominated solutions for multi-objective problem. Experimental results demonstrate that the proposed approach outperform traditional sub-pixel mapping algorithms, and hence provide an effective option for sub-pixel mapping of hyperspectral remote sensing imagery.
COMBINING LOCAL FEATURES AND PROGRESSIVE SUPPORT VECTOR MACHINE FOR URBAN CHANGE DETECTION OF VHR IMAGES
Authors: Huo C. , Fan B. , Pan C. , Zhou Z.
Published: October 2012

Abstract. The difficulties about change detection of VHR images are analyzed from different perspectives. Motivated by perception and cognition mechanism of human vision, visual change detection principles are discussed, and a unified change detection framework is proposed. To address the difficulties in change detection of VHR images, a novel approach is presented within the framework, which exploits the combination of local features and change vector displacement field to represent the complex changes of VHR images and utilizes transductive SVM (Support Vector Machine) to classify change features progressively. Experiments demonstrate the effectiveness of the proposed approach.
A CHANGE DETECTION METHOD FOR REMOTE SENSING IMAGE BASED ON MULTI-FEATURE DIFFERENCING KERNEL SVM
Authors: Lin Y. , Liu B. , Lv Q.-l. , Pan C. , Lu Y.
Published: October 2012

Abstract. Based on the support vector machine (SVM) tools and multiple kernel method, the combinations of kernel functions were mainly discussed. The construction method of image differencing kernel with multi-feature (spectral feature and textural feature) has been developed. Through this method and weighting of the categories' samples, the improved SVM change detection model has been proposed, which could realize the direct extraction of spatial distribution information from several change classes. From the experiments we can draw the following conclusions: with the help of multiple kernel function integrating spectral features and texture information, the new change detection model can achieve higher detection accuracy than the traditional methods and is suitable for the small-sample experiment. Furthermore, it avoids the complex and uncertainty in determining change threshold required in the old detection methods.
SEASONAL TRENDS IN TIBETAN LAKE LEVEL CHANGES AS OBSERVED BY ICESAT LASER ALTIMETRY
Authors: Phan V. H. , Lindenbergh R. , Menenti M.
Published: October 2012

Abstract. The Tibetan plateau is covered by hundreds of larger and smaller lakes. Until recently there was no method to monitor their water level variations due to lack of in-situ measurements or unfitness of available remote sensing methods. However the ICESat/GLA14 laser altimetry data provide global surface elevations for land during 18 one-month campaigns between 2003 and 2009. This product could be used to accurately monitor water level variations and to estimate annual water level trends of about 150 Tibetan lakes. Based on the ICESat campaign schedule, lake levels derived from the GLA14 data are classified into three groups referenced to the Tibetan seasons: late dry, early wet, and early dry. For each lake sampled by sufficient ICESat campaigns, seasonal water level trends could be estimated and inter-seasonal lake level variations could be determined. The results indicate that most of the southern Tibetan lakes have a downward seasonal trend while most lakes elsewhere in Tibet have a positive seasonal trend. This means that these seasonal trends are similar to the annual trends. Moreover, lake level variations between seasons are much larger in the south than in the north and the west of Tibet. Based on the spatial pattern of the lakes, the Tibetan plateau is divided into four sub-areas corresponding to seasonal lake level trends and inter-seasonal lake level variations. The results confirm climatic trends as discussed in meteorological literature. Therefore, this analysis is expected to improve the understanding of the limnological processes on the Tibetan plateau and their impacts on the surrounding regions.
CHANGE DETECTION IN LAND-USE AND LAND-COVER DYNAMICS AT A REGIONAL SCALE FROM MODIS TIME-SERIES IMAGERY
Authors: Setiawan Y. , Yoshino K.
Published: October 2012

Abstract. Remote sensing has long been used as a means of detecting and classifying changes on the land. Analysis of multi-year time series of land surface attributes and their seasonal change indicates a complexity of land use land cover change (LULCC). This paper explores the temporal complexity of land change considering temporal vegetation dynamics, in other words, distinguishing the changes regarding to their properties in long-term image analysis. This study is based on the hypothesis that land cover might be dynamics; however, consistent land use has a typical, distinct and repeated temporal pattern of vegetation index inter-annually. Therefore, pixels represent a change when the inter-annual temporal dynamics is changed. We analysed the dynamics pattern of long-term image data of wavelet-filtered MODIS EVI from 2001 to 2007. The change of temporal vegetation dynamics was detected by differentiating distance between two successive annual EVI patterns. Moreover, we defined the type of changes using the clustering method, which were then validated by ground check points and secondary data sets.
EDGE FEATURE MATCHING OF REMOTE SENSING IMAGES VIA PARAMETER DECOMPOSITION OF AFFINE TRANSFORMATION MODEL
Authors: Chen T. , Gongjian W. , Zhongliang J. , Bangwam Y.
Published: October 2012

Abstract. An approach of the edge feature matching of remote sensing images based on parameter decomposition of the affine transformation model is presented. First, the adaptability of affine transformation model used in image matching is analyzed, and parameters of the affine transformation model are decomposed. Second, the sum of squared gradient (SSG) similarity is constructed based on the edge feature in the images, and the parameters of the affine transformation model between the images are solved with the Genetic Algorithms (GA) which is used to obtain the global optimum solution of the similarity. Finally, the performance of the approach is analyzed in theory and validated with remote sensing image matching experiments.
RESEARCH ON IMAGE TRANSLATION BETWEEN SAR AND OPTICAL IMAGERY
Authors: Z. Fu  , W. Zhang
Published: October 2012

Abstract. Compare to optical sensors, Synthetic Aperture Radar (SAR) sensors can work at all time and under all weather conditions. However, SAR images are less intuitive and more difficult to understand. To complement advantages of optical and SAR sensors, a technique of image translation is put forward. Firstly, the concept named as remote sensing image translation is presented, and a set of technology thinking for multi-source remote sensing image translation is also given. Image understanding, object transformation and representation are considered as three key steps for image translation, and some specific solutions for the three steps are proposed later. Finally, an ENVISAT-ASAR image is translated into a TM image by means of feature extraction of grey scale and texture, SVM classification algorithm, seed-fill algorithm and exemplar-based texture synthesis algorithm. The experiment results demonstrate that the translated SAR images are visually similar to related optical images, while the main spatial structure information of original image is preserved, it could fill the blank regions in the incomplete TM image. All the experiments show that the proposed techniques of image translation are rational and effective.
A PROPOSED FRAMEWORK TO UNMIX SCATTERING MECHANISMS OF POLARIMETRIC RADAR IMAGES USING VERY HIGH RESOLUTION OPTICAL IMAGES
Authors: Giordano S. , Mercier G. , Rudant J.-P.
Published: October 2012

Abstract. A new approach has been proposed for radar and optical image fusion. Candidate images for fusion are polarimetric radar images and very high resolution stereoscopic optical images. The fused product is expected to produce more reliable large scale land cover classifications. In the first part of this paper, observation-based state-of-the-art methods for optical and radar image fusion are discussed. The idea of unmixing physical radar scattering mechanisms with the optical images has been proposed as a suitable means to improve the resolution of the polarimetric radar images. The second part focuses on a general description of the target algorithm. The suggested physical approach simulating synthetic scattering matrices with stereoscopic optical images is developed. Finally, future work to develop this unmixing algorithm is discussed.
AN IMPROVED HIGH FREQUENCY MODULATING FUSION METHOD BASED ON MODULATION TRANSFER FUNCTION FILTERS
Authors: Y. Jia  , M. Wu  , X. Zhang
Published: October 2012

Abstract. GeoEye-1 is the most advanced and highest resolution commercial earth imaging satellite in the world today. It provides multispectral images (MS) and Panchromatic image (PAN) with spatial resolutions of 2.0 m and 0.5 m respectively. Image fusion is very important for mapping and image interpretation because it can take advantage of the complementary spatial/spectral resolution characteristics of remote sensing imagery. So an improved high frequency modulation fusion method based on MTF is proposed. Modulation transfer functions (MTF) are firstly measured from GeoEye-1 images, and then the degraded images based on MTF filters are obtained. Secondly, modulating parameter is obtained based on Minimum Mean Square Error, and image fusion is performed and measured in the degraded version. Finally, fused images with the high spatial resolution are produced by using the proposed method. Compared with fusion methods of weighted high passing filtering(w-HPF) in ERDAS IMAGINE and general image fusion based on MTF( MTF-GIF), The results of fused GeoEye-1 images show that the proposed method is an efficient way for GeoEye-1 image fusion, which can keep spectral information with the high spatial resolution.
THE INFLUENCE OF SPECTRAL WAVELENGTH ON THE QUALITY OF PANSHARPENED IMAGE SIMULATED USING HYPERSPECTRAL DATA
Authors: Matsuoka M.
Published: October 2012

Abstract. Preservation of the spectral characteristics in multispectral images is important in the development of pansharpening methods because it affects the accuracy of subsequent applications, such as visual interpretation, land cover classification, and change detection. The combinations of the spectral properties (observation wavelength and width of spectral bands) of multispectral and panchromatic images affect both the spatial and spectral quality of pansharpened images. Therefore, the clarification of the relations between spectral bands and quality of pansharpened image is important for improving our understanding of pansharpening methods, and for developing better schemes for image fusion. This study investigated the influence of the spectral waveband of panchromatic images on the image quality of multispectral (MS) images using simulated images produced from hyperspectral data. Panchromatic images with different spectral band position and multispectral images with degraded spatial resolution were generated from airborne visible/infrared imaging spectrometer (AVIRIS) images and pansharpened using seven methods: additive wavelet intensity, additive wavelet principal component, generalized Laplacian pyramid with spectral distortion minimization, generalized intensity-huesaturation (GIHS) transform, GIHS adaptive, Gram–Schmidt spectral sharpening, and block-based synthetic variable ratio. The pansharpened near-infrared band was visually and statistically compared with the non-degraded image. Wide variation in quality was identified visually within and between methods depending on the spectral wavelengths of the panchromatic images. Quantitative evaluations using three frequently used indices, the correlation coefficient, erreur relative globale adimensionnelle de synthèse (ERGAS), and the Q index, showed the individual behaviors of the pansharpening methods in terms of the spectral similarity in panchromatic and near-infrared, though all methods had similar qualities in the case with the lowest similarity. These findings are discussed in terms of the fundamentals and structures of the methods.
FUSION OF ACTIVE AND PASSIVE MICROWAVE OBSERVATIONS TO CREATE AN ESSENTIAL CLIMATE VARIABLE DATA RECORD ON SOIL MOISTURE
Authors: Wagner W. , Dorigo W. , de Jeu R. , Fernandez D. , Benveniste J. , Haas E. , Ertl M.
Published: October 2012

Abstract. Soil moisture was recently included in the list of Essential Climate Variables (ECVs) that are deemed essential for IPCC (Intergovernmental Panel on Climate Change) and UNFCCC (United Nations Framework Convention on Climate Change) needs and considered feasible for global observation. ECVs data records should be as long, complete and consistent as possible, and in the case of soil moisture this means that the data record shall be based on multiple data sources, including but not limited to active (scatterometer) and passive (radiometer) microwave observations acquired preferably in the low-frequency microwave range. Among the list of sensors that can be used for this task are the C-band scatterometers on board of the ERS and METOP satellites and the multi-frequency radiometers SMMR, SSM/I, TMI, AMSR-E, and Windsat. Together, these sensors already cover a time period of more than 30 years and the question is how can observations acquired by these sensors be merged to create one consistent data record? This paper discusses on a high-level possible approaches for fusing the individual satellite data. It is argued that the best possible approach for the fusion of the different satellite data sets is to merge Level 2 soil moisture data derived from the individual satellite data records. This approach has already been demonstrated within the WACMOS project (http://wacmos.itc.nl/) funded by European Space Agency (ESA) and will be further improved within the Climate Change Initiative (CCI) programme of ESA (http://www.esa-cci.org/).
SEA SURFACE ALTIMETRY BASED ON AIRBORNE GNSS SIGNAL MEASUREMENTS
Authors: Yu K. , Rizos C. , Dempster A.
Published: October 2012

Abstract. In this study the focus is on ocean surface altimetry using the signals transmitted from GNSS (Global Navigation Satellite System) satellites. A low-altitude airborne experiment was recently conducted off the coast of Sydney. Both a LiDAR experiment and a GNSS reflectometry (GNSS-R) experiment were carried out in the same aircraft, at the same time, in the presence of strong wind and rather high wave height. The sea surface characteristics, including the surface height, were derived from processing the LiDAR data. A two-loop iterative method is proposed to calculate sea surface height using the relative delay between the direct and the reflected GNSS signals. The preliminary results indicate that the results obtained from the GNSS-based surface altimetry deviate from the LiDAR-based results significantly. Identification of the error sources and mitigation of the errors are needed to achieve better surface height estimation performance using GNSS signals.
ULTRASHORT-BASELINE PERSISTENT SCATTERER RADAR INTERFEROMETRY FOR SUBSIDENCE DETECTION
Authors: Liu G. , Jia H. , Zhang R. , Li Z. , Chen Q. , Luo X. , Cai G.
Published: October 2012

Abstract. This paper presents an improved approach of multi-temporal interferometric synthetic aperture radar (InSAR) for detecting land subsidence phenomena by using time series of high resolution SAR images. Our algorithm extends the capability of the temporarily coherent point (TCP) InSAR technique proposed previously to detect subsidence even in the case of a small number of SAR images available for a study area. The approach proposed in this paper is implemented by using the interferograms with ultrashort spatial baselines (USB) through several procedures, including selection of USB interferometric pairs, TCP identification, TCP networking and modeling, as well as TCP solution. As the topographic effects are negligible in the USB interferograms, an external digital elevation model is no longer necessary for differential processing, thus simplifying both TCP modeling and parameter estimating. The algorithm has been tested with the high resolution TerraSAR-X (TSX) images acquired over Tianjin (China), and validated by using the ground-based leveling measurements. The testing results indicate that the density and coverage extent of TCPs can be increased dramatically, and the quality of subsidence measurements derived by the USB-based TCPInSAR can be raised.
SOIL SPECTRAL IMAGING: MOVING FROM PROXIMAL SENSING TO SPATIAL QUANTITATIVE DOMAIN
Authors: Dor E. B.
Published: October 2012

Abstract. Imaging spectroscopy (IS) is a relatively new technique that has attracted the attention of workers in many fields. In the soil sciences, this technology is not well developed and additional research is required – despite the fact that a large number of soil properties in the soil environment have already been studied from a reflectance perspective with much success (e.g. organic matter, cation exchange capacity, carbonate content and specific surface area). Going from proximal sensing to image spectrometry is not only a journey from the micro to macro scales; it is a lengthy one that is fraught with problems, such as dealing with data having a low signal-to-noise level, contamination of the atmosphere, large data sets, the Bidirectional Reflectance Distribution Function (BRDF) effect and more. In this paper, provide a brief history of both near infrared spectroscopy (NIRS) and IS approaches and attempt to understand why, despite its promise, IS has not yet been well developed for the soil sciences. We assume that research, education, exposure of the technology to end-users and governmental involvement are the major factors that require attention in this venue. Also provide some personal thoughts on the future of IS in soil and conclude that in 5 to 10 years, this application will have matured into one that is ready to use and well-known among soil scientists, end-users and decision-makers.
MEASURING THE PARTICULATE BACKSCATTERING OF INLAND WATERS: A COMPARISON OF TECHNIQUES
Authors: Campbell G. , Phinn S. R.
Published: October 2012

Abstract. The objective of this work was to examine whether the standard particulate backscattering IOP (Inherent Optical Properties) measurement method could be simplified. IOP measurements are essential for parameterising several forms of algorithms used to estimate water quality parameters from airborne and satellite images. Field measurements of the backscattering IOPs are more difficult to make than absorption measurements as correction of the raw Hydroscat-6 backscattering sensor observations is required to allow for the systematic errors associated with the water and water quality parameter absorption. The standard approach involves making simultaneous measurement of the absorption and attenuation of the water with an absorption and attenuation meter (ac-9) or making assumptions about the particulate backscattering probability. Recently, a number of papers have been published that use an alternative method to retrieve the particulate backscattering spectrum by using laboratory measured absorption values and in situ spectroradiometric observations. The alternative method inverts a model of reflectance iteratively using non-linear least squares fitting to solve for the particulate backscattering at 532 nm (bbp0(532)) and the particulate backscattering spectral slope (γ). In this paper, eleven observations made at Burdekin Falls Dam, Australia are used to compare the alternative reflectance method to the conventional corrected Hydroscat-6 observations. Assessment of the alternative reflectance method showed that the result of the inversions were highly dependent on the starting conditions. To overcome this limitation, Particle Swarm Optimisation, a stochastic search technique which includes a random element in the search approach, was used. It was found that when compared to the conventionally corrected Hydroscat-6 observations, the alternative reflectance method underestimated bbp0(532) by approximately 50% and overestimated γ by approximately 40%. Differences of this scale in specific backscattering spectra will have a pronounced effect on the parameterisation and subsequent performance of semi-analytical water quality parameter retrieval algorithms. This has implications for any water quality monitoring regimes that rely on semi-analytical algorithms.
HYPERSPECTRAL ANALYSIS OF RICE PHENOLOGICAL STAGES IN NORTHEAST CHINA
Authors: Gnyp M. L. , Yao Y. , Yu K. , Huang S. , Aasen H. , Lenz-Wiedemann V. I. S. , Miao Y. , Bareth G.
Published: October 2012

Abstract. The objective of this contribution is to monitor rice (Oryza sativa L., irrigated lowland rice) growth with multitemporal hyperspectral data during different phenological stages in Northeast China (Sanjiang Plain). Multitemporal hyperspectral data were measured with field spectroradiometers (ASD Inc.: QualitySpec and FieldSpec3) for two field experiments and nine farmers' fields. The field measurements were carried out together with corresponding measurements of agronomic data (aboveground biomass [AGB], Leaf Area Index [LAI], number of tillers). Eight selected standard hyperspectral vegetation indices (VIs), proved in several studies to be highly correlated with AGB or LAI, were calculated on the measured experimental field data. Additionally, the best two-band combinations for the Normalized Ratio Index (NRI) were determined. The results indicate that the NRI performed better than the selected standard VIs at the stages of stem elongation, booting and heading and also across all stages. Especially during the stem elongation stage (R2 = 0.76) and across all stages (R2 = 0.70), the NRI performed best. When applying the NRI on the farmers' field data, the performance was lower (R2 < 0.60). Overall, the sensitive individual wavelengths (±10 nm) for the best two-band combinations were detected at 711 and 799 nm (for tillering stage), 1575 and 1678 nm (for stem elongation stage), 515 and 695 nm (for booting stage), and 533 and 713 nm (for all stages). The results suggest that hyperspectral-based methods can estimate paddy rice AGB with a satisfying accuracy. In the context of precision agriculture, the findings are useful for future development of new hyperspectral devices such as scanners or cameras which could be fixed on tractors or unmanned aerial vehicles (UAVs).
ASSESSING HYPERSPECTRAL VEGETATION INDICES FOR ESTIMATING LEAF CHLOROPHYLL CONCENTRATION OF SUMMER BARLEY
Authors: Yu K. , Lenz-Wiedemann V. , Leufen G. , Hunsche M. , Noga G. , Chen X. , Bareth G.
Published: October 2012

Abstract. Hyperspectral reflectance data were collected at 7 critical phenological stages in a summer barley field with 7 varieties in 2010, without artificial nutrient gradients. Throughout the range of 350 to 1800 nm, all possible two-bands combinations for the simple ratio (SR = Rj/Ri) and the normalized difference vegetation index (NDVI = (Rj−Ri)/(Rj+Ri)) were evaluated using linear regression analysis against the leaf chlorophyll concentration (LCC). This study introduces a more comprehensive way of using the "correlation matrix" method for selecting sensitive bands and shows that in this way the newly selected SRs may outperform the NDVIs for estimating LCC. With this method, the selection of two-bands combinations for the SRs and NDVIs improved the performance for estimating LCC. Both the new SR (734, 629) and the new NDVI (667, 740) explained more than 74% of the variation in LCC across all the growth stages and all varieties. Compared with published indices, newly selected SRs and NDVIs improved the predictive ability for LCC. The most significant improvement was observed with increasing of R2 values by 13% for SR and 6% for NDVI. The overall performances of both newly selected indices and published indices were significantly influenced by the varieties. Moreover, Ultraviolet, Violet and Blue bands are more effective for estimating the LCC for a single variety, whereas Red-edge bands are more effective for that across all varieties. Therefore, a conclusion can be drawn that selecting twobands combinations significantly improves the capability of SRs and NDVIs for estimating the LCC of summer barley.
Periprocedural Thromboembolic Events Associated with Angioplasty and Stenting of the Extra- and Intracranial Carotid Artery Assessed by Neurological Status and Diffusion-Weighted Magnetic Resonance Imaging (DWI)
Authors: Ahlhelm Frank , Lieb Johanna , Ulmer Stefan , Ahlhelm Dirk , Reith Wolfgang
Published: October 2012

Objective. The purpose of this study was to determine the frequency of thromboembolic events associated with angioplasty and stenting of the carotid artery with special regard to extra- or intracranial localization of stenosis.
Methods. Twenty patients with symptomatic intracranial or extracranial internal carotid artery stenosis were treated with stenting and/or angioplasty. In 4 patients stenting was technically not feasible (all in the group with intracranial stenosis). All patients underwent diffusion-weighted imaging (DWI) and neurological examination within 48 hours before and after the procedure to detect periprocedural thrombembolic events.
Results. Extracranial carotid angioplasty and stenting (eCAS) was technically feasible and successfull without procedure-related neurological complications in all cases. Intracranial stenting (iCAS) was not feasible in four cases including one patient with a fateful course. Concerning the restoration of the vessel diameter intracranial stenting was not as successful as eCAS, but more effective than balloon angioplasty alone. Incidence of thrombembolic events assessed by DWI was low. The detected periprocedural thrombembolic events were small and clinically silent.
Conclusion. The risk of thromboembolic events during the endovascular treatment of symptomatic carotid artery stenosis was rather low for intra- and extracranial stenosis of the ICA in our patient sample, but one fatal course was observed.
Analysis of impedance measurements of a suspension of microcapsules using a variable length impedance measurement cell
Authors: Križaj Dejan , Pečar Borut
Published: October 2012

Electrical impedance measurements of a suspension have to take into account the double layer impedance that results from a very thin charged layer formed at the electrode-electrolyte interface. A dedicated measuring cell that enables variation of the distance between the electrodes was developed to investigate the electrical properties of suspensions using two-electrode impedance measurements. By varying the distance between the electrodes it is possible to separate the double layer and the suspension impedance from the measured data. Electrical ‘lumped’ models have been developed from measured and extracted impedances. The error of non-inclusion of the double layer impedance has been analyzed. The error depends on the frequency of the measurement as well as the distance between the electrodes.
“Untangling” Alzheimer's Disease and Epilepsy
Authors: Scharfman Helen E.
Published: October 2012

There is a substantial body of evidence that spontaneous recurrent seizures occur in a subset of patients with Alzheimer disease (AD), especially the familial forms that have an early onset. In transgenic mice that simulate these genetic forms of AD, seizures or reduced seizure threshold have also been reported. Mechanisms underlying the seizures or reduced seizure threshold in these mice are not yet clear and are likely to be complex, because the synthesis of amyloid β (Aβ) involves many peptides and proteases that influence excitability. Based on transgenic mouse models of AD where Aβ and its precursor are elevated, it has been suggested that seizures are caused by the downregulation of the Nav1.1 sodium channel in a subset of GABAergic interneurons, leading to a reduction in GABAergic inhibition. Another mechanism of hyperexcitability appears to involve tau, because deletion of tau reduces seizures in some of the same transgenic mouse models of AD. Therefore, altered excitability may be as much a characteristic of AD as plaques and tangles—especially for the familial forms of AD.
Spectrophotometric and Stability–Indicating High–Performance Liquid Chromatographic Determinations of Terbutaline Sulfate
Authors: Hashem Hisham A , Elmasry Manal S , Hassan Wafaa E , Tründelberg Clemens , Jira Thomas
Published: October 2012

Spectrophotometric and stability-indicating HPLC procedures are described for determination of terbutaline sulfate in bulk powder and dosage form. The first procedure is based on diazo coupling of the phenolic groups of terbutaline sulfate with fast red B salt in the presence of sodium hydroxide. The colored compound developed in alkaline medium was measured at 475 nm. Different variables affecting the reaction were studied. Beer's Law is obeyed in the concentration range of 1–6 μg/mL. In the HPLC procedure, the separation was carried out on a Caltrex® AIII column, a relatively new packing material consisting of silica-bonded calix[8] arene, using an isocratic binary mobile phase, acetonitrile–ammonium acetate (50 + 50, v/v), at pH 6.2. A diode array detector was used at 280 nm. The method was validated for system suitability, linearity, precision, LOD, LOQ, specificity, stability, and robustness. The LOD and LOQ were 0.196 and 0.781 μg/mL, respectively. The recovery values of this method were between 98 and 102%, and the reproducibility was within 0.92%. Statistical comparison of the results obtained from the analysis of the studied drug to those of the official British Pharmacopoeia (2007) method using t- and F-tests showed no significant difference between them.
Quantification of Chlorogenic Acid and Hyperoside Directly from Crude Blueberry (Vaccinium angustifolium) Leaf Extract by NMR Spectroscopy Analysis: Single-Laboratory Validation
Authors: Hicks Joshua M , Muhammad Asim , Ferrier Jonathan , Saleem Ammar , Cuerrier Alain , Arnason John T , Colson Kimberly L
Published: October 2012

A single-laboratory-validated NMR spectroscopy method was established for determining the quantity of chlorogenic acid and hyperoside from crude extract material of blueberry leaves of the species Vaccinium angustifolium var. laevifolium House. The calibration curve of chlorogenic acid showed a highly linear regression, R = 0.99998. NMR spectroscopy identification and quantification of the constituents directly from the mixture, within the error of HPLC-diode array detector analysis, were determined as 7.53 mM chlorogenic acid (64.0 mg chlorogenic acid/g powdered leaf) and 0.77 mM hyperoside (8.58 mg hyperoside/g powdered leaf). The LOD was calculated to be 0.01 mM and the LOQ 0.01 mM by the 9 min and 13 s NMR spectroscopy experiment utilized. The assay showed no significant interference from different field strengths, extraction mesh size, gravimetric scale precision, NMR spectroscopy tube type, pulse program, amount of starting dry material, or day-to-day operation. The robustness of NMR spectroscopy as a means of definitively monitoring chlorogenic acid and hyperoside content directly from crude extracts was demonstrated by Youden statistical analysis.
Recovery of Salmonella from Internally and Externally Contaminated Whole Tomatoes Using Several Different Sample Preparation Procedures
Authors: Wang Hua , Gill Vikas S , Irvin Kari A , Byrd Mindi , Bolger Cathryn M , Zheng Jie , Dickey Erin E , Duvall Robert E , Jacobson Andrew P , Hammack Thomas S
Published: October 2012

Studies were conducted to determine the relative effectiveness of whole soak [current Bacteriological Analytical Manual-(BAM) Salmonella method], quarter, stomach, and blend methods for the recovery of Salmonella organisms from internally and externally contaminated tomatoes. Tomatoes were subjected to three inoculation methods: surface inoculation, internal inoculation by injection, and immersion with single Salmonella serovars. The inoculation levels ranged from 1 to 100 CFU/tomato for surface and injection inoculation or 1 to 100 CFU/mL for immersion inoculation. Tomatoes were held for 3 days after inoculation at 2–6°C prior to initiation of analysis. Contaminated tomatoes were soaked, quartered, stomached, and blended in appropriate portions of Universal Pre-enrichment broth, and incubated for 24 h at 35 ± 2°C. The BAM Salmonella culture method was followed thereafter, and tomatoes were treated as a low-microbial-load food. The stomaching procedure was significantly (P< 0.05) more effective than the whole soak procedure for recovery of internalized Salmonella from tomatoes (by injection). The blending procedure was arithmetically superior to the stomaching procedure for detection of internalized Salmonella from tomatoes (by immersion). The blending procedure showed the same effectiveness as the whole soak procedure for the detection of Salmonella on tomato surfaces. Comparisons between test portion-to-broth ratios (weight to volume) showed that a 1:3 test portion-to-broth ratio had a better buffering capacity for blended tomatoes than a 1:1 test portion-to-broth ratio. It is recommended that the current whole soak BAM tomato sample preparation procedure be replaced with a blending procedure and a 1:3 test portion-to-broth ratio.
Inclusion of 1-Naphthylacetic Acid and 2-(1-Naphthyl)acetamide into Three Typical Multiresidue Methods for LC/MS/MS Analysis of Tomatoes and Zucchini
Authors: Lozano Ana , Pérez-Parada Andrés , Heinzen Horacio , Fernández-Alba Amadeo R
Published: October 2012

In spite of high plant growth regulator application rates, little has been reported in the literature on determination of their residues in fruits and vegetables. This would be useful in monitoring good manufacturing practices and overall safety through the enforcement of maximum residue levels (MRLs). The present work describes method validation for the determination of 1-naphthylacetic acid (NAA) and 2(1-naphthyl)acetamide (NAAm) in tomato and zucchini using the mini-Luke, ethyl acetate (EtOAc) and acetate-buffered quick, easy, cheap, effective, rugged, and safe (QuEChERS) methods. Samples were spiked at two different levels: 50 and 100 μg/kg for NAA and 20 and 100 μg/kg for NAAm. These compounds were analyzed within the same chromatographic run with LC coupled to triple quadrupole MS (LC/(QqQ)MS/MS) in positive and negative electrospray ionization [ESI(+) and ESI(–)] modes for NAAm and NAA, respectively. For analyte confirmation, LC/ESI(-)QTOF-MS was also investigated given that NAA has only one multiple reaction monitoring transition (185.1→140.9 m/z). These three common methods were used to determine linearity, recoveries, precision (RSD), matrix effects, repeatability, and reproducibility (n = 5) for the selected matrixes. In terms of the Directorate-General for Health and Consumers (DG-SANCO) guidelines, only insignificant differences were found for the multiresidue methods tested, regardless of the commodity. Matrix-matched calibration was used, and LODs were below 10.1 μg/kg for NAA and 6.0 μg/kg for NAAm, which were lower than the MRLs established in current European Union legislation for these compounds. Obtained recoveries for NAA ranged from 87 to 107% with RSD values below 10% for mini-Luke, 83 to 107% with RSD <11% for EtOAc, and 76 to 85% with RSD ≤7% for QuEChERS. NAAm recoveries ranged from 74 to 102% with RSD ≤ 15% for mini-Luke, 76 to 97% with RSD <4% for EtOAc, and 76 to 93% with RSD ≤ 5% for QuEChERS. The linearity of the response over two orders of magnitude was demonstrated (r2 > 0.996) for all methods used. Good repeatability and reproducibility in terms of RSD were obtained (11.3–17.8%) for these analytical methods. The results were acceptable within the studied ranges for both analytes in all methods. As these multiresidue methods are used at the present time in many laboratories, this survey indicates that these analytes should be included in their monitoring scope.
Development and Validation of a Procedure for Determination of Sulfonamide Residues in Pasteurized Milk Using Modified QuEChERS Method and Liquid Chromatography/Tandem Mass Spectrometry
Authors: Parab Swati Ramkrishna , Amritkar Priti Nilesh
Published: October 2012

An LC method for determination of 10 sulfonamides in milk using a modified Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method was developed. Unlike the standard QuEChERS method, addition of primary secondary amine was not required for the cleanup step. Sulfonamides were analyzed from the acetonitrile layer using LC/MS/MS with electrospray ionization. Sulfonamides studied included sulfanilamide, sulfadiazine, sulfathiazole, sulfamerazine, sulfamethiazole, sulfamethazine, sulfamethoxypyridazine, sulfamethoxazole, sulfadoxin, and sulfamethoxine. Three types of milk matrixes, namely, low- and high-fat liquid pasteurized milk and milk powder, were used in the study. Matrix effects of all three matrixes were studied. The LOQs for the 10 analytes for high-fat milk were 5.3–11.2 μg/L. The combined LOQ of the 10 sulfonamides was 83.15 μg/L, which is below the maximum residue limit recommended by the European Union for sulfonamides in milk.
Determination of Direct Available Phosphate in Fertilizers by a Discrete Analyzer: Single-Laboratory Validation
Authors: Nimick Ryan , Mehlbrech Laura , Novotny Lawrence , Thiex Nancy
Published: October 2012

To improve throughput during peak seasonal demand, a screening method for the determination of fertilizer-available phosphate using a discrete analyzer for semi-automation was validated in a single laboratory. The fertilizer materials were extracted using a neutral EDTA-ammonium citrate solution as detailed in AOAC Official MethodSM 993.31. Phosphate was subsequently freed from the matrix and converted to orthophosphate using an alkaline persulfate digestion modified from a U. S. Geological Survey water method. Phosphorus was determined colorimetrically on a discrete analyzer. Twelve check samples from the Magruder Fertilizer Check Sample Program and Association of Fertilizer and Phosphate Chemists Fertilizer Check Program were used for method validation experiments. The proposed method is linear from 0.01 to 20 mg/L (ppm) phosphorus. Recovery for all materials averaged 101%, with a range of 99.2 to 103%. Bias for all materials averaged 0.59% with a range of –0.11 to 1.68%, with bias increasing at concentrations of available phosphate exceeding 40%. The LOD was calculated to be 0.001% available phosphate and the LOQ 0.002% available phosphate. The method was found fit for purpose as a screening method for available phosphate analysis in fertilizers.
Analysis of Free and Total Myo-Inositol in Foods, Feeds, and Infant Formula by High-Performance Anion Exchange Chromatography with Pulsed Amperometric Detection, Including a Novel Total Extraction Using Microwave-Assisted Acid Hydrolysis and Enzymatic Treatment
Authors: Ellingson David , Pritchard Ted , Foy Pamela , King Kathryn , Mitchell Barbara , Austad John , Winters Doug , Sullivan Darryl
Published: October 2012

A method for the analysis of free and total myo-inositol in foods, feeds, and infant formulas has been developed and validated using high-performance anion exchange chromatography with pulsed amperometric detection. The option of a free myo-inositol determination or a complete total myo-inositol determination from main bound sources can be achieved. These sources include phytates, lower phosphorylated forms, and phosphatidylinositol. This approach gives the option for subtraction of myo-inositol from nonbioavailable sources when it is quantified using other methods if a total bioavailable myo-inositol result is desired for nutritional labeling of a product. The free analysis was validated in a milk-based infant formula, giving RSDR of 2.29% and RSDr of 2.06%. A mean recovery of 97.9% was achieved from various spike levels of myo-inositol. Certified National Institute of Standards and Technology reference material verified the method's compatibility and specificity. Two different total analyses were validated in a soy-based infant formula and compared. One technique involved using a conventional acid hydrolysis with autoclave incubation for 6 h, while the other used a novel technique of microwave-assisted acid hydrolysis with enzymatic treatment that can minimize extraction to 1 day. The autoclave analysis had RSDR of 2.08% and RSDr of 1.55%, along with a mean spike recovery of 102.1% at various myo-inositol spike levels. The microwave/enzyme total analysis had RSDR of 4.34% and RSDr of 4.70%, along with a mean spike recovery of 104.2% at various spike levels of myo-inositol. Main sources of myo-inositol including phytic acid and phosphatidylinositol were tested with both total analyses. Mean recoveries of phytic acid and phosphatidylinositol through the autoclave total analysis were 90.4 and 98.3%, respectively. Mean spike recoveries for these same sources in soy-based infant formula through the microwave/enzyme total analysis were 97.2 and 96.3%, respectively. Comparison of soy-based infant formula and corn grain samples with high levels of these main sources showed in similar results, indicating both total analyses are acceptable for use. An additional glycerol kinase step was also developed to remove glycerol from the chromatographic elution window of myo-inositol in samples with high levels of glycerol.