The boom in water infrastructure in the Mekong Basin has raised concerns over the annual supply of water and sediment among its riparian communities. By consolidating various datasets, continuous ...series of sediment load data were estimated for several stations located within the Lower Mekong Basin. At Chiang Saen in Thailand, the nearest station to the Chinese dams, the average sediment load was 79 ± 32 Mt./yr during the pre-dam period of 1965–1991. However, from 2010 to 2019 – during which a series of mega-dams were built in China – the sediment load decreased drastically by 84 % to only 12.5 ± 4.6 Mt./yr. This phenomenon of reduced annual sediment load during the mega-dam era (2010–2019) as compared to during the pre-dam era (1965–1991) can be observed at stations downstream from Luang Prabang (−53 %) to Nong Khai (−62 %) to Khong Chiam (−33 %).
One of the drivers of this sediment load crisis is the rapid development of upstream dams. Especially after 2003, Chinese dams have reduced sediment supply to the downstream Mekong Basin severely. Concurrently, there was an increase in sediment contribution from the stretch of the Mekong River from Chiang Saen to Khong Chiam. A positive outcome of this increased sediment contribution was its buffering effect against the reduction in sediment load from the Chinese part of the Mekong Basin. Although sediment load at Kratie – the gateway station before the alluvial stretch comprising the Cambodian floodplains and Vietnam Mekong Delta – decreased from 78 ± 22 Mt./yr (1995–2009) to only 60 ± 21 Mt./yr (2010–2019), the reduction would have been higher without the increased sediment from the Chiang Saen – Khong Chiam stretch. However, with upcoming planned dams in Laos and Cambodia, this buffering effect is likely to be temporary, implying that the sediment load crisis as already experienced by the downstream communities can only become more severe.
•Sediment load declined drastically in the Mekong Basin.•Upstream Chinese dams played a large role in the decline.•Increased sediment contribution from Chiang Saen – Khong Chiam stretch.•Sediment crisis will get much more severe.
Theory and Application of Multiphase Lattice Boltzmann Methods presents a comprehensive review of all popular multiphase Lattice Boltzmann Methods developed thus far and is aimed at researchers and ...practitioners within relevant Earth Science disciplines as well as Petroleum, Chemical, Mechanical and Geological Engineering. Clearly structured throughout, this book will be an invaluable reference on the current state of all popular multiphase Lattice Boltzmann Methods (LBMs). The advantages and disadvantages of each model are presented in an accessible manner to enable the reader to choose the model most suitable for the problems they are interested in. The book is targeted at graduate students and researchers who plan to investigate multiphase flows using LBMs. Throughout the text most of the popular multiphase LBMs are analyzed both theoretically and through numerical simulation. The authors present many of the mathematical derivations of the models in greater detail than is currently found in the existing literature. The approach to understanding and classifying the various models is principally based on simulation compared against analytical and observational results and discovery of undesirable terms in the derived macroscopic equations and sometimes their correction. A repository of FORTRAN codes for multiphase LBM models is also provided.
While 1992 marked the first major dam – Manwan – on the main stem of the Mekong River, the post‐2010 era has seen the construction and operationalisation of mega dams such as Xiaowan (started ...operations in 2010) and Nuozhadu (started operations in 2014) that were much larger than any dams built before. The scale of these projects implies that their operations will likely have significant ecological and hydrological impacts from the Upper Mekong Basin to the Vietnamese Delta and beyond. Historical water level and water discharge data from 1960 to 2020 were analysed to examine the changes to streamflow conditions across three time periods: 1960–1991 (pre‐dam), 1992–2009 (growth) and 2010–2020 (mega‐dam). At Chiang Saen, the nearest station to the China border, monthly water discharge in the mega‐dam period has increased by up to 98% during the dry season and decreased up as much as −35% during the wet season when compared to pre‐dam records. Similarly, monthly water levels also rose by up to +1.16 m during the dry season and dropped by up to −1.55 m during the wet season. This pattern of hydrological alterations is observed further downstream to at least Stung Treng (Cambodia) in our study, showing that Mekong streamflow characteristics have shifted substantially in the post‐2010 era. In light of such changes, the 2019–2020 drought – the most severe one in the recent history in the Lower Mekong Basin – was a consequent of constructed dams reducing the amount of water during the wet season. This reduction of water was exacerbated by the decreased monsoon precipitation in 2019. Concurrently, the untimely operationalisation of the newly opened Xayaburi dam in Laos coincided with the peak of the 2019–2020 drought and could have aggravated the dry conditions downstream. Thus, the mega‐dam era (post‐2010) may signal the start of a new normal of wet‐season droughts.
In humans, Interleukin-8 (IL-8 or CXCL8) is a granulocytic chemokine with multiple roles within the tumor microenvironment (TME), such as recruiting immunosuppressive cells to the tumor, increasing ...tumor angiogenesis, and promoting epithelial-to-mesenchymal transition (EMT). All of these effects of CXCL8 on individual cell types can result in cascading alterations to the TME. The changes in the TME components such as the cancer-associated fibroblasts (CAFs), the immune cells, the extracellular matrix, the blood vessels, or the lymphatic vessels further influence tumor progression and therapeutic resistance. Emerging roles of the microbiome in tumorigenesis or tumor progression revealed the intricate interactions between inflammatory response, dysbiosis, metabolites, CXCL8, immune cells, and the TME. Studies have shown that CXCL8 directly contributes to TME remodeling, cancer plasticity, and the development of resistance to both chemotherapy and immunotherapy. Further, clinical data demonstrate that CXCL8 could be an easily measurable prognostic biomarker in patients receiving immune checkpoint inhibitors. The blockade of the CXCL8-CXCR1/2 axis alone or in combination with other immunotherapy will be a promising strategy to improve antitumor efficacy. Herein, we review recent advances focusing on identifying the mechanisms between TME components and the CXCL8-CXCR1/2 axis for novel immunotherapy strategies.
The prevalence of HIV among men who have sex with men (MSM) has become a significant public health challenge. The aim was to comprehensively estimate the national prevalence of HIV among MSM and its ...time trends through a large-scale systematic analysis.
Systematic search of Cochrane Library, PubMed, EMBASE, CNKI, VIP, and Wanfang Data databases without language restriction for studies on the prevalence of HIV among MSM published before Dec.31, 2018. Studies were eligible for inclusion if they were published in the peer-reviewed literature and used validated assessment methods to assess the prevalence of HIV among MSM. Estimates were pooled using random-effects analysis.
Data were extracted from 355 cross-sectional studies (571,328 individuals) covered 59 cities from 30 provinces and municipalities of China. The overall national prevalence of HIV among MSM from 2001 to 2018 was estimated to be 5.7% (95% CI: 5.4-6.1%), with high between-study heterogeneity (I
= 98.0%, P < 0.001). Our study showed an increased tendency in the HIV prevalence as time progressed by meta-regression analysis (I
= 95.9%, P < 0.0001). HIV prevalence was the highest in those aged 50 years and older with HIV prevalence of 19.3% (95%CI: 13.1-27.4%, N = 13). HIV was more prevalent in the illiterate population (16.8%), than in those who had received an education. Although the internet was a major venue for Chinese MSM seeking male sex partners (35.6, 95%CI: 32.3-39.9%, N = 101), seeking MSM in bathhouses/saunas had the highest associated prevalence of HIV (13.4, 95%CI: 10.3-17.1%, N = 22). The HIV prevalence among MSM varied by location: compared with other regions in China, HIV was highly prevalent among MSM in the southwest (10.7, 95%CI: 9.3-12.2%, N = 91). Compared to participants who sometimes or always used condoms, participants who had never used a condom in the past 6 months had a higher risk of HIV infection, with odds ratios of 0.1 (95%CI: 0.08-0.14).
Our analysis provided reliable estimates of China's HIV burden among MSM, which appears to present an increasing national public health challenge. Effective government responses are needed to address this challenge and include the implementation of HIV prevention.
With the rapid development of tourism and the Internet, the mode of "tourism" + "Internet" has attracted wide attention, among which the importance of tourism network word-of-mouth in the development ...of tourism enterprises has been increasingly recognized, which also prompts the academic circle to study this. Based on this, on the basis of previous online word-of-mouth literature, this paper explores the connotation and characteristics of online word-of-mouth in tourism, and puts forward strategies to improve online word-of-mouth in tourism, so as to promote the sustainable development of tourism enterprise.
Previous research has reported that hypoxic conditions and ethylene treatments greatly trigger programmed cell death (PCD) occurrence and induce the formation of aerenchyma to adapt stress ...environment in Helianthus annuus stem. Caspase 3‐like protease (CLP) as regulatory signals, also be involved in the process of PCD to adapt the low oxygen environment. However, the relationships between ethylene and CLP have seldom been reported. Herein, To understand the regulatory role of ethylene and CLP signaling molecules in aerenchyma formation, we investigated the effects of exogenous ethephon (ET), ethylene perception inhibitor 1‐methylcyclopropene (1‐MCP), and the treatment of 1‐MCP + ET on morphological, physiological characteristics and aerenchyma formation in H. annuus stem. The results showed that lysigenous aerenchyma formation in H. annuus stem is induced by ET, and immunohistochemistry assay indicate CLP activity is raised at the formation stage of aerenchyma formation, and decreased at the expanding phase of aerenchyma formation. Western blotting illustrate the expression of CLP is also increased within 8 h after ethylene signaling inducing aerenchyma formation, and the activities of CLP are higher in ET treated seedlings than the control and 1‐MCP treated seedlings. The same phenomenon was also observed by caspase‐3 activity assay. These results revealed there is a causal and interdependent relationship between ET and CLP signaling during the process of aerenchyma formation, which regulating PCD initiation in H. annuus stem.
The role and relationship between ET and CLP signaling in regulating PCD initiation during the process of aerenchyma formation in H. annu.
Abstract
This paper considers options for a future Indian power economy in which renewables, wind and solar, could meet 80% of anticipated 2040 power demand supplanting the country’s current reliance ...on coal. Using a cost optimization model, here we show that renewables could provide a source of power cheaper or at least competitive with what could be supplied using fossil-based alternatives. The ancillary advantage would be a significant reduction in India’s future power sector related emissions of CO
2
. Using a model in which prices for wind turbines and solar PV systems are assumed to continue their current decreasing trend, we conclude that an investment in renewables at a level consistent with meeting 80% of projected 2040 power demand could result in a reduction of 85% in emissions of CO
2
relative to what might be expected if the power sector were to continue its current coal dominated trajectory.
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