Submesoscale dynamics and transport properties in the Gulf of Mexico

Submesoscale processes, characterized by O(1km) horizontal scale and O(1) Rossby number, are ubiquitous in the world ocean and play an important role in the vertical flux of mass, buoyancy and tracers in the upper ocean. However, they have not been intensively studied due to the requirement of uniquely high spatial and temporal resolution in the observation and computer modeling. In this thesis, using a suite of high-resolution numerical experiments in the northwestern Gulf of Mexico, where rich submesoscale structures are accompanied by the strong mesoscale Loop Current eddies, the impact of resolving submesoscales on the tracer distribution and 3-D transport was extensively examined. It was concluded that, submesoscale dynamics aggregated the surface tracers and formed characteristic patterns at scales of kilometers near the ocean surface by enhanced convergence/divergence zones associated with strong ageostrophic processes. This distinctive phenomenon was evident in recent ocean color satellite images which showed similar extensive lines and spirals of floating Sargassum in the western Gulf of Mexico. In addition, better-resolved submesoscale activities increased the horizontal resolution dramatically and elevated local vertical velocity both within and below the mixed layer while leaving the horizontal component almost unaltered. The vertical dispersion increased by several fold with the largest difference close to the surface. Considering the pervasive presence of submesoscale structures at the surface ocean, these models predict that submesoscale processes may serve as an important nutrient supply mechanism in the upper ocean and potentially make a significant contribution on balancing the global biogeochemical tracer budget.Ph.D

Dynamical Controls of the Eastward Transport of Overwintering Calanus finmarchicus From the Lofoten Basin to the Continental Slope

Diapausing populations of Calanus finmarchicus at depth in the Lofoten Basin (LB) return to the continental shelf and slope off the Lofoten-Vesterålen Islands during the phytoplankton spring bloom to feed and spawn, forming surface swarms with a great abundance. To study how overwintering populations of C. finmarchicus move with the deep currents and return to the shelf, Lagrangian transport characteristics of particles in deep water between 2008 and 2019 were analyzed using Global Ocean Reanalysis and Simulation re-analysis data and Lagrangian Coherent Structures (LCSs). Our analyses revealed that persistent eastward transport of diapausing C. finmarchicus between LB and continental slope occurred mainly between 600 and 1,100 m in the Arctic Intermediate Water. The consistency of the vertical distributions of C. finmarchicus abundance and salinity further suggests that physical factors control the horizontal distribution of the species. Hovmöller diagrams of kinetic energy indicate that there is an eastward advection of mean current at depth. The co-occurrence between the eastward transport of LCSs and the eastward advection of the mean current provides direct evidence that the life history of C. finmarchicus is subjected to physical control in the Norwegian Sea

Combined effects of fronts, upwelling and the biological pump on organophosphate esters in the Changjiang (Yangtze) River estuary during summer

<p>The deposition contains experiment details, instrument conditions, sampling information, environmental parameters, physicochemical properties of focus compounds, QA/QC, and detected target concentrations.</p&gt

Overexpression of miR-27b-3p Targeting Wnt3a Regulates the Signaling Pathway of Wnt/β-Catenin and Attenuates Atrial Fibrosis in Rats with Atrial Fibrillation

MicroRNAs (miRNAs) are regarded as a potential method for the treatment of atrial fibrillation (AF) although its molecular mechanism remains unknown. We found in our previous study that the level of peripheral blood miR-27b-3p and the expression of atrial tissue CX43 were both significantly downregulated in AF patients. In the present study, we propose and test this hypothesis that overexpression of miR-27b-3p attenuates atrial fibrosis, increases CX43 expression, and regulates the signaling pathway of Wnt/β-Catenin by targeting Wnt3a. miR-27b-3p overexpression was induced by rat tail vein injection of adeno-associated virus. Two weeks after transfection of adeno-associated virus, the rat AF model was established by tail vein injection of acetylcholine- (ACh-) CaCl2 for 7 days, and 1 ml/kg was injected daily. The incidence and duration of AF were recorded with an electrocardiogram. Cardiac function was monitored by cardiac ultrasound. Serum cardiac enzyme was detected by ELISA. The expression of atrial miR-27b-3 and Wnt3a was assayed by quantitative RT-PCR. Atrial fibrosis was determined by Masson’s trichrome staining. Expression of atrial Collagen-I and Collagen-III was tested by the immunohistochemical method. Expression of CX43 was measured by immunofluorescence. The expression of Collagen-I, a-SMA, Collagen-III, TGF-β1, CX43, Wnt3a, β-Catenin, and p-β-Catenin was assayed by western blot. Our results showed that miR-27b-3p overexpression could reduce the incidence and duration of AF, alleviate atrial fibrosis, increase atrial CX43 expression, and decrease the expression of Collagen-I, a-SMA, Collagen-III, TGF-β1, Wnt3a, and p-β-Catenin. In addition, the results of luciferase activity assay showed that Wnt3a is a validated miR-27b-3p target in HEK 293T cells. Our results provide a new evidence that miR-27b-3p regulates the signaling pathway of Wnt/β-Catenin by targeting Wnt3a, which may play an important role in the development of atrial fibrosis and AF

The Impact of Typhoon “Mangkhut” on Surface Water Nutrient and Chlorophyll Inventories of the South China Sea in September 2018

The influence of the exceptionally strong typhoon Mangkhut on the availability of nutrients and changes in primary production were studied in the northern South China Sea in September 2018. A tight station grid was sampled to analyze major nutrients, chlorophyll_a, particulate and dissolved organic carbon and nitrogen. Based on interpolated profiles, nutrients and organic matter budgets were determined for the upper 100 m of the water column prior to and after Mangkhut's passage. An upper layer of 100 m was found to reflect the important changes by the typhoon. Considerable differences between the on‐shelf, shelf edge and the deep‐sea stations were determined. Nitrate and phosphate increased by about 80% and 36% on the shelf, respectively, and both by almost 40% at the shelf edge. The open deep‐sea part of the study area reflects some deviating results that may be caused by just displacement of water or by mixing water of different origin. However, right on Mangkhut's track on the shelf even contact between surface waters and bottom waters was enabled, increasing phosphate and silicate, but declining nitrate. The inventory of organic carbon of the upper 100 m of the study area (138,000 km2) of 92 Gmol had increased within a few days after the typhoon's passage by 5 Gmol on the shelf and about 2 Gmol in the shelf edge area. Chlorophyll_a doubled during our stay and might have reached a factor of 3 increase in the subsequent time by nitrate supply and excess phosphate.Plain Language Summary: The influence of the super typhoon Mangkhut on the waters of the northern South China Sea was studied in September 2018. Nutrients and organic material were measured on 63 stations from the Chinese research vessel HAI YANG DI ZHI SHI HAO. Amounts of nutrients and biogenic matter were calculated for the on‐shelf, shelf edge and deep‐sea stations for the pre‐ and post‐Mangkhut period. An important finding was that the stations of the different areas, on‐shelf, shelf edge and the deep‐sea appeared to be differently impacted by Mangkhut. Even differences between the stations right on its track and in the other parts of the study area were found. In general, nutrients were supplied in enormous amounts and caused immediate algae growth. Moreover, enough nutrients were supplied to support algae growth for a couple of weeks. In summary, it was found that Manghut's upper water column mixing and shifting caused an almost tripling of primary production compared to the normal situation.Key Points: The typhoon Mangkhut clearly impacted the water column differently on the continental shelf, at the shelf edge and in the deep sea. On Mangkhut's track a maximum nitrate supply of 162 mmol m−2 was caused by induced upwelling at the shelf edge. The chlorophyll inventory of 2.8 Gg was almost tripled by contributing 4.7 Gg estimated from an additional nutrient supply.Federal Ministry of Education and Research, BMBF http://dx.doi.org/10.13039/501100002347National Natural Science Foundation of China http://dx.doi.org/10.13039/501100001809https://doi.pangaea.de/10.1594/PANGAEA.936352https://doi.pangaea.de/10.1594/PANGAEA.93609

Transport Barriers and the Retention of Calanus finmarchicus on the Lofoten Shelf in Early Spring

Large aggregations of the copepod Calanus finmarchicus occur each spring in the shelf-slope-oceanic regions off the Lofoten-Vesterålen Islands where productive fisheries have traditionally supported local economies. The retention and off-shelf transport of populations of C. finmarchicus populations were studied by analyzing ocean color remote sensing, satellite altimetry data, and Lagrangian Coherent Structures (LCS) between 2010 and 2019. Our analysis revealed the existence of a transport barrier reoccurring at the shelf break that retains C. finmarchicus on the shelf for 30–70 days in the spring when C. finmarchicus were seasonally ascending to the surface layer. The analysis of baroclinic and barotropic energy conversions indicated that the topographically steered Norwegian Atlantic Current is the primary mechanism in the formation of the transport barrier, which restricts exchanges of C. finmarchicus populations between shelf and oceanic waters. In the mid- to late April, an increase in baroclinicity leads to an increase in mesoscale eddies generated on the shelf break near Lofoten-Vesterålen Islands, breaking down transport barriers and causing off-shelf transport of C. finmarchicus. The transport barrier predictably reoccurs in early spring which supports the entrapment of C. finmarchicus in the shelf region

Pan-cancer integrated analysis of ANKRD1 expression, prognostic value, and potential implications in cancer

Abstract There is substantial evidence demonstrating the crucial role of inflammation in oncogenesis. ANKRD1 has been identified as an anti-inflammatory factor and is related to tumor drug resistance. However, there have been no studies investigating the prognostic value and molecular function of ANKRD1 in pan-cancer. In this study, we utilized the TCGA, GTEx, GSCALite, ENCORI, CTRP, DAVID, AmiGO 2, and KEGG databases as well as R language, to explore and visualize the role of ANKRD1 in tumors. We employed the ROC curve to explore its diagnostic significance, while the Kaplan–Meier survival curve and Cox regression analysis were used to investigate its prognostic value. Additionally, we performed Pearson correlation analysis to evaluate the association between ANKRD1 expression and DNA methylation, immune cell infiltration, immune checkpoints, TMB, MSI, MMR, and GSVA. Our findings indicate that ANKRD1 expression is dysregulated in pan-cancer. The ROC curve revealed that ANKRD1 expression is highly sensitive and specific in diagnosing CHOL, LUAD, LUSC, PAAD, SKCM, and UCS (AUC > 85.0%, P < 0.001). Higher ANKRD1 expression was related to higher overall survival (OS) in LGG, but with lower OS in COAD and STAD (P < 0.001). Moreover, Cox regression and nomogram analyzes suggested that ANKRD1 is an independent factor for COAD, GBM, HNSC, and LUSC. Dysregulation of ANKRD1 expression in pan-cancer involves DNA methylation and microRNA regulation. Using the CTRP database, we discovered that ANKRD1 may influence the half-maximal inhibitory concentration (IC50) of several anti-tumor drugs. ANKRD1 expression showed significant correlations with immune cell infiltration (including cancer-associated fibroblast and M2 macrophages), immune checkpoints, TMB, MSI, and MMR. Furthermore, ANKRD1 is involved in various inflammatory and immune pathways in COAD, GBM, and LUSC, as well as cardiac functions in HNSC. In vitro experiments demonstrated that ANKRD1 promotes migration, and invasion activity, while inhibiting apoptosis in colorectal cancer cell lines (Caco2, SW480). In summary, ANKRD1 represents a potential prognostic biomarker and therapeutic target in human cancers, particularly in COAD