The IgE-FcepsilonRI network plays a central role in allergic inflammation. IgE levels control cell surface levels of FcepsilonRI and, in turn, FcepsilonRI levels modulate the intensity of effector ...responses. Treatment of allergic patients with anti-IgE Abs has been shown to induce a decrease in FcepsilonRI expression on basophils and a decrease in Ag-triggered histamine release. However, the mechanisms underlying IgE-mediated regulation of FcepsilonRI expression remain unclear. Here, we designed an in vitro model system to establish the minimal cellular requirements for regulation of FcepsilonRI by IgE. Using this system, we demonstrate that transcriptional regulation, hemopoietic-specific factors, and signaling are not required for IgE-mediated increases in FcepsilonRI expression. IgE binding to the alpha-chain is the minimal requirement for the induction of FcepsilonRI up-regulation. The rate of up-regulation is independent of the baseline level of expression. The mechanism of this up-regulation is the result of a combination of three factors: 1) stabilization of the receptor at the cell surface, which prevents receptor internalization and degradation; 2) use of a preformed pool of receptor comprising recycled and recently synthesized receptors; and 3) continued basal level of protein synthesis. It is possible that in vivo additional factors contribute to modulate the basic regulatory mechanism described here.
Voltage-gated ion channels support electrochemical activity in cells and are largely responsible for information flow throughout the nervous systems. The voltage sensor domains in these channels ...sense changes in transmembrane potential and control ion flux across membranes. The X-ray structures of a few voltage-gated ion channels in detergents have been determined and have revealed clear structural variations among their respective voltage sensor domains. More recent studies demonstrated that lipids around a voltage-gated channel could directly alter its conformational state in membrane. Because of these disparities, the structural basis for voltage sensing in native membranes remains elusive. Here, through electron-crystallographic analysis of membrane-embedded proteins, we present the detailed view of a voltage-gated potassium channel in its inactivated state. Contrary to all known structures of voltage-gated ion channels in detergents, our data revealed a unique conformation in which the four voltage sensor domains of a voltage-gated potassium channel from Aeropyrum pernix (KvAP) form a ring structure that completely surrounds the pore domain of the channel. Such a structure is named the voltage sensor ring. Our biochemical and electrophysiological studies support that the voltage sensor ring represents a physiological conformation. These data together suggest that lipids exert strong effects on the channel structure and that these effects may be changed upon membrane disruption. Our results have wide implications for lipid–protein interactions in general and for the mechanism of voltage sensing in particular.
Statistical data constitute one of the elements providing the basis for the establishment of indicators and factors facilitating the assessment and monitoring of spatial development. The primary ...objective of the study was to analyse statistical data collected in the Geostatistics Portal (GP) from the perspective of integrated land management, and particularly crop production. GP satisfactorily fulfilled its role with respect to data obtained from the 2010 General Agricultural Census. GP is an extremely useful tool in strategic decision making process at almost every level of management, also in terms of sustainable land management.
The estimation of dendrometric parameters has become an important issue for the agricultural planning and management. Since the classical field measurements are time consuming and inefficient, ...Airborne Laser Scanning (ALS) data can be used for this purpose. Point clouds acquired for orchard areas allow to determine orchard structures and geometric parameters of individual trees. In this research we propose an automatic method that allows to determine geometric parameters of individual olive trees using ALS data. The method is based on the α-shape algorithm applied for normalized point clouds. The algorithm returns polygons representing crown shapes. For points located inside each polygon, we select the maximum height and the minimum height and then we estimate the tree height and the crown base height. We use the first two components of the Principal Component Analysis (PCA) as the estimators for crown diameters. The α-shape algorithm requires to define the radius parameter R. In this study we investigated how sensitive are the results to the radius size, by comparing the results obtained with various settings of the R with reference values of estimated parameters from field measurements. Our study area was the olive orchard located in the Castellon Province, Spain. We used a set of ALS data with an average density of 4 points m−2. We noticed, that there was a narrow range of the R parameter, from 0.48 m to 0.80 m, for which all trees were detected and for which we obtained a high correlation coefficient (> 0.9) between estimated and measured values. We compared our estimates with field measurements. The RMSE of differences was 0.8 m for the tree height, 0.5 m for the crown base height, 0.6 m and 0.4 m for the longest and shorter crown diameter, respectively. The accuracy obtained with the method is thus sufficient for agricultural applications.
3D GIS FOR FLOOD MODELLING IN RIVER VALLEYS Tymkow, P.; Karpina, M.; Borkowski, A.
International archives of the photogrammetry, remote sensing and spatial information sciences.,
06/2016, Volume:
XLI-B8
Journal Article
Peer reviewed
Open access
The objective of this study is implementation of system architecture for collecting and analysing data as well as visualizing results for hydrodynamic modelling of flood flows in river valleys using ...remote sensing methods, tree-dimensional geometry of spatial objects and GPU multithread processing. The proposed solution includes: spatial data acquisition segment, data processing and transformation, mathematical modelling of flow phenomena and results visualization. Data acquisition segment was based on aerial laser scanning supplemented by images in visible range. Vector data creation was based on automatic and semiautomatic algorithms of DTM and 3D spatial features modelling. Algorithms for buildings and vegetation geometry modelling were proposed or adopted from literature. The implementation of the framework was designed as modular software using open specifications and partially reusing open source projects. The database structure for gathering and sharing vector data, including flood modelling results, was created using PostgreSQL. For the internal structure of feature classes of spatial objects in a database, the CityGML standard was used. For the hydrodynamic modelling the solutions of Navier-Stokes equations in two-dimensional version was implemented. Visualization of geospatial data and flow model results was transferred to the client side application. This gave the independence from server hardware platform. A real-world case in Poland, which is a part of Widawa River valley near Wroclaw city, was selected to demonstrate the applicability of proposed system.
The fluvial transport is the surface process that has a strong impact on the topography changes, especially in mountain areas. Traditional hydrological measurements usually give a good understanding ...of the river flow, however, the information of the bedload movement in the rivers is still insufficient. In particular, there is limited knowledge about the movement of the largest clasts, i.e. boulders. This investigation addresses mentioned issues by employing Terrestrial Laser Scanning (TLS) to monitor annual changes of the mountain river bed. The vertical changes were estimated based on the Digital Elevation Model (DEM) of difference (DoD) while transported boulders were identified based on the distances between point clouds and RGB-coloured points. Combined RGB point clouds allowed also to measure 3D displacements of boulders. The results showed that the highest dynamic of the fluvial process occurred between years 2012-2013. Obtained DoD clearly indicated alternating zones of erosion and deposition of the sediment finer fractions in the local sedimentary traps. The horizontal displacement of the rock material in the river bed showed high complexity resulting in the displacement of large boulders (major axis about 0.8 m) for the distance up to 2.3 m.
We examined the dependency of the pixel reflectance of hyperspectral imaging spectrometer data (HISD) on a normalized total insolation index (NTII). The NTII was estimated using a light detection and ...ranging (LiDAR)-derived digital surface model (DSM). The NTII and the pixel reflectance were dependent, to various degrees, on the band considered, and on the properties of the objects. The findings could be used to improve land cover (LC)/land use (LU) classification, using indices constructed from the spectral bands of imaging spectrometer data (ISD). To study this possibility, we investigated the normalized difference vegetation index (NDVI) at various NTII levels. The results also suggest that the dependency of the pixel reflectance and NTII could be used to mitigate the shadows in ISD. This project was carried out using data provided by the Hyperspectral Image Analysis Group and the NSF-funded Centre for Airborne Laser Mapping (NCALM), University of Houston, for the purpose of organizing the 2013 Data Fusion Contest (IEEE 2014). This contest was organized by the IEEE GRSS Data Fusion Technical Committee.
To evaluate whether genotyping for 18 prostate cancer founder variants is helpful in identifying high-risk individuals and for determining optimal screening regimens.
A serum PSA level was measured ...and a digital rectal examination (DRE) was performed on 2907 unaffected men aged 40-90. Three hundred and twenty-three men with an elevated PSA (≥4 ng ml⁻¹) or an abnormal DRE underwent a prostate biopsy. All men were genotyped for three founder alleles in BRCA1 (5382insC, 4153delA and C61G), for four alleles in CHEK2 (1100delC, IVS2+1G>A, del5395 and I157T), for one allele in NBS1 (657del5), for one allele in HOXB13 (G84E), and for nine low-risk single-nucleotide polymorphisms (SNPs).
On the basis of an elevated PSA or an abnormal DRE, prostate cancer was diagnosed in 135 of 2907 men (4.6%). In men with a CHEK2 missense mutation I157T, the cancer detection rate among men with an elevated PSA or an abnormal DRE was much higher (10.2%, P=0.0008). The cancer detection rate rose with the number of SNP risk genotypes observed from 1.2% for men with no variant to 8.6% for men who carried six or more variants (P=0.04). No single variant was helpful on its own in predicting the presence of prostate cancer, however, the combination of all rare mutations and SNPs improved predictive power (area under the curve=0.59; P=0.03).
These results suggest that testing for germline CHEK2 mutations improves the ability to predict the presence of prostate cancer in screened men, however, the clinical utility of incorporating DNA variants in the screening process is marginal.
Eleven novel U(VI)-containing coordination polymers have been synthesized under hydrothermal conditions and characterized via single-crystal X-ray diffraction and fluorescence spectroscopy. These ...inorganic/organic hybrid materials represent an important advance in the synthesis of polymeric materials in that multiple organic species have been employed in an effort to influence topology and properties. This family of materials is thus the result of a systematic pairing of the uranyl cation, UO2 2+, with aliphatic dicarboxylates (see part I, this issue) and the dipyridyl species, 4,4‘-dipyridyl and 1,2-bis(4-pyridyl)ethane. This second organic component assumes a number of roles in these structures, including direct coordination, charge balance, and structure direction. Distinction between which role(s) the dipyridyl species will assume appears to be correlated to the size (length) matching between it and the dicarboxylate linker used. Further, polymerization of primary building units (i.e., monomeric uranyl species) to form novel tetrameric secondary building units is observed in four compounds, possibly as a compensation for size differential between the organic species.
Manual in-situ measurements of geometric tree parameters for the biomass volume estimation are time-consuming and economically non-effective. Photogrammetric techniques can be deployed in order to ...automate the measurement procedure. The purpose of the presented work is an automatic tree growth estimation based on Unmanned Aircraft Vehicle (UAV) imagery. The experiment was conducted in an agriculture test field with scots pine canopies. The data was collected using a Leica Aibotix X6V2 platform equipped with a Nikon D800 camera. Reference geometric parameters of selected sample plants were measured manually each week. In situ measurements were correlated with the UAV data acquisition. The correlation aimed at the investigation of optimal conditions for a flight and parameter settings for image acquisition. The collected images are processed in a state of the art tool resulting in a generation of dense 3D point clouds. The algorithm is developed in order to estimate geometric tree parameters from 3D points. Stem positions and tree tops are identified automatically in a cross section, followed by the calculation of tree heights. The automatically derived height values are compared to the reference measurements performed manually. The comparison allows for the evaluation of automatic growth estimation process. The accuracy achieved using UAV photogrammetry for tree heights estimation is about 5cm.
PDF
