Response of the North Atlantic thermohaline circulation and ventilation to increasing carbon dioxide in CCSM3

Author Posting. © American Meteorological Society 2006. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Climate 19 (2006): 2382–2397, doi:10.1175/JCLI3757.1.The response of the North Atlantic thermohaline circulation to idealized climate forcing of 1% per year compound increase in CO2 is examined in three configurations of the Community Climate System Model version 3 that differ in their component model resolutions. The strength of the Atlantic overturning circulation declines at a rate of 22%–26% of the corresponding control experiment maximum overturning per century in response to the increase in CO2. The mean meridional overturning and its variability on decadal time scales in the control experiments, the rate of decrease in the transient forcing experiments, and the rate of recovery in periods of CO2 stabilization all increase with increasing component model resolution. By examining the changes in ocean surface forcing with increasing CO2 in the framework of the water-mass transformation function, we show that the decline in the overturning is driven by decreasing density of the subpolar North Atlantic due to increasing surface heat fluxes. While there is an intensification of the hydrologic cycle in response to increasing CO2, the net effect of changes in surface freshwater fluxes on those density classes that are involved in deep-water formation is to increase their density; that is, changes in surface freshwater fluxes act to maintain a stronger overturning circulation. The differences in the control experiment overturning strength and the response to increasing CO2 are well predicted by the corresponding differences in the water-mass transformation rate. Reduction of meridional heat transport and enhancement of meridional salt transport from mid- to high latitudes with increasing CO2 also act to strengthen the overturning circulation. Analysis of the trends in an ideal age tracer provides a direct measure of changes in ocean ventilation time scale in response to increasing CO2. In the subpolar North Atlantic south of the Greenland–Scotland ridge system, there is a significant increase in subsurface ages as open-ocean deep convection is diminished and ventilation switches to a predominance of overflow waters. In middle and low latitudes there is a decrease in age within and just below the thermocline in response to a decrease in the upwelling of old deep waters. However, when considering ventilation within isopycnal layers, age increases for layers in and below the thermocline due to the deepening of isopycnals in response to global warming

Esophageal metastasis of renal cell carcinoma resected by endoscopic submucosal dissection: a case report

Background: Esophageal metastasis of renal cell carcinoma (RCC) is extremely rare. We have described herein a case of a 59-year-old man with esophageal metastasis of RCC that was endoscopically resected.Case presentation: The case was a 59-year-old man who had undergone left nephrectomy for renal clear cell carcinoma 17 years ago and splenectomy for splenic metastasis 3 years ago. Esophagogastroduodenoscopy (EGD) performed 9 years ago revealed a small reddish elevated lesion with a smooth surface in the middle esophagus; this lesion increased in size 4 years ago. However, no biopsy was performed. The lesion continued to grow in size and was found to have become nodular during the present observation. Biopsy revealed clear cell carcinoma. Endoscopic ultrasound (EUS) revealed that the lesion had not invaded the submucosa, and contrast-enhanced computed tomog-raphy did not reveal any other metastasis. The lesion was successfully removed en bloc via endoscopic submucosal dissection (ESD). Pathologically, the tumor was detected in the subepithelium with focal infiltration of the muscularis mucosa. It consisted of monotonous cells with small nuclei and a clear cytoplasm. Immunohistological findings indi-cated that the tumor was a metastasis of RCC. The lateral and vertical margins were noted to be free.Conclusions: We have presented herein a case of esophageal metastasis of RCC that had progressed over 9 years and was then resected en bloc through endoscopic submucosal dissection

Extracellular vesicles from senescent hepatic stellate cells promote cell viability of hepatoma cells through increasing EGF secretion from differentiated THP?1 cells

Since the discovery of the senescence-associated secretory phenotype, the role of senescent hepatic stellate cells (HSCs) in hepatocellular carcinoma (HCC) development has gained increasing attention. Similar to cytokines, extracellular vesicles (EVs) are essential for intercellular communication. However, the function of EVs derived from senescent HSCs in HCC progression has not been extensively studied. The aims of the present study were to characterize the EVs derived from senescent HSCs and determine their role in the tumor microenvironment. Cellular senescence was induced in human hepatic stellate cells (HHSteCs) with various concentrations of etoposide. Induction was confirmed using EdU staining and 53BP1 and p21 immunostaining. EVs were isolated by ultracentrifugation and analyzed by nanoparticle tracking analysis. Multiplex immunoassays were used to compare the levels of growth factors secreted from hepatoma cell lines and macrophage cells pretreated with EVs derived from senescent HHSteCs (senescent EVs) with those pretreated with EVs derived from normal cultured HHSteCs (normal EVs). Treatment with 25 μM etoposide for 3 days was the most effective at inducing senescence in HHSteCs. This finding was confirmed by induction of irreversible cell-cycle arrest, upregulation of 53BP1 and p21 expression, and increased SA-β-gal staining. Senescent HHSteCs released increased quantities of EV particles compared with normally cultured HHSteCs. Multiplex analysis revealed that there was no difference between hepatoma cell lines treated with normal EVs and those treated with senescent EVs in growth factor secretion. In contrast, the secretion of epidermal growth factor (EGF) was increased by macrophage cells treated with senescent EVs compared with those treated with normal EVs. Furthermore, senescent EVs did not affect the viability of hepatoma cells but increased the viability of hepatoma cells co-cultured with macrophage cells. In conclusion, the release of EVs from senescent HSCs was higher compared with normal HSCs. Furthermore, senescent EVs promoted HCC development by upregulating EGF secretion from macrophages

エネルギー生産によって生じるCO_2や吸着性物質の海域における輸送過程に関する研究

第1章 序論 第2章 外洋におけるCO₂の拡散現象 第3章 沿岸域における物質の拡散現象 第4章 結論Made available in DSpace on 2012-09-05T02:23:37Z (GMT). No. of bitstreams: 3 nakashiki1.pdf: 8977497 bytes, checksum: 29a42e12d3bc9879e5e7524604dbc037 (MD5) nakashiki2.pdf: 14701400 bytes, checksum: b1351281ef11f8310c42438dbfb3843b (MD5) nakashiki3.pdf: 10134746 bytes, checksum: 4e880b5f241a9f1604e6db92e6a012ea (MD5) Previous issue date: 1997-01-23主1-参1工学_環境都