13,956 research outputs found
Optimal sequencing of a set of positive numbers with the variance of the sequence's partial sums maximized
We consider the problem of sequencing a set of positive numbers. We try to
find the optimal sequence to maximize the variance of its partial sums. The
optimal sequence is shown to have a beautiful structure. It is interesting to
note that the symmetric problem which aims at minimizing the variance of the
same partial sums is proved to be NP-complete in the literature.Comment: 12 pages;Accepted for publication in Optimization Lette
Universal critical properties of the Eulerian bond-cubic model
We investigate the Eulerian bond-cubic model on the square lattice by means
of Monte Carlo simulations, using an efficient cluster algorithm and a
finite-size scaling analysis. The critical points and four critical exponents
of the model are determined for several values of . Two of the exponents are
fractal dimensions, which are obtained numerically for the first time. Our
results are consistent with the Coulomb gas predictions for the critical O()
branch for and the results obtained by previous transfer matrix
calculations. For , we find that the thermal exponent, the magnetic
exponent and the fractal dimension of the largest critical Eulerian bond
component are different from those of the critical O(2) loop model. These
results confirm that the cubic anisotropy is marginal at but irrelevant
for
Spousal concordance in adverse childhood experiences and the association with depressive symptoms in middle-aged and older adults: findings across China, the US, and Europe
Copyright \ua9 2023 Sun, Ren, Zhu, Cheng, Liu, Li, Xia, Yuan, Adeloye, Rudan, Canoy, Song, on behalf of the Global Health Epidemiology Research Group (GHERG). Background: Adverse childhood experiences (ACEs) are associated with higher depressive risks in adulthood. Whether respondents’ ACEs are associated with their own depressive symptoms in adulthood and whether this association extends to their spouses’ depressive symptoms remain unexplored. Methods: Data were from China Health and Retirement Longitudinal Study (CHARLS), the Health and Retirement Study (HRS), and the Survey of Health, Ageing and Retirement in Europe (SHARE). ACEs were categorized into overall, intra-familial, and extra-familial ACEs. Correlations of couples’ ACEs were calculated using Cramer’s V and partial Spearman’s correlation. Associations of respondents’ ACEs with spousal depressive symptoms were assessed using logistic regression, and mediation analyses were conducted to explore the mediating role of respondents’ depressive symptoms. Results: Significant associations between husbands’ ACEs and wives’ depressive symptoms, with odds ratios (ORs) and 95% confidence intervals (CIs) of 2.09 (1.36–3.22) for 4 or more ACEs in CHARLS, and 1.25 (1.06–1.48) and 1.38 (1.06–1.79) for 2 or more ACEs in HRS and SHARE. However, wives’ ACEs were associated with husbands’ depressive symptoms only in CHARLS and SHARE. Findings in intra-familial and extra-familial ACEs were consistent with our main results. Additionally, respondents’ depressive symptoms mediated more than 20% of the effect of respondents’ ACEs on spousal depressive symptoms. Conclusion: We found that ACEs were significantly correlated between couples. Respondents’ ACEs were associated with spousal depressive symptoms, with respondents’ depressive symptoms mediating the association. The bidirectional implications of ACEs on depressive symptoms should be considered within household and effective interventions are warranted
Study of the radiation damage caused by ion implantation in ZnO and its relation to magnetism
Defects play an important role in causing room temperature ferromagnetism in ZnO films. Multi-energy ion implantation has been employed to introduce different concentrations of non-magnetic ions, including argon, arsenic and krypton, into high-quality ZnO films and room temperature ferromagnetism has been observed for As and Kr implanted ZnO while none was observed for Ar doped films. The Monte Carlo simulation code SRIM was adopted to simulate the distributions of the implanted ions, the induced zinc and oxygen vacancies and the resulting interstitials. A common radiation damage parameter, known as the atomic displacements per atom (dpa), was calculated to quantify the primary radiation damage production. Our results show that the observed magnetic moment measured at low temperatures due to implantation with a given ion is proportional to the dpa. The constant of proportionality between the magnetism and the dpa depends on the implanted ion. This constant is largest for heavy, large ions. To obtain room temperature d0 magnetism in ZnO, non-magnetic ions with high mass are suggested to be implanted into ZnO films
Alternative Splicing of CEACAM1 by Hypoxia-Inducible Factor-1α Enhances Tolerance to Hepatic Ischemia in Mice and Humans
Although alternative splicing (AS) drives transcriptional responses and cellular adaptation to environmental stresses, its contributions in organ transplantation have not been appreciated. We have shown that carcinoembryonic antigen-related cell adhesion molecule (Ceacam1; CD66a), a transmembrane biliary glycoprotein expressed in epithelial, endothelial, and immune cells, determines donor liver transplant quality. Here, we studied how AS of Ceacam1 affects ischemia-reperfusion injury (IRI) in mouse and human livers. We found that the short cytoplasmic isoform Ceacam1-S increased during early acute and late resolution phases of warm IRI injury in mice. Transfection of Ceacam1-deficient mouse hepatocytes with adenoviral Ceacam1-S mitigated hypoxia-induced loss of cellular adhesion by repressing the Ask1/p-p38 cell death pathway. Nucleic acid-blocking morpholinos, designed to selectively induce Ceacam1-S, protected hepatocyte cultures against temperature-induced stress in vitro. Luciferase and chromatin immunoprecipitation assays identified direct binding of hypoxia-inducible factor-1α (Hif-1α) to the mouse polypyrimidine tract binding protein 1 (Ptbp1) promoter region. Dimethyloxalylglycine protected mouse livers from warm IR stress and hepatocellular damage by inhibiting prolyl hydroxylase domain-containing protein 1 and promoting AS of Ceacam1-S. Last, analysis of 46 human donor liver grafts revealed that CEACAM1-S positively correlated with pretransplant HIF1A expression. This also correlated with better transplant outcomes, including reduced TIMP1, total bilirubin, proinflammatory MCP1, CXCL10 cytokines, immune activation markers IL17A, and incidence of delayed complications from biliary anastomosis. This translational study identified mouse Hif-1α-controlled AS of Ceacam1, through transcriptional regulation of Ptbp1 promoter region, as a functional underpinning of hepatoprotection against IR stress and tissue damage in liver transplantation
Implications of a W^+W^- (ZZ) - Higgs - t c-bar$ Interaction for e^+e^- -> t c-bar \nu_e \nu_e-bar, t c-bar e^+ e^-, t c-bar Z and for t -> cW^+W^-, cZZ in a Two Higgs Doublet Model
The Standard Model with one extra Higgs doublet may give rise to enhanced
TREE-LEVEL flavor-changing-scalar coupling of a neutral Higgs to a pair of
top-charm quarks. This coupling may drive a large TREE-LEVEL effective
W^+W^-(ZZ) - Higgs - t c-bar interaction. As a result we find that the
reactions e^+e^- -> t c-bar \nu_e \nu_e-bar, t c-bar e^+ e^-, t c-bar Z and the
two rare top decays t -> cW^+W^-, t -> cZZ become very sensitive probes of such
an effective interaction. The most promising ones, e^+e^- -> t c-bar \nu_e
\nu_e-bar, t c-bar e^+ e^-, may yield several hundreds and up to thousands of
such events at the Next Linear Collider with a center of mass energy of
\sqrt{s}=0.5 - 2 TeV if the mass of the lightest neutral Higgs is a few hundred
GeV. The rare decays t -> cW^+W^- and t -> cZZ may be accessible at the LHC if
the mass of the lightest neutral Higgs lies in the narrow window 150 GeV < m_h
< 200 GeV.Comment: 18 pages, plain latex, 12 figures embadded in the text using epsfi
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