6,965 research outputs found
Expression of bgt gene in transgenic birch (Betula platyphylla Suk.)
Study on the characteristics of integration and expression is the basis of genetic stability of foreign genes in transgenic trees. To obtain insight into the relationship of transgene copy number and expression level, we screened 22 transgenic birch lines. Southern blot analysis of the transgenic birch plants indicated that the copy number of bgt varies from one to four, of which 18.2% were single copy. Copy number of bgt and gus was different in 68% of transgenic birch plants, indicating that rearrangement or partial deletion appeared in the process of T-DNA integration. Transcriptional expression of bgt gene in transgenic birch plants was analyzed by Northern blot. TGS has been found in two transgenic lines with one and four copies of bgt. The ELISA result showed that the BGT protein expression level in the transgenic birch plants ranged from 0.000 to 0.283% of total soluble protein. In contrary to most studies, this research showed no significant correlation was found between copy number and expression level of bgt gene. Effective resistance of transgenic plants against Lymantria dispar was verified in feeding bioassays with the insects. Bioassays results were mostly consistent with the expression level of BGT insecticidal protein detected by ELISA and Western blot in transgenic birch. The paper showed transgenic birch had the high lethal effect on gypsy moth larvae (L. dispar). The practicality of this work will benefit not only the birch producers, but also the environment worldwide
Newton-Hooke Limit of Beltrami-de Sitter Spacetime, Principles of Galilei-Hooke's Relativity and Postulate on Newton-Hooke Universal Time
Based on the Beltrami-de Sitter spacetime, we present the Newton-Hooke model
under the Newton-Hooke contraction of the spacetime with respect to the
transformation group, algebra and geometry. It is shown that in Newton-Hooke
space-time, there are inertial-type coordinate systems and inertial-type
observers, which move along straight lines with uniform velocity. And they are
invariant under the Newton-Hooke group. In order to determine uniquely the
Newton-Hooke limit, we propose the Galilei-Hooke's relativity principle as well
as the postulate on Newton-Hooke universal time. All results are readily
extended to the Newton-Hooke model as a contraction of Beltrami-anti-de Sitter
spacetime with negative cosmological constant.Comment: 25 pages, 3 figures; some misprints correcte
The stability of transgene expression and effect of DNA methylation on post transcriptional gene silencing (PTGS) in birch
In this paper, we selected transgenic birch (Betula platyphylla Suk) plants, which included nonsilencing plants, transcriptional silence plants including TP96, TP74, TP73 and the post-transcriptional silence ones (TP67 and TP72). The transcription of the bgt gene in different tissues and organs were significantly different. The transcriptional level of bgt gene in the different tissues and organs was in the following order: leaf > female flower and male flower > branch bark > phloem > root. The transgenic lines were monitored for foreign gene expression for a long-term period of 8 years during their continuous growth under field conditions. GUS protein expression was not reactivated in the transgene silencing lines TP72 and TP67 when cultured in field conditions for long-term period. Meanwhile, no cases of gene silencing were observed again during the study period in the field conditions. Our results suggest that transgene expression in transgenic birch plants appears to be stable under field conditions. The frequencies of methylated cytosines in the code regions of gus gene was studied. Relation of transgene expression and DNA methylation was analysed. The data of restriction enzyme digestion (HpaII and MspI) indicated that DNA methylation resulted in post transcriptional gene silencing (PTGS) in transgenic birch.Key words: Transgenic birch, DNA methylation, gene silencing
Mass Hierarchy Determination Using Neutrinos from Multiple Reactors
We report the results of Monte Carlo simulations of a medium baseline reactor
neutrino experiment. The difference in baselines resulting from the 1 km
separations of Daya Bay and Ling Ao reactors reduces the amplitudes of 1-3
oscillations at low energies, decreasing the sensitivity to the neutrino mass
hierarchy. A perpendicular detector location eliminates this effect. We
simulate experiments under several mountains perpendicular to the Daya Bay/Ling
Ao reactors, considering in particular the background from the TaiShan and
YangJiang reactor complexes. In general the hierarchy can be determined most
reliably underneath the 1000 meter mountain BaiYunZhang, which is 44.5 km from
Daya Bay. If some planned reactors are not built then nearby 700 meter
mountains at 47-51 km baselines gain a small advantage. Neglecting their low
overhead burdens, hills near DongKeng would be the optimal locations. We use a
weighted Fourier transform to avoid a spurious dependence on the high energy
neutrino spectrum and find that a neural network can extract quantities which
determine the hierarchy marginally better than the traditional RL + PV.Comment: 22 pages, added details on the neural network (journal version
A comprehensive study of the open cluster NGC 6866
We present CCD photometry of the field of the open cluster NGC 6866.
Structural parameters of the cluster are determined utilizing the stellar
density profile of the stars in the field. We calculate the probabilities of
the stars being a physical member of the cluster using their astrometric data
and perform further analyses using only the most probable members. The
reddening and metallicity of the cluster were determined by independent
methods. The LAMOST spectra and the ultraviolet excess of the F and G type
main-sequence stars in the cluster indicate that the metallicity of the cluster
is about the solar value. We estimated the reddening
mag using the vs two-colour diagram. The distance modula, the
distance and the age of NGC 6866 were derived as mag,
pc and Myr, respectively, by fitting
colour-magnitude diagrams of the cluster with the PARSEC isochrones. The
Galactic orbit of NGC 6866 indicates that the cluster is orbiting in a slightly
eccentric orbit with . The mass function slope was
derived by using the most probable members of the cluster.Comment: 14 pages, including 16 figures and 7 tables, accepted for publication
in MNRAS. Table 4 in the manuscript will be published electronicall
The pseudokinase CaMKv is required for the activity-dependent maintenance of dendritic spines
published_or_final_versio
Fabrication and characterization of complex coacervates utilizing gelatin and carboxymethyl starch
BackgroundModified polysaccharides have greatly expanded applications in comparison with native polysaccharides due to their improved compatibility and interactions with proteins and active compounds in food-related areas. Nonetheless, there is a noticeable dearth of research concerning the utilization of carboxymethyl starch (CMS) as a microcapsule wall material in food processing, despite its common use in pharmaceutical delivery. The development of an economical and safe embedding carrier using CMS and gelatin (GE) holds immense importance within the food-processing industry. In this work, the potential of innovative coacervates formed by the combination of GE and CMS as a reliable, stable, and biodegradable embedding carrier is evaluated by turbidity measurements, thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and rheological measurements.ResultsThe results indicate that GE-CMS coacervates primarily resulted from electrostatic interactions and hydrogen bonding. The optimal coacervation was observed at pH 4.6 and with a GE/CMS blend ratio of 3:1 (w/w). However, the addition of NaCl reduced coacervation and made it less sensitive to temperature changes (35–55 \ub0C). In comparison with individual GE or CMS, the coacervates exhibited higher thermal stability, as shown by TGA. X-ray diffraction analysis shows that the GE-CMS coacervates maintained an amorphous structure. Rheological testing reveals that the GE-CMS coacervates exhibited shear-thinning behavior and gel-like properties.ConclusionOverall, attaining electroneutrality in the mixture boosts the formation of a denser structure and enhances rheological properties, leading to promising applications in food, biomaterials, cosmetics, and pharmaceutical products. \ua9 2023 Society of Chemical Industry
Geometries for Possible Kinematics
The algebras for all possible Lorentzian and Euclidean kinematics with
isotropy except static ones are re-classified. The geometries
for algebras are presented by contraction approach. The relations among the
geometries are revealed. Almost all geometries fall into pairs. There exists correspondence in each pair. In the viewpoint of
differential geometry, there are only 9 geometries, which have right signature
and geometrical spatial isotropy. They are 3 relativistic geometries, 3
absolute-time geometries, and 3 absolute-space geometries.Comment: 40 pages, 7 figure
Obvious enhancement of the total reaction cross sections for P with Si target and the possible relavent mechanisms
The reaction cross sections of P and the corresponding isotones on
Si target were measured at intermediate energies. The measured reaction cross
sections of the N=12 and 13 isotones show an abrupt increase at . The
experimental results for the isotones with as well as P can
be well described by the modified Glauber theory of the optical limit approach.
The enhancement of the reaction cross section for P could be explained
in the modified Glauber theory with an enlarged core. Theoretical analysis with
the modified Glauber theory of the optical limit and few-body approaches
underpredicted the experimental data of P. Our theoretical analysis
shows that an enlarged core together with proton halo are probably the
mechanism responsible for the enhancement of the cross sections for the
reaction of P+Si.Comment: 16 pages, 5 figures, to be published in Phys.Rev.
Neutron scattering and muon-spin spectroscopy studies of the magnetic triangular-lattice compounds LaNiWO ( = Sr, Ba)
We report on the geometrically frustrated two-dimensional triangular-lattice
magnets LaNiWO ( = Sr, Ba) studied mostly by means of
neutron powder diffraction (NPD) and muon-spin rotation and relaxation
(SR) techniques. The chemical pressure induced by the Ba-for-Sr
substitution suppresses the ferromagnetic (FM) transition from 6.3 K in the
Ba-compound to 4.8 K in the Sr-compound. We find that the space
group reproduces the NPD patterns better than the previously reported
space group. Both compounds adopt the same magnetic structure with
a propagation vector , in which the Ni
magnetic moments are aligned ferromagnetically along the -axis. The
zero-field {\textmu}SR results reveal two distinct internal fields (0.31 and
0.10 T), caused by the long-range ferromagnetic order. The small transverse
muon-spin relaxation rates reflect the homogeneous internal field distribution
in the ordered phase and, thus, further support the simple FM arrangement of
the Ni moments. The small longitudinal muon-spin relaxation rates, in
both the ferromagnetic- and paramagnetic states of ALaNiWO,
indicate that spin fluctuations are rather weak. Our results demonstrate that
chemical pressure indeed changes the superexchange interactions in
LaNiWO compounds, with the FM interactions being dominant.Comment: 8 pages, 7 figures; accepted by Phys. Rev. Material
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