A Unified Hard-Constraint Framework for Solving Geometrically Complex PDEs

We present a unified hard-constraint framework for solving geometrically complex PDEs with neural networks, where the most commonly used Dirichlet, Neumann, and Robin boundary conditions (BCs) are considered. Specifically, we first introduce the "extra fields" from the mixed finite element method to reformulate the PDEs so as to equivalently transform the three types of BCs into linear forms. Based on the reformulation, we derive the general solutions of the BCs analytically, which are employed to construct an ansatz that automatically satisfies the BCs. With such a framework, we can train the neural networks without adding extra loss terms and thus efficiently handle geometrically complex PDEs, alleviating the unbalanced competition between the loss terms corresponding to the BCs and PDEs. We theoretically demonstrate that the "extra fields" can stabilize the training process. Experimental results on real-world geometrically complex PDEs showcase the effectiveness of our method compared with state-of-the-art baselines.Comment: 10 pages, 6 figures, NeurIPS 202

Task Aware Dreamer for Task Generalization in Reinforcement Learning

A long-standing goal of reinforcement learning is to acquire agents that can learn on training tasks and generalize well on unseen tasks that may share a similar dynamic but with different reward functions. A general challenge is to quantitatively measure the similarities between these different tasks, which is vital for analyzing the task distribution and further designing algorithms with stronger generalization. To address this, we present a novel metric named Task Distribution Relevance (TDR) via optimal Q functions of different tasks to capture the relevance of the task distribution quantitatively. In the case of tasks with a high TDR, i.e., the tasks differ significantly, we show that the Markovian policies cannot differentiate them, leading to poor performance. Based on this insight, we encode all historical information into policies for distinguishing different tasks and propose Task Aware Dreamer (TAD), which extends world models into our reward-informed world models to capture invariant latent features over different tasks. In TAD, we calculate the corresponding variational lower bound of the data log-likelihood, including a novel term to distinguish different tasks via states, to optimize reward-informed world models. Extensive experiments in both image-based control tasks and state-based control tasks demonstrate that TAD can significantly improve the performance of handling different tasks simultaneously, especially for those with high TDR, and demonstrate a strong generalization ability to unseen tasks

The Aroma Composition of Baby Ginger Paocai

The purpose of this study was to analyze the volatile compounds in baby ginger paocai and the fresh baby ginger and identify the key aroma components that contribute to the flavor of baby ginger paocai. A total of 86 volatile compounds from the two baby ginger samples were quantified; these compounds were extracted by headspace solid-phase microextraction (HS-SPME) and analyzed by gas chromatography–mass spectrometry (GC-MS). The aroma composition of baby ginger paocai was different from that of fresh baby ginger. Baby ginger paocai was characterized by the presence of aroma-active compounds which varied in concentration from 0.03 to 28.14%. Geranyl acetate was the aroma component with the highest relative content in baby ginger paocai. β-myrcene, eucalyptol, trans-β-ocimene, Z-ocimene, linalool, decanal, cis-citral, geraniol, geranyl acetate, curcumene, and β-bisabolene contributed to the overall aroma of the product of baby ginger paocai which had gone through a moderate fermentation process

TEMPO-oxidized biodegradable bacterial cellulose (BBC) membrane coated with biologically-synthesized silver nanoparticles (AgNPs) as a potential antimicrobial agent in aquaculture (In vitro)

The emergence of drug-resistance pathogens is one of the major challenges in aquaculture. Finding an alternative remedy for diseases control is now crucial and indispensable. The present study aimed to develop different silver nanocomposite BBC membranes and verified their bactericidal activity either synergistically or independently against seven threatening aquatic pathogens (Vibrio harveyi, V. parahaemolyticus, V. alginolyticus, V. vulnificus, Aeromonas hydrophila, A. veronii and Streptococcus iniae) using membrane disc diffusion and antibacterial log reduction assays. The aqueous extract of Pseudomonas sp. was used for the synthesis of AgNPs and the composite BBC materials were characterized using FTIR, XRD, EDS, and FESEM to confirm their holding capacity of integrated AgNPs. Results evidenced that the TEMPO-oxidized BBC membrane coated with bacterial-based AgNPs exhibited an excellent crystallinity, porous properties, and strongest holding capacity. The membrane also showed potent bactericidal activity represented by wide inhibitory zones (17–20 mm), high killing ratios (95.93–99.86%). and high antibacterial log-reduction values (1.39–2.85). In conclusion, the synergism between TEMPO-oxidized BBC membrane and biologically synthesized AgNPs is an eco-friendly alternative remedy to control aquatic diseases without serious impact

Targeting PPARα for the Treatment and Understanding of Cardiovascular Diseases

Three members of the peroxisome proliferator-activated receptor (PPAR) family, PPARα, PPARγ, and PPARβ/δ, have been investigated widely over the past few decades. Although the roles of these PPARs and their agonists/antagonists were defined in clinical and basic studies, the conflicting results from these studies indicate that more analysis is needed to understand the roles of PPARs. PPARα is a ligand-activated transcription factor that contributes to the regulation of a variety of processes, ranging from inflammation and immunity to nutrient metabolism and energy homeostasis. In this review, we focus on the function and mechanisms of PPARα in the cardiovascular system under various pathological conditions, including vascular and heart injury, blood pressure regulation, and lipid disorder-related cardiovascular injury, as well as its polymorphisms and pharmacogenetic associations with cardiovascular diseases. The anti-inflammatory effect of PPARα in cardiovascular injury is mainly through inhibition of pro-inflammatory signaling pathways and improvement of the lipid profile. Moreover, PPARα also modulates the activity of endothelial nitric oxide synthase and resets the renin-angiotensin system to regulate vascular tone. PPARα gene variants appear to be associated with some cardiovascular risk factors, such as higher plasma lipid levels, cardiac growth, and increased risk of coronary artery disease. Nowadays, novel PPARα drugs with broad safety margins and therapeutic potential for metabolic syndrome and cardiovascular diseases are being developed and applied in the clinical setting. The insights from the current review shed new light on areas of further study and provide a better understanding of the role of PPARα in cardiovascular diseases

Kinetic Inference Resolves Epigenetic Mechanism of Drug Resistance in Melanoma

We resolved a mechanism connecting tumor epigenetic plasticity with non-genetic adaptive resistance to therapy, with MAPK inhibition of BRAF-mutant melanomas providing the model. These cancer cells undergo multiple, reversible drug-induced cell-state transitions, ultimately yielding a drug-resistant mesenchymal-like phenotype. A kinetic series of transcriptome and epigenome data, collected over two months of drug treatment and release, revealed changing levels of thousands of genes and extensive chromatin remodeling. However, a 3-step computational algorithm greatly simplified the interpretation of these changes, and revealed that the whole adaptive process was controlled by a gene module activated within just three days of treatment, with RelA driving chromatin remodeling to establish an epigenetic program encoding long-term phenotype changes. These findings were confirmed across several patient-derived cell lines and in melanoma patients under MAPK inhibitor treatment. Co-targeting BRAF and histone-modifying enzymes arrests adaptive transitions towards drug tolerance in epigenetically plastic melanoma cells and may be exploited therapeutically

The Association of Hypertension with Obesity and Metabolic Abnormalities among Chinese Children

A total of 8898 Chinese children (4580 boys and 4318 girls) aged 7–13 years in 6 cities of east China were recruited. Data on height, weight, waist circumference, blood pressure, serum lipid profiles, glucose, and insulin were collected. The overall prevalence of hypertension was 11.1%. Overweight and obese children had a higher risk of developing hypertension than their counterparts (29.1%, 17.4%, and 7.8%, resp.) (P=0.0001). The means levels of triglycerides, glucose, insulin, and HOMA-IR (1.0 mmol/L, 4.5 mmol/L, 8.4 mU/mL and 1.7, resp.) among hypertensive children were all significantly higher than their normotensive counterparts (0.8 mmol/L, 4.5 mmol/L, 5.9 mU/mL, and 1.2, resp.) (P=0.0001). Compared with the healthy children, the risk (odds ratio, OR) of having hypertension among children with high triglycerides, hyperglycemia, and metabolic syndrome was 1.4 (95% confidence interval (CI): 1.0–2.0, P=0.0334), 1.5 (95% CI: 0.9–2.5, P=0.0890), and 2.8 (95%CI: 1.5–5.4, P=0.0014), respectively, after controlling for age, gender, BMI, income level, parents' education level and puberty. In conclusion, overweight and obese children have higher risk of having hypertension and children with dyslipidemia, hyperglycemia, and metabolic syndrome and higher HOMA-IR have higher risk of developing hypertension

Variant rs9939609 in the FTO gene is associated with body mass index among Chinese children

<p>Abstract</p> <p>Background</p> <p>Fat-mass and obesity-associated (<it>FTO</it>) gene is a gene located in chromosome region 16q12.2. Genetic variants in <it>FTO </it>are associated with the obesity phenotype in European and Hispanic populations. However, this association still remains controversial in Asian population. We aimed to test the association of <it>FTO </it>genetic variants with obesity and obesity-related metabolic traits among children living in Beijing, China.</p> <p>Methods</p> <p>We genotyped <it>FTO </it>variants rs9939609 in 670 children (332 girls and 338 boys) aged 8-11 years living in Beijing, and analyzed its association with obesity and obesity-related metabolic traits. Overweight and obesity were defined by age- and sex-specific BMI reference for Chinese children. Obesity-related metabolic traits included fasting plasma glucose, lipid profiles, leptin, ghrelin, adiponectin and blood pressures.</p> <p>Results</p> <p>The frequency of rs9939609 A allele was 12.2%, which was 21.9% for the heterozygote and 1.2% for the homozygote of the A allele. The obesity prevalence among the carriers of AA/AT genotypes was significantly higher than that among those with TT genotype (36.4% <it>vs</it>. 22.6%, <it>P </it>= 0.004). Compared to the carrier of TT genotype, the likelihood of obesity was 1.79 (95% confidence interval (95% CI) 1.20-2.67, <it>P </it>= 0.004) for the carrier of AA/AT genotype, after adjustment of sex, age and puberty stages. The BMI Z-score of children with AA/AT genotype were significantly higher than that of their counterparts with the TT genotype (1.1 ± 0.1 <it>vs</it>. 0.8 ± 0.1, <it>P </it>= 0.02). The concentration of triglyceride was 1.03 ± 0.52 mmol/L among TT carrier and 1.13 ± 0.68 mmol/L among AA/AT carrier (<it>P </it>= 0.045). While, the concentrations of adiponectin were 18.0 ± 0.4 μg/ml among carriers of TT and 16.2 ± 0.7 μg/ml among subjects with AA/AT genotype (<it>P </it>= 0.03). The level of glucose marginally increased in the AA/AT genotype subjects (4.67 ± 0.40 mmol/L <it>vs</it>. 4.60 ± 0.35 mmol/L, <it>P </it>= 0.08). The evidence of association was reduced after adjustment for BMI (<it>P </it>= 0.38 for triglyceride, <it>P </it>= 0.20 for adiponectin and glucose). There was weak evidence of association between rs9939609 and other obesity-related metabolic traits including total cholesterol (3.92 ± 0.03 mmol/L <it>vs</it>. 4.02 ± 0.05 mmol/L, <it>P </it>= 0.10), insulin (2.69 ± 1.77 ng/ml <it>vs</it>. 3.12 ± 2.91 ng/ml, <it>P </it>= 0.14), and insulin resistance (HOMA-IR 0.56 ± 0.03 <it>vs</it>. 0.66 ± 0.05, <it>P </it>= 0.10).</p> <p>Conclusions</p> <p>Genetic variation in the <it>FTO </it>gene associates with obesity in Chinese children.</p

A numerical method for solving variable coefficient elliptic equation with interfaces

A new 2nd order accurate numerical method is proposed for solving the variable coecient elliptic equation in the presence of interfaces where the variable coecients, the source term, and hence the solution itself and its derivatives may be discontinuous. Jump conditions at interface are prescribed. The boundary and the interface are only required to be Lipschitz continuous instead of smooth, and the interface is allowed to intersect with the boundary. The method is derived from a weak formulation of the variable coecient elliptic equation [12]. Numerical experiments show that the method is 2nd order accurate in L norm. 1