This paper focuses on the relationship between remotely-sensed urban site characteristics (USCs) and land surface temperature (LST). Particular emphasis is put on an extensive comparison of ...two-dimensional (2D) and three-dimensional (3D) USCs as potential indicators of the surface urban heat island (UHI) effect and as potential predictors for thermal sharpening applications. Both widely-used as well as more recently proposed metrics of the urban remote sensing literature are investigated within a single experiment. While some of these USCs have already been used earlier, others have never been analyzed before in the context of urban temperature studies. In addition to the comparison of 2D and 3D USCs, the spatio-temporal dependencies of their relation to LST are examined. To this end, the experimental setup of this work includes two study areas, 26 USCs, and 16 LST scenes covering four seasons. Use is made of a comprehensive database compiled for the cities of Berlin and Cologne, Germany. After data preparation, very high resolution (VHR) multi-spectral and height data are employed to map fine-scale urban land cover (LC). The resulting LC maps are then used in conjunction with the height information to compute 2D and 3D USCs. Subsequently, multi-temporal LST images are retrieved from Landsat Enhanced Thematic Mapper Plus (ETM+) scenes. The spatio-temporal investigation of the USC–LST connection constitutes the final stage of the workflow and is achieved in the framework of a dedicated correlation analysis. The results of this study highlight that the linkage between USCs and LST sensed at small scan angles is not stronger when 3D parameters are considered. Even though they may offer more holistic representations of the urban landscape, 3D USCs are consistently outperformed by some of the most widely-used 2D metrics. The analysis of spatial dependencies reveals that the USC–LST interplay does not only differ between, but also within the two test sites. This is due to their distinct geographies, with urban form and compactness, green spaces and street trees, and the structural composition of LC elements being some of the determining factors. The examination of temporal dependencies yielded that the association between USCs and LST is fairly stable over time but can be subject to larger inter- and intra-season variations for different reasons, including the season of acquisition, vegetation phenology, and meteorological conditions. Since previous research was based on the analysis of a single study area, a limited number of (mainly 2D) USCs, and/or only a few LST scenes acquired in specific seasons, it is concluded that the findings of this study provide researchers and practitioners with a more complete picture of the USC–LST relationship.
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•Spatio-temporal analysis of the statistical relationship between 2D/3D USCs and LST•Detailed inspection of 2 study areas, 26 USCs, and 16 LST scenes covering 4 seasons•3D USCs are consistently outperformed by some of the most widely-used 2D indicators.•Correlations are spatially dependent due to the distinct geographies of the cities.•Larger inter-/intra-season variations are mainly driven by environmental conditions.
Automated in situ instrumentation captured high-resolution surface water pCO2, CH4 and 222Rn data at the creek mouth, and ∼500m upstream in a sub-tropical mangrove ecosystem (Southern Moreton Bay, ...Australia, S27.78°, E153.38°) over a spring-neap-spring tidal cycle (∼15days) during November 2013. The partial pressure of CO2 (pCO2) ranged from 385 to 26,106μatm, CH4 from 1.8 to 889nM, and 222Rn from 280 to 108,172dpmm−3. Average surface water pCO2, CH4 and 222Rn were 4-fold higher at the upstream station. Surface water fluxes of CO2 and CH4 ranged from 9.4 to 629.2mmolCO2m−2d−1 and 13.1 to 632.9μmolCH4m−2d−1 depending upon the gas transfer model used and station location. Creek pCO2, CH4 and 222Rn displayed changes over both semi-diurnal and spring–neap–spring tidal scales. Semi-diurnally, all gases had a significant inverse relationship with water depth. Over the spring–neap–spring cycle, all gases exhibited an inverse relationship with tidal amplitude, with higher values during neap tides than spring tides. Estimated fluxes, porewater observations, and the significant positive relationship between surface water pCO2 and CH4, and 222Rn suggests groundwater exchange (i.e., tidal pumping) drives pCO2 and CH4 within the mangrove creek. We hypothesize that a combination of hourly and weekly groundwater–surface water exchange processes drive surface water pCO2 and CH4 in mangrove creeks. Semi-diurnally, flushing of crab burrows leads to high pCO2 and CH4 concentrations at low tide. During the spring–neap–spring cycle, older groundwater enriched in CO2, CH4 and 222Rn seeps into the creek as tidal amplitude decreases, leading to higher concentrations at neap tides.
Gas transfer velocities (k) of CO₂ and CH₄ were determined from 209 deployments of a newly designed floating chamber in six mangrove dominated estuaries in Australia and the United States to estimate ...mangrove system specific k. k
600-CO₂ and k
600-CH₄ (k normalized to the Schmidt number of 600) varied greatly within and between mangrove creeks, ranging from 0.9 cm h−1 to 28.3 cm h−1. The gas transfer velocity correlated well with current velocity at all study sites suggesting current generated turbulence was the main driver controlling k. An empirical relationship that accounts for current velocity and a linearly additive contribution of wind speed and water depth was a good predictor of k
600-CO₂ (R² = 0.67) and k
600-CH₄ (R² = 0.57) in the mangrove creeks in Australia. In a side-by-side study, good agreement was found between k determined from this new floating chamber and a ³He/SF₆ dual tracer release experiment (∼5% discrepancy). k
600-CH₄ correlated well with k
600-CO₂ (R² = 0.81), however, k
600-CH₄ was on average 1.2 times higher than k
600-CO₂, most likely reflecting a microbubble flux contribution. The microbubble flux contributed up to 73% of the total CH₄ flux and was best predicted by a model that included CH₄ supersaturation, temperature, and current velocity. A large overestimation was found for both CO₂ and CH₄ fluxes when calculated using empirically derived k models from previous studies in estuaries. The high temporal and spatial variabilities of kCO₂ and kCH₄ highlights the importance of site specific transfer velocity measurements in dynamic ecosystems such as mangrove estuaries.
Using selective reaction chemistry, our present research has developed an online, real-time sensor capable of monitoring toxic cyanide at both drinking water standard and environmental regulatory ...concentrations. Through the use of a flow cell, aqueous samples containing cyanide are reacted with a gold electrode of a piezoelectric crystal to indirectly sense cyanide concentration by the dissolution of metallic gold. The quartz crystal is an AT-cut wafer sandwiched between two neoprene O-rings within the liquid flow cell. The presence of cyanide in solution results in the selective formation of a soluble dicyano−gold complex according to the Elsner reaction: 4Au + 8CN- + 2H2O + O2 ⇄ 4Au(CN)2 - + 4OH-. The resulting loss of gold from the electrode is detected by the piezoelectric crystal as a resonant frequency change. Since free cyanide is a weak acid (pK a = 9.3), available protons compete for cyanide ligands. Therefore, increased sample pH provides higher sensitivity. The detection limits at pH 12 are 16.1 and 2.7 ppb for analysis times of 10 min and 1 h, respectively. The incorporation of the flow cell improves both analyte sensitivity and instrument precision, with an average signal intensity drift of only 5% over a 2-h analysis. The calibrations show excellent linearity over a variety of cyanide concentrations ranging from low ppb to hundreds of ppm. This detection method offers the advantage of selectively detecting cyanides posing a biohazard while avoiding detection of stable metal cyanides. This aspect of the system is based on competitive exchange of available metals and gold with cyanide ligands. Stable metal cyanide complexes possess a higher formation constant than cyanoaurate. This detection system has been configured into a flow injection analysis array for simple adaptation to automation. Anions commonly found in natural waters have been examined for interference effects. Additionally, the sensor is free from interference by aqueous cyanide analogues including thiocyanate. The developed detection system provides rapid cyanide determinations with little sample preparation or instrument supervision.
Extraversion, social support processes, and stress Swickert, Rhonda J; Rosentreter, Christina J; Hittner, James B ...
Personality and individual differences,
04/2002, Letnik:
32, Številka:
5
Journal Article
Recenzirano
This study was designed to determine the role extraversion plays in influencing the utilization of social support and how this support might then subsequently influence extraverts' and introverts' ...differential experience of stress. Ninety-nine undergraduate introductory psychology students served as participants in the study. Participants were administered questionnaires that assessed level of extraversion, perceived available support, enacted support, social network characteristics, and stress, as measured by daily hassles. Results of the study revealed positive correlations between extraversion and perceived availability of support (Belonging and Tangible), enacted support (Directive Guidance, Nondirective Support, Positive Social Interaction, Tangible Assistance), and social network characteristics (network size and contact with network members). Extraversion was also positively correlated with stress. Results of path analyses suggested that perceived availability of support, in particular Belonging support, might mediate the relationship between extraversion and stress.
Biosensing methods utilize the intrinsic selectivity of a biorecognition process to create relatively simple, low cost, analytical alternatives for a variety of research investigations. Here, ...biosensor applications of the piezoelectric quartz crystal (PQC) are reviewed. The discussion is divided into sections focusing on the development of PQC based analytical techniques, applications in solution phase sensing pertaining to PQC biosensors, and the current state of knowledge in PQC biosensing applications. Immobilization procedures, dip and dry assay techniques, and solution phase sensing methods are considered in detail.
Die einzelnen Datenbanken unterscheiden sich in Art, Umfang, Einstufung des Schweregrads und Evidenzniveau der Informationen sowie hinsichtlich ihrer Eignung für die jeweilige Fragestellung 9, 10. ...Wahrscheinlichkeit und Relevanz schwerwiegender AMI wurden mithilfe der aktuellen Fachinformationen (EMA-Homepage, Herstellerhomepage) und den Datenbanken bccancer.bc.ca (www.bccancer.bc.ca), drugs.com (www.drugs.com), Lexi-interact (www.uptodate.com) sowie dem Cancer Drug Interactions Checker (www.cancer-druginteractions.org) geprüft. In die Übersichtstabelle wurden nur AMI aufgenommen, die nach Analyse der Literatur und Evidenzbewertung als sehr schwerwiegend oder schwerwiegend (farblich codiert mit Rot bzw. Die vier häufigsten Empfehlungen zum klinischen Management (Spalte 5) lauten Monitoring der Plasmakonzentration bzw.
To date, no experimental technique has been used to monitor DNA-protein crosslink formation in real-time. Real-time data is important for understanding the underlying chemical mechanisms associated ...with this reaction process. Here, the novel adaptation of existing piezoelectric quartz crystal (PQC) or quartz crystal microbalance (QCM) technology was used to monitor, in real-time, the formation of a crosslink bond induced by formaldehyde between lysine and guanine. Previous results showed complexes of lysine and guanine constitute a major portion of the DNA-protein crosslinks formed. Thus, poly-lysine
5 and poly-deoxyguanosine
11 were used as a model system to develop this detection method. Poly-lysine
5 was immobilized on QCM electrode surfaces by covalent attachment through polyethylenimine (PEI). Immobilization was confirmed by the decrease in dry QCM frequency; data consistency suggested uniform coatings were produced. The QCM sensor was configured within a thermostatic environmental chamber. The system was calibrated and baseline responses to variations in the analyte solution matrix were identified. QCMs with immobilized poly-lysine
5 were placed in contact with formaldehyde and poly-deoxyguanosine
11, and crosslink formation was monitored in real-time. Crosslink formation was verified through evaluation of controls. Control assays indicated some of the frequency signal was as aresult of non-specific association. Further assays were conducted after saturation of non-specific binding. This real-time data represents a significant advancement in the state of knowledge of the crosslinking process and provides the experimental foundation for further QCM crosslink investigations.
Abstract Gas transfer velocities ( k ) of CO 2 and CH 4 were determined from 209 deployments of a newly designed floating chamber in six mangrove dominated estuaries in Australia and the United ...States to estimate mangrove system specific k . k 600 ‐ CO 2 and k 600 ‐ CH 4 ( k normalized to the Schmidt number of 600) varied greatly within and between mangrove creeks, ranging from 0.9 cm h −1 to 28.3 cm h −1 . The gas transfer velocity correlated well with current velocity at all study sites suggesting current generated turbulence was the main driver controlling k . An empirical relationship that accounts for current velocity and a linearly additive contribution of wind speed and water depth was a good predictor of k 600 ‐CO 2 ( R 2 = 0.67) and k 600 ‐CH 4 ( R 2 = 0.57) in the mangrove creeks in Australia. In a side‐by‐side study, good agreement was found between k determined from this new floating chamber and a 3 He/SF 6 dual tracer release experiment (∼5% discrepancy). k 600 ‐ CH 4 correlated well with k 600 ‐ CO 2 ( R 2 = 0.81), however, k 600 ‐ CH 4 was on average 1.2 times higher than k 600 ‐ CO 2 , most likely reflecting a microbubble flux contribution. The microbubble flux contributed up to 73% of the total CH 4 flux and was best predicted by a model that included CH 4 supersaturation, temperature, and current velocity. A large overestimation was found for both CO 2 and CH 4 fluxes when calculated using empirically derived k models from previous studies in estuaries. The high temporal and spatial variabilities of k CO 2 and k CH 4 highlights the importance of site specific transfer velocity measurements in dynamic ecosystems such as mangrove estuaries.
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