Reconstructing seawater carbonate chemistry using foraminiferal B/Ca

Planktonic B/Ca holds promise of reconstructing the surface seawater carbonate chemistry, which is linked to the past levels of atmospheric partial pressure of CO2. However, it is still not clear to what extent the carbonate chemistry control on planktonic B/Ca is complicated by physiological activities of foraminifera. In this thesis, the environmental controls on B/Ca in two planktonic foraminiferal species, Globigerinoides ruber (white) and Globigerinoides sacculifer (without final sac-like chamber), are examined using core-top samples from the Atlantic Ocean. For an accurate estimation of the ambient calcification environments, the calcification depths and seasonality of the studied species at these core-top locations are determined by planktonic Mg/Ca. The dissolution effect on B/Ca, which is evident from planktonic B/Ca data from three depth transects, proves to have little impact on the interpretation of planktonic B/Ca data from the Atlantic core-tops. While the carbonate chemistry control on planktonic B/Ca can be detected from these core-top data, a strong calcification rate control on planktonic B/Ca is demonstrated by the correlation between B/Ca and Sr/Ca, where Sr/Ca is employed as an indicator of the calcification rate. This calcification rate control on planktonic B/Ca complicates the direct link between planktonic B/Ca and seawater carbonate chemistry. Nevertheless, based on the different responses of B/Ca in the two studied species to the calcification rate, it is possible that B/Ca in some species are less susceptible to this influence, and thus can be employed for carbonate chemistry reconstructions. Benthic B/Ca is a recently developed quantitative proxy for deepwater carbonate ion concentration ([CO32-]). In this thesis, deepwater [CO32-] variations during the last 150 thousand years are reconstructed using two cores from the deep Southwestern Pacific, a critical but not fully investigated region to regulate the carbon inventory in the deep ocean. Since Marine Isotope Stage (MIS) 5a, the deep the SW Pacific [CO32-] varied in concert with benthic carbon isotopes (δ13Cb). These covariations, on the timescale of ~10 kyr, are similar to those observed in the deep Atlantic. This suggests that the deep SW Pacific [CO32-] could be affected by changes in the Atlantic Overturning Circulation and the biological pump. However, the deep SW Pacific [CO32-] showed little change during Termination II (T II), despite that variations of δ13Cb, neodymium isotopes (εNd), and foraminifer-bound nitrogen isotopes (δ15N) were similar to those during Termination I (T I). This difference is interpreted as the result of coral reef regrowth on continental shelves, which decreased the whole ocean [CO32-] and counteracted the [CO32-] increase due to the influences from Atlantic Overturning Circulation and the biological pump changes during T II

Distinct responses of planktonic foraminiferal B/Ca to dissolution on seafloor

We have measured B/Ca in four core-top planktonic foraminiferal species (Globigerinoides ruber (white), Globigerinoides sacculifer (without final sac-like chamber), Neogloboquadrina dutertrei, and Pulleniatina obliquiloculata) from three depth transects (the Caribbean Sea, the southwestern Indian Ocean, and the Ontong Java Plateau) to evaluate the effect of dissolution on planktonic foraminiferal B/Ca. At each transect, G. ruber (w) and G. sacculifer (w/o sac) show decreasing B/Ca with increasing water depth. This decrease in B/Ca is accompanied with decreases in shell weights, Mg/Ca, and bottom water calcite saturation state. This indicates a postdepositional dissolution effect on B/Ca in these two species. The strong correlation observed between changes in B/Ca and bottom water calcite saturation state offers an approach to correcting for the dissolution bias. By contrast, B/Ca in N. dutertrei and P. obliquiloculata remains unchanged along depth transects, although shell weights and Mg/Ca display significant declines. Overall, our core-top results suggest species-specific dissolution effects on B/Ca in different planktonic foraminiferal species

Optimal scheduling of industrial task-continuous load management for smart power utilization

In the context of climate change and energy crisis around the world, an increasing amount of attention has been paid to developing clean energy and improving energy efficiency. The penetration of distributed generation (DG) is increasing rapidly on the user’s side of an increasingly intelligent power system. This paper proposes an optimization method for industrial task-continuous load management in which distributed generation (including photovoltaic systems and wind generation) and energy storage devices are both considered. To begin with, a model of distributed generation and an energy storage device are built. Then, subject to various constraints, an operation optimization problem is formulated to maximize user profit, renewable energy efficiency, and the local consumption of distributed generation. Finally, the effectiveness of the method is verified by comparing user profit under different power modes

Pathological Evidence Exploration in Deep Retinal Image Diagnosis

Though deep learning has shown successful performance in classifying the label and severity stage of certain disease, most of them give few evidence on how to make prediction. Here, we propose to exploit the interpretability of deep learning application in medical diagnosis. Inspired by Koch's Postulates, a well-known strategy in medical research to identify the property of pathogen, we define a pathological descriptor that can be extracted from the activated neurons of a diabetic retinopathy detector. To visualize the symptom and feature encoded in this descriptor, we propose a GAN based method to synthesize pathological retinal image given the descriptor and a binary vessel segmentation. Besides, with this descriptor, we can arbitrarily manipulate the position and quantity of lesions. As verified by a panel of 5 licensed ophthalmologists, our synthesized images carry the symptoms that are directly related to diabetic retinopathy diagnosis. The panel survey also shows that our generated images is both qualitatively and quantitatively superior to existing methods.Comment: to appear in AAAI (2019). The first two authors contributed equally to the paper. Corresponding Author: Feng L

Modification of Transition-Metal Redox by Interstitial Water in Hexacyanometalate Electrodes for Sodium-Ion Batteries.

A sodium-ion battery (SIB) solution is attractive for grid-scale electrical energy storage. Low-cost hexacyanometalate is a promising electrode material for SIBs because of its easy synthesis and open framework. Most hexacyanometalate-based SIBs work with aqueous electrolyte, and interstitial water in the material has been found to strongly affect the electrochemical profile, but the mechanism remains elusive. Here we provide a comparative study of the transition-metal redox in hexacyanometalate electrodes with and without interstitial water based on soft X-ray absorption spectroscopy and theoretical calculations. We found distinct transition-metal redox sequences in hydrated and anhydrated NaxMnFe(CN)6·zH2O. The Fe and Mn redox in hydrated electrodes are separated and are at different potentials, leading to two voltage plateaus. On the contrary, mixed Fe and Mn redox in the same potential range is found in the anhydrated system. This work reveals for the first time how transition-metal redox in batteries is strongly affected by interstitial molecules that are seemingly spectators. The results suggest a fundamental mechanism based on three competing factors that determine the transition-metal redox potentials. Because most hexacyanometalate electrodes contain water, this work directly reveals the mechanism of how interstitial molecules could define the electrochemical profile, especially for electrodes based on transition-metal redox with well-defined spin states

MiT family translocation renal cell carcinoma with retroperitoneal metastasis in childhood: a case report

RCC accounts for only 0.1%–0.3% of all kidney tumors and 2%–6% of malignant kidney tumors in children. Accounting for approximately one-third of the total number of cases in children and adolescents with RCC, Xp11.2 tRCC is the most common subtype of the MiT family translocation renal cell carcinoma, which is a group of rare childhood and adult tumors, characterized by recurrent gene rearrangements of TFE3. Here we report a rare case of a 6-year-old male patient with MiT family translocation renal cell carcinoma (MiTF tRCC) where the patient developed retroperitoneal metastasis. The patient underwent partial nephrectomy (PN), radical nephrectomy (RN), abdominal lymph node resection, and intestinal adhesion lysis. Microscopically, we detected focal and nest clump-shaped clusters of tumor cells whose cytoplasm was bright and clear. Immunohistochemistry (IHC) showed tumor cells diffusely expressed TFE3, and fluorescence in situ hybridization (FISH) demonstrated disruption of the TFE3 locus, confirming the diagnosis of Xp11.2 tRCC, the most common subtype of MiTF tRCC. Eventually, the patient obtained a good therapeutic result. This case can provide a good reference and guidance for pediatric urologists and oncologists to recognize and diagnose rare renal cell carcinoma in children

A case with sarcomatoid hepatocellular carcinoma and literature review

Sarcomatoid hepatocellular carcinoma (SHC) is a relatively rare subtype of liver cancer reported in 1.8–2.0% of surgically resected cases. Previous studies have found that SHC was more likely to occur in patients who received repeated anticancer therapies, but the underlying mechanism has not been exactly illustrated. We report a case of a 62-year-old man with SHC. With the initial implication of abscess suspected liver mass by radiological exams (enhanced Computed Tomography and liver Magnetic Resonance Imaging), the patient underwent a laparoscopic pus debridement and biopsy. The diagnosis of SHC was considered by pathologists. After a short recovery, a second radical resection of the liver tumor and hepatic hilar lymph node dissection were conducted. Postoperative pathology revealed a tumor-free incisal margin and negative lymph node. The recovery of the patient was uneventful. When confronting an occasional liver mass with previous Hepatitis B virus infection, SHC should be included for a candidate diagnosis. If diagnosis is confirmed, high biological malignancy and poor survival should be expected. Surgery is still a main option to treat SHC

Exercise therapy in the application of sleep disorders

Sleep disorders often accompany neurological injuries, significantly impacting patient recovery and quality of life.The efficacy and adherence of traditional treatment methods have certain limitations. Exercise has been found to be a highly beneficial treatment method, capable of preventing and alleviating neurological injuries and sleep disorders. This article reviews relevant research findings from both domestic and international sources over the past few decades, systematically summarizing and analyzing the application of exercise therapy in sleep disorders,strategy of exercise intervention program and the potential molecular mechanisms by which exercise therapy improves sleep disorders. Shortcomings in current research and suggestions are presented, providing a reference for future in-depth studies on exercise interventions for sleep disorders

Ultrathin MgB2 films fabricated on Al2O3 substrate by hybrid physical-chemical vapor deposition with high Tc and Jc

Ultrathin MgB2 superconducting films with a thickness down to 7.5 nm are epitaxially grown on (0001) Al2O3 substrate by hybrid physical-chemical vapor deposition method. The films are phase-pure, oxidation-free and continuous. The 7.5 nm thin film shows a Tc(0) of 34 K, which is so far the highest Tc(0) reported in MgB2 with the same thickness. The critical current density of ultrathin MgB2 films below 10 nm is demonstrated for the first time as Jc ~ 10^6 A cm^{-2} for the above 7.5 nm sample at 16 K. Our results reveal the excellent superconducting properties of ultrathin MgB2 films with thicknesses between 7.5 and 40 nm on Al2O3 substrate.Comment: 7 pages, 4 figures, 2 table