An Inherent Optical Properties Data Processing System for Achieving Consistent Ocean Color Products From Different Ocean Color Satellites

We used field measurements and multimission satellite data to evaluate how well an inherent optical properties (IOPs) data processing system performed at correcting the residual error of the atmospheric correction in satellite remote sensing reflectance (R-rs) and how well the system simultaneously minimized intermission biases between different remote sensing systems. We developed the IOPs data processing system as a semianalytical algorithm called IDAS. Our results show that IDAS generates accurate and consistent IOPs products from two ocean color missions: Sea-viewing Wide Field-of-View Sensor (SeaWiFS) and Moderate Resolution Imaging Spectroradiometer Aqua (MODISA). Specifically, with "high-quality" SeaWiFS and MODISA R-rs data, IDAS provided temporally consistent IOPs products for the oligotrophic open ocean resulting in an annual mean intermission difference of less than 3%, which is significantly lower than what a quasi-analytical algorithm (QAA) provided. We used IDAS to generate a long time series of b(b)(555) from the Northwest Atlantic Subtropical Gyre using SeaWiFS (1998 to 2002) and MODISA (2003 to 2017) images. Our results show that the IDAS-derived annual b(b)(555) decreased monotonically by 2.81% per decade from 1998 to 2017. Comparing the IDAS-generated annual trend for b(b)(555) to the same data processed with the QAA algorithm, we found that the QAA results differed because of impacts of the residual errors of the atmospheric correction and intermission biases. The differences in the annual trends existed despite the same temporal changing patterns of in situ particulate organic carbon existing in the Sargasso Sea and in the satellite chlorophyll-a concentration in the Northwest Atlantic Subtropical Gyre

Evaluation of ocean color remote sensing algorithms for diffuse attenuation coefficients and optical depths with data collected on BGC-Argo floats

The vertical distribution of irradiance in the ocean is a key input to quantify processes spanning from radiative warming, photosynthesis to photo-oxidation. Here we use a novel dataset of thousands local-noon downwelling irradiance at 490 nm (Ed(490) and photosynthetically available radiation (PAR) profiles captured by 103 BGC-Argo floats spanning three years (from October 2012 to January 2016) in the world\u27s ocean, to evaluate several published algorithms and satellite products related to diffuse attenuation coefficient (Kd). Our results show: (1) MODIS-Aqua Kd(490) products derived from a blue-to-green algorithm and two semi-analytical algorithms show good consistency with the float-observed values, but the Chla-based one has overestimation in oligotrophic waters; (2) The Kd(PAR) model based on the Inherent Optical Properties (IOPs) performs well not only at sea-surface but also at depth, except for the oligotrophic waters where Kd(PAR) is underestimated below two penetration depth (2zpd), due to the model\u27s assumption of a homogeneous distribution of IOPs in the water column which is not true in most oligotrophic waters with deep chlorophyll-a maxima; (3) In addition, published algorithms for the 1% euphotic-layer depth and the depth of 0.415 mol photons m-2 d-1 isolume are evaluated. Algorithms based on Chla generally work well while IOPs-based ones exhibit an overestimation issue in stratified and oligotrophic waters, due to the underestimation of Kd(PAR) at depth

Visualizing Drug Release from a Stimuli-Responsive Soft Material Based on Amine-Thiol Displacement

In this research, we developed a photoluminescent platform using amine-coupled fluorophores, generated from a single conjugate acceptor containing bis-vinylogous thioesters. Based on the experimental and computational results, the fluorescence turn-on mechanism was proposed to be charge separated induced energy radiative transition for the amine-coupled fluorophore, while the sulfur-containing precursor was not fluorescent since the energy internal conversion occurred through vibrational 2RS- (R represents alkyl groups) as energy acceptor(s). Further utilizing the conjugate acceptor, we establish a new fluorogenic approach via a highly cross-linked soft material to selectively detect cysteine under neutral aqueous conditions. Turn-on fluorescence emission and macroscopic degradation occurred in the presence of cysteine as the stimuli, which can be visually tracked due to the generation of an optical indicator and the cleavage of linkers within the matrix. Furthermore, a novel drug delivery system was constructed, achieving controlled release of sulfhydryl drug (6-mercaptopurine) which was tracked by photoluminescence and high-performance liquid chromatography. The photoluminescent molecules developed herein are suitable for visualizing polymeric degradation, making them suitable for additional “smart” material applications.</p

Analyzing urban traffic demand distribution and the correlation between traffic flow and the built environment based on detector data and POIs

Purpose This paper aims to determine the urban traffic flow spatiotemporal characteristics and correlation with the built environment using SCATS (Sydney Coordinated Adaptive Traffic System) and POIs (Point of Interests) data of Shenyang, China. Methods A standard analysis framework based on these data is proposed in the paper. The study analyzes the traffic volume spatiotemporal distributions and built environment influence factors determined by the geographical detector. An improved gravity model using simple structural parameters (lanes number and road length) is proposed to estimate the traffic flows of day and peak hour scales for specific flow ranges. Results The results show that the peak hours of different intersections and roads are heterogeneous and reveal trip time flexibility. The correlation between peak hour flows and day flows is significant in the multidimensional analysis. Based on the investigation of lanes, more interesting conclusions are found. In this case, when the numbers of lanes of intersections and roads are more than 14 and 4 respectively, the lane resources are wasted to a great extent. There is also a certain correlation between these factors. Proposed gravity model establishes the connection between structure and function of urban roads. Conclusions Flexible work time and places will be effective methods to reduce traffic congestion. The day flows could be estimated via a traffic survey on peak hour flows, especially in developing cities. The traffic flow mainly concentrates in a relatively small part of city roads. The maximum service traffic volumes exhibit segmentation, we should reconsider the maximum optimal lanes number of intersections and roads under better performance and utilization rate of the network. The effect of lanes number on the service traffic volumes is found to be more significant compared with the other factors. Our conclusions will be helpful for policy-makers and sustainable urban planning. Document type: Articl

Visualizing Drug Release from a Stimuli-Responsive Soft Material Based on Amine-Thiol Displacement

In this research, we developed a photoluminescent platform using amine-coupled fluorophores, generated from a single conjugate acceptor containing bis-vinylogous thioesters. Based on the experimental and computational results, the fluorescence turn-on mechanism was proposed to be charge separated induced energy radiative transition for the amine-coupled fluorophore, while the sulfur-containing precursor was not fluorescent since the energy internal conversion occurred through vibrational 2RS- (R represents alkyl groups) as energy acceptor(s). Further utilizing the conjugate acceptor, we establish a new fluorogenic approach via a highly cross-linked soft material to selectively detect cysteine under neutral aqueous conditions. Turn-on fluorescence emission and macroscopic degradation occurred in the presence of cysteine as the stimuli, which can be visually tracked due to the generation of an optical indicator and the cleavage of linkers within the matrix. Furthermore, a novel drug delivery system was constructed, achieving controlled release of sulfhydryl drug (6-mercaptopurine) which was tracked by photoluminescence and high-performance liquid chromatography. The photoluminescent molecules developed herein are suitable for visualizing polymeric degradation, making them suitable for additional “smart” material applications.</p

Improved correction for non-photochemical quenching of in situ chlorophyll fluorescence based on a synchronous irradiance profile

In situ chlorophyll fluorometers have been used to quantify the distribution of chlorophyll concentration in natural waters for decades. However, chlorophyll fluorescence is depressed during daylight hours due to non-photochemical quenching (NPQ). Corrections attempted to date have provided improvement but still remain unsatisfactory, often over-estimating the expected value. In this study, we examine the relationship between NPQ and instantaneous Photosynthetically Active Radiation (iPAR) using field data from BGC-Argo floats equipped with Chlorophyll-a fluorometers and radiometers. This analysis leads to an improved NPQ correction that incorporates both iPAR and mixed layer depth (MLD) and is validated against data collected at sunrise or sunset. The optimal NPQ light threshold is found to be iPAR = 15 μmol quanta m−2 s−1, and the proposed methods based on such a light threshold correct the NPQ effect more accurately than others, except in “shallow-mixing” waters (NPQ light threshold depth deeper than MLD). For these waters, an empirical-relationship-based method is proposed for improvement of NPQ correction using an iPAR profile. It is therefore recommended that, for optimal NPQ corrections, profiling floats measuring chlorophyll fluorescence in daytime be equipped with iPAR radiometers

Sulphur and cerium co-doped mesoporous titanium dioxide photocatalysts and their photocatalytic activity in the degradation of methylene orange

A series of sulphur and cerium co-doped mesoporous titanium dioxide photocatalysts have been prepared by a template method using thiourea, ammonium ceric nitrate and tetrabutyl titanate as precursors and Pluronic P123 as a template. The morphology, crystal structure, surface structure and optical absorption properties of the prepared samples are characterized by scanning electron microscopy, X-ray diffraction, N2 adsorption-desorption measurements and UV-vis absorption spectra. The microcrystal of the co-doped photocatalyst comprises the anatase­ phase. Compared with mesoporous titanium dioxide, the co-doped samples extends the photoabsorption edge into the visible light region. The photocatalytic activities of the obtained photocatalysts under UV and visible light have been estimated by measuring the degradation rate of methylene orange in aqueous solution. Results show that the co-doped mesoporous titanium dioxide exhibits higher photocatalytic activity than mesoporous titanium dioxide under light irradiation. The synergistic effect of sulphur and cerium co-doping plays an important role in improving the photocatalytic activity.

A Dual-Band Model for the Vertical Distribution of Photosynthetically Available Radiation (PAR) in Stratified Waters

Based on the optical properties of water constituents, the vertical variation of photosynthetically available radiation (PAR) can be well modeled with hyperspectral resolution; the intensive computing load, however, demands simplified modeling that can be easily embedded in marine physical and biogeochemical models. While the vertical PAR profile in homogeneous waters can now be accurately modeled with simple parameterization, it is still a big challenge to model the PAR profile in stratified waters with limited variables. In this study, based on empirical equations and simulations, we propose a dual-band model to characterize the vertical distribution of PAR using the chlorophyll concentration (Chl). With an inclusive dataset including cruise data collected in the Southeast Pacific and BGC-Argo data in the global ocean, the model was thoroughly evaluated for its general applicability in three aspects: 1) estimating the entire PAR profile from sea-surface PAR and the Chl profile, 2) estimating the euphotic layer depth from the Chl profile, and 3) estimating PAR just below the sea surface from in situ radiometry measurements. It is demonstrated that the proposed dual-band model is capable of generating similar estimates as that from a hyperspectral model, thus offering an effective module that can be incorporated in large-scale ecosystem and/or circulation models for efficient calculations

The association between dietary intake of flavonoids and its subclasses and the risk of metabolic syndrome

BackgroundThe healthiest way to prevent metabolic syndrome (MetS) is through behavioral and nutritional adjustments. We examined the relationship between total flavonoids intake, flavonoid subclasses, and clinically manifest MetS.MethodsA cross-sectional analysis was conducted among 28,719 individuals from the National Health and Nutrition Examination Survey (NHANES) and Food and Nutrient Database for Dietary Studies (FNDDS) 2007–2011 and 2017–2018. Two 24-h reviews were conducted to determine flavonoids intake and subclasses. The link between flavonoids intake and MetS was investigated using a multivariate logistic regression model.ResultsQ2 and Q3 of total flavonoids intake were associated with 20 and 19% lower risk of incident MetS after adjusting age and sex. Anthocyanidins and flavanones intake in Q2 and Q3 substantially reduced the MetS risk compared to Q1. MetS risk decreased steadily as the total intake of flavonoids increased to 237.67 mg/d. Flavanones and anthocyanidins also displayed V-shaped relationship curves (34.37 and 23.13 mg/d).ConclusionMetS was adversely linked with total flavonoids intake, flavanones, and anthocyanidins. Moreover, the most effective doses of total flavonoids, flavanones, and anthocyanidins were 237.67, 34.37, and 23.13 mg/d, respectively, potentially preventing MetS