Metal/metalloid and phosphorus characteristics in porewater associated with manganese geochemistry: A case study in the Jiulong River Estuary, China.

Sediment porewater can be an important source of contaminants in the overlying water, but the mechanisms of metal(loid) and phosphorus (P) remobilization remain to be investigated. In this study, high-resolution dialysis (HR-Peeper) and diffusive gradients in thin films (DGT) samplers were used to determine the porewater dissolved iron (Fe), manganese (Mn), cobalt (Co), chromium (Cr), vanadium (V), selenium (Se), arsenic (As), P and DGT-Labile S in coastal sediments in the Jiulong River Estuary (JRE), China. The results showed that high concentrations of dissolved Mn, Se and P were present in the overlying water, indicating potential water pollution with excessive amounts of Mn, Se and P. The dissolved Mn concentrations in the porewater were higher than the dissolved Fe concentrations, especially at submerged sites, demonstrating that Mn(III/IV) reduction is the dominant diagenetic pathway for organic carbon (OC) degradation, which directly affects Fe cycling by the competitive inhibition of Fe(III) reduction and Fe(II) reoxidation. Dissolved Co, Cr, V, Se, As and P show significant positive correlations with Mn but nearly no correlations with Fe, suggesting that the mobility of these metal(loid)s and P is associated with Mn but not Fe cycling in this region. In addition, the coelevated concentrations of the metal(loid)s, P and Mn at the submerged sites are attributed to the strengthened Mn reduction coupled with OC degradation fueled by hypoxia. The higher positive diffusion fluxes of Mn, Se and P were consistent with the excess Mn, Se and P concentrations in the overlying water, together with the approximately positive fluxes of the other metal(loid)s, indicating that sediment Mn(III/IV) reduction and concomitant metal(loid) and P remobilization might be vital pathways for metal(loid) and P migration to the overlying water

Metal/metalloid and phosphorus characteristics in porewater associated with manganese geochemistry: A case study in the Jiulong River Estuary, China

Abstract(#br)Sediment porewater can be an important source of contaminants in the overlying water, but the mechanisms of metal(loid) and phosphorus (P) remobilization remain to be investigated. In this study, high-resolution dialysis (HR-Peeper) and diffusive gradients in thin films (DGT) samplers were used to determine the porewater dissolved iron (Fe), manganese (Mn), cobalt (Co), chromium (Cr), vanadium (V), selenium (Se), arsenic (As), P and DGT-Labile S in coastal sediments in the Jiulong River Estuary (JRE), China. The results showed that high concentrations of dissolved Mn, Se and P were present in the overlying water, indicating potential water pollution with excessive amounts of Mn, Se and P. The dissolved Mn concentrations in the porewater were higher than the dissolved Fe concentrations, especially at submerged sites, demonstrating that Mn(III/IV) reduction is the dominant diagenetic pathway for organic carbon (OC) degradation, which directly affects Fe cycling by the competitive inhibition of Fe(III) reduction and Fe(II) reoxidation. Dissolved Co, Cr, V, Se, As and P show significant positive correlations with Mn but nearly no correlations with Fe, suggesting that the mobility of these metal(loid)s and P is associated with Mn but not Fe cycling in this region. In addition, the coelevated concentrations of the metal(loid)s, P and Mn at the submerged sites are attributed to the strengthened Mn reduction coupled with OC degradation fueled by hypoxia. The higher positive diffusion fluxes of Mn, Se and P were consistent with the excess Mn, Se and P concentrations in the overlying water, together with the approximately positive fluxes of the other metal(loid)s, indicating that sediment Mn(III/IV) reduction and concomitant metal(loid) and P remobilization might be vital pathways for metal(loid) and P migration to the overlying water

Highly coherent mid-infrared supercontinuum generations in a strip titanium dioxide waveguide with three zero-dispersion wavelengths

A strip titanium dioxide (TiO2) waveguide is designed for highly coherent mid-infrared (MIR) supercontinuum (SC) generation. For the designed TiO2 waveguide, three zero-dispersion wavelengths (ZDWs) are obtained through adjusting the waveguide structure parameters. The three ZDWs are located at 1.53, 3.96, and 5.43 μm, respectively. The nonlinearity coefficient γ is calculated as 1.12 W − 1 m − 1 at wavelength 3.1 μm. By optimizing the pump pulse parameters, the highly coherent MIR SCs are generated when the hyperbolic secant pump pulse with a duration of 80 fs, peak power of 1 kW, and wavelength of 3.1 μm is launched into the TiO2 waveguide and propagated 4.2-mm in length. The obtained SC covers a wavelength range from 1.71 to 9.90 μm (more than 2.5 octaves). Our research results can find important applications in MIR photonics and spectroscopy, biophotonics, optical precision measurement, etc

Behavior-Based Herding Algorithm for Social Force Model Based Sheep Herd

Inspired by real-world sheepdog herding behavior, in this paper, four behavior-based herding algorithms have been proposed for the social force model-based sheep herd. First, a basic behavior-based herding algorithm is designed where four types of critical sheep are rigorously defined. The decision of the sheepdog is made by constantly checking the positions of these four critical sheep. Then, on top of this basic herding algorithm, two extra mechanisms are considered to improve the performance of the basic herding algorithm, namely the dynamic far-end mechanism and the pausing mechanism, thus, forming the other three herding algorithms. The dynamic far-end mechanism helps to avoid the undesired circling behavior of the sheepdog around the destination area, while the pausing mechanism can greatly reduce the control cost of the sheepdog. To validate the effectiveness of the proposed herding algorithms, comprehensive tests have been conducted. The performance of the four algorithms is evaluated and compared from three aspects, namely, success rate, completion step, and control cost. Moreover, parameter analysis is provided to examine how different design parameters will affect the performance of the proposed algorithm. Finally, it is shown that when the size of the sheep herd increases, as expected, it takes more time and control effort to complete herding

Low-carbon generation expansion planning considering uncertainty of renewable energy at multi-time scales

With the development of carbon electricity, achieving a low-carbon economy has become a prevailing and inevitable trend. Improving low-carbon expansion generation planning is critical for carbon emission mitigation and a low- carbon economy. In this paper, a two-layer low-carbon expansion generation planning approach considering the uncertainty of renewable energy at multiple time scales is proposed. First, renewable energy sequences considering the uncertainty in multiple time scales are generated based on the Copula function and the probability distribution of renewable energy. Second, a two-layer generation planning model considering carbon trading and carbon capture technology is established. Specifically, the upper layer model optimizes the investment decision considering the uncertainty at a monthly scale, and the lower layer one optimizes the scheduling considering the peak shaving at an hourly scale and the flexibility at a 15-minute scale. Finally, the results of different influence factors on low-carbon generation expansion planning are compared in a provincial power grid, which demonstrate the effectiveness of the proposed model

Beam-Doppler Unitary ESPRIT for Multitarget DOA Estimation

High-resolution direction of arrival (DOA) estimation is a critical issue for mainbeam multitarget tracking in ground-based or airborne early warning radar system. A beam-Doppler unitary ESPRIT (BD-UESPRIT) algorithm is proposed to deal with this problem. Firstly, multiple snapshots without spatial aperture loss are obtained by using the technique of time-smoothing. Then the conjugate centrosymmetric discrete Fourier transform (DFT) matrix is used to transform the extracted data into beam-Doppler domain. Finally, the rotational invariance property of the space-time beam is exploited to estimate DOA of the target. The DOA estimation accuracy is improved greatly because the proposed algorithm takes full advantage of temporal information of the signal. Furthermore, the computational complexity of the presented algorithm is reduced dramatically, because the degree of freedom after beam transformation is very small and most of the operations are implemented in real-number domain. Numerical examples are given to verify the effectiveness of the proposed algorithm

DataSheet_1_Development and validation of a high-resolution T2WI-based radiomic signature for the diagnosis of lymph node status within the mesorectum in rectal cancer.docx

PurposeThe aim of this study was to explore the feasibility of a high-resolution T2-weighted imaging (HR-T2WI)-based radiomics prediction model for diagnosing metastatic lymph nodes (LNs) within the mesorectum in rectal cancer.MethodA total of 604 LNs (306 metastatic and 298 non-metastatic) from 166 patients were obtained. All patients underwent HR-T2WI examination and total mesorectal excision (TME) surgery. Four kinds of segmentation methods were used to select region of interest (ROI), including method 1 along the border of LNs; method 2 along the expanded border of LNs with an additional 2–3 mm; method 3 covering the border of LNs only; and method 4, a circle region only within LNs. A total of 1,409 features were extracted for each method. Variance threshold method, Select K Best, and Lasso algorithm were used to reduce the dimension. All LNs were divided into training and test sets. Fivefold cross-validation was used to build the logistic model, which was evaluated by the receiver operating characteristic (ROC) with four indicators, including area under the curve (AUC), accuracy (ACC), sensitivity (SE), and specificity (SP). Three radiologists with different working experience in diagnosing rectal diseases assessed LN metastasis respectively. The diagnostic efficiencies with each of four segmentation methods and three radiologists were compared to each other.ResultsFor the test set, the AUCs of four segmentation methods were 0.820, 0.799, 0.764, and 0.741; the ACCs were 0.725, 0.704, 0.709, and 0.670; the SEs were 0.756, 0.634, 0.700, and 0.589; and the SPs were 0.696, 0.772, 0.717, and 0.750, respectively. There was no statistically significant difference in AUC between the four methods (p > 0.05). Method 1 had the highest values of AUC, ACC, and SE. For three radiologists, the overall diagnostic efficiency was moderate. The corresponding AUCs were 0.604, 0.634, and 0.671; the ACCs were 0.601, 0.632, and 0.667; the SEs were 0.366, 0.552, and 0.392; and the SPs were 0.842, 0.715, and 0.950, respectively.ConclusionsThe proposed HR-T2WI-based radiomic signature exhibited a robust performance on predicting mesorectal LN status and could potentially be used for clinicians in order to determine the status of metastatic LNs in rectal cancer patients.</p

SIRT5 deficiency suppresses mitochondrial ATP production and promotes AMPK activation in response to energy stress.

Sirtuin 5 (SIRT5) is a member of the NAD+-dependent sirtuin family of protein deacylase that catalyzes removal of post-translational modifications, such as succinylation, malonylation, and glutarylation on lysine residues. In light of the SIRT5's roles in regulating mitochondrion function, we show here that SIRT5 deficiency leads to suppression of mitochondrial NADH oxidation and inhibition of ATP synthase activity. As a result, SIRT5 deficiency decreases mitochondrial ATP production, increases AMP/ATP ratio, and subsequently activates AMP-activated protein kinase (AMPK) in cultured cells and mouse hearts under energy stress conditions. Moreover, Sirt5 knockout attenuates transverse aortic constriction (TAC)-induced cardiac hypertrophy and cardiac dysfunction in mice, which is associated with decreased ATP level, increased AMP/ATP ratio and enhanced AMPK activation. Our study thus uncovers an important role of SIRT5 in regulating cellular energy metabolism and AMPK activation in response to energy stress