74 research outputs found
Sovereignty over the Paracel Islands in 1884-1945: an approach from the rivalry between France, China, and Japan
The Paracel Islands are situated in the South China Sea geographic center and have an important strategic location for the military and the economy. Since 1884, France has represented the Vietnamese state as a protectorate to manage the archipelago. In the context of France seeking to expand its influence into the Asia-Pacific region, disputes over sovereignty over the Paracel Islands occurred during the colonial period between France (representing Vietnam), China, and Japan. The article aims to analyze the importance of the Paracel Islands in the policies of France, China, and Japan in general. Moreover, the specific activities of France in the struggle with China and Japan to affirm and protect sovereignty over the Paracel Islands would also be analyzed. Based on primary and secondary data, along with historical research methods, research methods in international relations, and other interdisciplinary research strategies, the article concludes that the Paracel Islands play an important role in the strategies of France, China, and Japan. Hence, the Paracel issue in this period has gone beyond the framework of traditional territorial disputes, becoming "internationalizationâ with consequences that persist to the present day. France's policy to exploit and administer the Paracel Islands was persistent, thorough, and systematic in the military, economic, political, and diplomatic spheres
Stable isotopes as an effective tool for N nutrient source identification in a heavily urbanized and agriculturally intensive tropical lowland basin
Š 2020, Springer Nature Switzerland AG. We present the application of dual stable isotope analyses of NO3 (δ15N-NO3 and δ18O-NO3) to provide a comprehensive assessment of the provenance, partitioning, and conversion of nitrate across the Day River Basin (DRB), Vietnam, which is heavily impacted by agriculture and urbanization. Stable isotope compositions of river water δ18O-H2O, in addition to their δ15N-NO3 and δ18O-NO3 signatures, were sampled at 12 locations in the DRB. Sample collection was conducted during three different periods to capture changes in regional weather and agricultural fertilization regimes; April (the dry season and key fertilization period), July (the rainy season and another key fertilization period) and October (the rainy season with no regional fertilization). Ranges of NO3 stable isotopes are â 7.1 to + 9.2â° and â 3.9 to + 13.2â° for δ18O and δ15N, respectively. Interpretation of the stable isotope data characterizes 4 main sources of NO3 in the DRB; (1) nitrified urea fertilizer derived from an intensive agricultural irrigation network, (2) soil and groundwater leaching from within the basin (3) manure and sewage inputs (which is more prevalent in downstream river sections) and (4) upstream inflow from the Red River which discharges into the Day River through the Dao River. We applied a mixing model for the DRB consisting of 4 variables, representing these 4 different sources. The partition calculation shows that during the fertilization and rainy period of July, more than 45% of river NO3 is derived from nitrified urea sources. During the other sampling periods (April and October), manure and sewage contribute more than 50% of river NO3 and are derived from the middle portion of the DRB, where the Day River receives domestic wastewater from the Vietnamese capital, Hanoi. Stable isotope data of O and N reveal that nitrification processes are more prevalent in the rainy season than in dry season and that this predominantly takes place in paddy field agricultural zones. In general, data demonstrate that nitrate loss in the DRB is due to denitrification which takes place in polluted stretches of the river and dominates in the dry season. This study highlights that (i) domestic waste should be treated prior to its discharge into the Day River and (ii) the need for better catchment agricultural fertilization practices as large portions of fertilizer currently discharge into the river, which greatly impacts regional water quality
Comparative ability of mesenchymal stromal cells from different tissues to limit neutrophil recruitment to inflamed endothelium
Mesenchymal stromal cells (MSC) are tissue-resident stromal cells capable of modulating immune responses, including leukocyte recruitment by endothelial cells (EC). However, the comparative potency of MSC from different sources in suppressing recruitment, and the necessity for close contact with endothelium remain uncertain, although these factors have implications for use of MSC in therapy. We thus compared the effects of MSC isolated from bone marrow, Wharton's jelly, and trabecular bone on neutrophil recruitment to cytokine-stimulated EC, using co-culture models with different degrees of proximity between MSC and EC. All types of MSC suppressed neutrophil adhesion to inflamed endothelium but not neutrophil transmigration, whether directly incorporated into endothelial monolayers or separated from them by thin micropore filters. Further increase in the separation of the two cell types tended to reduce efficacy, although this diminution was least for the bone marrow MSC. Immuno-protective effects of MSC were also diminished with repeated passage; with BMMSC, but not WJMSC, completing losing their suppressive effect by passage 7. Conditioned media from all co-cultures suppressed neutrophil recruitment, and IL-6 was identified as a common bioactive mediator. These results suggest endogenous MSC have a homeostatic role in limiting inflammatory leukocyte infiltration in a range of tissues. Since released soluble mediators might have effects locally or remotely, infusion of MSC into blood or direct injection into target organs might be efficacious, but in either case, cross-talk between EC and MSC appears necessary
3D human liver tissue from pluripotent stem cells displays stable phenotype in vitro and supports compromised liver function in vivo.
Liver disease is an escalating global health issue. While liver transplantation is an effective mode of therapy, patient mortality has increased due to the shortage of donor organs. Developing renewable sources of human liver tissue is therefore attractive. Pluripotent stem cell-derived liver tissue represents a potential alternative to cadaver derived hepatocytes and whole organ transplant. At present, two-dimensional differentiation procedures deliver tissue lacking certain functions and long-term stability. Efforts to overcome these limiting factors have led to the building of three-dimensional (3D) cellular aggregates. Although enabling for the field, their widespread application is limited due to their reliance on variable biological components. Our studies focused on the development of 3D liver tissue under defined conditions. In vitro generated 3D tissues exhibited stable phenotype for over 1Â year in culture, providing an attractive resource for long-term in vitro studies. Moreover, 3D derived tissue provided critical liver support in two animal models, including immunocompetent recipients. Therefore, we believe that our study provides stable human tissue to better model liver biology 'in the dish', and in the future may permit the support of compromised liver function in humans
Nitrate pollution in the Red River Delta
The Red River Delta is home to the capital of Vietnam, Hanoi. The large
population relies on the catchment for the provision of primary water resources
for its industry and agriculture. This critical reserve is rapidly becoming impacted
by anthropogenic activities and we demonstrate how nitrate pollution, in
particular, is influencing the health of the Red River Delta
Identifying the controls on nitrate and metabolic state within the Red River delta (Vietnam) with the use of stable isotopes
In many places around the world, anthropogenic activities have resulted in nitrate (NO3â) pollution and changes in the metabolic state of aquatic ecosystems. Here we combined stable isotope and physico-chemical monitoring to assess the sources of NO3â and the overall metabolic state within the Red River delta, Vietnam. River water stable isotope compositions (δ18O-H2O) ranged between â11.2 and â2.7 â°, δ18O-NO3â between â7.1 and + 29.7 â° and δ15N-NO3â between â3.9 and + 14.0 â°. We identified the dominant NO3â sources as: 1) soil leachate, 2) domestic waste flushed from urban areas, and 3) NH4+ fertilizers washed from paddy fields. The relative impact of each source depends on geographical location within the delta and the time of year, due to dilution and concentration effects during wet and dry seasons. The primary NO3âsource upstream is natural soil leachates, predominantly from tributaries connected to the Red Riverâs main stream. Within the middle-lower section of Red River delta, urban pollution from manure and septic waste reaches as high as 50 % of the total NO3â load during dry season. NO3â leached from fertilizers is also high at sites in the middle of the delta, related to agricultural activities. Dissolved oxygen isotope (δ18O-O2) values calculated from δ18O-H2O and δ18O-NO3â values indicate that the aquatic metabolism is net autotrophic (oxygen from primary production exceeds consumption by respiration), but high inputs of biodegradable organic matter from untreated domestic waste and high rates of sediment oxygen demand (SOD) and chemical oxygen demand (COD) have resulted in the whole river system becoming undersaturated in oxygen. High NO3â loads and low DO saturation are of critical concern and require mitigation practices to improve water quality for millions of people
Study on total lipid content, lipid class composition of some fire and soft corals collected in Nha Trang, Vietnam
For the first time, the total lipid content and lipid class composition of the Vietnamese soft corals (Sinularia brassica, Sinularia flexibilis) and fire corals (Millepora dichotoma, Millepora platyphylla) were investigated. The results indicated that the total lipid content of the investigated species was significantly different. Compositions of the lipid classes were analyzed using TLC and image analysis program Sorbfil TLC Videodensitometer DV and the results showed that phospholipids (PL, 10.91â16.02%), monoalkyldiacylglycerols (MADAG, 20.69-39.92%) and hydrocarbon wax (HW, 29.83-37.17%) were the main lipid classes of the total lipid in soft coral species. Meanwhile, PL (24.11-33.23%), TG (14.27â34.92%), ST (10.10â14.50%) and HW (12.08â19.95%) were predominant in fire coral species. ST, TG and FFA contents in soft and fire corals were at low level. DG was only present in the Sinularia flexibilis but not in other studied corals
Community, Family, and Partner-Related Stigma Experienced by Pregnant and Postpartum Women with HIV in Ho Chi Minh City, Vietnam
Pregnant and postpartum women with HIV often face stigma and discrimination at home and in the community. In Vietnam, associations between HIV and the âsocial evilsâ of drug use and sex work contribute to stigmatization of people with HIV. We conducted a qualitative study to explore discrimination experienced by HIV-positive pregnant and postpartum women in Ho Chi Minh City at home and in the community. We conducted 20 in-depth interviews and two focus group discussions. Participants described managing disclosure of their HIV infection because of fear of stigma and discrimination, particularly to the wider community. In cases where their HIV status was disclosed, women experienced both discrimination and support. The findings highlight the need for targeted interventions to support pregnant and postpartum women with HIV, particularly during this period when they are connected to the healthcare system and more readily available for counseling
Sphingosine-1-phosphate Prevents Egress of Hematopoietic Stem Cells From Liver to Reduce Fibrosis
N, P, Si budgets for the Red River Delta (northern Vietnam): how the delta affects river nutrient delivery to the sea
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