[1] Mesoscale eddy properties in the northwestern subtropical Pacific Ocean are investigated by analyzing 22,567 cyclonic eddies (CEs) and 26,365 anticyclonic eddies (AEs) detected from 19 year altimetric sea level records. Eddy occurrence frequency and kinetic energy are prevailingly high in the Subtropical Countercurrent zonal band between 19 N and 26 N and further elevated near the Luzon-Taiwan coast. A general superiority of AEs is observed at most latitudes except between 19 N and 22 N, where the CE number is larger. The modal radius and mean lifespan of the CEs (AEs) are 134 km and 11.2 weeks (121 km and 10.9 weeks), respectively. After generation, most eddies propagate westward with a mean speed of 7.2 cm s À1 and deflect northward following the Kuroshio along the Luzon-Taiwan coast. Three-dimensional eddy structures are further explored with composite eddy images in five subregions constructed by surfacing Argo temperature/salinity data into altimeter-detected eddy areas. Due to the existence of mode waters in the main thermocline, eddy-induced temperature anomaly exhibits a double-core vertical structure which is especially evident in CE images. Because of the vertical water mass distribution, salinity anomaly features a sandwich-like pattern which is more evident in AE images. Also revealed is the significant structure difference in these five subregions. Eddies are greatly intensified as they approach the western boundary, inducing larger temperature and salinity anomalies and influencing deeper ocean. Along the Luzon-Taiwan coast, AEs are preferentially strengthened by the northward background flow.
This paper investigates the structure and dynamics of the Equatorial Undercurrent (EUC) of the Indian Ocean by analyzing in situ observations and reanalysis data and performing ocean model experiments using an ocean general circulation model and a linear continuously stratified ocean model. The results show that the EUC regularly occurs in each boreal winter and spring, particularly during February and April, consistent with existing studies. The EUC generally has a core depth near the 20°C isotherm and can be present across the equatorial basin. The EUC reappears during summer–fall of most years, with core depth located at different longitudes and depths. In the western basin, the EUC results primarily from equatorial Kelvin and Rossby waves directly forced by equatorial easterly winds. In the central and eastern basin, however, reflected Rossby waves from the eastern boundary play a crucial role. While the first two baroclinic modes make the largest contribution, intermediate modes 3–8 are also important. The summer–fall EUC tends to occur in the western basin but exhibits obvious interannual variability in the eastern basin. During positive Indian Ocean dipole (IOD) years, the eastern basin EUC results largely from Rossby waves reflected from the eastern boundary, with directly forced Kelvin and Rossby waves also having significant contributions. However, the eastern basin EUC disappears during negative IOD and normal years because westerly wind anomalies force a westward pressure gradient force and thus westward subsurface current, which cancels the eastward subsurface flow induced by eastern boundary–reflected Rossby waves. Interannual variability of zonal equatorial wind that drives the EUC variability is dominated by the zonal sea surface temperature (SST) gradients associated with IOD and is much less influenced by equatorial wind associated with Indian monsoon rainfall strength.
The Luzon Undercurrent (LUC) was discovered about 20 years ago by geostrophic calculation from conductivity-temperature-depth (CTD) data. But it was not directly measured until 2010. From November 2010 to July 2011, the LUC was first directly measured by acoustic Doppler current profiler (ADCP) from a subsurface mooring at 18.0°N, 122.7°E to the east of Luzon Island. A number of new features of the LUC were identified from the measurements of the current. Its depth covers a range from 400 m to deeper than 700 m. The observed maximum velocity of the LUC, centered at about 650 m, could exceed 27.5 cm s" ', four times stronger than the one derived from previous geostrophic calculation with hydrographie data. According to the time series available, the seasonality of the LUC strength is in winter > summer > spring. Significant intraseasonal variability (ISV; 70-80 days) of the LUC is exposed. Evidence exists to suggest that a large portion of the intraseasonal variability in the LUC is related to the westward propagation of mesoscale eddies from the east of the mooring site.
Background: This study aimed to investigate the effect of long noncoding ribonucleic acids (RNAs) metastasis-associated lung adenocarcinoma transcript 1 (lnc-MALAT1) on regulating neuron apoptosis, neurite outgrowth and inflammation, and further explore its molecule mechanism in Alzheimer’s disease (AD). Methods: Control overexpression, lnc-MALAT1 overexpression, control shRNA, and lnc-MALAT1 shRNA were transfected into NGF-stimulated PC12 cellular AD model and cellular AD model from primary cerebral cortex neurons of rat embryo, which were established by Aβ1-42 insult. Rescue experiments were performed by transferring lnc-MALAT1 overexpression and lnc-MALAT1 overexpression & miR-125b overexpression plasmids. Neuron apoptosis, neurite outgrowth and inflammation were detected by Hoechst-PI/apoptosis marker expressions, and observations were made using microscope and RT-qPCR/Western blot assays. PTGS2, CDK5 and FOXQ1 expressions in rescue experiments were also determined. Results: In two AD models, lnc-MALAT1 overexpression inhibited neuron apoptosis, promoted neurite outgrowth, reduced IL-6 and TNF-α levels, and increased IL-10 level compared to control overexpression, while lnc-MALAT1 knockdown promoted neuron apoptosis, repressed neurite outgrowth, elevated IL-6 and TNF-α levels, but reduced IL-10 level compared to control shRNA. Additionally, lnc- MALAT1 reversely regulated miR-125b expression, while miR-125b did not influence the lnc- MALAT1 expression. Subsequently, rescue experiments revealed that miR-125b induced neuron apoptosis, inhibited neurite outgrowth and promoted inflammation, also increased PTGS2 and CDK5 expressions but decreased FOXQ1 expression in lnc-MALAT1 overexpression treated AD models. Conclusion: Lnc-MALAT1 might interact with miR-125b to inhibit neuron apoptosis and inflammation while promote neurite outgrowth in AD.
The equatorial eastern Indian Ocean (EIO) upwelling occurs in the Indian Ocean warm pool, differing from the equatorial Pacific and Atlantic upwelling that occurs in the cold tongue. By analyzing observations and performing ocean model experiments, this paper quantifies the remote versus local forcing in causing interannual variability of the equatorial EIO upwelling from 2001 to 2011 and elucidates the associated processes. For all seasons, interannual variability of thermocline depth in the EIO, as an indicator of upwelling, is dominated by remote forcing from equatorial Indian Ocean winds, which drive Kelvin waves that propagate along the equator and subsequently along the Sumatra–Java coasts. Upwelling has prominent signatures in sea surface temperature (SST) and chlorophyll-a concentration but only in boreal summer–fall (May–October). Local forcing plays a larger role than remote forcing in producing interannual SST anomaly (SSTA). During boreal summer–fall, when the mean thermocline is relatively shallow, SSTA is primarily driven by the upwelling process, with comparable contributions from remote and local forcing effects. In contrast, during boreal winter–spring (November–April), when the mean thermocline is relatively deep, SSTA is controlled by surface heat flux and decoupled from thermocline variability. Advection affects interannual SSTA in all cases. The remote and local winds that drive the interannual variability of the equatorial EIO upwelling are closely associated with Indian Ocean dipole events and to a lesser degree with El Niño–Southern Oscillation.
Because of its prolific growth, oilseed rape (Brassica napus L.) can be grown advantageously for phytoremediation of the lands contaminated by industrial wastes. Therefore, toxic effect of cadmium on the germination of oilseed rape, the capability of plants for cadmium phytoextraction, and the effect of exogenous application of plant growth regulators to mitigate phytotoxicity of cadmium were investigated. For the lab study of seedlings at early stage, seeds were grown on filter papers soaked in different solutions of Cd 2? (0, 10, 50, 100, 200 and 400 lM). In greenhouse study, seedlings were grown in soil for 8 weeks, transferred to hydroponic pots for another 6 weeks growth, and then treated with plant growth regulators and cadmium. Four plant growth regulators viz. jasmonic acid (12.5 lM), abscisic acid (10 lM), gibberellin (50 lM) and salicylic acid (50 lM); and three levels of Cd 2? (0, 50 and 100 lM) were applied. Data indicated that lower concentration of Cd 2? (10 lM) promoted the root growth, whereas the severe stresses (200 or 400 lM) had negative effect on the establishment of germinating seedlings. Plants treated with any of the tested plant growth regulators alleviated cadmium toxicity symptoms, which were reflected by more fresh weight, less malondialdehyde concentration in leaves and lower antioxidant enzyme activities. The application of abscisic acid to the plants cultivated in the medium containing 100 lM Cd 2? resulted in significantly lower plant internal cadmium accumulation.
Intraseasonal sea surface salinity (SSS) variability in the equatorial Indo-Pacific Ocean is investigated using the Aquarius/SAC-D satellite measurements and Hybrid Coordinate Ocean Model (HYCOM). Large-scale SSS variations at 20-90 day time scales induced by Madden-Julian oscillations (MJOs) are prominent in the central-to-eastern Indian Ocean (IO) and western Pacific Ocean (PO) with a standard deviation of $0.15 psu. The relationship between SSS anomaly and freshwater flux is nearly in phase in the central-toeastern IO and out of phase in the western PO during a MJO cycle. A series of HYCOM experiments are performed to explore the causes for SSS variability. In most areas of the equatorial Indo-Pacific Ocean, wind stress-forced ocean dynamical processes act as the main driver of intraseasonal SSS, while precipitation plays a secondary role. In some areas of the western PO and western IO, however, precipitation effect is the leading contributor. In comparison, evaporation effect induced by radiation and wind speed changes is generally much smaller. Besides the external forcing by MJOs, ocean internal variability can also cause considerable intraseasonal SSS changes, explaining 10-20% of the total variance in some regions. Composite analysis for MJO events reveals that the effects of wind stress, precipitation, and evaporation vary at different phases of a MJO cycle. The MJO-induced SSS signature is the result of complicated superimposition and interaction of these effects. The effect of wind stress also varies significantly from event to event. It affects SSS variability primarily through horizontal ocean current advection and to a lesser extent through vertical entrainment.
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