ABSTRACT
Wetlands serve as atmospheric carbon dioxide (CO2) sinks, as well as atmospheric methane (CH4) source due to the anaerobic soil environment. Although some studies report that the CH4 emission from wetlands partially offset their net CO2 uptake, there is no global data analysis on the offset of net ecosystem exchange of CO2 (NEE) by CH4 emission in wetland ecosystems. In this study, we collected the data sets of NEE and CH4 flux which were simultaneously measured in the inland wetlands (peatland and non-peatland wetland) and coastal wetlands (seagrass beds, salt marshes and mangroves) around the world. The results showed that all types of wetlands were atmospheric CO2 sink, with the NEE values ranking as follows: mangrove (-2011.0 g CO2·m-2·a-1) < salt marsh (-1636.6 g CO2·m-2·a-1) < non-peatland wetland (-870.8 g CO2·m-2·a-1) < peatland (-510.7 g CO2·m-2·a-1) < seagrass bed (-61.6 g CO2·m-2·a-1). When CH4 flux being converted into CO2-equivalent flux (CO2-eq flux) based on the 100-year scale global warming potentials, we found that the CH4 emissions partially offset 19.4%, 14.0%, 36.1%, 64.9% and 60.1% of the net CO2 uptake in seagrass beds, salt marshes, mangroves, non-peatland wetland and peatland, respectively. Over the 20-year scale, CH4 emissions partially offset 57.3%, 41.4%, 107.0%, 192.0% and 177.3% of the net CO2 uptake, respectively. Some mangroves, peatlands, and non-peatland wetlands acted as net CO2 equivalent source. Over the 100-year scale, the net greenhouse gas balance of each wetland ecosystem was negative value, which indicated that even accounting CH4 emission, wetland ecosystem was still an atmospheric carbon sink. Our results indicated that clarifying the main regulation mechanism of CH4 emission from wetland ecosystems and proposing reasonable CH4 reduction measures are crucial to maintain the carbon sink function in wetland ecosystems, and to mitigate the trend of climate warming.
Subject(s)
Ecosystem , Wetlands , Carbon Sequestration , Carbon Dioxide , MethaneABSTRACT
In this study, we screened adjuvants for an inactivated vaccine against Erysipelothrix rhusiopathiae (E. rhusiopathiae). Inactivated cells of E. rhusiopathiae strain HG-1 were prepared as the antigen in five adjuvanted inactivated vaccines, including a mineral-oil-adjuvanted vaccine (Oli vaccine), aluminum-hydroxide-gel-adjuvanted vaccine (Alh vaccine), ISA201-biphasic-oil-emulsion-adjuvanted vaccine (ISA201 vaccine), GEL02-water-soluble-polymer-adjuvanted vaccine (GEL vaccine), and IMS1313-water-soluble-nanoparticle-adjuvanted vaccine (IMS1313 vaccine). The safety test results of subcutaneous inoculation in mice showed that Oli vaccine had the most severe side effects, with a combined score of 35, followed by the ISA201 vaccine (25 points), Alh vaccine (20 points), GEL vaccine (10 points), and IMS1313 vaccine (10 points). A dose of 1.5LD50 of strain HG-1 was used to challenge the mice intraperitoneally, 14 days after their second immunization. The protective efficacy of Oli vaccine and Alh vaccine was 100% (8/8), whereas that of the other three adjuvanted vaccines was 88% (7/8). Challenge with 2.5LD50 of strain HG-1 resulted in a 100% survival rate, demonstrating the 100% protective efficacy of the Oli vaccine, followed by the GEL vaccine (71%, 5/7), IMS1313 vaccine (57%, 4/7), ISA201 vaccine (43%, 3/7), and Alh vaccine (29%, 2/7). Challenge with 4LD50 of strain HG-1 showed 100% (7/7) protective efficacy of the Oli vaccine and 71% (5/7) protective efficacy of the GEL vaccine, whereas the protective efficacy of other three adjuvanted vaccine was 14% (1/7). The Alh and GEL vaccines were selected for comparative tests in piglets, and both caused minor side effects. A second immunization with these two adjuvanted vaccines conferred 60 and 100% protective efficacy, respectively, after the piglets were challenged via an ear vein with 8LD100 of strain HG-1. After challenge with 16LD100 of strain HG-1, the Alh and GEL vaccines showed 40% and 100% protective efficacy, respectively. Our results suggested that GEL is the optimal adjuvant for an inactivated vaccine against E. rhusiopathiae.
ABSTRACT
BACKGROUND: The goal of this study was to investigate the impact of mean corpuscular volume (MCV) in patients with esophageal squamous cell carcinoma (ESCC) who underwent surgical resection. METHODS: A total of 615 patients with ESCC who underwent esophagectomy were analyzed. Patients were divided into two groups according to the standard MCV: the high MCV group (>100 fl) and the low MCV group (≤100 fl). Survival analyses were performed to calculate overall survival (OS) and cancer-specific survival (CSS) and investigate the independent prognostic factors. RESULTS: Fifty-one patients (8.3%) were in the high MCV group, and the other 564 patients (91.7%) were defined as the low MCV group. MCV was significantly correlated with sex, habitual alcohol or tobacco use, tumor length, body mass index, and multiple primary malignancies (P < 0.05). Elevated MCV was significantly correlated with poor survival in univariate and multivariate analyses. However, in subgroup analyses, MCV was found to be correlated with survival only in patients with alcohol or tobacco consumption and not in patients without alcohol or tobacco consumption. CONCLUSIONS: Pretreatment MCV was correlated with survival in ESCC patients after esophagectomy. However, its prognostic value might only exist in patients with alcohol or tobacco consumption.
ABSTRACT
Anthropic activities lead to a high risk of peatland degradation in the alpine regions. Along with the declined plant productivity and the impaired functioning of the soil carbon sink, the diversity and structure of soil microbial communities are also affected in a degraded peatland ecosystem. Tibetan pig herding is a unique peatland management strategy, which can significantly affect the peatland ecosystem, but it has been rarely studied. The changes in the microbial community structure and its responses to disturbances were studied using a 16S rRNA high throughput sequencing technique in an alpine meadow peatland under Tibetan pig herding disturbance and under control (without Tibetan pig herding) in the Northwestern Yunnan province. The results showed that Tibetan pig herding significantly reduced the α diversity of soil microbes, and the soil microbial community structures were significantly changed by pig herding. The soil microbial communities in the peatland soils were dominated by Proteobacteria, Acidobacteria, and Chloroflexi. Compared with those at the phylum level, the changes at the genus level under pig disturbance were more obvious. It was seen that the relative abundances of Sphingomonas and Hymenobacter significantly increased, while the abundances of Nitrospira and Rhodoplanes significantly decreased under pig herding. Venn diagram analysis revealed that there were 71 and 136 core OTUs in the soil under pig herding and in the control group soil, respectively. Burkholderiales, Pseudomonadales, and Sphingomonadales were the main taxa exclusively found under Tibetan pig herding, and could serve as indicators of soil disturbance. CCA ordination further showed that the distribution of Nitrospira and Rhodoplanes were mainly controlled by soil moisture, available phosphorus, and organic matter contents. Our findings provide an insight into the linkages between the soil microbial communities and the degradation of peatlands in alpine regions.
Subject(s)
Bacteria/classification , Grassland , Soil Microbiology , Swine , Animals , RNA, Ribosomal, 16S/genetics , Soil , TibetABSTRACT
With litter bag methods, we examined mass loss rates and different chemical fractions of litters from two wetland plant species, Zizania caduciflora and Hippuris vulgaris. Those two species examined here varied significantly in their initial litter chemical traits. Experiment was performed under simulated rising temperature (1.5-2.0 â), and under three different habitats (air, air-water interface and water-soil interface). The results showed that, during one-year decomposition period, the mass resi-dual rates exhibited distinct seasonal dynamics, and there were strong interactive effects between seasonal dynamics and environmental factors. Different factors contributed differently for the variation of litter decomposition, 28.8% of which being explained by litter quality, 6.3% of which being explained by rising temperature, and 34.9% being explained by habitat. Along with the decomposition, the contents of different chemical fractions (easy or hard to decompose) varied greatly. Among them, nitrogen contents in H. vulgaris decreased by 53.1%, while the lignin contents increased by 45.4%. Overall, habitat was the most important factor driving litter decomposition, the second was litter quality, and rising temperature had minor effect.
