Janus aramid nanofiber aerogel incorporating plasmonic nanoparticles for high-efficiency interfacial solar steam generation

Interfacial solar steam generation (ISSG) is a novel and potential solution to global freshwater crisis. Here, based on a facile sol-gel fabrication process, we demonstrate a highly scalable Janus aramid nanofiber aerogel (JANA) as a high-efficiency ISSG device. JANA performs near-perfect broadband optical absorption, rapid photothermal conversion and effective water transportation. Owning to these features, efficient desalination of salty water and purification of municipal sewage are successfully demonstrated using JANA. In addition, benefiting from the mechanical property and chemical stability of constituent aramid nanofibers, JANA not only possesses outstanding flexibility and fire-resistance properties, but its solar steaming efficiency is also free from the influences of elastic deformations and fire treatments. We envision JANA provides a promising platform for mass-production of high-efficiency ISSG devices with supplementary capabilities of convenient transportation and long-term storage, which could further promote the realistic applications of ISSG technology

Comparative study of the reproductive biology of two congeneric and introduced goby species: implications for management strategies

A full understanding of life history characteristics of invasive species is a fundamental prerequisite for the development of management strategies. Two introduced goby species (Rhinogobius cliffordpopei and Rhinogobius giurinus) have established highly abundant populations in Lake Erhai (China). In the present study, we examined the reproductive biology of these two species with the aim of improving the efficiency of management strategy. The results indicated that R. cliffordpopei spawned from February to June, whereas R. giurinus spawned from April to August. Rhinogobius cliffordpopei showed higher gonado-somatic indices and had larger eggs than R. giurinus. The adult sex ratio of R. cliffordpopei was female skewed, but that of R. giurinus was equal. Rhinogobius cliffordpopei showed a male-skewed sexual size dimorphism, whereas the body size of R. giurinus varied only slightly between males and females. The different reproductive traits appear as a crucial biologic aspect for developing control programs. Specifically, control measures should be implemented and/or intensified from September to February for R. cliffordpopei and from January to April for R. giurinus. The body size of the smaller R. cliffordpopei females is the determinant for minimal mesh size of the nets used in physical removals of R. cliffordpopei.A full understanding of life history characteristics of invasive species is a fundamental prerequisite for the development of management strategies. Two introduced goby species (Rhinogobius cliffordpopei and Rhinogobius giurinus) have established highly abundant populations in Lake Erhai (China). In the present study, we examined the reproductive biology of these two species with the aim of improving the efficiency of management strategy. The results indicated that R. cliffordpopei spawned from February to June, whereas R. giurinus spawned from April to August. Rhinogobius cliffordpopei showed higher gonado-somatic indices and had larger eggs than R. giurinus. The adult sex ratio of R. cliffordpopei was female skewed, but that of R. giurinus was equal. Rhinogobius cliffordpopei showed a male-skewed sexual size dimorphism, whereas the body size of R. giurinus varied only slightly between males and females. The different reproductive traits appear as a crucial biologic aspect for developing control programs. Specifically, control measures should be implemented and/or intensified from September to February for R. cliffordpopei and from January to April for R. giurinus. The body size of the smaller R. cliffordpopei females is the determinant for minimal mesh size of the nets used in physical removals of R. cliffordpopei

Habitat segregation between two congeneric and introduced goby species

Spatial segregation is one of the most important mechanisms that facilitates coexistence among competing species. Large populations of two introduced and congeneric goby species (Rhinogobius giurinus and Rhinogobius cliffordpopei) now co-occur in Lake Erhai, a plateau lake in the Yunnan-Guizhou Plateau (China). Herein we quantified the spatio-temporal distribution of the two species to determine whether spatial segregation occurred within the same ecosystem. A total of 67,819 individuals of R. giurinus and 36,043 of R. cliffordpopei were sampled across four seasons. The results indicated that R. giurinus mostly occupied profundal habitat (PH) while R. cliffordpopei mainly used littoral habitat (LH). Correlation analysis revealed the abundance of R. giurinus was positively associated with deep water, silt and coarse sand substrata, whereas the distribution of R. cliffordpopei was positively associated with high densities of macrozooplanktons and high abundances of other fish species, high concentration of dissolved oxygen and high densities of submerged macrophytes. Except in spring, the body condition of R. giurinus was significantly higher in the PH than in the LH. The body condition of R. cliffordpopei did not differ significantly between habitats in the four seasons. These findings demonstrate that the two congeneric and introduced goby species occupy distinct habitats, indicating that spatial segregation enables coexistence of the two invasive species at high abundances within an ecosystem.Spatial segregation is one of the most important mechanisms that facilitates coexistence among competing species. Large populations of two introduced and congeneric goby species (Rhinogobius giurinus and Rhinogobius cliffordpopei) now co-occur in Lake Erhai, a plateau lake in the Yunnan-Guizhou Plateau (China). Herein we quantified the spatio-temporal distribution of the two species to determine whether spatial segregation occurred within the same ecosystem. A total of 67,819 individuals of R. giurinus and 36,043 of R. cliffordpopei were sampled across four seasons. The results indicated that R. giurinus mostly occupied profundal habitat (PH) while R. cliffordpopei mainly used littoral habitat (LH). Correlation analysis revealed the abundance of R. giurinus was positively associated with deep water, silt and coarse sand substrata, whereas the distribution of R. cliffordpopei was positively associated with high densities of macrozooplanktons and high abundances of other fish species, high concentration of dissolved oxygen and high densities of submerged macrophytes. Except in spring, the body condition of R. giurinus was significantly higher in the PH than in the LH. The body condition of R. cliffordpopei did not differ significantly between habitats in the four seasons. These findings demonstrate that the two congeneric and introduced goby species occupy distinct habitats, indicating that spatial segregation enables coexistence of the two invasive species at high abundances within an ecosystem

Status and historical changes in the fish community in Erhai Lake

Erhai Lake is the second largest freshwater lake on the Yunnan Plateau, Southwest China. In recent decades, a number of exotic fish species have been introduced into the lake and the fish community has changed considerably. We evaluated the status of the fish community based on surveys with multimesh gillnet, trap net, and benthic fyke-net between May 2009 and April 2012. In addition, we evaluated the change in the community using historical data (1952-2010) describing the fish community and fishery harvest. The current fish community is dominated by small-sized fishes, including Pseudorasbora parva, Rhinogobius giurinus, Micropercops swinhonis, Hemiculter leucisculus, and Rhinogobius cliffordpopei. These accounted for 87.7% of the 22 546 total specimens collected. Omnivorous and carnivorous species dominated the community. A canonical correspondence analysis (CCA) plot revealed that the distribution of fishes in the lake is influenced by aquatic plants, water temperature, pH, and season. The abundance of indigenous species has declined sharply, and a majority of endemic species have been extirpated from the lake (a decrease from seven to two species). In contrast, the number of exotic species has increased since the 1960s to a total of 22 at present. The fishery harvest decreased initially following the 1960s, but has since increased due to the introduction of non-native fish and stocking of native fish. The fishery harvest was significantly correlated with total nitrogen, not total phosphorus, during the past 20 years. Based on our results, we discuss recommendations for the restoration and conservation of the fish resources in Erhai Lake.Erhai Lake is the second largest freshwater lake on the Yunnan Plateau, Southwest China. In recent decades, a number of exotic fish species have been introduced into the lake and the fish community has changed considerably. We evaluated the status of the fish community based on surveys with multimesh gillnet, trap net, and benthic fyke-net between May 2009 and April 2012. In addition, we evaluated the change in the community using historical data (1952-2010) describing the fish community and fishery harvest. The current fish community is dominated by small-sized fishes, including Pseudorasbora parva, Rhinogobius giurinus, Micropercops swinhonis, Hemiculter leucisculus, and Rhinogobius cliffordpopei. These accounted for 87.7% of the 22 546 total specimens collected. Omnivorous and carnivorous species dominated the community. A canonical correspondence analysis (CCA) plot revealed that the distribution of fishes in the lake is influenced by aquatic plants, water temperature, pH, and season. The abundance of indigenous species has declined sharply, and a majority of endemic species have been extirpated from the lake (a decrease from seven to two species). In contrast, the number of exotic species has increased since the 1960s to a total of 22 at present. The fishery harvest decreased initially following the 1960s, but has since increased due to the introduction of non-native fish and stocking of native fish. The fishery harvest was significantly correlated with total nitrogen, not total phosphorus, during the past 20 years. Based on our results, we discuss recommendations for the restoration and conservation of the fish resources in Erhai Lake

Effects of Predation Stress on the Physiological Responses of Juvenile Four Major Chinese Carps

As low-level aquatic vertebrates, fish are highly dependent on the water environment, and general activities such as growth, foraging, and reproduction are easily affected by changes in the external environment. Changes in environmental factors can lead to different degrees of stress response in fish, and trigger a series of physiological changes, which then affect the stability of the organism's internal environment. Predation is one of the main environmental factors affecting the survival of individuals. In nature, almost all species face the risk of predation. Brief encounters with predators can reduce feeding and other health-related activities in prey fish and/or trigger primary and secondary stress responses, including the release of stress substances into the bloodstream. In predation stress, after initially sensing stress, fish initiate a stress response to overcome the stress and restore homeostasis. The degree of physiological stress depends primarily on the intensity and duration of the stress. If the appearance of predators is intermittent, then the physiological state of the prey fish returns to normal quickly, which allows the stress response to promote physiological changes in the prey fish to better adapt to the environment. However, repeated or persistent and unavoidable stress situations cause the normal physiological response mechanisms of prey fish to become compromised. Physiological stress may have long-term negative effects on the immune system, growth, or reproduction, and may reduce the adaptability and survivability of prey fish in the environment. Many studies have confirmed that predation stress can cause physiological stress in fish. Different species of fish and even different groups of the same species vary greatly in the degree of stress and stress mode. More species-specific studies are required to determine the effects of different levels of predation stress on physiological stress in fish.Black carp (Mylopharyngodon piceus), grass carp (Ctenopharyngodon idellus), silver carp (Hypophthalmichthys molitrix), and bighead carp (Aristichthys nobilis) are known as the four major Chinese carps. As common fish species in Chinese inland watersheds, the four major Chinese carps are ecologically and economically valuable. Over the years, many reasons such as hydraulic construction, environmental pollution, and overfishing have led to sharp declines in wild populations. In addition, the prevalence of predators in natural waters also threaten population growth. It remains unclear how the juveniles of the four major Chinese carps adjust their physiological processes to cope with predation stress. We investigate the physiological and energy metabolism adaptations by black carp, grass carp, silver carp, and bighead carp to predatory stress. We selected the common local enemies of natural waters, the snakehead carp (Channa argus) and the southern catfish (Silurus meridionalis) as predators. The levels of serum cortisol and biochemical parameters in the juveniles of the four major Chinese carps under the stress of no-predation (control), low-predation (indirect stress) and high-predation (direct stress) over 0 d, 7 d, and 14 d were investigated. Changes in the biochemical parameters were analyzed. The effects of different predation stress levels on serum cortisol and biochemical parameters were also analyzed. The results showed: (1) under different levels of predation stress, the biochemical parameters and serum cortisol levels of juveniles of the four major Chinese carps varied to different degrees but the trends were consistent; (2) the serum cortisol levels of juveniles of the four major Chinese carps increased significantly with the degree of predation stress and the stress duration, and showed the following patterns: non-predation group < low predation group < high predation group, 0 d < 7 d < 14 d. (3) Among the biochemical parameters, serum total protein concentration and cholesterol concentration were relatively stable and did not vary significantly. Glucose concentration and alkaline phosphatase increased with predation stress, while triglyceride had a decreasing trend. The results showed that juveniles of the four major Chinese carps adjust their physiological responses to enhance their own survivability according to the predation risk. After the predation stress treatment, the juveniles of the four major Chinese carps all underwent a stress response. Compared with indirect predation, direct predation had a more significant effect on the physiological response of fish, and the degree of stress increased with the stress duration. Among the detection parameters, serum total protein and cholesterol may not be sensitive parameters for stress in fish under predation stress. The most significant changes were in cortisol and glucose and may compensate for the increased energy demand by the organism during stress. The adaptation of physiological stress and energy metabolism to predation stress in juveniles of the four major Chinese carps under predation stress conditions provides a theoretical basis for the stress responses of an organism to environmental changes, and can also provide a scientific reference for exploring the ecological interactions between predator and prey

Comparative Analysis of Metabolites between Different Altitude <i>Schizothorax nukiangensis</i> (Cyprinidae, Schizothoracine) on the Qinghai-Tibet Plateau in Nujiang River

In order to investigate the influence of the high-altitude aquatic environment on indigenous fish metabolites, metabolomics studies were applied in this study. Widespread throughout the main stem of the Nujiang River of Schizothorax nukiangensis, we established sampling sites at high (3890 m) and low (2100 m) altitudes and selected six S. nukiangensis at each location, each weighing approximately 150 g and looking healthy. Then, metabolomics analysis was performed to compare the various metabolites of the two groups. Low concentrations of amino acids, dipeptides, eicosapentaenoic acid, docosahexaenoic acid, pentadecanoic acid, Thioetheramide-PC, 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine, 1-Stearoyl-sn-glycerol-3-phosphocholine, 1-Myristoyl-sn-glycero-3-phosphocholine and 1-Palmitoyl-sn-glycero-3-phosphocholine, high concentrations in S-Methyl-5’-thioadenosine, creatine, D-mannose-6-phosphate, D-mannose-1-phosphate, oleic acid and myristoleic acid were found in high-altitude fish liver. These differentially accumulated metabolites were involved in oxidative stress, energy metabolism, carbohydrate metabolism and lipid metabolism. mTOR signaling pathway, apoptosis and lysosome were the KEGG pathways that were enriched between different groups to ensure energy supply and limit tissue damage of fish at high altitudes. All these results contributed to the understanding of the high-altitude adaptation of S. nukiangensis in the Nujiang River. Nicotine and methoprene, two organic pollutants, performed differently in fish at different altitudes. Overall, our findings advanced the fundamental understanding of fish responses to high-altitude environments, adaptive mechanisms and organic contaminants pollution in the Nujiang River

Age, growth and population dynamics of two congeneric and invasive gobies, Rhinogobius giurinus and R. cliffordpopei (Actinopterygii, Gobiidae) in a plateau lake, southwestern China

Although many goby species have become widely established outside of their native ranges, little is known yet about invasive population biology. The age, growth and population dynamics of two introduced goby species (Rhinogobius giurinus and Rhinogobius cliffordpopei) were quantified in Lake Erhai (southwest China) with the general aim to improve empirical knowledge and management strategies. The results revealed that their lifespan ranges 2 years. The size and time at sexual maturity for R. cliffordpopei was lower than for R. giurinus. R. cliffordpopei displayed higher total mortality, fishing mortality and exploitation rates than R. giurinus, whereas the natural mortality of R. cliffordpopei was lower than that of R. giurinus. The catch per unit effort of benthic fyke nets was low from April to June in R. cliffordpopei and from July to September in R. giurinus, whereas it was high from July to September in R. cliffordpopei and from April to June in R. giurinus. Thus, several specific strategies are suggested to improve the cost-efficiency of the current management practices related to the mesh size of benthic fyke nets used for physical removals, the timing of deployment of control actions and the use of synergic control methods

Healthy regulation of Tibetan Brassica rapa L. polysaccharides on alleviating hyperlipidemia: A rodent study

Hyperlipidemia is a common metabolic disorder, which can lead to obesity, hypertension, diabetes, atherosclerosis and other diseases. Studies have shown that polysaccharides absorbed by the intestinal tract can regulate blood lipids and facilitate the growth of intestinal flora. This article aims to investigate whether Tibetan turnip polysaccharide (TTP) plays a protective role in blood lipid and intestinal health via hepatic and intestinal axes. Here we show that TTP helps to reduce the size of adipocytes and the accumulation of liver fat, playing a dose-dependent effect on ADPN levels, suggesting an effect on lipid metabolism regulation. Meantime, TTP intervention results in the downregulation of intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and serum inflammatory factors (interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α)), implying that TTP suppresses the progression of inflammation in the body. The expression of key enzymes associated with cholesterol and triglyceride synthesis, such as 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), cholesterol 7α-hydroxylase (CYP7A1), peroxisome proliferator-activated receptors γ (PPARγ), acetyl-CoA carboxylase (ACC), fatty acid synthetase (FAS) and sterol-regulatory element binding proteins-1c (SREBP-1c), can be modulated by TTP. Furthermore, TTP also alleviates the damage to intestinal tissues caused by high-fat diet, restores the integrity of the intestinal barrier, improves the composition and abundance of the intestinal flora and increases the levels of SCFAs. This study provides a theoretical basis for the regulation of body rhythm by functional foods and potential intervention in patients with hyperlipidemia

Status and historical changes in the fish community in Erhai Lake

Erhai Lake is the second largest freshwater lake on the Yunnan Plateau, Southwest China. In recent decades, a number of exotic fish species have been introduced into the lake and the fish community has changed considerably. We evaluated the status of the fish community based on surveys with multimesh gillnet, trap net, and benthic fyke-net between May 2009 and April 2012. In addition, we evaluated the change in the community using historical data (1952-2010) describing the fish community and fishery harvest. The current fish community is dominated by small-sized fishes, including Pseudorasbora parva, Rhinogobius giurinus, Micropercops swinhonis, Hemiculter leucisculus, and Rhinogobius cliffordpopei. These accounted for 87.7% of the 22 546 total specimens collected. Omnivorous and carnivorous species dominated the community. A canonical correspondence analysis (CCA) plot revealed that the distribution of fishes in the lake is influenced by aquatic plants, water temperature, pH, and season. The abundance of indigenous species has declined sharply, and a majority of endemic species have been extirpated from the lake (a decrease from seven to two species). In contrast, the number of exotic species has increased since the 1960s to a total of 22 at present. The fishery harvest decreased initially following the 1960s, but has since increased due to the introduction of non-native fish and stocking of native fish. The fishery harvest was significantly correlated with total nitrogen, not total phosphorus, during the past 20 years. Based on our results, we discuss recommendations for the restoration and conservation of the fish resources in Erhai Lake