4,758 research outputs found
Cluster X-ray line at from axion-like dark matter
The recently reported X-ray line signal at
from a stacked spectrum of various galaxy clusters and the Andromeda galaxy may
be originating from a decaying dark matter particle of the mass . A
light axion-like scalar is suggested as a natural candidate for dark matter and
its production mechanisms are closely examined. We show that the right amount
of axion relic density with the preferred parameters, and , can be naturally obtainable
from the decay of inflaton. If the axions were produced from the saxion decay,
it could not have constituted the total relic density due to the bound from
structure formation. Nonetheless, the saxion decay is an interesting
possibility, because the line and dark radiation can be
addressed simultaneously, being consistent with the Planck data. Small
misalignment angles of the axion, ranging between depending on the reheating temperature, can also be the source of
axion production. The model with axion misalignment can satisfy the constraints
for structure formation and iso-curvature perturbation.Comment: 14 pages, significant changes in the form, matched to the journal
versio
Diboson Excesses Demystified in Effective Field Theory Approach
We study the collider implication of a neutral resonance which decays to
several diboson final states such as , , and via a
minimal set of effective operators. We consider both CP-even and CP-odd bosonic
states with spin 0, 1, or 2. The production cross sections for the bosonic
resonance states are obtained with the effective operators involving gluons
(and quarks), and the branching fractions are obtained with the operators
responsible for the interactions with electroweak gauge bosons. We demonstrate
that each scenario allows for a broad parameter space which could accommodate
the recently-reported intriguing excesses in the ATLAS diboson final states,
and discuss how the CP states and spin information of the resonance can be
extracted at the LHC run II.Comment: 22 pages, 6 figures, main text slightly modified with results
unchange
A study on the change in the characteristics of the gait of elderly people when somatosensory stimulation was applied to their ankle joint
The gait is the most complicated, habitual, and involuntary activity of humans and is a result of the cooperation of the central and peripheral nervous systems that harmoniously mobilize the sensory receptors, nervous system, and muscles. A sensory signal binds to a somatosensory system proprioceptor to obtain information on posture. This study was designed to analyze the change in the characteristics of a gait when stimulation is applied in the somatosensory system that controls the balance of the body. A result of the GRF obtained from the force plate and gyroscope signals from the sensor attached on ankle joint were obtained to compare the change before and after the somatosensory stimulation. The result of this study proved a potential of somatosensory stimulation in improving balance, which could be used in studies on the balance of positions and gait improvement
Broad Phase Transition of Fluorite-Structured Ferroelectrics for Large Electrocaloric Effect
Field-induced ferroelectricity in (doped) hafnia and zirconia has attracted increasing interest in energy-related applications, including energy harvesting and solid-state cooling. It shows a larger isothermal entropy change in a much wider temperature range compared with those of other promising candidates. The field-induced phase transition occurs in an extremely wide temperature range, which contributes to the giant electrocaloric effect. This article examines the possible origins of a large isothermal entropy change, which can be related to the extremely broad phase transitions in fluorite-structured ferroelectrics. While the materials possess a high entropy change associated with the polar–nonpolar phase transition, which can contribute to the high energy performance, the higher breakdown field compared with perovskites practically determines the available temperature range
Functional enhancement of neuronal cell behaviors and differentiation by elastin-mimetic recombinant protein presenting Arg-Gly-Asp peptides
Background: Integrin-mediated interaction of neuronal cells with extracellular matrix (ECM) is important for the control of cell adhesion, morphology, motility, and differentiation in both in vitro and in vivo systems. Arg-Gly-Asp (RGD) sequence is one of the most potent integrin-binding ligand found in many native ECM proteins. An elastin-mimetic recombinant protein, TGPG[VGRGD(VGVPG)6]20WPC, referred to as [RGD-V6]20, contains multiple RGD motifs to bind cell-surface integrins. This study aimed to investigate how surface-adsorbed recombinant protein can be used to modulate the behaviors and differentiation of neuronal cells in vitro. For this purpose, biomimetic ECM surfaces were prepared by isothermal adsorption of [RGD-V6]20 onto the tissue culture polystyrene (TCPS), and the effects of protein-coated surfaces on neuronal cell adhesion, spreading, migration, and differentiation were quantitatively measured using N2a neuroblastoma cells.Results: The [RGD-V6]20 was expressed in E. coli and purified by thermally-induced phase transition. N2a cell attachment to either [RGD-V6]20 or fibronectin followed hyperbolic binding kinetics saturating around 2 μM protein concentration. The apparent maximum cell binding to [RGD-V6]20 was approximately 96% of fibronectin, with half-maximal adhesion on [RGD-V6]20 and fibronectin occurring at a coating concentration of 2.4 × 10-7 and 1.4 × 10-7 M, respectively. The percentage of spreading cells was in the following order of proteins: fibronectin (84.3% ± 6.9%) > [RGD-V6]20 (42.9% ± 6.5%) > [V7]20 (15.5% ± 3.2%) > TCPS (less than 10%). The migration speed of N2a cells on [RGD-V6]20 was similar to that of cells on fibronectin. The expression of neuronal marker proteins Tuj1, MAP2, and GFAP was approximately 1.5-fold up-regulated by [RGD-V6]20 relative to TCPS. Moreover, by the presence of both [RGD-V6]20 and RA, the expression levels of NSE, TuJ1, NF68, MAP2, and GFAP were significantly elevated.Conclusion: We have shown that an elastin-mimetic protein consisting of alternating tropoelastin structural domains and cell-binding RGD motifs is able to stimulate neuronal cell behaviors and differentiation. In particular, adhesion-induced neural differentiation is highly desirable for neural development and nerve repair. In this context, our data emphasize that the combination of biomimetically engineered recombinant protein and isothermal adsorption approach allows for the facile preparation of bioactive matrix or coating for neural tissue regeneration. © 2012 Jeon et al.; licensee BioMed Central Ltd.1
Federated Learning with Intermediate Representation Regularization
In contrast to centralized model training that involves data collection,
federated learning (FL) enables remote clients to collaboratively train a model
without exposing their private data. However, model performance usually
degrades in FL due to the heterogeneous data generated by clients of diverse
characteristics. One promising strategy to maintain good performance is by
limiting the local training from drifting far away from the global model.
Previous studies accomplish this by regularizing the distance between the
representations learned by the local and global models. However, they only
consider representations from the early layers of a model or the layer
preceding the output layer. In this study, we introduce FedIntR, which provides
a more fine-grained regularization by integrating the representations of
intermediate layers into the local training process. Specifically, FedIntR
computes a regularization term that encourages the closeness between the
intermediate layer representations of the local and global models.
Additionally, FedIntR automatically determines the contribution of each layer's
representation to the regularization term based on the similarity between local
and global representations. We conduct extensive experiments on various
datasets to show that FedIntR can achieve equivalent or higher performance
compared to the state-of-the-art approaches. Our code is available at
https://github.com/YLTun/FedIntR.Comment: IEEE BigComp 202
Trends and Associated Factors of Use of Opioid, Heroin, and Cannabis Among Patients for Emergency Department Visits in Nevada: 2009–2017
To examine trends and contributing factors of opioid, heroin, and cannabis-associated emergency department (ED) visits in Nevada. The 2009 to 2017 Nevada State ED database (n = 7,950,554 ED visits) were used. Use of opioid, heroin, and cannabis, respectively, was identified by the International Classification of Diseases, 9th & 10th Revisions. Three multivariable models, one for each of the 3 dependent variables, were conducted. Independent variables included year, insurance status, race/ethnicity, use of other substance, and mental health conditions. The number of individuals with opioid, heroin, cannabis-associated ED visits increased 3%, 10%, and 23% annually from 2009 to 2015, particularly among 21 to 29 age group, females, and African Americans. Use of other substance (odds ratio [OR] = 3.91; 95% confidence interval [CI] = 3.84, 3.99; reference - no use of other substance), mental health conditions (OR = 2.48; 95% CI = 2.43, 2.53; reference – without mental health conditions), Medicaid (OR = 1.41; 95% CI = 1.38, 1.44; reference – non-Medicaid), Medicare (OR = 1.44; 95% CI = 1.39, 1.49; reference – non-Medicare) and uninsured patients (OR = 1.52; 95% CI = 1.49, 1.56; reference - insured) were predictors of all three substance-associated ED visits. With a steady increase in trends of opioid, heroin, and cannabis-associated ED visits in recent years, the main contributing factors include patient sociodemographic factors, mental health conditions, and use of other substances
A Surgically Treated Case of Chronic Necrotizing Aspergillosis with Pleural Invasion
Aspergillus is a ubiquitous fungus and can cause many levels of disease severity. Chronic necrotizing aspergillosis is a rare disease and few cases have been reported in Korea. We experienced a case of pleural aspergillosis that was treated successfully with medical and surgical interventions. The 52-year-old man who was diagnosed with chronic necrotizing pulmonary aspergillosis underwent surgical treatment including a lobectomy, decortication, and myoplasty. The patient was also medically treated with amphotericin B followed by voriconazole. Pleural irrigation with amphotericin B was also performed. A multi-dimensional approach should be considered for treating chronic necrotizing pulmonary aspergillosis
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