This paper is the second in a pair of papers presenting data release 1 (DR1) of the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS), the largest single open-time key project carried out ...with the Herschel
Space Observatory. The H-ATLAS is a wide-area imaging survey carried out in five photometric bands at 100, 160, 250, 350 and 500 μm covering a total area of 600 deg2. In this paper, we describe the identification of optical counterparts to submillimetre sources in DR1, comprising an area of 161 deg2 over three equatorial fields of roughly 12 × 4.5 deg centred at 9h, 12h and 14
${^{\rm h}_{.}}$
5, respectively. Of all the H-ATLAS fields, the equatorial regions benefit from the greatest overlap with current multi-wavelength surveys spanning ultraviolet (UV) to mid-infrared regimes, as well as extensive spectroscopic coverage. We use a likelihood ratio technique to identify Sloan Digital Sky Survey counterparts at r < 22.4 for 250-μm-selected sources detected at ≥4σ (≈28 mJy). We find ‘reliable’ counterparts (reliability R ≥ 0.8) for 44 835 sources (39 per cent), with an estimated completeness of 73.0 per cent and contamination rate of 4.7 per cent. Using redshifts and multi-wavelength photometry from GAMA and other public catalogues, we show that H-ATLAS-selected galaxies at z < 0.5 span a wide range of optical colours, total infrared (IR) luminosities and IR/UV ratios, with no strong disposition towards mid-IR-classified active galactic nuclei in comparison with optical selection. The data described herein, together with all maps and catalogues described in the companion paper, are available from the H-ATLAS website at www.h-atlas.org.
Calmodulins (CaMs) are the most ubiquitous calcium sensors in eukaryotes. A number of CaM-binding proteins have been identified through classical methods, and many proteins have been predicted to ...bind CaMs based on their structural homology with known targets. However, multicellular organisms typically contain many CaM-like (CML) proteins, and a global identification of their targets and specificity of interaction is lacking. In an effort to develop a platform for large-scale analysis of proteins in plants we have developed a protein microarray and used it to study the global analysis of CaM/CML interactions. An Arabidopsis thaliana expression collection containing 1,133 ORFs was generated and used to produce proteins with an optimized medium-throughput plant-based expression system. Protein microarrays were prepared and screened with several CaMs/CMLs. A large number of previously known and novel CaM/CML targets were identified, including transcription factors, receptor and intracellular protein kinases, F-box proteins, RNA-binding proteins, and proteins of unknown function. Multiple CaM/CML proteins bound many binding partners, but the majority of targets were specific to one or a few CaMs/CMLs indicating that different CaM family members function through different targets. Based on our analyses, the emergent CaM/CML interactome is more extensive than previously predicted. Our results suggest that calcium functions through distinct CaM/CML proteins to regulate a wide range of targets and cellular activities.
The upcoming Ice, Cloud and Land Elevation Satellite-2 (ICESat-2) mission will offer prospects for mapping and monitoring biomass and carbon of terrestrial ecosystems over large areas using photon ...counting LiDAR data. In this paper, we aim to develop a methodology to derive terrain elevation and vegetation canopy height from test-bed sensor data and further pre-validate the capacity of the mission to meet its science objectives for the ecosystem community. We investigated a novel methodological framework with two essential steps for characterizing terrain and canopy height using Multiple Altimeter Beam Experimental LiDAR (MABEL) data and simulated ICESat-2 data with various vegetation conditions. Our algorithm first implements a multi-level noise filtering approach to minimize noise photons and subsequently classifies the remaining photons into ground and top of canopy using an overlapping moving window method and cubic spline interpolation. Results of noise filtering show that the design of the multi-level filtering process is effective to identify background noise and preserve signal photons in the raw data. Moreover, calibration results using MABEL and simulated ICESat-2 data share similar trends with the retrieved terrain being more accurate than the retrieved canopy height, and the nighttime results being better than corresponding daytime results. Compared to the results of simulated ICESat-2 data, MABEL data achieve lower accuracy for ground and canopy heights in terms of root mean square error (RMSE), which may partly result from the inconsistency between MABEL and reference data. Specifically, simulated ICESat-2 data using 115 various nighttime and daytime scenarios, yield average RMSE values of 1.83 m and 2.80 m for estimated ground elevation, and 2.70 m and 3.59 m for estimated canopy height. Additionally, the accuracy assessment of percentile heights of simulated ICESat-2 data further substantiates the robustness of the methodology from different perspectives. The methodology developed in this study illustrates plausible ways of processing the data that are structurally similar to expected ICESat-2 data and holds the potential to be a benchmark for further method adjustment once genuine ICESat-2 are available.
•An adaptive methodological framework was developed to process upcoming ICESat-2 data.•Basic algorithms for ground and canopy photon classification with ICESat-2-like data.•Terrain and canopy height measurements with MABEL and simulated ICESat-2 data.
In this paper, we present a new scheme for dynamic adaptation of transmission power and contention window (CW) size to enhance performance of information dissemination in Vehicular Ad-hoc Networks ...(VANETs). The proposed scheme incorporates the Enhanced Distributed Channel Access (EDCA) mechanism of 802.11e and uses a joint approach to adapt transmission power at the physical (PHY) layer and quality-of-service (QoS) parameters at the medium access control (MAC) layer. In our scheme, transmission power is adapted based on the estimated local vehicle density to change the transmission range dynamically, while the CW size is adapted according to the instantaneous collision rate to enable service differentiation. In the interest of promoting timely propagation of information, VANET advisories are prioritized according to their urgency and the EDCA mechanism is employed for their dissemination. The performance of the proposed joint adaptation scheme was evaluated using the ns-2 simulator with added EDCA support. Extensive simulations have demonstrated that our scheme features significantly better throughput and lower average end-to-end delay compared with a similar scheme with static parameters.
In this letter, we present a hybrid spectrum sharing approach in cognitive radio (CR) systems with dynamic users in which the secondary users (SU) may not accurately detect the presence of primary ...users (PU). As a consequence, there is an increased probability of collision between PU and SU transmissions, resulting in interference at the PU receiver. The proposed hybrid framework combines the interweave and underlay spectrum sharing paradigms, and limits interference to the PU through a mathematical expression that provides bounds on the SU power based on its sensing performance. The framework requires that the PU only share this expression and does not require that the PU reveal its waveform or other operating parameters to the SU. An example illustrating the proposed approach is also presented.
Covering the natural fibers with metal oxides enhances the antibacterial properties of textiles. The efficiency of the nanostructured layer is determined by its thickness, uniformity, configuration ...and adherence to the flexible substrate. Conformal coatings with ZnO and Al2O3 of cotton and viscose fabrics were achieved by Atomic Layer Deposition (ALD) at low temperature. Morphological examination conducted by Scanning Electron Microscopy (SEM) displayed the surface functionalization, elemental mapping provided by Energy Dispersive X-ray Spectroscopy (EDS) illustrated the uniform distribution of Zn and Al oxides, and the chemical structure stability was demonstrated by Fourier Transform Infrared Spectrometry (FTIR). The inhibition of Escherichia coli and Staphylococcus aureus evaluated after 18 h of incubation disclosed very good antibacterial properties of the organic-inorganic composites, with emphasis on viscose coated with metal oxides. In vitro cytotoxic studies developed through direct and indirect contact methods, highlighted the non-toxic effects of Al2O3 on human fibroblasts and keratinocytes.
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•Low temperature ALD provides ultrathin ZnO and Al2O3 uniform coatings on textiles.•Good gram-negative and gram-positive bacterial inhibition•Potential toxic effects of ZnO and no cytotoxicity observed for Al2O3
This paper proposes a supervised classification scheme to identify 40 tree species (2 coniferous, 38 broadleaf) belonging to 22 families and 36 genera in high spatial resolution QuickBird ...multispectral images (HMS). Overall kappa coefficient (OKC) and species conditional kappa coefficients (SCKC) were used to evaluate classification performance in training samples and estimate accuracy and uncertainty in test samples. Baseline classification performance using HMS images and vegetation index (VI) images were evaluated with an OKC value of 0.58 and 0.48 respectively, but performance improved significantly (up to 0.99) when used in combination with an HMS spectral-spatial texture image (SpecTex). One of the 40 species had very high conditional kappa coefficient performance (SCKC ≥ 0.95) using 4-band HMS and 5-band VIs images, but, only five species had lower performance (0.68 ≤ SCKC ≤ 0.94) using the SpecTex images. When SpecTex images were combined with a Visible Atmospherically Resistant Index (VARI), there was a significant improvement in performance in the training samples. The same level of improvement could not be replicated in the test samples indicating that a high degree of uncertainty exists in species classification accuracy which may be due to individual tree crown density, leaf greenness (inter-canopy gaps), and noise in the background environment (intra-canopy gaps). These factors increase uncertainty in the spectral texture features and therefore represent potential problems when using pixel-based classification techniques for multi-species classification.
We present a detailed investigation into the effects of galaxy environment on their star formation rates (SFRs) using galaxies observed in the Galaxy And Mass Assembly (GAMA) survey. We use three ...independent volume-limited samples of galaxies within z < 0.2 and M
r
< −17.8. We investigate the known SFR-density relationship and explore in detail the dependence of SFR on stellar mass and density. We show that the SFR-density trend is only visible when we include the passive galaxy population along with the star-forming population. This SFR-density relation is absent when we consider only the star-forming population of galaxies, consistent with previous work. While there is a strong dependence of the EWHα on density we find, as in previous studies, that these trends are largely due to the passive galaxy population and this relationship is absent when considering a 'star-forming' sample of galaxies. We find that stellar mass has the strongest influence on SFR and EWHα with the environment having no significant effect on the star formation properties of the star-forming population. We also show that the SFR-density relationship is absent for both early- and late-type star-forming galaxies. We conclude that the stellar mass has the largest impact on the current SFR of a galaxy, and any environmental effect is not detectable. The observation that the trends with density are due to the changing morphology fraction with density implies that the time-scales must be very short for any quenching of the SFR in infalling galaxies. Alternatively, galaxies may in fact undergo predominantly in situ evolution where the infall and quenching of galaxies from the field into dense environments is not the dominant evolutionary mode.
The overall goal of this study was to develop methods for assessing crown base height for individual trees using airborne lidar data in forest settings typical for the southeastern United States. ...More specific objectives are to: (1) develop new lidar-derived features as multiband height bins and processing techniques for characterizing the vertical structure of individual tree crowns; (2) investigate several techniques for filtering and analyzing vertical profiles of individual trees to derive crown base height, such as Fourier and wavelet filtering, polynomial fit, and percentile analysis; (3) assess the accuracy of estimating crown base height for individual trees, and (4) investigate which type of lidar data, point frequency or intensity, provides the most accurate estimate of crown base height. A lidar software application, TreeVaW, was used to locate individual trees and to obtain per tree measurements of height and crown width. Tree locations were used with lidar height bins to derive the vertical structure of tree crowns and measurements of crown base height. Lidar-derived crown base heights of individual trees were compared to field observations for 117 trees, including 94 pines and 23 deciduous trees. Linear regression models were able to explain up to 80% of the variability associated with crown base height for individual trees. Fourier filtering used for smoothing the vertical crown profile consistently provided the best results when estimating crown base height.
Magnetic skyrmions are topologically nontrivial particles with a potential application as information elements in future spintronic device architectures. While they are commonly portrayed as two ...dimensional objects, in reality magnetic skyrmions are thought to exist as elongated, tube-like objects extending through the thickness of the host material. The study of this skyrmion tube state (SkT) is vital for furthering the understanding of skyrmion formation and dynamics for future applications. However, direct experimental imaging of skyrmion tubes has yet to be reported. Here, we demonstrate the real-space observation of skyrmion tubes in a lamella of FeGe using resonant magnetic x-ray imaging and comparative micromagnetic simulations, confirming their extended structure. The formation of these structures at the edge of the sample highlights the importance of confinement and edge effects in the stabilisation of the SkT state, opening the door to further investigation into this unexplored dimension of the skyrmion spin texture.
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