Transcriptomic analysis of Synechocystis sp PCC6803 under low-temperature stress

In this study, cDNA microarrays were developed from 3569 mRNA reads to analyze the expression profiles of the transcriptomes of Synechocystis sp. PCC6803 under low temperature (LT) stress. Among the genes on the cDNA microarrays, 899 LT-affected genes exhibited a 1.5-fold (or greater) difference in expression compared with the genes from normal unstressed Synechocystis sp. PCC6803. Of the differentially expressed genes, 353 were up-regulated and 246 were down-regulated. The results showed that genes involved in photosynthesis were activated at LT (10A degrees C), including genes for photosystem I, photosystem II, photosynthetic electron transport, and cytochrome b6/f complex. Moreover, desB, one of four genes that encode the fatty acid desaturases, was also induced by LT. However, the LT conditions to some degree enhanced the transcription of some genes. In addition, LT (10A degrees C) may reduce cellular motility by regulating the transcription of spkA (sll1575), a serine/threonine protein kinase. The results reported in this study may contribute to a better understanding of the responses of the Synechocystis cell to LT, including pathways involved in photosynthesis and repair.In this study, cDNA microarrays were developed from 3569 mRNA reads to analyze the expression profiles of the transcriptomes of Synechocystis sp. PCC6803 under low temperature (LT) stress. Among the genes on the cDNA microarrays, 899 LT-affected genes exhibited a 1.5-fold (or greater) difference in expression compared with the genes from normal unstressed Synechocystis sp. PCC6803. Of the differentially expressed genes, 353 were up-regulated and 246 were down-regulated. The results showed that genes involved in photosynthesis were activated at LT (10A degrees C), including genes for photosystem I, photosystem II, photosynthetic electron transport, and cytochrome b6/f complex. Moreover, desB, one of four genes that encode the fatty acid desaturases, was also induced by LT. However, the LT conditions to some degree enhanced the transcription of some genes. In addition, LT (10A degrees C) may reduce cellular motility by regulating the transcription of spkA (sll1575), a serine/threonine protein kinase. The results reported in this study may contribute to a better understanding of the responses of the Synechocystis cell to LT, including pathways involved in photosynthesis and repair

Prognostication of chronic disorders of consciousness using brain functional networks and clinical characteristics

Disorders of consciousness are a heterogeneous mixture of different diseases or injuries. Although some indicators and models have been proposed for prognostication, any single method when used alone carries a high risk of false prediction. This study aimed to develop a multidomain prognostic model that combines resting state functional MRI with three clinical characteristics to predict one year outcomes at the single-subject level. The model discriminated between patients who would later recover consciousness and those who would not with an accuracy of around 90% on three datasets from two medical centers. It was also able to identify the prognostic importance of different predictors, including brain functions and clinical characteristics. To our knowledge, this is the first implementation reported of a multidomain prognostic model based on resting state functional MRI and clinical characteristics in chronic disorders of consciousness. We therefore suggest that this novel prognostic model is accurate, robust, and interpretable.Comment: Although some prognostic indicators and models have been proposed for disorders of consciousness, each single method when used alone carries risks of false prediction. Song et al. report that a model combining resting state functional MRI with clinical characteristics provided accurate, robust, and interpretable prognostications. 52 pages, 1 table, 7 figure

Sloan Digital Sky Survey IV: Mapping the Milky Way, Nearby Galaxies, and the Distant Universe

We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median $z\sim 0.03$). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between $z\sim 0.6$ and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July

Measurement and analysis of the radial motion error of aerostatic ultra-precision spindle

The measurement of the rotation error of an aerostatic ultra-precision spindle is critically important to evaluate and hence ensure the precision of machine tools. The Donaldson reversal method, which was taken as the efficient method for error separation theoretically, has been widely used to separate shape errors of standard artifact. However, the accuracy analysis of the Donaldson reversal method has not been fully studied and understood. In this study, a nanometer system for measuring the radial rotation error of aerostatic ultra-precision spindle was constructed based on the Donaldson reversal method. The comparative experiments were carried out to investigate the effects of the motor drive, and an angle correction algorithm was proposed to alleviate the effect of angle deviation. The method of harmonic analysis was applied to investigate the effect of artifact eccentricity, and the relationship between the axial motion and measuring error was also studied. The measuring accuracy can be improved by reducing the cogging torque of motor, the angle deviation, artifact eccentricity and spindle axial motion. Experimental results showed that the measurement uncertainty of both the spindle rotation error and artifact form error can be controlled in nanometer level. Besides, the separated value of the artifact form error was very close to the nominal roundness, which verifies the accuracy of the measurement system and the validity of the error separation method

Numerical analysis of the dynamic performance of aerostatic thrust bearings with different restrictors

This study utilizes a dynamic mesh technology to investigate the dynamic performance of aerostatic thrust bearings with orifice restrictor, multiple restrictors, and porous restrictor. An experiment, which investigates the bearing static load capacity, was carried out to verify the calculation accuracy of dynamic mesh technology. Further, the impact of incentive amplitude, incentive frequency, axial eccentricity ratio, and non-flatness on the bearing dynamic performance was also studied. The results show incentive amplitude effect can be ignored at the condition of amplitude less than 5% film thickness, while the relationship between dynamic characteristics and incentive frequency presented a strong nonlinear relationship in the whole frequency range. The change law of dynamic stiffness and damping coefficient for porous restrictor was quite different from orifice restrictor and multiple restrictors. The bearing dynamic performance increased significantly with the growth of axial eccentricity ratio, and the surface non-flatness enhanced dynamic performance of aerostatic thrust bearings

A Calculation Method to Investigate the Effects of Geometric Parameters and Operational Conditions on the Static Characteristics of Aerostatic Spherical Bearings

In this paper, a calculation method based on matlab partial differential equations (PDE) tool is proposed to investigate the static characteristics of aerostatic spherical bearings. The Reynolds equation of aerostatic spherical bearings is transformed into a standard elliptic equation. The effects of geometric parameters and operational conditions on the film pressure, bearing film force, and stiffness are studied. The axial and radial eccentricities result in different film pressure distributions; the bearing film force and stiffness are significantly influenced by geometric parameters and operational conditions. The relative optimal parameters are confirmed based on the calculation results. A comparison between the numerical and experimental results is also presented. The highest relative error between the numerical results and the experimental data is 11.3%; the calculation results show good agreements with the experimental data, thus verifying the accuracy of the calculation method used in this paper

Transient expression of the enhanced green fluorescent protein (egfp) gene in Sargassum horneri

Sargassum horneri is a macroalga widespread in North Asia-Pacific region, and these years its bloom has caused huge damage to the environment and the economic in China. To make up the blank on genetic engineering research, a transient transformation system for the multicellular marine brown alga S . horneri was established in this research. The algae used in this research were collected from the Yellow Sea of China and verified as a same species S . horneri with analysis of molecular markers. The S . horneri parietal leaves were transformed with the enhanced green fluorescent gene as the reporter by micro-particle bombardment. The results show that green fluorescent protein (GFP) is an effective transgene reporter for S . horneri and that particle bombardment is a suitable method for transformation of S . horneri . Through selection of four different promoters for EGFP and six groups' bombardment characters, the highest transformation efficiency approximately 1.31% was got with the vector pEGFP-N1 at bombardment characters 900 spi and 6 cm distance. This research paves a way for the further research and application of S . horneri

Plasticity Improvement of Ball-Spun Magnesium Alloy Tube Based on Stress Triaxiality

The effects of thickness reduction, feed ratio, and ball diameter, and their coupling effects, on the average relative stress triaxiality during spinning are discussed via simulation results. The relationships among the parameters and the average value of relative stress triaxiality (AVRST) are fitted with multiple nonlinear functions to calculate the optimal process parameters. According to the trend of stress triaxiality, the corresponding process parameters are calculated for the minimum average value of relative stress triaxiality (AVRST). Room temperature experiments performed on an AZ31 magnesium alloy thin-walled tube with the optimal parameters reveal an improvement of cracking of the tube surface. The study reveals changes in the minimum AVRST and aids in selecting the process parameters to improve plastic performance