Effects of LED spectrum on circadian rhythmic expression of clock genes and Aanat2 in the brain of juvenile European seabass (Dicentrarchus labrax)

The circadian rhythm is a physiological phenomenon that occurs in various organisms with a cycle of about 24 hours. Light is one of the important environmental factors affecting biological rhythm. To clarify whether a shift in light spectrum can influence the circadian expression in fish brain, a total of 175 European seabasses [body weight: 32.5 ± 0.71) g; body length: (13.78 ± 0.35) cm] were exposed to white light (WL), red light (RL), yellow light (YL), green light (GL) or blue light (BL). After 50 days of exposure, circadian expressions of four core clock genes (Clock, Bmal1, Per2, Cry1) and Aanat2 gene in brain were examined. The results showed that the temporal expression patterns of positive clock gens (Clock and Bmal1) showed increases during the scotophase and decreases during the photophase, with peaks near the middle of the darkness. Clock gene expression showed a stable circadian rhythm (R2 = 0.578-0.824, P=0.000- 0.027) in all light groups while Bmal1 showed circadian rhythm in WL, GL and RL, not in BL and YL. Daily expression patterns of the negative clock genes oscillated in the opposite phase from the positive clock genes, showing increasing mRNA levels during the light, decreases during the dark, and peaks near the shift from night to day, except Per2 in RL and Cry1 in BL. Compared with WL, the acrophases of Clock and Bmal1 were delayed under all light treatments (BL: + 3.7h, +6.73h; RL: +2.4h,+1.35h; YL: + 4.94h, 2.00h; GL: +0.05, +0.16h). Cry1 showed advanced acrophase under all light treatments (BL: -10.74 h, GL: -3.81 h, RL: -3.93 h, YL: -7.56 h) but Per2 showed delayed acrophase in all light treatments (GL: +0.86 h, RL: +10.35 h, YL: +9.62 h), except in BL (-0.43 h). The acrophase of Aanat2 was advanced by all monochromatic light, the Aanat2 level was significantly increased in RL compared with other light treatment. Therefore, the results indicate that RL may regulate the expression of Aanat2 gene by affecting the expression of clock gene in fish brain. Spectrum can affect the biological clock system of fish, and unreasonable spectrum may disturb the rhythm of gene expression of biological clock of fish. Under the irradiation of light spectrum, some clock genes still maintain obvious circadian oscillation, while the rhythm of some clock genes is not obvious and may be destroyed. Our findings suggest a primary role of light spectrum information to the fish brain circadian system

Numerical Analysis and Prediction of Coal Mine Methane Drainage Based on Gas–Solid Coupling Model

Methane drainage using boreholes is one of the most effective means of preventing coal mine methane disasters. However, the distributions of stress and permeability around the borehole and the effective influence radius of methane drainage are not clearly known. To solve this problem, a mathematical model of gas–solid coupling of coal rock was first established in this study based on the Kozeny–Carman equation. In this model, the coal rock was considered as a fracture–porosity dual medium. Methane’s flow was seepage in the fracture system and diffused in the pore system. Second, the finite volume method was used to discretize the coupling model. The Newton–Raphson iteration and generalized minimal residual algorithm method were used to solve the nonlinear coupling equation after diffusion. Finally, Fortran language was used to simulate the process of methane drainage using a borehole. Results showed that there was respectively stress concentration on the left and right sides of the borehole. This area was associated with the lower permeability in these zones and destroyed the borehole, which is the one of the main reasons for the low efficiency of methane drainage. The relationship between the effective influence radius and the drainage time could be described by a power function. The effective influence radius of the borehole, cumulative methane drainage volume, and residual methane content distribution obtained by simulation were well consistent with the data obtained by the actual measurements, which proves the credibility of the gas–solid coupling and solving methods. This study provides some theoretical reference for methane drainage and the solution of multi-physics field coupling model in coal mines

Analysis of expressed sequence tags generated from full-length enriched cDNA libraries of melon

Abstract Background Melon (Cucumis melo), an economically important vegetable crop, belongs to the Cucurbitaceae family which includes several other important crops such as watermelon, cucumber, and pumpkin. It has served as a model system for sex determination and vascular biology studies. However, genomic resources currently available for melon are limited. Result We constructed eleven full-length enriched and four standard cDNA libraries from fruits, flowers, leaves, roots, cotyledons, and calluses of four different melon genotypes, and generated 71,577 and 22,179 ESTs from full-length enriched and standard cDNA libraries, respectively. These ESTs, together with ~35,000 ESTs available in public domains, were assembled into 24,444 unigenes, which were extensively annotated by comparing their sequences to different protein and functional domain databases, assigning them Gene Ontology (GO) terms, and mapping them onto metabolic pathways. Comparative analysis of melon unigenes and other plant genomes revealed that 75% to 85% of melon unigenes had homologs in other dicot plants, while approximately 70% had homologs in monocot plants. The analysis also identified 6,972 gene families that were conserved across dicot and monocot plants, and 181, 1,192, and 220 gene families specific to fleshy fruit-bearing plants, the Cucurbitaceae family, and melon, respectively. Digital expression analysis identified a total of 175 tissue-specific genes, which provides a valuable gene sequence resource for future genomics and functional studies. Furthermore, we identified 4,068 simple sequence repeats (SSRs) and 3,073 single nucleotide polymorphisms (SNPs) in the melon EST collection. Finally, we obtained a total of 1,382 melon full-length transcripts through the analysis of full-length enriched cDNA clones that were sequenced from both ends. Analysis of these full-length transcripts indicated that sizes of melon 5' and 3' UTRs were similar to those of tomato, but longer than many other dicot plants. Codon usages of melon full-length transcripts were largely similar to those of Arabidopsis coding sequences. Conclusion The collection of melon ESTs generated from full-length enriched and standard cDNA libraries is expected to play significant roles in annotating the melon genome. The ESTs and associated analysis results will be useful resources for gene discovery, functional analysis, marker-assisted breeding of melon and closely related species, comparative genomic studies and for gaining insights into gene expression patterns.This work was supported by Research Grant Award No. IS-4223-09C from BARD, the United States-Israel Binational Agricultural Research and Development Fund, and by SNC Laboratoire ASL, de Ruiter Seeds B.V., Enza Zaden B.V., Gautier Semences S.A., Nunhems B.V., Rijk Zwaan B.V., Sakata Seed Inc, Semillas Fitó S.A., Seminis Vegetable Seeds Inc, Syngenta Seeds B.V., Takii and Company Ltd, Vilmorin and Cie S.A. and Zeraim Gedera Ltd (all of them as part of the support to ICuGI). CC was supported by CNRS ERL 8196.Peer Reviewe

Synthesis and characterization of starch ether/alginate hydrogels with reversible and tunable thermoresponsive properties

A thermoresponsive hydrogel that was composed of 2-hydroxy-3-isopropoxypropyl starch (HIPS) and alginate was synthesized via cross-linking with hybrid crosslinkers including ethylene glycol diglycidyl ether (EDGE) and calcium chloride (CaCl _2 ). Attenuated total reflection infrared spectroscopy (ATR-IR), thermogravimetric analysis (TGA) and derivative thermogravimetry (DTG) were used to confirm that cross-linking occurred. The porous architecture of the HIPS/SA composite hydrogels was investigated using scanning electron microscopy (SEM). Composite hydrogels had a tunable volume phase transition temperature (VPTT) that was in the range from 29.4 to 40.2 °C and resulted from changes in the compositions (HIPS concentration from 5.5 to 7.5 wt%). It was also found that the presence of NaCl (0 to 20 g l ^−1 ) or organic solvents (alcohols, 0 to 50 g l ^−1 ) in aqueous medium changed the VPTT of the composite hydrogels; also, the VPTT decreased as the concentration of NaCl or organic solvents increased. Additionally, alcohols that have long carbon chains (isopropanol > ethanol > methanol) exhibited a more significant effect on the VPTT of hydrogel. The hydrogel could shed and absorb most of the water in a very short time and demonstrate a stable reversible swelling-deswelling property after 5 swelling-deswelling cycles

The Nitrogen-Removal Efficiency of a Novel High-Efficiency Salt-Tolerant Aerobic Denitrifier, Halomonas Alkaliphile HRL-9, Isolated from a Seawater Biofilter

Aerobic denitrification microbes have great potential to solve the problem of NO3−-N accumulation in industrialized recirculating aquaculture systems (RASs). A novel salt-tolerant aerobic denitrifier was isolated from a marine recirculating aquaculture system (RAS) and identified as Halomonas alkaliphile HRL-9. Its aerobic denitrification performance in different dissolved oxygen concentrations, temperatures, and C/N ratios was studied. Investigations into nitrogen balance and nitrate reductase genes (napA and narG) were also carried out. The results showed that the optimal conditions for nitrate removal were temperature of 30 °C, a shaking speed of 150 rpm, and a C/N ratio of 10. For nitrate nitrogen (NO3−-N) (initial concentration 101.8 mg·L−1), the sole nitrogen source of the growth of HRL-9, the maximum NO3−-N removal efficiency reached 98.0% after 24 h and the maximum total nitrogen removal efficiency was 77.3% after 48 h. Nitrogen balance analysis showed that 21.7% of NO3−-N was converted into intracellular nitrogen, 3.3% of NO3−-N was converted into other nitrification products (i.e., nitrous nitrogen, ammonium nitrogen, and organic nitrogen), and 74.5% of NO3−-N might be converted to gaseous products. The identification of functional genes confirmed the existence of the napA gene in strain HRL-9, but no narG gene was found. These results confirm that the aerobic denitrification strain, Halomonas alkaliphile HRL-9, which has excellent aerobic denitrification abilities, can also help us understand the microbiological mechanism and transformation pathway of aerobic denitrification in RASs

Dual-Responsive Hydrogels with Three-Stage Optical Modulation for Smart Windows

Since room temperature management consumes a large amount of building energy, thermochromic smart windows have been extensively used for temperature regulation and energy management. However, the development of the smart window is still limited by its simple thermochromic performance, unreasonable thermochromic temperature, and the lack of additional stimulation conditions. In this work, a dual-responsive hydrogel was developed by introducing sodium dodecyl sulfate (SDS) and sodium chloride into the cross-linking network of poly(N-isopropylacrylamide) (PNIPAM) and polyacrylamide (PAM) for energy-saving and privacy protection. By controlling the temperature from low (<15 °C) to medium (15–28 °C) to high (>28 °C), the dual-responsive hydrogel achieved a reversible three-stage transition of opaque–transparent–translucent. The hydrogel exhibited a satisfactory solar modulation ability (Tlum = 80.3%, ΔTsol,15–18°C = 72.9%, ΔTsol,18–35°C = 42.7%) and effective IR and UV shielding at high (or low) temperatures. Moreover, compared with traditional windows, smart windows made of dual-responsive hydrogels could offer better thermal insulation and heat preservation. The electrochromic properties of the dual-responsive hydrogel presented a facile strategy to meet the needs of different situations. The dual-responsive hydrogel features energy-saving, privacy protection, three-stage optical modulation, and multistimulus responsiveness, making it an ideal smart window candidate

Right, but not left, posterior superior temporal gyrus is causally involved in vocal feedback control

The posterior superior temporal gyrus (pSTG) has been implicated in the integration of auditory feedback and motor system for controlling vocal production. However, the question as to whether and how the pSTG is causally involved in vocal feedback control is currently unclear. To this end, the present study selectively stimulated the left or right pSTG with continuous theta burst stimulation (c-TBS) in healthy participants, then used event-related potentials to investigate neurobehavioral changes in response to altered auditory feedback during vocal pitch regulation. The results showed that, compared to control (vertex) stimulation, c-TBS over the right pSTG led to smaller vocal compensations for pitch perturbations accompanied by smaller cortical N1 and larger P2 responses. Enhanced P2 responses received contributions from the right-lateralized temporal and parietal regions as well as the insula, and were significantly correlated with suppressed vocal compensations. Surprisingly, these effects were not found when comparing c-TBS over the left pSTG with control stimulation. Our findings provide evidence, for the first time, that supports a causal relationship between right, but not left, pSTG and auditory-motor integration for vocal pitch regulation. This lends support to a right-lateralized contribution of the pSTG in not only the bottom-up detection of vocal feedback errors but also the involvement of driving motor commands for error correction in a top-down manner