Grand-canonical variational approach for the t-J model

Gutzwiller-projected BCS wave function or the resonating-valence-bond (RVB) state in the 2D extended t-J model is investigated by using the variational Monte Carlo technique. We show that the results of ground-state energy and excitation spectra calculated in the grand-canonical scheme allowing particle number to fluctuate are essentially the same as previous results obtained by fixing the number of particle in the canonical scheme if the grand thermodynamic potential is used for minimization. To account for the effect of Gutzwiller projection, a fugacity factor proposed by Laughlin and Anderson few years ago has to be inserted into the coherence factor of the BCS state. Chemical potential, particle number fluctuation, and phase fluctuation of the RVB state, difficult or even impossible to be calculated in the canonical ensemble, have been directly measured in the grand-canonical picture. We find that except for La-214 materials, the doping dependence of chemical potential is consistent with experimental findings on several cuprates. Similar to what has been reported by scanning tunneling spectroscopy experiments, the tunneling asymmetry becomes much stronger as doping decreases. We found a very large enhancement of phase fluctuation in the underdoped regime.Comment: 9 pages, 6 figure

Convergence of quantum random walks with decoherence

In this paper, we study the discrete-time quantum random walks on a line subject to decoherence. The convergence of the rescaled position probability distribution $p(x,t)$ depends mainly on the spectrum of the superoperator $\mathcal{L}_{kk}$. We show that if 1 is an eigenvalue of the superoperator with multiplicity one and there is no other eigenvalue whose modulus equals to 1, then $\hat {P}(\frac{\nu} {\sqrt t},t)$ converges to a convex combination of normal distributions. In terms of position space, the rescaled probability mass function $p_t (x, t) \equiv p(\sqrt t x, t)$, $x \in Z/\sqrt t$, converges in distribution to a continuous convex combination of normal distributions. We give an necessary and sufficient condition for a U(2) decoherent quantum walk that satisfies the eigenvalue conditions. We also give a complete description of the behavior of quantum walks whose eigenvalues do not satisfy these assumptions. Specific examples such as the Hadamard walk, walks under real and complex rotations are illustrated. For the O(2) quantum random walks, an explicit formula is provided for the scaling limit of $p(x,t)$ and their moments. We also obtain exact critical exponents for their moments at the critical point and show universality classes with respect to these critical exponents

Enhancing National Chi Nan University Campus’s Ecological Friendliness by Creating a Butterfly Habitat Using Reclaimed Water

The campus of National Chi Nan University (NCNU), Taiwan is about 150 hectares, and surrounded by dense valleys and forests that provides a habitat for many wild animals. In order to further enhance the ecological friendliness of the campus, the school implemented courses to create habitats for butterflies around the Sun Pond in the campus. The reclaimed water, originated from Water Treatment Factory, in the Sun Pond is used to irrigate the vegetation in the habitat to enhance the ecological conservation value. From 2019 to 2020, a number of 17 species with 670 individuals and food plants for butterflies was planted, and special instruction signs focusing on butterfly ecology were set up, so that staff and students can better understand the actions and goals in ecological conservation of green university. From 2020 to mid-2021, a total of 6 courses with 750 students (13% of the total number of students) visited the wonderful habit. The number of 22 species of butterflies was recorded in the habitat and this number was an average of 132 per 30 minutes, which shows that the construction of the habitats is successful. The creation of the butterfly habitat is in line with United Nations Sustainable Development Goal (SDG) 6 and SDG 15. The habitat has become a distinguished place for environmental education in the university. In the future, more community residents and tourists can experience this fantastic place and realize the efforts and achievements in ecological conservation succeeded by NCNU.Keyword: Butterfly Habitat, Reclaimed Water, Green University, Environmental Education, Community Resident

Vesicular translocation of PARP-1 to cytoplasm causes ADP-ribosylation and disassembly of vimentin filaments during microglia activation induced by LPS

ADP-ribosylation plays a significant role in various biological processes including genomic stability maintenance, transcriptional regulation, energy metabolism, and cell death. Using macrodomain pull-down assay with microglia lysates and MALDI-TOF-MS analysis, we identified vimentin as a major protein highly ADP-ribosylated by the poly(ADP-ribose) polymerases-1 (PARP-1) in response to LPS. ABT-888, a potent inhibitor of PARP-1/2 blocks the disassembly and ADP-ribosylation of vimentin. PARP-1 is a highly abundant nuclear protein. Its nuclear functions in repairing DNA damages induced by various stress signals, such as inflammatory stresses, have been well studied. In contrast, limited studies have been done on the cytoplasmic role(s) of PARP-1. Our study focuses on the cytoplasmic role of PARP-1 during microglia activation. Using immunofluorescence microscopy and Western blotting, we showed that a significant amount of PARP-1 is present in the cytosol of microglia cells stimulated and activated by LPS. Live cell imaging showed the translocation of nuclear PARP-1-EGFP to the cytoplasm in vesicular structures upon LPS stimulation. ABT-888 and U0126 can block this translocation. Immunofluorescence staining with various organelle marker antibodies revealed that PARP-1 vesicles show colocalization with Lamin A/C, suggesting they might be derived from the nuclear envelope through nuclear envelope budding. In conclusion, we demonstrated that PARP-1 is translocated from the nucleus to cytoplasm via vesicles upon LPS stimulation and that cytoplasmic PARP-1 causes ADP-ribosylation and disassembly of vimentin filaments during microglia activation induced by LPS

Serum repressing efflux pump CDR1 in Candida albicans

BACKGROUND: In the past decades, the prevalence of candidemia has increased significantly and drug resistance has also become a pressing problem. Overexpression of CDR1, an efflux pump, has been proposed as a major mechanism contributing to the drug resistance in Candida albicans. It has been demonstrated that biological fluids such as human serum can have profound effects on antifungal pharmacodynamics. The aim of this study is to understand the effects of serum in drug susceptibility via monitoring the activity of CDR1 promoter of C. albicans. RESULTS: The wild-type C. albicans cells (SC5314) but not the cdr1/cdr1 mutant cells became more susceptible to the antifungal drug when the medium contained serum. To understand the regulation of CDR1 in the presence of serum, we have constructed CDR1 promoter-Renilla luciferase (CDR1p-RLUC) reporter to monitor the activity of the CDR1 promoter in C. albicans. As expected, the expression of CDR1p-RLUC was induced by miconazole. Surprisingly, it was repressed by serum. Consistently, the level of CDR1 mRNA was also reduced in the presence of serum but not N-acetyl-D-glucosamine, a known inducer for germ tube formation. CONCLUSION: Our finding that the expression of CDR1 is repressed by serum raises the question as to how does CDR1 contribute to the drug resistance in C. albicans causing candidemia. This also suggests that it is important to re-assess the prediction of in vivo therapeutic outcome of candidemia based on the results of standard in vitro antifungal susceptibility testing, conducted in the absence of serum

Metastable Charge Distribution Between Degenerate Landau Levels

We study two dimensional electron systems confined in wide quantum wells whose subband separation is comparable with the Zeeman energy. Two N = 0 Landau levels from different subbands and with opposite spins are pinned in energy when they cross each other and electrons can freely transfer between them. When the disorder is strong, we observe clear hysteresis in our data corresponding to instability of the electron distribution in the two crossing levels. When the intra-layer interaction dominates, multiple minima appear when a Landau level is 1/3 or 2/3 filled and fractional quantum hall effect can be stabilized

Differential Regulation of Adhesion and Phagocytosis of Resting and Activated Microglia by Dopamine

Microglia, the immune competent cells of the central nervous system (CNS), normally exist in a resting state characterized by a ramified morphology with many processes, and become activated to amoeboid morphology in response to brain injury, infection, and a variety of neuroinflammatory stimuli. Many studies focused on how neurotransmitters affect microglia activation in pathophysiological circumstances. In this study, we tried to gain mechanistic insights on how dopamine (DA) released from neurons modulates cellular functions of resting and activated microglia. DA induced the reduction of the number of cellular processes, the increase of cell adhesion/spreading, and the increase of vimentin filaments in resting primary and BV2 microglia. In contrast to resting cells, DA downregulated the cell spreading and phagocytosis of microglia activated by LPS. DA also significantly downregulated ERK1/2 phosphorylation in activated microglia, but not in resting microglia. Downregulation of ERK1/2 by DA in activated microglia required receptor signaling. In contrast, we found a significant increase of p38MAPK activity by DA treatment in resting, but not in activated microglia. These latter effects required the uptake of DA through the high-affinity transporter but did not require receptor signaling. Activation of p38MAPK resulted in the increase of focal adhesion number via phosphorylation of paxillin at Ser83. These results indicate that DA might have a differential, depending upon the activation stage of microglia, impact on cellular functions such as adhesion and phagocytosis

Association between Depressive Symptoms and Food Insecurity among Indonesian Adults: Results from the 2007–2014 Indonesia Family Life Survey

Background: Depressive symptoms and food insecurity are two of the public health concerns in developing countries. Food insecurity is linked to several chronic diseases, while little is known about the association between food insecurity and depressive symptoms among adults. A person with limited or uncertain availability or access to nutritionally sucient, socially relevant, and safe foods is defined as a food-insecure person. Materials and methods: Data were obtained from 8613 adultswho participated in the Indonesia Family Life Survey (IFLS) in 2007 and 2014. The 10 items of the food frequency questionnaire (FFQ) were used in food consumption score analysis to assess food insecurity based on the concept of the World Food Program (WFP). Depressive symptoms were assessed using 10 items of the self-reported Center for Epidemiologic Studies Depression (CES-D) questionnaire. A linear and multiple logistic regression model with a generalized estimating equation was used to test the hypothesis while accounting for the health behaviors and sociodemographic characteristics. Results: Food consumption score was negatively associated with CES-D 10 score (-coe cients: 9.71 10 3 to 1.06 10 2; 95% CIs: 7.46 10 3 to 1.26 10 2). The borderline and poor food consumption group was positively associated with the depressive symptoms, both in the unadjusted and adjusted models (exponentiated –coe cients: 1.13 to 1.18; 95% CIs: 1.06 to 1.28). Conclusions: Depressive symptoms were positively significantly associated with food insecurity. Thus, health professionals must be aware of the issue, and should consider health and nutrition programs for adults at risk of food insecurit

A powerful and efficient multivariate approach for voxel-level connectome-wide association studies

We describe an approach to multivariate analysis, termed structured kernel principal component regression (sKPCR), to identify associations in voxel-level connectomes using resting-state functional magnetic resonance imaging (rsfMRI) data. This powerful and computationally efficient multivariate method can identify voxel-phenotype associations based on the whole-brain connectivity pattern of voxels, and it can detect linear and non-linear signals in both volume-based and surface-based rsfMRI data. For each voxel, sKPCR first extracts low-dimensional signals from the spatially smoothed connectivities by structured kernel principal component analysis, and then tests the voxel-phenotype associations by an adaptive regression model. The method's power is derived from appropriately modelling the spatial structure of the data when performing dimension reduction, and then adaptively choosing an optimal dimension for association testing using the adaptive regression strategy. Simulations based on real connectome data have shown that sKPCR can accurately control the false-positive rate and that it is more powerful than many state-of-the-art approaches, such as the connectivity-wise generalized linear model (GLM) approach, multivariate distance matrix regression (MDMR), adaptive sum of powered score (aSPU) test, and least-square kernel machine (LSKM). Moreover, since sKPCR can reduce the computational cost of non-parametric permutation tests, its computation speed is much faster. To demonstrate the utility of sKPCR for real data analysis, we have also compared sKPCR with the above methods based on the identification of voxel-wise differences between schizophrenic patients and healthy controls in four independent rsfMRI datasets. The results showed that sKPCR had better between-sites reproducibility and a larger proportion of overlap with existing schizophrenia meta-analysis findings. Code for our approach can be downloaded from https://github.com/weikanggong/sKPCR. [Abstract copyright: Copyright © 2018 Elsevier Inc. All rights reserved.

Vascular endothelial growth factor regulates myeloid cell leukemia-1 expression through neuropilin-1-dependent activation of c-MET signaling in human prostate cancer cells

<p>Abstract</p> <p>Background</p> <p>Myeloid cell leukemia-1 (Mcl-1) is a member of the Bcl-2 family, which inhibits cell apoptosis by sequestering pro-apoptotic proteins Bim and Bid. Mcl-1 overexpression has been associated with progression in leukemia and some solid tumors including prostate cancer (PCa). However, the regulatory mechanism for Mcl-1 expression in PCa cells remains elusive.</p> <p>Results</p> <p>Immunohistochemical analyses revealed that Mcl-1 expression was elevated in PCa specimens with high Gleason grades and further significantly increased in bone metastasis, suggesting a pivotal role of Mcl-1 in PCa metastasis. We further found that vascular endothelial growth factor (VEGF) is a novel regulator of Mcl-1 expression in PCa cells. Inhibition of endogenous Mcl-1 induced apoptosis, indicating that Mcl-1 is an important survival factor in PCa cells. Neuropilin-1 (NRP1), the "co-receptor" for VEGF₁₆₅isoform, was found to be highly expressed in PCa cells, and indispensible in the regulation of Mcl-1. Intriguingly, VEGF₁₆₅promoted physical interaction between NRP1 and hepatocyte growth factor (HGF) receptor c-MET, and facilitated c-MET phosphorylation <it>via </it>a NRP1-dependent mechanism. VEGF₁₆₅induction of Mcl-1 may involve rapid activation of Src kinases and signal transducers and activators of transcription 3 (Stat3). Importantly, NRP1 overexpression and c-MET activation were positively associated with progression and bone metastasis in human PCa specimens and xenograft tissues.</p> <p>Conclusions</p> <p>This study demonstrated that Mcl-1 overexpression is associated with PCa bone metastasis. Activation of VEGF₁₆₅-NRP1-c-MET signaling could confer PCa cells survival advantages by up-regulating Mcl-1, contributing to PCa progression.</p