164 research outputs found
Economic Effects of Bridal Ceremonies on Small Business Enterprises in USA: An exploratory Study
The wedding industry plays a significant role in the U.S. society and economy. The internal and external treats of the wedding industry remain one of the major issues the industry is encountering. The current intense competition and declining marriage rates remain vital challenges and must be well managed to stimulate the industry growth. This research is investigating the motives behind the industry challenges to propose the most efficient solutions and overcome these underperformances. Our research data reveals that the rapid development and utilization of technology have increased wedding costs, inspired labor market changes and raised moral laxity in society. Hence, the collaboration between small business enterprises and the US government is imperative to instigate the industry expansion. Keywords: wedding, bridal ceremonies, small business, vertical integration, instigat
Implicit Chain Particle Model for Polymer Grafted Nanoparticles
Matrix-free nanocomposites made from polymer grafted nanoparticles (PGN)
represent a paradigm shift in materials science because they greatly improve
nanoparticle dispersion and offer greater tunability over rheological and
mechanical properties in comparison to neat polymers. Utilizing the full
potential of PGNs requires a deeper understanding of how polymer graft length,
density, and chemistry influence interfacial interactions between particles.
There has been great progress in describing these effects with molecular
dynamics (MD). However, the limitations of the length and time scales of MD
make it prohibitively costly to study systems involving more than a few PGNs.
Here, we address some of these challenges by proposing a new modeling paradigm
for PGNs using a strain-energy mapping framework involving potential of mean
force (PMF) calculations. In this approach, each nanoparticle is coarse-grained
into a representative particle with chains treated implicitly, namely, the
implicit chain particle model (ICPM). Using a chemistry-specific CG-MD model of
PMMA as a testbed, we derive the effective interaction between particles
arranged in a closed-packed lattice configuration by matching bulk
dilation/compression strain energy densities. The strain-rate dependence of the
mechanical work in ICPM is also discussed. Overall, the ICPM model increases
the computational speed by approximately 5-6 orders of magnitude compared to
the CG-MD models. This novel framework is foundational for particle-based
simulations of PGNs and their blends and accelerates the understanding and
predictions of emergent properties of PGN materials
Learning Pair Potentials using Differentiable Simulations
Learning pair interactions from experimental or simulation data is of great
interest for molecular simulations. We propose a general stochastic method for
learning pair interactions from data using differentiable simulations
(DiffSim). DiffSim defines a loss function based on structural observables,
such as the radial distribution function, through molecular dynamics (MD)
simulations. The interaction potentials are then learned directly by stochastic
gradient descent, using backpropagation to calculate the gradient of the
structural loss metric with respect to the interaction potential through the MD
simulation. This gradient-based method is flexible and can be configured to
simulate and optimize multiple systems simultaneously. For example, it is
possible to simultaneously learn potentials for different temperatures or for
different compositions. We demonstrate the approach by recovering simple pair
potentials, such as Lennard-Jones systems, from radial distribution functions.
We find that DiffSim can be used to probe a wider functional space of pair
potentials compared to traditional methods like Iterative Boltzmann Inversion.
We show that our methods can be used to simultaneously fit potentials for
simulations at different compositions and temperatures to improve the
transferability of the learned potentials.Comment: 12 pages, 10 figure
A Study of the Merger History of the Galaxy Group HCG 62 Based on X-Ray Observations and SPH Simulations
We choose the bright compact group HCG 62, which was found to exhibit both
excess X-ray emission and high Fe abundance to the southwest of its core, as an
example to study the impact of mergers on chemical enrichment in the intragroup
medium. We first reanalyze the high-quality Chandra and XMM-Newton archive data
to search for the evidence for additional SN II yields, which is expected as a
direct result of the possible merger-induced starburst. We reveal that, similar
to the Fe abundance, the Mg abundance also shows a high value in both the
innermost region and the southwest substructure, forming a high-abundance
plateau, meanwhile all the SN Ia and SN II yields show rather flat
distributions in in favor of an early enrichment. Then we carry
out a series of idealized numerical simulations to model the collision of two
initially isolated galaxy groups by using the TreePM-SPH GADGET-3 code. We find
that the observed X-ray emission and metal distributions, as well as the
relative positions of the two bright central galaxies with reference to the
X-ray peak, can be well reproduced in a major merger with a mass ratio of 3
when the merger-induced starburst is assumed. The `best-match' snapshot is
pinpointed after the third pericentric passage when the southwest substructure
is formed due to gas sloshing. By following the evolution of the simulated
merging system, we conclude that the effects of such a major merger on chemical
enrichment are mostly restricted within the core region when the final relaxed
state is reached.Comment: Accepted for publication in the Astrophysical Journa
Leptin deficiency in CD8+ T cells ameliorates non-segmental vitiligo by reducing interferon-γ and Granzyme B
BackgroundVitiligo is an autoimmune skin disease mainly mediated by CD8+ T cells, which affects about 0.1%-2% population of the world. Leptin plays a critical role in regulating the activation of CD8+ T cells. However, the effect of Leptin on vitiligo remains unclear.ObjectivesTo explore the effect of leptin on CD8+ T cells and its influence on vitiligo.MethodsRNA sequencing and Quantitative Real-time PCR (RT-qPCR) were used to explore the differentially expressed genes. Immunofluorescence staining was performed on skin lesions. Leptin in serum was detected by enzyme linked immunosorbent assay (ELISA). The peripheral blood mononuclear cells were detected by flow cytometry after leptin stimulation for 72 hours. A vitiligo model was established by monobenzone on Leptin KO mice.Results557 differentially expressed genes were found, including 154 up-regulated and 403 down-regulated genes. Lipid metabolism pathways showed a close relationship to the pathogenesis of vitiligo, especially the PPAR signaling pathway. RT-qPCR (p = 0.013) and immunofluorescence staining (p = 0.0053) verified that LEPR expressed significantly higher in vitiligo. The serum leptin level of vitiligo patients was significantly lower than that of healthy controls (p = 0.0245). The interferon-γ subset of CD8+LEPR+ T cells from vitiligo patients was significantly higher (p = 0.0189). The protein level of interferon-γ was significantly increased after leptin stimulation in vitro (p = 0.0217). In mice, Leptin deficiency resulted in less severe hair depigmentation. Leptin deficiency also resulted in significantly lower expressed vitiligo-related genes, such as Cxcl9 (p = 0.0497), Gzmb (p < 0.001), Ifng (p = 0.0159), and Mx1 (p < 0.001) after modeling.ConclusionLeptin could promote the progression of vitiligo by enhancing the cytotoxic function of CD8+ T cells. Leptin may become a new target for vitiligo treatment
Attribute-Based Conditional Proxy Re-Encryption in the Standard Model under LWE
Attribute-based conditional proxy re-encryption (AB-CPRE) allows delegators to carry out attribute-based control on the delegation of decryption by setting policies and attribute vectors. The fine-grained control of AB-CPRE makes it suitable for a variety of applications, such as cloud storage and distributed file systems. However, all existing AB-CPRE schemes are constructed under classical number-theoretic assumptions, which are vulnerable to quantum cryptoanalysis. Therefore, we propose the first AB-CPRE scheme based on the learning with errors (LWE) assumption. Constructed from fully key-homomorphic encryption (FKHE) and key-switching techniques, our scheme is unidirectional, single-hop, and enables a polynomial-deep boolean circuit as its policy. Furthermore, we split the ciphertext into two independent parts to avoid two-level or multi-level encryption/decryption mechanisms. Taking advantage of it, we then extend our single-hop AB-CPRE into an efficient and concise multi-hop one. No matter how many transformations are performed, the re-encrypted ciphertext is in constant size, and only one encryption/decryption algorithm is needed. Both of our schemes are proved to be selective secure against chosen-plaintext attacks (CPA) in the standard model
A New Direct Process to Prepare YBa2Cu3O7- films on Biaxially Textured Ag{110}<211>
YBCO films were successfully prepared on biaxially textured Ag{110}
substrates by using pulsed laser deposition. X-ray diffraction results showed
that the degree of preferential orientation of Ag{110} substrates varied
with increasing annealing temperature. With a thin template layer deposited at
low temperature, YBCO film with c-axis orientation and in-plane biaxial
alignment could be obtained at high deposition temperature. Scanning electron
microscopy observation revealed that YBCO grains enlarged but Ag grains on the
surface of the YBCO films became smaller with increasing deposition
temperature. At optimal deposition conditions, Ag atoms diffuse into the YBCO
grain boundaries, and then fill in the weak-link regions in the YBCO film,
resulting in the conduction easier. Jc value of 5105A/cm2 was obtained
at 77K and zero magnetic field for the best YBCO film in our work.Comment: 9 pages, 4 figure
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