35,992 research outputs found
A note on a result of Guo and Isaacs about p-supersolubility of finite groups
No full textIn this note, global information about a finite group is obtained by assuming that certain subgroups of some given order are S-semipermutable. Recall that a subgroup H of a finite group G is said to be S-semipermutable if H permutes with all Sylow subgroups of G of order coprime to |H|. We prove that for a fixed prime p, a given Sylow p-subgroup P of a finite group G, and a power d of p dividing |G| such that 1≤dd . This extends the main result of Guo and Isaacs in (Arch. Math. 105:215-222 2015). We derive some theorems that extend some known results concerning S-semipermutable subgroups
The SNP g.133A>C in SCD promoter affects gene expression and quali-quantitative properties of river buffalo milk.
No full textThe stearolyl-CoA desaturase (SCD) gene has been deeply investigated in ruminants because of its effect on milk fat composition. In river buffalo, the SNP g.133A>C at the gene promoter has been associated with milk quality and yield. However, the biological reason for such effects remained unexplored. In this study we have combined mRNA profile analysis, electromobility shift assay and q-PCR to elucidate the role of this SNP on gene transcription and its effects on milk fat traits. A preliminary genotyping of the SNP g.133A>C was carried out on a sample of 303 river buffaloes for the choosing individuals for the downstream applications. Allele frequencies showed an increase of the minor allele C (0.25) compared with previous findings (0.16). Six animals (two for each genotype) were chosen for cloning and a total of 216 positive cDNA recombinant clones for SCD (72 per genotype) were analyzed by PCR. All clones showed the same length on agarose gel, therefore random clones were chosen for the sequencing. No qualitative differences were found and all gene transcripts resulted correctly assembled. Electrophoretic mobility shift assay was performed to evaluate the binding of the transcription factor Sp1 to DNA sequences including the SNP g.133A>C. The genotype CC showed a stronger intensity binding than the genotype AA in two different conditions as result of Sp1 motif cluster. The following q-PCR confirmed an up-regulation of the CC compared with AA and AC genotypes. The association study with milk fat traits revealed a favourable effect of the allele C. The heterozygous genotype had the highest values for MUFAs, oleic acid (C18:1 c9), PUFAs and odd branched-chain fatty acids (OBCFAs), and the lowest values for SFAs, atherogenic and thrombogenic indices, and significantly differed from the AA genotype. The AC genotype had been previously associated with higher milk yield. Therefore, the SNP g.133A>C is a marker with a dual impact and it is an interesting candidate for assisted selection programs in river buffalo. These data clarified the biological role of the SNP g.133A>C in the SCD promoter and how it affects the gene function, providing important knowledge on the genetic background of lipid metabolism, including the future possibility of selecting 1 alleles with quantitative or qualitative favourable effects
The single nucleotide polymorphism g.133A>C in the stearoyl CoA desaturase gene (SCD) promoter affects gene expression and quali-quantitative properties of river buffalo milk
No full textThe stearoyl-CoA desaturase (SCD) gene has been
investigated in depth in ruminants because of its effect
on milk fat composition. In river buffalo, the single
nucleotide polymorphism (SNP) g.133A>C in the gene
promoter has been associated with milk quality and
yield. However, the biological reason for such effects
remains unexplored. In this study, we combined mRNA
profile analysis, an electromobility shift assay, and
quantitative PCR to elucidate the role of this SNP on
gene transcription and its effects on milk fat traits. A
preliminary genotyping of g.133A>C was carried out
on a group of 303 river buffaloes to choose individuals
for the downstream applications. Analysis of allele
frequencies showed an increase in the minor allele C
(0.25) compared with previous findings (0.16). Six animals
(2 for each genotype) were chosen for cloning and
216 positive cDNA recombinant clones for SCD (72 per
genotype) were analyzed by PCR. All clones showed the
same length on agarose gel; therefore, random clones
were chosen for sequencing. No qualitative differences
were found and all gene transcripts assembled correctly.
An electrophoretic mobility shift assay was performed
to evaluate the binding of the transcription factor Sp1
to DNA sequences including g.133A>C. Genotype CC
showed a higher binding affinity (mean ± standard
error of the mean) than genotype AA in 2 different
conditions [Enzo buffer (EB), Enzo Life Science Inc.,
Farmingdale, NY: 201.77 ± 4.06 vs. 141.65 ± 3.77 band
intensity values and Poletto buffer (PB): 95.90 ± 1.15
vs. 67.30 ± 2.14 band intensity values]. The subsequent
quantitative PCR confirmed the upregulation of the CC
genotype compared with the AA and AC genotypes.
The association study with milk fat traits revealed a favorable effect of allele C. The heterozygous genotype
had the highest values for monounsaturated fatty acids,
oleic acid (C18:1 cis-9), polyunsaturated fatty acids,
and odd- and branched-chain fatty acids, and the lowest
values for saturated fatty acids and atherogenic
and thrombogenic indices; the heterozygous genotype
differed significantly from the AA genotype. The AC
genotype has previously been associated with higher
milk yield. Therefore, the g.133A>C SNP is a marker
with dual effects and is an interesting candidate for
assisted selection programs in river buffalo. These data
clarified the biological role of the SNP g.133A>C in the
SCD promoter and how it affects gene function, providing
important knowledge on the genetic background
of lipid metabolism, including the future possibility
of selecting alleles with quantitatively or qualitatively
favorable effects
Kinematic Simulation and Structure Analysis of a Morphing Flap
No full textThis thesis presents a study on the design and analysis of a morphing flap
structure integrated with actuation mechanism for potential application to large
aircraft. Unlike the conventional rigid flap mounted on the wing trailing edge,
the morphing flap is designed as a unitized structural system integrated with
three primary components: the upper and lower flexible skins reinforced by
stringers, an eccentric beam actuation mechanism (EBAM) with discs fixed on it,
and the connection of the discs with the stringers. Based on the EBAM concept
proposed by Dr Guo in previous research [1], the current study has been
focused on the EBAM design and optimization, kinematic simulation and
structural modelling of the morphing flap.
Although a lot of efforts have been made to develop the morphing flap in
previous research, it is lack of detailed design of the disc-skin linkage and clear
view on the mechanism optimization in relation to the shape requirement. The
main objective of this research is to meet the morphing shape requirements and
calculate the actuation torque for a specified morphing flap. Firstly effort was
made to design and optimize the disc shape and locations in the EBAM for the
best matching of the specified morphing shape with minimum actuation torque
demand. It is found that minimum three discs are required and their locations
have little effect on the actuation torque. Secondly attention was focused on
designs of the disc and a C-linkage with the stringers. To ensure that the C-
linkage works in practice, a twisted stringer flange design was proposed. Thirdly
the actuation mechanism was integrated with the stiffened skin to play the role
of an active rib in the flap structure. Based on the design, FE modelling and
analysis of the morphing flap structure was carried out. The behaviour of the
morphing flap under the internal actuation and external aerodynamic load was
applied for stress analysis and detailed design of the structures. Finally the
kinematics of the integrated morphing flap was simulated by using CATIA to
demonstrate the feasibility and the effectiveness of the improved design
Investigating the Role of Guanosine on Human Neuroblastoma Cell Differentiation and the Underlying Molecular Mechanisms
No full textNeuroblastoma arises from neural crest cell precursors failing to complete the process of differentiation. Thus, agents helping tumor cells to differentiate into normal cells can represent a valid therapeutic strategy. Here, we evaluated whether guanosine (GUO), a natural purine nucleoside, which is able to induce differentiation of many cell types, may cause the differentiation of human neuroblastoma SH-SY5Y cells and the molecular mechanisms involved. We found that GUO, added to the cell culture medium, promoted neuron-like cell differentiation in a time- and concentration-dependent manner. This effect was mainly due to an extracellular GUO action since nucleoside transporter inhibitors reduced but not abolished it. Importantly, GUO-mediated neuron-like cell differentiation was independent of adenosine receptor activation as it was not altered by the blockade of these receptors. Noteworthy, the neuritogenic activity of GUO was not affected by blocking the phosphoinositide 3-kinase pathway, while it was reduced by inhibitors of protein kinase C or soluble guanylate cyclase. Furthermore, the inhibitor of the enzyme heme oxygenase-1 but not that of nitric oxide synthase reduced GUO-induced neurite outgrowth. Interestingly, we found that GUO was largely metabolized into guanine by the purine nucleoside phosphorylase (PNP) enzyme released from cells. Taken together, our results suggest that GUO, promoting neuroblastoma cell differentiation, may represent a potential therapeutic agent; however, due to its spontaneous extracellular metabolism, the role played by the GUO-PNP-guanine system needs to be further investigated
On injectors of Finite Soluble Groups
No full textGuo, W. On injectors of Finite Soluble Groups / Wenbin Guo, N. T. Vorob’ev // Communications in Algebra. – 2008. – Vol. 36, № 9. – P. 3200–3208.In this article, we give the description of the f)-injectors of a finite soluble group, for a Hartley class f).The authors are grateful for the helpful suggestions of the referee. Research of the first author is supported by a NNSF grant of China(#10771180)
Some restrictions on normalizers or centralizers in finite p-groups
No full textWe study three restrictions on normalizers or centralizers in finite p-groups, namely: (i) |NG(H):H|≤pk for every (Formula Presented.), (ii) |NG(〈g〉):〈g〉|≤pk for every (Formula Presented.), and (iii) |CG(g): 〈g〉 ≤ pk for every (Formula Presented.). We prove that (i) and (ii) are equivalent, and that the order of a non-Dedekind finite p-group satisfying any of these three conditions is bounded for p > 2. (For condition (i) this fact was proved earlier by Zhang and Guo [14].) More precisely, we get the best possible bound for the order of G in all three cases, which is |G| ≤ p2k+2. The order of the group cannot be bounded for p = 2, but we are able to identify two infinite families of 2-groups out of which |G| ≤ 2f(k) for some function f(k) depending only on k
Constraining the p-Mode-g-Mode Tidal Instability with GW170817
No full textWe analyze the impact of a proposed tidal instability coupling p modes and g modes within neutron stars on GW170817. This nonresonant instability transfers energy from the orbit of the binary to internal modes of the stars, accelerating the gravitational-wave driven inspiral. We model the impact of this instability on the phasing of the gravitational wave signal using three parameters per star: An overall amplitude, a saturation frequency, and a spectral index. Incorporating these additional parameters, we compute the Bayes factor (lnB!pgpg) comparing our p-g model to a standard one. We find that the observed signal is consistent with waveform models that neglect p-g effects, with lnB!pgpg=0.03-0.58+0.70 (maximum a posteriori and 90% credible region). By injecting simulated signals that do not include p-g effects and recovering them with the p-g model, we show that there is a ≃50% probability of obtaining similar lnB!pgpg even when p-g effects are absent. We find that the p-g amplitude for 1.4 MâŠneutron stars is constrained to less than a few tenths of the theoretical maximum, with maxima a posteriori near one-Tenth this maximum and p-g saturation frequency ∼70 Hz. This suggests that there are less than a few hundred excited modes, assuming they all saturate by wave breaking. For comparison, theoretical upper bounds suggest a103 modes saturate by wave breaking. Thus, the measured constraints only rule out extreme values of the p-g parameters. They also imply that the instability dissipates a1051 erg over the entire inspiral, i.e., less than a few percent of the energy radiated as gravitational waves
Why are stock market returns correlated with future economic activities?
No full textStock price, because it is a forward-looking variable, forecasts economic activities. An unexpected increase in stock price reflects that (i) future dividend growth is higher and/or (ii) future discount rates are lower than previously anticipated; therefore, the increase predicts higher output and investment. As well, other studies argue for an important relation between the expected stock market return and investment. In this paper, Hui Guo analyzes the relative importance of these mechanisms by using Campbell and Shiller’s (1988) method to decompose stock market return into three parts: expected return, a shock to the expected future return, and a shock to the expected future dividend growth. Contrary to the conventional wisdom, the author finds that dividend shocks are a rather weak predictor for future economic activities. Moreover, the expected return and shocks to the expected future return display different predictive patterns. The results shown here, collectively, explain why the forecasting power of stock market return is rather limited.Stock market
Estrous cycle- and acute stress-related changes of rat ovarian immunoreactive corticotropin-releasing factor
No full textCorticotropin-releasing factor (CRF), the major regulator of the stress response within the central nervous system, is also present at peripheral sites, including the gonads, and the gene encoding its own receptor can be finely induced in selective ovarian compartments in both control and stressful conditions during the gonadal life cycle. The present study, therefore, investigated the influence of both gonadal function and estrous cycle on the immunoreactive CRF (irCRF) contents in the immature and adult rat ovary. In addition, the effect of an acute (5 min) or chronic intermittent (twice a day for 4 days) cold swimming stress on ovarian irCRF contents was evaluated. High-performance liquid chromatography (HPLC), gel-chromatography (Sephadex G-75, 45 x 1 cm) and a direct radioimmunoassay were performed to measure irCRF ovarian contents. The HPLC elution profile of irCRF in ovarian tissues of adult rats was superimposable on that of synthetic rat/human CRF and gel-chromatograms performed according to the phase of the estrous cycle revealed higher irCRF contents at proestrus. Total irCRF ovarian content was undetectable both in control and acute stressed immature rats, while adult rats showed the highest values at proestrus (p < 0.0001). The acute stress exposure induced a significant increase (p < 0.0001) of irCRF ovarian contents only at proestrus, without affecting irCRF at the other phases of the estrous cycle. Finally, no significant changes were found in ovarian irCRF after chronic intermittent stress. The proestrus-related changes of ovarian irCRF, confirming the adult ovary as an extrahypothalamic source of CRF, may constitute a neuropeptidergic signal involved in the gonadal reproductive cycle. Furthermore, the stress-related changes of ovarian irCRF indicated that the gonad may be locally sensitive to acute stressful stimul
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