251 research outputs found
Improved Solution Search Performance of Constrained MOEA/D Hybridizing Directional Mating and Local Mating
In this study, we propose an improvement to the direct mating method, a
constraint handling approach for multi-objective evolutionary algorithms, by
hybridizing it with local mating. Local mating selects another parent from the
feasible solution space around the initially selected parent. The direct mating
method selects the other parent along the optimal direction in the objective
space after the first parent is selected, even if it is infeasible. It shows
better exploration performance for constraint optimization problems with
coupling NSGA-II, but requires several individuals along the optimal direction.
Due to the lack of better solutions dominated by the optimal direction from the
first parent, direct mating becomes difficult as the generation proceeds. To
address this issue, we propose a hybrid method that uses local mating to select
another parent from the neighborhood of the first selected parent, maintaining
diversity around good solutions and helping the direct mating process. We
evaluate the proposed method on three mathematical problems with unique Pareto
fronts and two real-world applications. We use the generation histories of the
averages and standard deviations of the hypervolumes as the performance
evaluation criteria. Our investigation results show that the proposed method
can solve constraint multi-objective problems better than existing methods
while maintaining high diversity.Comment: Revised paper presented at ISMSI2023, 9pages, 8 figures (Online
String Junction Model, Cluster Hypothesis, Penta-Quark Baryon and Tetra-Quark Meson
Thirty years ago we proposed string junction model of hadrons and examined
structure and reaction of hadrons including exotic ones. Mass of exotic
hadrons of light quarks is roughly given by , where
is the total number of junctions and GeV is the ordinary light
baryon mass. In this paper we introduce "cluster hypothesis" into the model by
which mass of a complex hadron is given by the sum of masses of clusters
composing it. The hypothesis guarantees the established picture that mass
differences of hadrons of the same string junction structure are due to those
of the constituent quarks. A candidate for penta-quark baryon (1530
MeV, including a strange anti-quark {\sb} and that for tetra-quark
meson (4430 MeV) recently reported by the Bell collaboration are examined
in parallel. is considered to have non-strange partners, which are
lighter by the mass difference between strange and non-strange
quarks. Mass of such light penta-quark baryons with is expected to be
about 3 GeV. Several parameters of the model are estimated such as mass of
junction of MeV. While mass of light tetra-quark meson with
is expected to be about 2 GeV, (4430 MeV) containing
(u,c,{\db},{\cb}) gives a clue to determine some parameters of the model,
e.g., inter-junction string energy .Comment: 17 pages, 4 figures, correction is made, extensively revise
Molecular Target Therapy against Neuroblastoma
Neuroblastoma, originated from neural crest cells, is the most common extracranial solid tumor in childhood. Treatment is of limited utility for high-risk neuroblastoma and prognosis is poor. The high incidence of resistance of advanced-stage neuroblastoma to conventional therapies has prompt investigators to search for novel therapeutic approaches. Activation of IGF-R/PI3K/Akt/mTOR signaling pathway correlates with oncogenesis, poor prognosis, and chemotherapy resistance in neuroblastoma. Therefore, we investigated the effect of IGF-R/PI3K/Akt/mTOR signaling inhibitors in neuroblastoma. Significantly, IGF-R/PI3K/Akt/mTOR signaling inhibitors effectively inhibited cell growth and induced cell cycle arrest, autophagy, and apoptosis in neuroblastoma cells. Moreover, IGF-R/PI3K/Akt/mTOR signaling inhibitors significantly reduced tumor growth in mice xenograft model without apparent toxicity. Therefore, these results highlight the potential of IGF-R/PI3K/Akt/mTOR signaling pathway as a promising target for neuroblastoma treatment. Therefore, IGF-1R/PI3K/Akt/mTOR signaling inhibitors should be further investigated for treatment in clinical trials for high-risk neuroblastoma
Acoustic performance of a metascreen-based coating for maritime applications
Time and frequency domain numerical models are developed to investigate the acoustic performance of metascreen-based coatings for maritime applications. The coating designs are composed of periodic air-filled cavities embedded in a soft elastic medium, which is attached to a hard backing and submerged in water. Numerical results for an acoustic coating with cylindrical cavities are favourably compared with analytical and experimental results from the literature. Frequencies associated with peak sound absorption as a function of the geometric parameters of the cavities and material properties of the host medium are predicted. Variation in the cavity dimensions that modifies the cylindrical-shaped cavities to flat disks or thin needles is modelled. Results reveal that high sound absorption occurs when either the diameter or length of the cavities is reduced. Physical mechanisms governing sound absorption for the various cavity designs are described
Two-week administration of rivaroxaban resolved left atrial thrombus
AbstractAn 89-year-old man visited our hospital complaining of palpitation. Electrocardiography showed atrial fibrillation, and transthoracic echocardiography demonstrated a mobile thrombus of 28.6mmΓ20.8mm in the left atrium. Administration of a direct factor Xa inhibitor rivaroxaban (10mg/day) was started. The thrombus reduced its size and disappeared completely 2 weeks after the commencement of rivaroxaban treatment. To our knowledge, this is the first case report that rivaroxaban successfully dissolved left atrial thrombus during a short period. Rivaroxaban might have a potential, not only to prevent de novo thrombus formation, but also to dissolve established thrombi by direct inhibition of free and thrombus-associated factor Xa.<Learning objective: The incidence of nonvalvular atrial fibrillation is increasing, and left atrial thrombus is the major cause of cardiogenic thrombo-embolism that we need to prevent. Recently, novel oral anticoagulants have been developed. The effects of these agents on intracardiac thrombus resolution have not been fully elucidated. Data from a large cohort study would be required to assess efficacy of novel oral anticoagulants for thrombus resolution.
The 3β²-Phosphoadenosine 5β²-Phosphosulfate Transporters, PAPST1 and 2, Contribute to the Maintenance and Differentiation of Mouse Embryonic Stem Cells
Recently, we have identified two 3β²-phosphoadenosine 5β²-phosphosulfate (PAPS) transporters (PAPST1 and PAPST2), which contribute to PAPS transport into the Golgi, in both human and Drosophila. Mutation and RNA interference (RNAi) of the Drosophila PAPST have shown the importance of PAPST-dependent sulfation of carbohydrates and proteins during development. However, the functional roles of PAPST in mammals are largely unknown. Here, we investigated whether PAPST-dependent sulfation is involved in regulating signaling pathways required for the maintenance of mouse embryonic stem cells (mESCs), differentiation into the three germ layers, and neurogenesis. By using a yeast expression system, mouse PAPST1 and PAPST2 proteins were shown to have PAPS transport activity with an apparent Km value of 1.54 Β΅M or 1.49 Β΅M, respectively. RNAi-mediated knockdown of each PAPST induced the reduction of chondroitin sulfate (CS) chain sulfation as well as heparan sulfate (HS) chain sulfation, and inhibited mESC self-renewal due to defects in several signaling pathways. However, we suggest that these effects were due to reduced HS, not CS, chain sulfation, because knockdown of mouse N-deacetylase/N-sulfotransferase, which catalyzes the first step of HS sulfation, in mESCs gave similar results to those observed in PAPST-knockdown mESCs, but depletion of CS chains did not. On the other hand, during embryoid body formation, PAPST-knockdown mESCs exhibited abnormal differentiation, in particular neurogenesis was promoted, presumably due to the observed defects in BMP, FGF and Wnt signaling. The latter were reduced as a result of the reduction in both HS and CS chain sulfation. We propose that PAPST-dependent sulfation of HS or CS chains, which is regulated developmentally, regulates the extrinsic signaling required for the maintenance and normal differentiation of mESCs
Novel DMFC Cathode Catalysts Derived from TiO2 Powder
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Estimation of Miniaturized Carbon Fibers Obtained through Exfoliation Process
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Sex-specific post-translational regulation of the gamete fusogen GCS1 in the isogamous volvocine alga Gonium pectorale
Male and female, generally defined based on differences in gamete size and motility, likely have multiple independent origins, appearing to have evolved from isogamous organisms in various eukaryotic lineages. Recent studies of the gamete fusogen GCS1/HAP2 indicate that this protein is deeply conserved across eukaryotes, and its exclusive and/or functional expression generally resides in males or in male homologues. However, little is known regarding the conserved or primitive molecular traits of males and females within eukaryotes. Here, using morphologically indistinguishable isogametes of the colonial volvocine Gonium pectorale, we demonstrated that GCS1 is differently regulated between the sexes. G. pectorale GCS1 molecules in one sex (homologous to βmaleβ) are transported from the gamete cytoplasm to the protruded fusion site, whereas those of the other sex (βfemalesβ) are quickly degraded within the cytoplasm upon gamete activation. This molecular trait difference might be conserved across various eukaryotic lineages and may represent male and female prototypes originating from a common eukaryotic ancestor
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