Long-Term Variations in Chlorophyll a

Based on long-term data of measurements of nutrient and chlorophyll a concentrations as well as estimates of primary production, the response of phytoplankton to nutrient enrichment was evaluated in the highly urbanized Jiaozhou Bay. Results showed that phytoplankton biomass, as indicated by chlorophyll a concentration, did not show a direct linear response to increased nutrient concentrations. Instead, chlorophyll a concentration was maintained at a constant level in the last two decades in Jiaozhou Bay, so did primary productivity. However, a reduction of zooplankton biomass was observed during the same period. Analysis showed that although the scale of phytoplankton blooms might be limited by availability of silicate due to low Si/N ratio and low concentration, top-down control on phytoplankton biomass by bivalve grazing may be an important factor in Jiaozhou Bay ecosystem

The world's largest macroalgal bloom in the Yellow Sea, China: Formation and implications

The world's largest trans-regional macroalgal blooms during 2008-2012 occurred in the Yellow Sea, China. This review addresses the causes, development and future challenges in this unique case. Satellite imagery and field observations showed that the macroalgal blooms in the Yellow Sea originated from the coast of Jiangsu province and that favorable geographic and oceanographic conditions brought the green macroalgae from the coast offshore. Optimal temperature, light, nutrients and wind contributed to the formation and transport of the massive bloom north into the Yellow Sea and its deposition onshore along the coast of Shandong province. Morphological and genetic evidence demonstrated that the species involved was Ulva prolifera, a fouling green commonly found growing on structures provided by facilities of Porphyra aquaculture. Large scale Porphyra aquaculture (covering >20,000 ha) along the Jiangsu coast thus hypothetically provided a nursery bed for the original biomass of U. prolifera. Porphyra growers remove U. prolifera from the mariculture rafts, and the cleaning releases about 5000 wet weight tonnes of green algae into the water column along the coast of Jiangsu province; the biomass then is dispersed by hydrographic forcing, and takes advantage of rather high nutrient supply and suitable temperatures to grow to impressive levels. Certain biological traits of U. prolifera -efficient photosynthesis, rapid growth rates, high capacity for nutrient uptake, and diverse reproductive systems- allowed growth of the original 5000 tonnes of U. prolifera biomass into more than one million tonnes of biomass in just two months. The proliferation of U. prolifera in the Yellow Sea resulted from a complex contingency of circumstances, including human activity (eutrophication by release of nutrients from wastewater, agriculture, and aquaculture), natural geographic and hydrodynamic conditions (current, wind) and the key organism's biological attributes. Better understanding of the complex biological-chemical-physical interactions in coastal ecosystems and the development of an effective integrated coastal zone management with consideration of scientific, social and political implications are critical to solving the conflicts between human activity and nature. (c) 2013 Elsevier Ltd. All rights reserved.The world's largest trans-regional macroalgal blooms during 2008-2012 occurred in the Yellow Sea, China. This review addresses the causes, development and future challenges in this unique case. Satellite imagery and field observations showed that the macroalgal blooms in the Yellow Sea originated from the coast of Jiangsu province and that favorable geographic and oceanographic conditions brought the green macroalgae from the coast offshore. Optimal temperature, light, nutrients and wind contributed to the formation and transport of the massive bloom north into the Yellow Sea and its deposition onshore along the coast of Shandong province. Morphological and genetic evidence demonstrated that the species involved was Ulva prolifera, a fouling green commonly found growing on structures provided by facilities of Porphyra aquaculture. Large scale Porphyra aquaculture (covering >20,000 ha) along the Jiangsu coast thus hypothetically provided a nursery bed for the original biomass of U. prolifera. Porphyra growers remove U. prolifera from the mariculture rafts, and the cleaning releases about 5000 wet weight tonnes of green algae into the water column along the coast of Jiangsu province; the biomass then is dispersed by hydrographic forcing, and takes advantage of rather high nutrient supply and suitable temperatures to grow to impressive levels. Certain biological traits of U. prolifera -efficient photosynthesis, rapid growth rates, high capacity for nutrient uptake, and diverse reproductive systems- allowed growth of the original 5000 tonnes of U. prolifera biomass into more than one million tonnes of biomass in just two months. The proliferation of U. prolifera in the Yellow Sea resulted from a complex contingency of circumstances, including human activity (eutrophication by release of nutrients from wastewater, agriculture, and aquaculture), natural geographic and hydrodynamic conditions (current, wind) and the key organism's biological attributes. Better understanding of the complex biological-chemical-physical interactions in coastal ecosystems and the development of an effective integrated coastal zone management with consideration of scientific, social and political implications are critical to solving the conflicts between human activity and nature. (c) 2013 Elsevier Ltd. All rights reserved

Vertical heterogeneity of hydrocarbon-degrading bacteria in a core sediment sample from the Central Indian Ridge

Hydrocarbons are ubiquitous in marine environments and might fuel hydrocarbon-metabolizing microbes in the ocean. Numerous studies have documented microbial hydrocarbon degradation in water columns and deep-sea surface sediment. However, the degradation potential and biogeochemical cycling of hydrocarbons in subsurface sediments remain largely unknown. In this study, we used two different hydrocarbons, n-hexadecane (HEX) and methylcyclohexane (MCH), to investigate the distribution and diversity of hydrocarbon-consuming bacteria in a core sediment sample from the Central Indian Ridge (CIR), which is adjacent to mid-ridge hydrothermal vents in the Indian Ocean. We observed different vertical profiles of HEX- and MCH-degrading bacteria in the core sediments. Specifically, HEX-degrading bacteria were universally distributed, while MCH-degrading bacteria were found only in the intermediate layers of the core sediments. Changing factors including dissolved oxygen might affect the natural distribution of different hydrocarbon consumers. We found that a novel species of the genus C1-B045 might play a pivotal role in metabolizing MCH in the CIR deep biosphere. Through amino acid identity comparison with published sequences, we determined that C1-B045 harbors two novel classes of cyclohexanone monooxygenases involved in MCH metabolism. This study sheds light on the structure and function of hydrocarbon-consuming microbes in deep biospheres

Altered Brain Signal Variability in Patients With Generalized Anxiety Disorder

Generalized anxiety disorder (GAD) is characterized by a chronic, continuous symptom of worry and exaggerated startle response. Although functional abnormality in GAD has been widely studied using functional magnetic resonance imaging (fMRI), the dynamic signatures of GAD are not fully understood. As a vital index of brain function, brain signal variability (BSV) reflects the capacity of state transition of neural activities. In this study, we recruited 47 patients with GAD and 38 healthy controls (HCs) to investigate whether or not BSV is altered in patients with GAD by measuring the standard deviation of fMRI signal of each voxel. We found that patients with GAD exhibited decreased BSV in widespread regions including the visual network, sensorimotor network, frontoparietal network, limbic system, and thalamus, indicating an inflexible brain state transfer pattern in these systems. Furthermore, the correlation between BSV and trait anxiety score was prone to be positive in patients with GAD but negative in HCs. The opposite relationships between BSV and anxiety level in the two groups indicate that the brain with moderate anxiety level may stay in the most stable rather than in the flexible state. As the first study of BSV in GAD, we revealed extensively decreased BSV in patients with GAD similar to that in other mental disorders but with a non-linear relationship between BSV and anxiety level indicating a novel neurodynamic mechanism of the anxious brain

Transcriptome profiling of genes regulated by phosphate-solubilizing bacteria Bacillus megaterium P68 in potato (Solanum tuberosum L.)

The insoluble phosphorus in the soil is extremely difficult to be absorbed and used directly through the potato root system. Although many studies have reported that phosphorus-solubilizing bacteria (PSB) can promote plant growth and uptake of phosphorus, the molecular mechanism of phosphorus uptake and growth by PSB has not been investigated yet. In the present study, PSB were isolated from rhizosphere soil in soybean. The data of potato yield and quality revealed that the strain P68 was the most effective In the present study, PSB identification, potato field experiment, pot experiment and transcriptome profiling to explored the role of PSB on potato growth and related molecular mechanisms. The results showed that the P68 strain (P68) was identified as Bacillus megaterium by sequencing, with a P-solubilizing ability of 461.86 mg·L−1 after 7-day incubation in National Botanical Research Institute’s Phosphate (NBRIP) medium. Compared with the control group (CK), P68 significantly increased the yield of potato commercial tubers by 17.02% and P accumulation by 27.31% in the field. Similarly, pot trials showed that the application of P68 significantly increased the biomass, total phosphorus content of the potato plants, and available phosphorus of the soil up by 32.33, 37.50, and 29.15%, respectively. Furthermore, the transcriptome profiling results of the pot potato roots revealed that the total number of bases was about 6G, and Q30 (%) was 92.35–94.8%. Compared with the CK, there were a total of 784 differential genes (DEGs) regulated when treated with P68, which 439 genes were upregulated and 345 genes were downregulated. Interestingly, most of the DEGs were mainly related to cellular carbohydrate metabolic process, photosynthesis, and cellular carbohydrate biosynthesis process. According to the KEGG pathway analysis, a total of 46 categorical metabolic pathways in the Kyoto Encyclopedia of Genes and Genomes (KEGG) database were annotated to 101 DEGs found in potato roots. Compared with the CK, most of the DEGs were mainly enriched in glyoxylate and dicarboxylate metabolism (sot00630), nitrogen metabolism (sot00910), tryptophan metabolism (sot00380), and plant hormone signal transduction (sot04075), and these DEGs might be involved in the interactions between Bacillus megaterium P68 and potato growth. The qRT-PCR analysis of differentially expressed genes showed that inoculated treatments P68 significantly upregulated expression of the phosphate transport, nitrate transport, glutamine synthesis, and abscisic acid regulatory pathways, respectively, and the data from qRT-PCR were consistent with that obtained from RNA-seq. In summary, PSB may be involved in the regulation of nitrogen and phosphorus nutrition, glutaminase synthesis, and abscisic acid-related metabolic pathways. This research would provide a new perspective for studying the molecular mechanism of potato growth promotion by PSB in the level of gene expression and related metabolic pathways in potato roots under the application of Bacillus megaterium P68

Studies on Regional Green Development Based on Social Network Analysis

Under the guidance of five development concepts, we should grasp regional overall economic, innovation, and traffic associated structure macroscopically, and analyze cities' status and role within the region when planning the regional green design. Through systematically considering regional overall structure, relationship between subjects and individual differences without prejudice to the ecological environment, it can play the greatest role of traffic led, city led, and market led, which can achieve regional green development. We build the traffic interaction network model, economic correlation network model, and innovation-driven network model to analyze network structures, identify key nodes and provide methodological guidance for regional green development plan. We bring Beijing-Tianjin-Hebei Urban Agglomeration for the case study and draw the following conclusions. The traffic interaction network is closer than the economic correlation network and the innovation-driven network, and the economic correlation network is closer than the innovation-driven network. The three networks all have a high degree of centralization, which means there is a great difference among cities. Beijing, Tianjin, Shijiazhuang develop relatively well, however, Chengde, Hengshui and Zhangjiakou relatively fall behind. Dezhou has a foundation to promote transportation integration and lacks the economic momentum and innovation driven. Chengde should increase the degree of innovation and communication to build connection with other cities

Ethanol Extract from Ulva prolifera Prevents High-Fat Diet-Induced Insulin Resistance, Oxidative Stress, and Inflammation Response in Mice

Ulva prolifera is the major causative species in the green tide, a serious marine ecological disaster, which bloomed in the Yellow Sea and the Bohai Sea of China. However, it is also a popular edible seaweed and its extracts exerts anti-inflammatory and antioxidant effects. The present study investigated the effects of ethanol extract of U. prolifera (EUP) on insulin sensitivity, inflammatory response, and oxidative stress in high-fat-diet- (HFD-) treated mice. HFD-treated mice obtained drinking water containing 2% or 5% EUP. The results showed that EUP supplementation significantly prevented HFD-induced weight gain of liver and fat. EUP supplementation also improved glucose tolerance and insulin resistance in HFD-treated mice. Moreover, EUP supplementation prevented the increased expression of genes involved in triglyceride synthesis and proinflammatory genes and the decreased expression of genes involved in fatty acid oxidation in liver of HFD-treated mice. Furthermore, EUP supplementation decreased reactive oxygen species content, while increasing glutathione content and glutathione peroxidase activity in HFD-treated mice. In conclusion, our results showed that EUP improved insulin resistance and had antilipid accumulation and anti-inflammatory and antioxidative effects on HFD-treated mice. We suggested that U. prolifera extracts may be regarded as potential candidate for the prevention of nonalcoholic fatty liver disease

The complete mitochondrial genome sequence of Bryopsis plumosa

In 2015, a novel macroalgae began to bloom in Qinhuangdao on the coast of the Bohai Sea, Northern China. Bryopsis plumosa, a green macroalga, is one of the causal species of the macroalgae blooms, which have severely affected the environment and ecosystem on the coast of Qinhuangdao. In the present study, we sequenced the mitochondrial genome of B. plumosa for the first time (GenBank accession number MN853874). It was found that the ring-shaped genome was made up of 110,912 base pairs, including 29 protein-coding genes, 23 tRNAs, and 2 rRNAs. Phylogenetic analysis showed B. plumosa had close genetic relationships with algae Ulva prolifera, Ulva linza, and Ulva flexuosa. The present data will provide important information on the phylogenetics and molecular evolution of Bryopsis species

Complete chloroplast genome of Ulva pertusa, one of the causal species of green macroalgal blooms in the coastal waters of Qinhuangdao, China

Since 2015, macroalgae blooms have appeared along the Qinhuangdao coast of the Bohai Sea in China and they have recurred annually during the months of April to September. One of the causal species that results in the macroalgal blooms, Ulva pertusa, has been detrimental to the environment and ecosystem along the coast of the Qinhuangdao, China. In the present study, we sequenced the chloroplast genome of U. pertusa for the first time (GenBank accession number MN853875) and found that the annular genome comprised 104,380 base pairs, including 71 protein-coding genes, 26 tRNAs, and 2 rRNAs. We then constructed a phylogenetic tree of U. pertusa and 17 other species based on core genes, which showed that U. pertusa is the closest sister species of U. fasciata