This study investigated the coupling of the spatial–temporal variations in nutrient distributions and physical conditions in the southern Yellow Sea (SYS) using data compiled from annual-cycle ...surveys conducted in 2006–2007 as well as satellite-derived sea-surface temperature (SST) images. The influence of physical dynamics on the distribution and transport of nutrients varied spatially and seasonally in the SYS. The Changjiang Diluted Water (CDW) plume (in summertime), the Subei Coastal Water (SCW) (year-round), and the Lubei Coastal Current (LCC) (in wintertime) served as important sources of nutrients in the inshore area in a dynamic environment. The saline Taiwan Warm Current (TWC) might transport nutrients to the northeast region of the Changjiang Estuary in the summer, and this nutrient source began to increase from spring to summer and decrease when autumn arrived. Three types of nutrient fronts, i.e., estuarine, offshore, and coastal, were identified. A circular nutrient front caused by cross-shelf transport of SCW in the southeast shelf bank area in the winter and spring was observed. The southeastward flow of western coastal cold water in the SYS might be an important conduit for cross-shelf nutrient exchange between the SYS and the East China Sea (ECS). The tongue-shaped low-nutrient region in the western study area in the wintertime was driven by the interaction of the southward Yellow Sea Western Coastal Current (YSWCC) and the biological activity. The vertically variable SCM (subsurface Chl-a maximum) in the central SYS was controlled by coupled physical–chemical processes that involved stratification and associated nutricline. The average nutrient fluxes into the euphotic zone due to upwelling near the frontal zone of the Yellow Sea Cold Water Mass (YSCWM) in the summer are estimated here for the first time: 1.4±0.9×103μmol/m2/d, 0.1±0.1×103μmol/m2/d, and 2.0±1.3×103μmol/m2/d for DIN, PO4–P, and SiO3–Si, respectively. The depletion of nutrients in the central SYS and the upwelled transport in the boundary of the YSCWM resulted in a spatial transfer of the high Chl-a zone, varying generally from the central SYS to the boundary of the YSCWM from spring to summer, and the nutrient flux associated with this upwelling could contribute significantly to local primary production. This study deepens our understanding of the mechanisms influencing the distribution and transport of nutrients in the SYS.
•Impacts of individual current on nutrient transport were investigated.•Influences of water masses on nutrient fronts were explored.•Types of nutrient fronts, i.e., estuarine, offshore, and coastal, were identified.•Mechanisms of the low-nutrient region in the western SYS in winter were examined.•Vertical transport of nutrients in cold-water patches in summer was illustrated.
In this work, a series of high strength, thermal stable and antioxidant proton exchange membranes were designed with solution processible polybenzimidazole (PBI) as the matrix and perfluorosulfonic ...acid (PFSA) as the fortifier for proton exchange. Solution processible PBI was successfully synthesized by introducing 4,4′-dicarboxydiphenyl ether into the molecular chains of PBI. PFSA/PBI composite membranes were obtained by solution blending and film casting. PBI and PFSA/PBI composite membranes exhibited greatly enhanced tensile strength and Young’s modulus compared to PFSA. PFSA/PBI composite membranes are stable below 300 °C which are suitable for practical application in proton exchange membrane fuel cells. The PFSA/PBI composite membranes show good dimensional stability with low water uptake and swelling rate. The PFSA/PBI composite membranes also exhibit excellent antioxidation stability with less than 5% initial mass loss over 120 h in Fenton reagent. The proton conductivity of PBI is greatly enhanced by blending with PFSA and the proton conductivities of the composite membranes are increased with the raise of PFSA content and temperature. This work offers valuable insights into the exploration of PBI based highperformance proton exchange membranes.
Phototropins (phot1 and phot2), the blue light receptors in plants, regulate hypocotyl phototropism in a fluence-dependent manner. Especially under high fluence rates of blue light (HBL), the ...redundant function mediated by both photl and phot2 drastically restricts the understanding of the roles of phot2. Here, systematic analysis of phototropin-related mutants and overexpression transgenic lines revealed that HBL specifically induced a transient increase in cytosolic Ca concentration (Ca²⁺
cyt
) in Arabidopsis (Arabidopsis thaliana) hypocotyls and that the increase in Ca²⁺
cyt
was primarily attributed to phot2. Pharmacological and genetic experiments illustrated that HBL-induced Ca²⁺ increases were modulated differently by phot1 and phot2. Phot2 mediated the HBL-induced increase in Ca²⁺
cyt
mainly by an inner store-dependent Ca²⁺-release pathway, not by activating plasma membrane Ca²⁺ channels. Further analysis showed that the increase in Ca²⁺
cyt
was possibly responsible for HBL-induced hypocotyl phototropism. An inhibitor of auxin efflux carrier exhibited significant inhibitions of both phototropism and increases in Ca²⁺
cyt
, which indicates that polar auxin transport is possibly involved in HBL-induced responses. Moreover, PHYTOCHROME KINASE SUBSTRATE1 (PKS1), the phototropin-related signaling element identified, interacted physically with phototropins, auxin efflux carrier PINFORMED1 and calcium-binding protein CALMODULIN4, in vitro and in vivo, respectively, and HBL-induced phototropism was impaired in pks multiple mutants, indicating the role of the PKS family in HBL-induced phototropism. Together, these results provide new insights into the functions of phototropins and highlight a potential integration point through which Ca²⁺ signalingrelated HBL modulates hypocotyl phototropic responses.
Current trends in the development of intelligent unmanned autonomous systems Zhang, Tao; Li, Qing; Zhang, Chang-shui ...
Frontiers of Information Technology & Electronic Engineering/Frontiers of Informaion Technology & Electronic Engineering,
2017, 1-2017, 2017-1-00, 20170101, Letnik:
18, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Intelligent unmanned autonomous systems are some of the most important applications of artificial intelligence （AI）. The development of such systems can significantly promote innovation in AI ...technologies. This paper introduces the trends in the development of intelligent unmanned autonomous systems by summarizing the main achievements in each technological platform. Furthermore, we classify the relevant technologies into seven areas, including AI technologies, unmanned vehicles, unmanned aerial vehicles, service robots, space robots, marine robots, and unmanned workshops/intelligent plants. Current trends and de- velopments in each area are introduced.
While it is well-acknowledged that neurovascular dysfunction in hypertension is tightly associated with accelerated brain aging, we contend that the deleterious effects of hypertension may extend ...beyond affecting only the arteries. Methylglyoxal (MG) derived from glycolysis, is involved in the accumulation of advanced glycated end products (AGEs), which are the hallmarks of neurodegenerative disorders. Therefore, the present study aims to firstly investigate the role of MG metabolism in the hypertension-accelerated brain aging process. The results of our study indicate that the levels of MG increase with age in both the plasma and hippocampus of SHRs at 12, 16, and 30 weeks old. AGE methylglyoxal-hydro imidazoline-1 (MG-H1) is primarily localized in astrocytes, while its presence was not observed in neurons and microglia within the hypertensive hippocampus. Our observations also suggest that angiotensin II (Ang II) enhances glucose uptake and glycolysis while reducing the expression of Glo1 in cultured astrocytes. N-acetylcysteine (NAC) was found to counteract the increase in escape latency and inhibit the activation of the AGEs-RAGE axis in 30-week-old SHRs. NAC decreased Iba-1 immunofluorescence intensity, inhibited the levels of pro-inflammatory markers, and enhanced the abundance of anti-inflammatory markers in the hippocampus of SHRs. Moreover, NAC reduced the immunofluorescence signal of 4HNE and increased the content of GSH and SOD in SHRs. Finally, NAC was observed to inhibit apoptosis in the hippocampus of SHRs. Collectively, we firstly showed the enhanced accumulation of MG in the hypertensive brain, whereas the clearance of MG by NAC treatment mitigated the aging process and attenuated AGEs generation, neuroinflammation, and oxidative damage.
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•Age-related elevation of methylglyoxal levels was observed in the hippocampus of SHRs.•The predominant localization of AGE methylglyoxal-hydroimidazolone-1 was in the hippocampus astrocytes in SHRs.•Angiotensin II on astrocytes promoted glucose uptake and glycolysis while suppressing the expression of Glo1.•N-acetylcysteine (NAC) hindered the AGEs-RAGE axis and prevented cognitive impairment in SHRs.•NAC inhibited oxidative stress and inflammatory responses in the hippocampus of SHRs.
Abstract Background Diabetes-associated cognitive impairment (DACI) poses a significant challenge to the self-management of diabetes, markedly elevating the risk of adverse complications. A ...burgeoning body of evidence implicates microglia as a central player in the pathogenesis of DACI. Methods We utilized proteomics to identify potential biomarkers in high glucose (HG)-treated microglia, followed by gene knockdown techniques for mechanistic validation in vitro and in vivo. Results Our proteomic analysis identified a significant upregulation of AKAP8L in HG-treated microglia, with concurrent dysregulation of autophagy and inflammation markers, making AKAP8L a novel biomarker of interest. Notably, the accumulation of AKAP8L was specific to HG-treated microglia, with no observed changes in co-cultured astrocytes or neurons, a pattern that was mirrored in streptozotocin (STZ)-induced diabetic mice. Further studies through co-immunoprecipitation and proximity ligation assay indicated that the elevated AKAP8L in HG-treated microglial cells interacts with the mTORC1. In the STZ mouse model, we demonstrated that both AKAP8L knockdown and rapamycin treatment significantly enhanced cognitive function, as evidenced by improved performance in the Morris water maze, and reduced microglial activation. Moreover, these interventions effectively suppressed mTORC1 signaling, normalized autophagic flux, mitigated neuroinflammation, and decreased pyroptosis. Conclusions Our findings highlight the critical role of AKAP8L in the development of DACI. By interacting with mTORC1, AKAP8L appears to obstruct autophagic processes and initiate a cascade of neuroinflammatory responses. The identification of AKAP8L as a key mediator in DACI opens up new avenues for potential therapeutic interventions.
We give an alternative definition of quantum fidelity for two density operators on qudits in terms of their Hilbert–Schmidt inner product and their purity. It can be regarded as the well-defined ...operator fidelity for the two operators and satisfies all Jozsa's four axioms up to a normalization factor. This fidelity is not computationally demanding.
Rare earth elements (REE) in marine minerals have been widely used as proxies for the redox status of depositional and/or diagenetic environments. Phosphate nodules, which are thought to grow within ...decimetres below the sediment–water interface and to be able to scavenge REE from the ambient pore water, are potential archives of subtle changes in REE compositions. Whether their REE signals represent specific redox conditions or they can be used to track the overlying water chemistry is worth exploring. Through in situ laser ablation – inductively coupled plasma – mass spectrometry (LA-ICP-MS), we investigate the REE compositions of a drill-core-preserved phosphate nodule from the lower Cambrian Niutitang Formation in the Daotuo area, northeastern Guizhou Province, South China. REE distributions of the nodule show concentric layers with systematic decreases in Ce anomalies (Ce/Ce*) from the core to the rim. The lowest Ce/Ce* appears in the outer rim where REE concentrations are relatively high. These results are interpreted to reflect REE exchange with pore water at a very early stage or bathymetric variation during apatite precipitation. The origin of the shale-normalized middle REE (MREE) enrichment in our sample is less constrained. Possible driving factors include preferential MREE substitution for Ca in the apatite lattice, degradation of organic matter and deposition beneath a ferruginous zone. Although speculative, the last possibility is consistent with the chemically stratified model for early Cambrian oceans, in which dynamic fluctuations of the chemocline provided an ideal depositional context for phosphogenesis.
Highlights • Calyxin Y induces caspase-dependent cell death in NCI-H460 cells. • Calyxin Y induces cytoprotective autophagy with upregulation of Atg proteins. • The cleavage of Atg proteins by ...caspases acted as a switch. • JNK activation is correlated with Calyxin Y-induced H2 O2 production. • JNK activation is correlated with the induction of autophagy and apoptosis.
Data from coastal fisheries are often incomplete, as these fisheries are usually small in scale, rendering them exempt from logbook submission requirements. The catch of Dolphinfish Coryphaena ...hippurus by Taiwanese fisheries once ranked second in the world but has dramatically declined to very low levels in recent years. To address this decline, assessment of a Dolphinfish abundance index was necessary. However, due to the small scale of the fisheries, logbook data were not available to calculate CPUE. This study aimed to estimate a statistically reliable index by (1) assigning effort matrices to landings data using coastal surveillance radar data; (2) standardizing the 2001–2015 CPUEs while using four approaches (classifying fishing tactics by multivariate techniques and principal components analysis) to differentiate the fisheries' effort toward catching Dolphinfish from the effort toward other target species; and (3) evaluating performance of the standardization models by using an R2 estimated by cross‐validation and bootstrap procedures. The approach that used a delta‐generalized additive model with a direct principal components procedure demonstrated the best fit. This study presents an example of deriving a statistically reliable abundance index from the data‐incomplete situations common for coastal fisheries, which allows for follow‐up population dynamics studies. The resulting index for Dolphinfish in the Taiwanese region showed two 7‐year cycles, with a prominent decline in 2015. Reasons for the fluctuation are unknown but may be due to environmental factors, the fast‐growing nature of the fish, and heavy exploitation of the stock by Taiwanese fisheries.
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