A Regularized Newton Method for Computing Ground States of Bose-Einstein condensates

In this paper, we propose a regularized Newton method for computing ground states of Bose-Einstein condensates (BECs), which can be formulated as an energy minimization problem with a spherical constraint. The energy functional and constraint are discretized by either the finite difference, or sine or Fourier pseudospectral discretization schemes and thus the original infinite dimensional nonconvex minimization problem is approximated by a finite dimensional constrained nonconvex minimization problem. Then an initial solution is first constructed by using a feasible gradient type method, which is an explicit scheme and maintains the spherical constraint automatically. To accelerate the convergence of the gradient type method, we approximate the energy functional by its second-order Taylor expansion with a regularized term at each Newton iteration and adopt a cascadic multigrid technique for selecting initial data. It leads to a standard trust-region subproblem and we solve it again by the feasible gradient type method. The convergence of the regularized Newton method is established by adjusting the regularization parameter as the standard trust-region strategy. Extensive numerical experiments on challenging examples, including a BEC in three dimensions with an optical lattice potential and rotating BECs in two dimensions with rapid rotation and strongly repulsive interaction, show that our method is efficient, accurate and robust.Comment: 25 pages, 6 figure

Silencing of rhomboid domain containing 1 to inhibit the metastasis of human breast cancer cells in vitro

Objective(s): A growing body of evidence indicates that rhomboid domain containing 1 (RHBDD1) plays an important role in a variety of physiological and pathological processes, including tumorigenesis. We aimed to determine the function of RHBDD1 in breast cancer cells. Materials and Methods: In this study, we used the Oncomine™ database to determine the expression patterns of RHBDD1 in normal and breast cancer tissues. We performed lentiviral transfection of RHBDD1-specific small interfering RNA into the breast cancer cell lines ZR-75-30 and MDA-MB-231 in order to investigate the effects of RHBDD1 deficiency on breast cancer metastasis. Results: We found that knockdown of RHBDD1 inhibited breast cancer cell migration and invasion in vitro. Moreover, knockdown of RHBDD1 promoted epithelial–mesenchymal transition (EMT) by suppressing the expression of MPP2, MPP9, fibronectin 1, vimentin, SRY-box 2, zinc finger E-box binding homeobox 1, and snail family transcriptional repressor 1, and promoting the expression of cadherin 1. Additionally, knockdown of RHBDD1 inhibited the protein expression and phosphorylation of Akt.Conclusion: Our data indicate that RHBDD1 overexpression may promote breast cancer metastasis via the regulation of EMT, suggesting that RHBDD1 may be an important regulator of breast cancer metastasis

NeurIPS 2020 EfficientQA Competition: Systems, Analyses and Lessons Learned

We review the EfficientQA competition from NeurIPS 2020. The competition focused on open-domain question answering (QA), where systems take natural language questions as input and return natural language answers. The aim of the competition was to build systems that can predict correct answers while also satisfying strict on-disk memory budgets. These memory budgets were designed to encourage contestants to explore the trade-off between storing retrieval corpora or the parameters of learned models. In this report, we describe the motivation and organization of the competition, review the best submissions, and analyze system predictions to inform a discussion of evaluation for open-domain QA

Molecular Mechanism of Secondary Endocrine Resistance in Luminal Breast Cancer

Objective. The molecular mechanism of secondary resistance in Luminal breast cancer was studied to provide new ideas for the treatment of breast cancer. Methods. The sensitivity of the downregulation of myeloid leukemia factor 1-interacting proteins (MLF1IP) to Tamoxifen (TAM) was tested by the Cell Counting Kit-8 (CCK-8). The apoptosis of MLF1IP-mediated resistance was analyzed by flow cytometry (FCM) with/without TAM. Western blot was used in detecting various kinds of apoptosis and the expression of the protein related to the phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway to study the molecular mechanism of secondary endocrine resistance in Luminal breast cancer. Results. The downregulation of MLF1IP could significantly increase the drug sensitivity of Michigan Cancer Foundation-7 (MCF-7) cells and also inhibit the proliferation of MCF-7 cells under the stimulation of drugs. Western blot results showed that the expression of Bcl-2-associated X (BAX), Caspase3, Caspase7, and Caspase9 proteins increased when MLF1IP was downregulated. The results of the PI3K/AKT signaling pathway revealed that the phosphatase and tensin homolog deleted on chromosome ten (PTEN) protein expression of MCF7-shRNA was higher than that of MCF7-NC cells, while the expression of p-AKT was lower than that of MCF7-NC cells. Conclusions. (1) MLF1IP-related apoptosis resistance plays an essential role in MLF1IP-mediated secondary resistance of breast cancer cells. (2) MLF1IP promotes AKT phosphorylation by inhibiting the PTEN expression, thus activating the PI3K/AKT signaling pathway and causing the secondary resistance of Luminal breast cancer. (3) MLF1IP can be used as a factor to predict the endocrine resistance of Luminal breast cancer

Major flavonoid constituents and short-term effects of Chun Mee tea in rats

Chun Mee tea is a kind of green tea produced in China mainly for export purposes. Foam quantity is usually used as an index for evaluating the quality of Chun Mee tea. In the current study, we compared the concentrations of total saponin and flavonoids between foamy and low-foam Chun Mee tea. Our research confirmed that the total saponin and O-glycosylated flavonoid concentrations were related to the foam quantity of Chun Mee teas. We also studied the short-term safety effects of extract supplementation with foamy and low-foam Chun Mee tea in rats by routine blood tests and analysis of liver and kidney function, and blood lipids. Our results showed that both types of tea extract supplementations did not cause any observable adverse effects or impair either liver or kidney function. Additionally, this study confirmed the beneficial effects of Chun Mee tea extract supplementation on the decrease of total plasma cholesterol

Causal effects of genetically predicted endometriosis on breast cancer: a two-sample Mendelian randomization study

Abstract This study used a Mendelian randomization (MR) approach to investigate the causal relationship between genetically predicted endometriosis (EMS) and breast cancer risk. A total of 122,977 cases and 105,974 controls were included in the analysis, with gene-level summary data obtained from the Breast Cancer Association Consortium (BCAC). An inverse variance-weighting approach was applied to assess the causal relationship between EMS and breast cancer risk, and weighted median and MR-Egger regression methods were used to evaluate pleiotropy. Results showed a causal relationship between EMS and a decreased risk of overall breast cancer (odds ratio [OR] 0.95; 95% CI 0.90–0.99, p = 0.02). Furthermore, EMS was associated with a lower risk for estrogen receptor (ER)-positive breast cancer in a subgroup analysis based on immunohistochemistry type (OR 0.91; 95% CI 0.86–0.97, p = 0.005). However, there was no causal association between ER-negative breast cancer and survival (OR 1.00; 95% CI 0.94–1.06, p = 0.89). Pleiotropy was not observed. These findings provide evidence of a relationship between EMS and reduced breast cancer risk in invasive breast cancer overall and specific tissue types, and support the results of a previous observational study. Further research is needed to elucidate the mechanisms underlying this association

Responses of Rhizosphere Bacterial and Fungal Communities to the Long-Term Continuous Monoculture of Water Oat

As an cultivated aquatic vegetable, the long-term continuous monocropping of water oat results in the frequent occurrence of diseases, the deterioration of ecological system and decreased quality of water oat. In this study, real-time quantitative PCR (qPCR) and Illumina high-throughput sequencing were used to determine the dynamic changes in bacterial and fungal communities in rhizosphere soil under continuous cropping of water oat for 1, 5, 10, 15 and 20 years (Y1, Y5, Y10, Y15 and Y20), and soil properties and enzyme activities were also determined. Results showed that the contents of soil organic carbon (SOC), total nitrogen (TN), alkali-hydrolyzable nitrogen (AN), available phosphorus (AP) and the activities of four soil enzymes increased in Y5 and Y10 and then decreased in Y15 and Y20. Spearman correlation analysis identified SOC, TN, AP and AN as the main factors that affect the four enzyme activities. The qPCR results showed that there was no significant difference in bacterial abundance between the different planting years, while the fungal abundance first increased and then decreased. The long-term continuous planting of water oat (Y15 and Y20) significantly reduced the operational taxonomic unit numbers and the Shannon, Chao1, and ACE indices of rhizosphere bacteria and fungi. The bacterial and fungal community compositions were markedly affected by the continuous planting year. The relative abundances of Bacteroidetes and Firmicutes decreased significantly in Y10 and Bacteroidetes increased significantly in Y15. Relative abundances of dominated Mortierellomycota and Ascomycota phyla increased with the continuous cropping years, while Rozellomycota presented the opposite trend. The AK, AN, and SOC were the main factors that changed the bacterial community, while AK and AP significantly shifted the fungal community. Thus, long-term continuous planting of water oat resulted in the deterioration of soil nutrients and microbial communities. The results provided a reference for the remediation of soil under continuous water oat planting and sustainable development of water oat industry