Quantitative assessment methodology framework of the impact of global climate change on the aquatic habitat of warm-water fish species in rivers.

Global climate change (GCC), with global warming as the main characteristic, has become a global issue widely concerned by people. GCC impacts the hydrological regime at the watershed scale and affects the hydrodynamic force and the habitat conditions of freshwater ecosystems at the river scale. The impact of GCC on water resources and the water cycle is a research hotspot. However, there are few studies on water environment ecology related to hydrology and the influence of changes in discharge and water temperature on warm-water fish habitats. This study proposes a quantitative assessment methodology framework for predicting and analyzing the impact of GCC on the warm-water fish habitat. This system integrates GCC, downscaling, hydrological, hydrodynamic, water temperature and habitat models and was applied to the middle and lower reaches of the Hanjiang River (MLHR), where there are four major Chinese carps resource reduction problems. The results showed that the calibration and validation of the statistical downscaling model (SDSM) and the hydrological, hydrodynamic, and water temperature models were carried out using the observed meteorological factors, discharge, water level, flow velocity and water temperature data. The change rule of the simulated value was in good agreement with the observed value, and the models and methods used in the quantitative assessment methodology framework were applicable and accurate. The rise of water temperature caused by GCC will ease the problem of low-temperature water in the MLHR, and the weighted usable area (WUA) for spawning of the four major Chinese carps will appear in advance. Meanwhile, the increase in future annual discharge will play a positive role in WUA. In general, the rise in confluence discharge and water temperature caused by GCC will increase WUA, which is beneficial to the spawning ground of four major Chinese carps.

Determining the position of a fish passage facility entrance based on endemic fish swimming abilities and flow field.

Hydropower development can significantly mitigate climate change and reduce carbon emissions, but it can also have substantial negative impacts on river environments and fish biodiversity. Fish passage facilities are built to ensure sustainable hydropower development and the biodiversity of fish populations. The locations of the entrances to these facilities play a key role in their efficiency. This study presents a reliable approach that combines the swimming ability of fish and a numerical flow field simulation to determine the optimal location for a fish passage facility entrance. In this study, we used the Gujun Reservoir upstream of the Yangtze River as a case study. A field experiment was conducted, and the swimming abilities of eight endemic fish species in the upstream region of the Yangtze River were measured. Among the tested species, the fastest induced swimming speed (0.14 m/s) was achieved by Glyptothorax sinense, while the slowest critical swimming speed (0.30 m/s) was observed for Paracobitis potanini. We propose that the velocity near the fish passage facility entrance should be higher than the maximum induced swimming speed and lower than the minimum critical swimming speed, making the suitable range between 0.14 and 0.30 m/s. On this basis, velocity fields 500 m downstream of the dam of the Gujun Reservoir under 4 operating conditions with discharge flows of 5.7 m3/s, 23.3 m3/s, 32.5 m3/s, and 41.1 m3/s were calculated. The results showed that the flow field variation downstream of the dam was between 0.1 and 0.9 m/s. After comparing the suitable areas for the target species, the left bank at location 2 was recommended as the optimal location for the fish passage facility entrance in the Gujun Reservoir.

The emerging roles of next-generation metabolomics in critical care nutrition.

Critical illness leads to millions of deaths worldwide each year, with a significant surge due to the COVID-19 pandemic. Patients with critical illness are frequently associated with systemic metabolic disorders and malnutrition. The idea of intervention for critically ill patients through enteral and parenteral nutrition has been paid more and more attention gradually. However, current nutritional therapies focus on evidence-based practice, and there have been lacking holistic approaches for nutritional support assessment. Metabolomics is a well-established omics technique in system biology that enables comprehensive profiling of metabolites in a biological system and thus provides the underlying information expressed and modulated by all other omics layers. In recent years, with the development of high-resolution and accurate mass spectrometry, metabolomics entered a new "generation", promoting its broader applications in critical care nutrition. In this review, we first described the technological development and milestones of next-generation metabolomics in the past 20 years. We then discussed the emerging roles of next-generation metabolomics in advancing our understanding of critical care nutrition, such as nutritional deficiency risk evaluation, metabolic mechanisms of nutritional therapies, and novel nutrition target identification.

River habitat assessment and restoration in high dam flood discharge systems with total dissolved gas supersaturation.

The success of river habitat restoration relies on accurate assessment proxies. However, determining how to quantitatively assess the impact of multiple stressors during flood discharge from high dams in riverine ecosystems and where and how to implement more reliable recovery interventions remain challenges. Here, we developed a bottom-up mechanistic framework for assessing the effects of total dissolved gas supersaturation (TDGS) and hydrodynamics on fish habitat quality and applied it to the downstream river reach of the Xiangjiaba Dam in Southwest China. The results showed that the available habitat area of river sturgeon was the smallest, while Chinese sucker had the largest available habitat area among the three target species under all discharge scenarios. Although the TDGS levels were evenly mixed laterally, the habitat suitability index indicated that the suitable habitats were primarily within both sides of the river reach under all scenarios, which is contrary to findings based on the traditional TDGS risk assessment model. The traditional TDGS risk assessment model overestimates the impact of dams on habitats. This divergence reflected the sensitivity of the habitat assessment to fish habitat preferences, fish tolerance to TDGS and the biological response of fish under TDGS. Additionally, the priority areas for restoration can be identified by habitat suitability index with lower values. We simulated twenty-four schemes and found that interventions such as stone groups, ecological spur dike, water-retaining weir and river dredging can enhance habitat suitability for fish species under multiple stressors, providing novel insights into where and how to mitigate the impact of TDGS. Our findings offer a transferable framework for the quantitative evaluation of fish habitat and implementation of restoration management during dam flood discharge periods, thus providing a new perspective for biodiversity conservation and habitat restoration in dam-regulated rivers with TDGS around the world.

Influence of socioeconomic development on river water quality: a case study of two river basins in China.

Social and economic development processes require large amounts of natural resources and in some cases seriously deteriorate river water quality. Since the reform and expansion era began, China has vigorously pursued socioeconomic development but neglected environmental protection. However, in recent years, improvements in environmental awareness and the implementation of environmental protection measures have led to a balanced relationship between economic development and the environment. In this study, the Yangtze River Basin and the Yellow River Basin were selected as research areas. We used a combination of canonical correlation analysis (CCA) and a distance-based influence assessment method to quantitatively assess the influence of socioeconomic development on river water quality. The results revealed a strong correlation between socioeconomic development and river water quality. The degree of influence of socioeconomic development on water quality varied not only temporally but also spatially due to differences in socioeconomic development and hydrometeorology in the two basins in North and South China. The average degree of influence in the Yangtze River Basin was between 0.22 and 0.27, and that in the Yellow River Basin was between 0.2 and 0.36. Moreover, the degree of influence in the Yangtze River Basin in the wet season was greater than that in the dry season, whereas the opposite pattern was observed in the Yellow River Basin. The degree of influence in both basins gradually declined after 2011, indicating that the coupling and coordination between socioeconomic development and environmental protection have continuously improved and that the water quality has gradually improved. By analysing the influences of various socioeconomic indicators on water quality, we found that the main factors that influence water quality are per capita GDP and urbanization rate in the Yangtze River Basin and urbanization rate in the Yellow River Basin. The results provide a basis for future sustainable development in the Yangtze River Basin and the Yellow River Basin.

Linking bait and feeding opportunities to fish foraging habitat for the assessment of environmental flows and river restoration.

The survival of aquatic biota in different life history stages depends on food availability, water quantity and specific hydrological conditions, and is particularly susceptible in degraded rivers due to the development of hydropower or are sensitive to climate change. Habitats with limited food availability and restricted feeding opportunities can strongly affect the habitat carrying capacity and fish growth with consequences for spawning. Few environmental flow regime frameworks are available that closely link bait and feeding opportunities to fish foraging habitat. In addition, river restoration has been widely implemented to resolve the conflict between ecological demand and power generation benefits. Nevertheless, whether in-stream structures are still suitable for the joint operation of foraging and spawning habitats remains unclear. In this study, a framework to integrate the requirements of both spawning and foraging habitats into environmental flow regime assessments was proposed by coupling the bait supply, fish spawning and fish feeding opportunities. Here, we used the Batang Reservoir, located in the Tibetan Plateau, as an example to determine the environmental flow regimes. The environmental flow regimes during Periods I, II and III for the conservation of the life history stages of Schizothorax dolichonem were determined, which provided high-quality food and was beneficial for increasing the probability of restoration success. After the implementation of measures, the ecological base flow rate decreased from 171.80 m3/s, 206.00 m3/s and 257.70 m3/s to 138.00 m3/s, 206.00 m3/s and 206.00 m3/s in Periods I, II and III, respectively. We concluded that traditional river restoration with the use of in-stream structures is still suitable for the joint operation of spawning and foraging habitats, but the design selection and placement of in-stream structures should be preoptimized. The framework proposed will help managers evaluate habitat conservation to protect degraded rivers or help develop strategies to build resilience to climate change.

Assessment of Phytochemicals and Herbal Formula for the Treatment of Depression through Metabolomics.

Depression is a widespread and persistent psychiatric disease. Due to various side effects and no curative treatments of conventional antidepressant drugs, botanical medicines have attracted considerable attention as a complementary and alternative approach. The pathogenesis of depression is quite complicated and unclear. Metabolomics is a promising new technique for the discovery of novel biomarkers for exploring the potential mechanisms of diverse diseases and assessing the therapeutic effects of drugs. In this article, we systematically reviewed the study of botanical medicine for the treatment of depression using metabolomics over a period from 2010 to 2019. Additionally, we summarized the potential biomarkers and metabolic pathways associated with herbal medicine treatment for depression. Through a comprehensive evaluation of herbal medicine as novel antidepressants and understanding of their pharmacomechanisms, a new perspective on expanding the application of botanical medicines for the treatment of depression is provided.

Experimental investigations on the dissipation process of supersaturated total dissolved gas: Focus on the adsorption effect of solid walls.

Hydropower, which utilizes energy from fast-moving water, can help alleviate the energy crisis and promote economic development. For safety and ecological purposes, dams must discharge periodically. This discharge process, which occurs with the supersaturation of total dissolved gas (TDG), affects the fish and other aquatic organisms living in downstream river areas. Previous studies have shown that the supersaturated TDG dissipation process is closely related to hydraulic properties such as the flow rate, water depth and turbulent kinetic energy. Additionally, the presence of solid walls such as vegetation leaves in water can adsorb dissolved gases in water, thereby promoting the supersaturated TDG dissipation process, and the adsorption effect is closely related to the solid wall material. However, systematic studies on how solid walls in water can quickly absorb dissolved gases from water and rapidly reduce the TDG saturation of water are lacking. Herein, a series of experiments was conducted to study the dissipation process of supersaturated TDG under the action of solid walls in water and to reveal the adsorption effect of solid wall surface properties on dissolved gas. The results showed that the surface roughness and hydrophobicity (contact angle) are the key factors related to the adsorption effect of solid walls on the TDG in water. Generally, the dissipation rate of supersaturated TDG first increased and then decreased with increasing surface roughness. The supersaturated TDG dissipation rate increased monotonically with increasing contact angle. Based on the experimental data, the adsorption coefficient, which represents the adsorption effect of the solid wall for dissolved gas in water, was proposed, and a prediction formula between the adsorption coefficient and the contact angle of the solid wall was established. These results can provide theoretical support for the utilization of the solid wall adsorption effect to mitigate the adverse effects of supersaturated TDG and protect fish.

An Approach Based on the Protected Object for Dam-Break Flood Risk Management Exemplified at the Zipingpu Reservoir.

Dam-break flooding is a potential hazard for reservoirs that poses a considerable threat to human lives and property in downstream areas. Assessing the dam-break flood risk of the Zipingpu Reservoir in Chengdu, Sichuan Province, China, is critically important because this reservoir is located on the Longmen Shan fault, which experiences high seismic activity. In this paper, we develop an approach based on the protected object for dam-break flood risk management. First, we perform a numerical simulation of dam-break flooding in four possible dam break scenarios. Next, the flood areas are divided into 71 analysis units based on the administrative division. Based on the numerical simulation results and the socio-economic demographic data affected by a flood, the importance and risk level of each analysis unit is confirmed, and the flood risk map is established according to the classification results. Finally, multi-level flood risk management countermeasures are proposed according to the results of the unit classification shown in the map.

Individual differences in pain sensitivity predict the experience of unfairness.

Pain has shaped our evolutionary history, and pain-free experiences are critical for our health. There are, however, enormous individual differences in pain sensitivity, and the psychological consequences of this heterogeneity are only poorly understood. Here, we investigated whether individual differences in pain sensitivity predicted the experience of unfairness. We found that the magnitude of pain sensitivity correlated with the extent to which participants experienced unfairness. This association was due to the shared human alarm system of unfairness and pain sensitivity. This finding may elucidate mechanisms for producing a new and positive cycle of a healthy experience between fairness and feeling pain-free.

Assessment of hemodynamics in a rat model of liver cirrhosis with precancerous lesions using multislice spiral CT perfusion imaging.

RATIONALE AND OBJECTIVES: To develop an optimal scanning protocol for multislice spiral CT perfusion (CTP) imaging to evaluate hemodynamic changes in liver cirrhosis with diethylnitrosamine- (DEN-) induced precancerous lesions. MATERIALS AND METHODS: Male Wistar rats were randomly divided into the control group (n = 80) and the precancerous liver cirrhosis group (n = 40). The control group received saline injection and the liver cirrhosis group received 50 mg/kg DEN i.p. twice a week for 12 weeks. All animals underwent plain CT scanning, CTP, and contrast-enhanced CT scanning. Scanning parameters were optimized by adjusting the diatrizoate concentration, the flow rate, and the delivery time. The hemodynamics of both groups was further compared using optimized multislice spiral CTP imaging. RESULTS: High-quality CTP images were obtained with following parameters: 150 kV; 150 mAs; 5 mm thickness, 5 mm interval; pitch, 1; matrix, 512 × 512; and FOV, 9.6 cm. Compared to the control group, the liver cirrhosis group had a significantly increased value of the hepatic arterial fraction and the hepatic artery perfusion (P < 0.05) but significantly decreased hepatic portal perfusion and mean transit time (P < 0.05). CONCLUSION: Multislice spiral CTP imaging can be used to evaluate the hemodynamic changes in the rat model of liver cirrhosis with precancerous lesions.

Assessment of myocardial bridge and mural coronary artery using ECG-gated 256-slice CT angiography: a retrospective study.

Recent clinical reports have indicated that myocardial bridge and mural coronary artery complex (MB-MCA) might cause major adverse cardiac events. 256-slice CT angiography (256-slice CTA) is a newly developed CT system with faster scanning and lower radiation dose compared with other CT systems. The objective of this study is to evaluate the morphological features of MB-MCA and determine its changes from diastole to systole phase using 256-slice CTA. The imaging data of 2462 patients were collected retrospectively. Two independent radiologists reviewed the collected images and the diagnosis of MB-MCA was confirmed when consistency was obtained. The length, diameter, and thickness of MB-MCA in diastole and systole phases were recorded, and changes of MB-MCA were calculated. Our results showed that among the 2462 patients examined, 336 have one or multiple MB-MCA (13.6%). Out of 389 MB-MCA segments, 235 sites were located in LAD2 (60.41%). The average diameter change of MCA in LAD2 from systole phase to diastole phase was 1.1 ± 0.4 mm, and 34.9% of MCA have more than 50% diameter stenosis in systole phase. This study suggested that 256-slice CTA multiple-phase reconstruction technique is a reliable method to determine the changes of MB-MCA from diastole to systole phase.

Mutational, proteomic and metabolomic analysis of a plant growth promoting copper-resistant Pseudomonas spp.

Pseudomonas sp. TLC6-6.5-4 is a multiple metal resistant plant growth-promoting bacteria isolated from copper-contaminated lake sediments. In this study, a comprehensive analysis of genes involved in copper resistance was performed by generating a library of transposon (Tn5) mutants. Two copper-sensitive mutants with significant reduction in copper resistance were identified: CSM1, a mutant disrupted in trpA gene (tryptophan synthase alpha subunit), and CSM2, a mutant disrupted in clpA gene (ATP-dependent Clp protease). Proteomic and metabolomic analyses were performed to identify biochemical and molecular mechanisms involved in copper resistance using CSM2 due to its lower minimum inhibitory concentration compared with CSM1 and the wild type. Proteomic analysis revealed that disruption of Clp protease gene up-regulated molecular chaperones and down-regulated the expression of enzymes related to tRNA modification, whereas metabolomic analysis showed that amino acid and oligosaccharide transporters that are part of ATP-binding cassette (ABC) transporters pathways were down-regulated. Further, copper stress altered metabolic pathways including the tricarboxylic acid cycle, protein absorption and glyoxylate metabolism.