2,050 research outputs found
Polymorphism of the H-FABP, MC4R and ADD1 genes in the Meishan and four other pig populations in China
Genes such as the Heart Fatty Acid-Binding Protein (H-FABP), the Melanocortin-4 Receptor (MC4R) and the Adipocyte Determination and Differentiation factor-1 (ADD1) play an important role in meat quality in pigs. The Meishan is one of the most prolific pig breeds in the world, but it is in danger, in China, of being replaced by other exotic pig breeds because of its slow growth rate and high body fat content. To know their present genetic status, the polymorphism of the three genes in the Meishan and four other pig populations (Sutai, Yorkshire×Sutai, Landrace×Sutai and Duroc×Landrace×Yorkshire) in China was analysed, using PCR-RFLP and PCR-SSCP, and were further compared with each other. The results showed that gene and genotype frequencies differed significantly between the Meishan and the other four populations. This is suggested to be one of the reasons for the good meat quality of the Meishan compared to the other breeds. In addition, since half of the genetic background of Sutai is from the Meishan, results also indicated that marker assisted selection (MAS) is very important for the development of new pig breeds. South African Journal of Animal Science Vol. 36(1) 2006: 1-
Phosphorylation of LCRMP-1 by GSK3β Promotes Filopoda Formation, Migration and Invasion Abilities in Lung Cancer Cells
LCRMP-1, a novel isoform of CRMP-1, can promote cancer cell migration, invasion and associate with poor clinical outcome in patients with non-small-cell lung cancer (NSCLC). However, the underlying regulatory mechanisms of LCRMP-1 in cancer cell invasiveness still remain obscure. Here, we report that GSK3β can phosphorylate LCRMP-1 at Thr-628 in consensus sequences and this phosphorylation is crucial for function of LCRMP-1 to promote filopodia formation, migration and invasion in cancer cells. Impediment of Thr-628 phosphorylation attenuates the stimulatory effects of LCRMP-1 on filopodia forming, migration and invasion abilities in cancer cells; simultaneously, kinase-dead GSK3β diminishes regulation of LCRMP-1 on cancer cell invasion. Furthermore, we also found that patients with low-level Ser-9-phosphorylated GSK3β expression and high-level LCRMP-1 expression have worse overall survival than those with high-level inactive GSK3β expressions and low-level LCRMP-1 expressions (P<0.0001). Collectively, these results demonstrate that GSK3β-dependent phosphorylation of LCRMP-1 provides an important mechanism for regulation of LCRMP-1 on cancer cell invasiveness and clinical outcome
Towards identification of a non-abelian state: observation of a quarter of electron charge at quantum Hall state
The fractional quantum Hall effect, where plateaus in the Hall resistance at
values of coexist with zeros in the longitudinal resistance, results from
electron correlations in two dimensions under a strong magnetic field. Current
flows along the edges carried by charged excitations (quasi particles) whose
charge is a fraction of the electron charge. While earlier research
concentrated on odd denominator fractional values of , the observation of
the even denominator state sparked a vast interest. This state is
conjectured to be characterized by quasiparticles of charge e/4, whose
statistics is non-abelian. In other words, interchanging of two quasi particles
may modify the state of the system to an orthogonal one, and does not just add
a phase as in for fermions or bosons. As such, these quasiparticles may be
useful for the construction of a topological quantum computer. Here we report
data of shot noise generated by partitioning edge currents in the
state, consistent with the charge of the quasiparticle being e/4, and
inconsistent with other potentially possible values, such as e/2 and e. While
not proving the non-abelian nature of the state, this observation is
the first step toward a full understanding of these new fractional charges
The addition of a pH-sensitive gel improves microemulsion stability for the targeted removal of colonic ammonia
<p>Abstract</p> <p>Background</p> <p>We prepared an oral W/O microemulsion for the removal of colonic ammonia (ME-RCA). The effect of this microemulsion was influenced by the digestion process in the gastrointestinal tract. In this paper, we aim to show that stability was improved by using a microemulsion-based gel for the removal of colonic ammonia (MBG-RCA).</p> <p>Methods</p> <p>MBG-RCA was prepared by adding sodium alginate to the ME-RCA. MBG-RCA and ME-RCA were passed through a simulated gastrointestinal environment, and the amount of colonic ammonia present was then determined by titration with a standard solution of hydrochloric acid. The pH of the gastrointestinal fluid was measured using a pH test paper and the size and form of the microemulsions were examined under the microscope. 18 healthy rats were randomly divided into three groups, fasted for 24 hours and allowed to drink normally. Three-way pipes were placed at the gastroduodenal junction in Group I, and at the terminal ileum in Group II. After the intragastric administration of ME-RCA, the stomach contents in Group I, the effluent from the terminal ileum in Group II and discharge from the anus in Group III were collected. The pH values of the gastrointestinal juice were measured by the pH test paper and those of the colon were determined by a universal indicator. These animal experiments were also used to test the effect of MBG-RCA.</p> <p>Results</p> <p>MBG-RCA showed a better removal rate of artificial colonic ammonia than ME-RCA (P < 0.05). The decrease in pH value of the artificial small intestinal fluid due to ME-RCA did not occur when MBG-RCA was used. In the simulated gastrointestinal process, MBG-RCA maintained greater stability and released the emulsion (ME-RCA) in the colonic fluid. In the gastrointestinal tract of normal SD rats, ME-RCA decreased in size and lost its stable form after entering the small intestine, while MBG-RCA remained stable and intact emulsion-drops were observed from the anus. Neither substance had any effect on the pH of the stomach or colon of normal rats (partly because normal rats were fasted for 24 hours and allowed to drink normally, which resulted in a low level of ammonia production in the colon). Unlike ME-RCA, MBG-RCA did not reduce the pH of the small intestine.</p> <p>Conclusions</p> <p>MBG-RCA was more stable in the gastrointestinal tract and more effective at removing colonic ammonia when a higher concentration of ammonia was present. This made it possible to achieve the targeted removal of colonic ammonia and is a promising method to prevent hepatic encephalopathy (HE) in future studies.</p
A computationally efficient method for hand–eye calibration
Purpose: Surgical robots with cooperative control and semiautonomous features have shown increasing clinical potential, particularly for repetitive tasks under imaging and vision guidance. Effective performance of an autonomous task requires accurate hand–eye calibration so that the transformation between the robot coordinate frame and the camera coordinates is well defined. In practice, due to changes in surgical instruments, online hand–eye calibration must be performed regularly. In order to ensure seamless execution of the surgical procedure without affecting the normal surgical workflow, it is important to derive fast and efficient hand–eye calibration methods. Methods: We present a computationally efficient iterative method for hand–eye calibration. In this method, dual quaternion is introduced to represent the rigid transformation, and a two-step iterative method is proposed to recover the real and dual parts of the dual quaternion simultaneously, and thus the estimation of rotation and translation of the transformation. Results: The proposed method was applied to determine the rigid transformation between the stereo laparoscope and the robot manipulator. Promising experimental and simulation results have shown significant convergence speed improvement to 3 iterations from larger than 30 with regard to standard optimization method, which illustrates the effectiveness and efficiency of the proposed method
Synthesis of Tapered CdS Nanobelts and CdSe Nanowires with Good Optical Property by Hydrogen-Assisted Thermal Evaporation
The tapered CdS nanobelts and CdSe nanowires were prepared by hydrogen-assisted thermal evaporation method. Different supersaturation leads to two different kinds of 1D nanostructures. The PL measurements recorded from the as-prepared tapered CdS nanobelts and CdSe nanowires show only a bandgap emission with relatively narrow full-width half maximum, which means that they possess good optical property. The as-synthesized high-quality tapered CdS nanobelts and CdSe nanowires may be excellent building blocks for photonic devices
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The ALMaQUEST Survey. VII. Star Formation Scaling Relations of Green Valley Galaxies
We utilize the ALMA-MaNGA QUEnch and STar formation (ALMaQUEST) survey to
investigate the kpc-scale scaling relations, presented as the resolved star
forming main sequence (rSFMS: vs. ), the
resolved Schmidt-Kennicutt relation (rSK: vs. ), and the resolved molecular gas main sequence (rMGMS: vs. ), for 11478 star-forming and 1414 retired spaxels
(oversampled by a factor of ) located in 22 green valley (GV) and 12
main sequence (MS) galaxies. For a given galaxy type (MS or GV), the retired
spaxels are found to be offset from the sequences formed by the star-forming
spaxels on the rSFMS, rSK, and rMGMS planes, toward lower absolute values of
sSFR, SFE, and by 1.1, 0.6, and 0.5 dex. The scaling
relations for GV galaxies are found to be distinct from that of the MS
galaxies, even if the analyses are restricted to the star-forming spaxels only.
It is found that for star-forming spaxels, sSFR, SFE, and in GV
galaxies are reduced by 0.36, 0.14, and 0.21 dex, respectively, compared
to those in MS galaxies. Therefore, the suppressed sSFR/SFE/ in
GV galaxies are associated with not only an increased proportion of retired
regions in GV galaxies but also a depletion of these quantities in star-forming
regions. Finally, the reduction of SFE and in GV galaxies
relative to MS galaxies is seen in both bulge and disk regions (albeit with
larger uncertainties), suggesting that statistically, quenching in the GV
population may persist from the inner to the outer regions
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ALMaQUEST. IV. The ALMA-MaNGA QUEnching and STar Formation (ALMaQUEST) Survey
The ALMaQUEST (ALMA-MaNGA QUEnching and STar formation) survey is a program
with spatially-resolved CO(1-0) measurements obtained with the Atacama
Large Millimeter Array (ALMA) for 46 galaxies selected from the Mapping Nearby
Galaxies at Apache Point Observatory (MaNGA) DR15 optical integral-field
spectroscopic survey. The aim of the ALMaQUEST survey is to investigate the
dependence of star formation activity on the cold molecular gas content at kpc
scales in nearby galaxies. The sample consists of galaxies spanning a wide
range in specific star formation rate (sSFR), including starburst (SB),
main-sequence (MS), and green valley (GV) galaxies. In this paper, we present
the sample selection and characteristics of the ALMA observations, and showcase
some of the key results enabled by the combination of spatially-matched stellar
populations and gas measurements. Considering the global (aperture-matched)
stellar mass, molecular gas mass, and star formation rate of the sample, we
find that the sSFR depends on both the star formation efficiency (SFE) and the
molecular gas fraction (), although the correlation with the
latter is slightly weaker. Furthermore, the dependence of sSFR on the molecular
gas content (SFE or ) is stronger than that on either the atomic
gas fraction or the molecular-to-atomic gas fraction, albeit with the small HI
sample size. On kpc scales, the variations in both SFE and
within individual galaxies can be as large as 1-2 dex thereby demonstrating
that the availability of spatially-resolved observations is essential to
understand the details of both star formation and quenching processes.STFC
ER
Primary skin fibroblasts as a model of Parkinson's disease
Parkinson's disease is the second most frequent neurodegenerative disorder. While most cases occur sporadic mutations in a growing number of genes including Parkin (PARK2) and PINK1 (PARK6) have been associated with the disease. Different animal models and cell models like patient skin fibroblasts and recombinant cell lines can be used as model systems for Parkinson's disease. Skin fibroblasts present a system with defined mutations and the cumulative cellular damage of the patients. PINK1 and Parkin genes show relevant expression levels in human fibroblasts and since both genes participate in stress response pathways, we believe fibroblasts advantageous in order to assess, e.g. the effect of stressors. Furthermore, since a bioenergetic deficit underlies early stage Parkinson's disease, while atrophy underlies later stages, the use of primary cells seems preferable over the use of tumor cell lines. The new option to use fibroblast-derived induced pluripotent stem cells redifferentiated into dopaminergic neurons is an additional benefit. However, the use of fibroblast has also some drawbacks. We have investigated PARK6 fibroblasts and they mirror closely the respiratory alterations, the expression profiles, the mitochondrial dynamics pathology and the vulnerability to proteasomal stress that has been documented in other model systems. Fibroblasts from patients with PARK2, PARK6, idiopathic Parkinson's disease, Alzheimer's disease, and spinocerebellar ataxia type 2 demonstrated a distinct and unique mRNA expression pattern of key genes in neurodegeneration. Thus, primary skin fibroblasts are a useful Parkinson's disease model, able to serve as a complement to animal mutants, transformed cell lines and patient tissues
The evolution of superluminous supernova LSQ14mo and its interacting host galaxy system
We present and analyse an extensive dataset of the superluminous supernova (SLSN) LSQ14mo (z = 0.256), consisting of a multi-colour light curve from-30 d to +70 d in the rest-frame (relative to maximum light) and a series of six spectra from PESSTO covering-7 d to +50 d. This is among the densest spectroscopic coverage, and best-constrained rising light curve, for a fast-declining hydrogen-poor SLSN. The bolometric light curve can be reproduced with a millisecond magnetar model with 4 M⊙ ejecta mass, and the temperature and velocity evolution is also suggestive of a magnetar as the power source. Spectral modelling indicates that the SN ejected 6 M⊙ of CO-rich material with a kinetic energy of 7 × 1051 erg, and suggests a partially thermalised additional source of luminosity between-2 d and +22 d. This may be due to interaction with a shell of material originating from pre-explosion mass loss. We further present a detailed analysis of the host galaxy system of LSQ14mo. PESSTO and GROND imaging show three spatially resolved bright regions, and we used the VLT and FORS2 to obtain a deep (five-hour exposure) spectra of the SN position and the three star-forming regions, which are at a similar redshift. The FORS2 spectrum at + 300 days shows no trace of SN emission lines and we place limits on the strength of [O i] from comparisons with other Ic supernovae. The deep spectra provides a unique chance to investigate spatial variations in the host star-formation activity and metallicity. The specific star-formation rate is similar in all three components,as is the presence of a young stellar population. However, the position of LSQ14mo exhibits a lower metallicity, with 12 + log (O/H) = 8.2 in both the R23 and N2 scales (corresponding to 0.3 Z⊙). We propose that the three bright regions in the host system are interacting, which could induce gas flows triggering star formation in low-metallicity regions. © ESO, 2017
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