A unified framework for isotropic meshing based on narrow-band Euclidean distance transformation

In this paper, we propose a simple-yet-effective method for isotropic meshing relying on Euclidean distance transformation based centroidal Voronoi tessellation (CVT). Our approach improves the performance and robustness of computing CVT on curved domains while simultaneously providing high-quality output meshes. While conventional extrinsic methods compute CVTs in the entire volume bounded by the input model, we restrict the computation to a 3D shell of user-controlled thickness. Taking voxels which contain surface samples as sites, we compute the exact Euclidean distance transform on the GPU. Our algorithm is parallel and memory-efficient, and can construct the shell space for resolutions up to 20483 at interactive speed. The 3D centroidal Voronoi tessellation and restricted Voronoi diagrams are also computed efficiently on the GPU. Since the shell space can bridge holes and gaps smaller than a certain tolerance, and tolerate non-manifold edges and degenerate triangles, our algorithm can handle models with such defects, which typically cause conventional remeshing methods to fail. Our method can process implicit surfaces, polyhedral surfaces, and point clouds in a unified framework. Computational results show that our GPU-based isotropic meshing algorithm produces results comparable to state-of- the-art techniques, but is significantly faster than conventional CPU-based implementations.MOE (Min. of Education, S’pore)Published versio

Prostate Apoptosis Response-4 (PAR4) suppresses growth and invasion of breast cancer cells and is positively associated with patient survival

BACKGROUND: Prostate apoptosis response-4 (PAR4) plays an important role in apoptosis and survival of cancer cells. The current study aimed to further elucidate its role in breast cancer. MATERIALS AND METHODS: PAR4 expression in human breast cancer tissue was examined using quantitative polymerase chain reaction (qPCR) and immunohistochemical staining (IHC). Plasmids containing full-length human PAR4 coding sequence were used to overexpress PAR4 in breast cancer cells and the effect on cellular functions was examined using both in vitro functional assays and an in vivo murine model. RESULTS: Patients with low PAR4 transcript levels had poorer overall survival. PAR4 expression may be associated with differential expression of oestrogen receptors α and β in the tumours. Overexpression of PAR4 in MDA-MB-231 cells resulted in reduced cell growth and invasion, and also reduced in vivo tumour growth. CONCLUSION: Decreased PAR4 expression in breast cancer is associated with shorter survival. PAR4 suppresses growth and invasiveness of breast cancer cells

Effects of the COVID-19 pandemic and nationwide lockdown on trust, attitudes toward government, and well-being

The contagiousness and deadliness of COVID-19 have necessitated drastic social management to halt transmission. The immediate effects of a nationwide lockdown were investigated by comparing matched samples of New Zealanders assessed before (N = 1,003) and during the first 18 days of lockdown (N = 1,003). Two categories of outcomes were examined: (a) institutional trust and attitudes toward the nation and government and (b) health and well-being. Applying propensity score matching to approximate the conditions of a randomized controlled experiment, the study found that people in the pandemic/lockdown group reported higher trust in science, politicians, and police, higher levels of patriotism, and higher rates of mental distress compared to people in the prelockdown prepandemic group. Results were confirmed in within-subjects analyses. The study highlights social connectedness, resilience, and vulnerability in the face of adversity and has applied implications for how countries face this global challenge. (PsycInfo Database Record (c) 2020 APA, all rights reserved)

Prejudice toward Muslims in New Zealand: insights from the New Zealand attitudes and values study

Following the March 15th Christchurch terrorist attack, members of our research team have been repeatedly asked to comment or provide summary statistics from the New Zealand Attitudes and Values Study (NZAVS) on prejudice toward Muslims. As the curators of the NZAVS, we think that these findings should be in the public domain and accessible to as wide an audience as possible. In this article, we aim to provide a comprehensive summary of what we know from the NZAVS about attitudes toward Muslims and prejudice in New Zealand more generally. From 2012 onwards, the NZAVS included a feeling thermometer rating of people’s level of warmth toward Muslims. Here, we summarize what we know from the NZAVS about levels of warmth toward Muslims in the New Zealand population. We describe the distribution of thermometer ratings of warmth toward Muslims annually from 2012 onward, and compare these with thermometer ratings of a range of other groups that we also track. We present a regression model documenting the extent to which a broad range of demographics and aspects of personality are associated with low levels of warmth toward Muslims, and present a parallel model assessing warmth ratings toward immigrants as a comparison. Finally, we present a series of growth curve models outlining the relative level and rate of change over time in warmth toward Muslims and other groups from 2012-2018. Results from these analyses indicate that over the 2012-2018 period, levels of warmth toward Muslims in New Zealand were comparatively low relative to warmth ratings of other groups. However, warmth toward Muslims has also been steadily but gradually increasing over time in New Zealand