118 research outputs found
SiC + Si threeāphase 48Ā V electric vehicle battery charger employing currentāSVPWM controlled SWISS AC/DC and variableāDCābus DC/DC converters
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163817/1/els2bf00146.pd
Laser Intensity Noise Suppression for Preparing Audio-Frequency 795 nm Squeezed Vacuum State of Light at Rubidium D1 Line
Laser intensity noise suppression has essential effects on preparation and
characterization of the audio-frequency squeezed vacuum state of light based on
a sub-threshold optical parametric oscillator (OPO).We have implemented two
feedback loops by using relevant acousto-optical modulators (AOM) to stabilize
the intensity of 795-nm near infrared (NIR) fundamental laser and 397.5-nm
ultraviolet (UV) laser generated by cavity-enhanced frequency doubling.Typical
peak-to-peak laser intensity fluctuation with a bandwidth of kHz in a
half hour has been improved from to for 795-nm NIR
laser beam, and from to for 397.5-nm UV laser beam,
respectively. The squeezing level of the squeezed vacuum state at 795 nm
prepared by the sub-threshold OPO with a PPKTP crystal has been improved from
-3.3 to -4.0 dB around 39 kHz of audio analysis frequency range.Comment: 5 pages, 4 figure
Kinematics of the Broad-line Region of 3C 273 from a Ten-year Reverberation Mapping Campaign
Despite many decades of study, the kinematics of the broad-line region of
3C~273 are still poorly understood. We report a new, high signal-to-noise,
reverberation mapping campaign carried out from November 2008 to March 2018
that allows the determination of time lags between emission lines and the
variable continuum with high precision. The time lag of variations in H
relative to those of the 5100 Angstrom continuum is days
in the rest frame, which agrees very well with the Paschen- region
measured by the GRAVITY at The Very Large Telescope Interferometer. The time
lag of the H emission line is found to be nearly the same as for
H. The lag of the Fe II emission is days, longer
by a factor of 2 than that of the Balmer lines. The velocity-resolved lag
measurements of the H line show a complex structure which can be
possibly explained by a rotation-dominated disk with some inflowing radial
velocity in the H-emitting region. Taking the virial factor of , we derive a BH mass of and an accretion rate of from the
H line. The decomposition of its images yields a host stellar mass
of , and a ratio of in agreement with the Magorrian relation. In the near
future, it is expected to compare the geometrically-thick BLR discovered by the
GRAVITY in 3C 273 with its spatially-resolved torus in order to understand the
potential connection between the BLR and the torus.Comment: 17 pages, 12 figures, 6 tables, accepted for publication in The
Astrophysical Journa
Diazotroph abundance and community structure are reshaped by straw return and mineral fertilizer in rice-rice-green manure rotation
Sub-MIC Tylosin Inhibits Streptococcus suis Biofilm Formation and Results in Differential Protein Expression
Streptococcus suis (S. suis) is a crucial zoonotic pathogen which causes severe diseases in humans and pigs. Biofilms of S. suis can induce persistent infections which are harder to treat. Sub-minimal inhibitory concentration (sub-MIC) of tylosin can inhibit biofilm formation in bacteria. By using iTRAQ strategy, we compared the protein expression profiles of S. suis grown with sub-MIC tylosin treatment or no treatement. The result showed that 96 proteins expression were changed with 77 up-regulated and 19 down-regulated proteins. Several metabolism proteins (such as phosphoglycerate kinase), as well as cell surface proteins (such as ABC transporter proteins), were found to be involved in biofilm formation. Overall, our results indicated that S. suis metabolic regulation, cell surface proteins, and virulence proteins appear to be of importance in biofilm growth by sub-MIC tylosin treated. Thus, our data analyzed rough regulation of biofilm formation that lay the foundation for the future research of mechanism and targets
On computing complex square roots of real matrices
We present an idea for computing complex square roots of matrices using only real
arithmetic.FundaĆ§Ć£o para a CiĆŖncia e a Tecnologia (FCT) - Project PEst-C/MAT/UI0013/2011, PTDC/MAT/112273/2009National Natural Science Foundation of China - Project PEst-C/MAT/UI0013/2011, PTDC/MAT/112273/2009, Portugal.Major Foundation of Educational Committee of Hunan Province - Grant No. 09A002 [2009]FEDER Funds- "Programa Operacional Factores de Competitividade - COMPETE
Response of Carex breviculmis to phosphorus deficiency and drought stress
IntroductionThe drought and phosphorus deficiency have inevitably become environmental issues globally in the future. The analysis of plants functional trait variation and response strategies under the stress of phosphorus deficiency and drought is important to explore their ability to respond to potential ecological stress.MethodsIn this study, Carex breviculmis was selected as the research object, and a 14-week pot experiment was conducted in a greenhouse, with two phosphorus treatment (add 0.5mmol/L or 0.05Ī¼mol/L phosphorus) and four drought treatment (add 0-5%PEG6000), totaling eight treatments. Biomass allocation characteristics, leaf anatomical characteristics, biochemical parameters, root morphology, chemical element content, and photosynthetic parameters were measured.ResultsThe results showed that the anatomical characteristics, chemical elements, and photosynthetic parameters of Carex breviculmis responded more significantly to main effect of phosphorus deficiency. Stomatal width, leaf phosphorus content and maximum net photosynthetic rate decreased by 11.38%, 59.39%, 38.18% significantly (p<0.05), while the change in biomass was not significant (p>0.05). Biomass allocation characteristics and root morphology responded more significantly to main effect of drought. Severe drought significantly decreased leaf fresh weight by 61% and increased root shoot ratio by 223.3% compared to the control group (p<0.05). The combined effect of severe drought and phosphorus deficiency produced the highest leaf N/P ratio (291.1% of the control) and MDA concentration (243.6% of the control). Correlation analysis and redundancy analysis showed that the contributions of phosphorus and drought to functional trait variation were similar. Lower epidermal cell thickness was positively correlated with maximum net photosynthetic rate, leaf phosphorus, chlorophyll ab, and leaf fresh weight (p<0.05).DiscussionIn terms of response strategy, Carex breviculmis was affected at the microscopic level under phosphorus deficiency stress, but could maintain the aboveground and underground biomass well through a series of mechanisms. When affected by drought, it adopted the strategy of reducing leaf yield and improving root efficiency to maintain life activities. Carex breviculmis could maintain its traits well under low phosphorus and moderate drought, or better conditions. So it may have good ecological service potential in corresponding areas if promoted. This study also provided a reference for plant response to combined drought and phosphorus deficiency stresses
Molecular characterization, expression pattern and immunologic function of CD82a in large yellow croaker (Larimichthys crocea)
Visceral white spot disease (VWND) caused by Pseudomonas plecoglossicida poses a major threat to the sustainable development of large yellow croaker (Larimichthys crocea) aquaculture. Genome-wide association analysis (GWAS) and RNA-seq research indicated that LcCD82a play an important role in resistance to visceral white spot disease in L. crocea, but the molecular mechanism of LcCD82a response to P. plecoglossicida infection is still unclear. In this study, we cloned and validated the Open Reading Frame (ORF) sequence of LcCD82a and explored the expression profile of LcCD82a in various tissues of L.crocea. In addition, two different transcript variants (LcCD82a-L and LcCD82a-S) of LcCD82a were identified that exhibit alternative splicing patterns after P. plecoglossicida infection, which may be closely related to the immune regulation during pathogenetic process of VWND. In order to explore the function of LcCD82a, we purified the recombinant protein of LcCD82a-L and LcCD82a-S. The bacterial agglutination and apoptosis function analysis showed that LcCD82a may involve in extracellular bacterial recognition, agglutination, and at the same time participate in the process of antigen presentation and induction of cell apoptosis. Collectively, our studies demonstrate that LcCD82a plays a crucial role in regulating apoptosis and antimicrobial immunity
Identification of SNPs in MITF associated with beak color of duck
Introduction: Beak colorāa pigment-related traitāis an important feature of duck breeds. Recently, little research has addressed genetic mechanism of the beak colors in poultry, whereas the process and the regulation factors of melanin deposition have been well described.Methods: To investigate the genetic mechanism of beak colors, we conducted an integrated analysis of genomic selection signatures to identify a candidate site associated with beak color. For this, we used black-billed (Yiyang I meat duck synthetic line H1, H2, H3&HF) and yellow-billed ducks (Cherry Valley ducks and white feather Putian black duck). Quantitative real-time PCR and genotyping approaches were used to verify the function of the candidate site.Results: We identified 3,895 windows containing 509 genes. After GO and KEGG enrichment analysis, nine genes were selected. Ultimately, MITF was selected by comparing the genomic differentiation (FST). After loci information selection, 41 extreme significantly different loci were selected, which are all located in intron regions of MITF and are in almost complete linkage disequilibrium. Subsequently, the site ASM874695v1:10:g.17814522T > A in MITF was selected as the marker site. Furthermore, we found that MITF expression is significantly higher in black-beaked ducks than in yellow-beaked ducks of the F2 generation (p < 0.01). After genotyping, most yellow-billed individuals are found with homozygous variant; at the same time, there are no birds with homozygous variant in black-billed populations, while the birds with homozygous and heterozygous variant share the same proportion.Conclusion:MITF plays a very critical role in the melanogenesis and melanin deposition of duck beaks, which can effectively affect the beak color. The MITF site, ASM874695v1:10:g.17814522T > A could be selected as a marker site for the duck beak color phenotype
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