LSA-PINN: Linear Boundary Connectivity Loss for Solving PDEs on Complex Geometry

We present a novel loss formulation for efficient learning of complex dynamics from governing physics, typically described by partial differential equations (PDEs), using physics-informed neural networks (PINNs). In our experiments, existing versions of PINNs are seen to learn poorly in many problems, especially for complex geometries, as it becomes increasingly difficult to establish appropriate sampling strategy at the near boundary region. Overly dense sampling can adversely impede training convergence if the local gradient behaviors are too complex to be adequately modelled by PINNs. On the other hand, if the samples are too sparse, existing PINNs tend to overfit the near boundary region, leading to incorrect solution. To prevent such issues, we propose a new Boundary Connectivity (BCXN) loss function which provides linear local structure approximation (LSA) to the gradient behaviors at the boundary for PINN. Our BCXN-loss implicitly imposes local structure during training, thus facilitating fast physics-informed learning across entire problem domains with order of magnitude sparser training samples. This LSA-PINN method shows a few orders of magnitude smaller errors than existing methods in terms of the standard L2-norm metric, while using dramatically fewer training samples and iterations. Our proposed LSA-PINN does not pose any requirement on the differentiable property of the networks, and we demonstrate its benefits and ease of implementation on both multi-layer perceptron and convolutional neural network versions as commonly used in current PINN literature.Comment: 11 pages, 7 figure

Removal of dyes from wastewaters by low-cost adsorbents

Dyes represent an objectionable pollutant to the environment. The removal of dyes has been of great concern because of their toxicity and persistency. The usage of commercial activated carbon to remove dyes in wastewater is limited due to its high cost. This prompted the search for alternative low-cost adsorbents. This chapter examines (i) historical aspects and pollution issues concerning dyes; (ii) main treatment technologies and their limitations; (iii) various studies using waste materials from agriculture and industry or naturally occurring biosorbents; and (iv) equilibrium and kinetic models used in batch and continuous systems that are important for design purpose

Removal of Hazardous Heavy Metals From Aqueous Environment by Low-Cost Adsorption Materials

The rapid growth of the human population and industrialization in the world has indirectly increased environmental problems such as water, air and land pollution. Amongst all, heavy metals can be considered as the most problematic pollutants. Numerous efforts have been attempted to minimize the impact of heavy metals. This chapter discusses the recent developments and technical applicability of different treatment methods for heavy metal removal. The adsorption process using various low-cost materials as the potential alternative for heavy metal removal is being highlighted and summarized

Dye Waste Treatment

© 2011 by the authors. Dye wastes represent one of the most problematic groups of pollutants because they can be easily identified by the human eye and are not easily biodegradable. This literature review paper highlights and provides an overview of dye waste treatments performed over the three years period from 2008-2010. Noteworthy processes for the treatment of dye waste include biological treatment, catalytic oxidation, filtration, sorption process and combination treatments

Colorectal cancer screening: Barriers to the faecal occult blood test (FOBT) and colonoscopy in Singapore

Introduction: This study aims to identify the barriers to adopting faecal occult blood test (FOBT) and colonoscopy as colorectal cancer (CRC) screening methods among the eligible target population of Singapore. Materials and methods: This study was previously part of a randomised controlled trial reported elsewhere. Data was collected from Singapore residents aged 50 and above, via a household sample survey. The study recruited subjects who were aware of CRC screening methods, and interviewed them about the barriers to screening that they faced. Collected results on barriers to each screening method were analysed separately. Results: Out of the 343 subjects, 85 (24.8%) recruited knew about FOBT and/or colonoscopy. Most of the respondents (48.9%) cited not having symptoms as the reason for not using the FOBT. This is followed by inconvenience (31.1%), not having any family history of colon cancer (28.9%), lack of time (28.9%) and lack of reminders/recommendation (28.9%). Of the respondents who indicated not choosing colonoscopy as a screening method, more than one-half (54.8%) identified not having any symptoms as the main barrier for them, followed by not having any family history (38.7%) and having a healthy/low-risk lifestyle (29.0%). There was no difference between the reported barriers to each of the screening methods and the respondents\u27 dwelling types. Conclusions: Lack of knowledge, particularly the misconceptions of not having symptoms and being healthy, were identified as the main barriers to FOBT and colonoscopy as screening methods. Interventions to increase the uptake of CRC screening in this population should be tailored to address this misconception

Inflammation following acute myocardial infarction: Multiple players, dynamic roles, and novel therapeutic opportunities

Acute myocardial infarction (AMI) and the heart failure that often follows, are major causes of death and disability worldwide. As such, new therapies are required to limit myocardial infarct (MI) size, prevent adverse left ventricular (LV) remodeling, and reduce the onset of heart failure following AMI. The inflammatory response to AMI, plays a critical role in determining MI size, and a persistent pro-inflammatory reaction can contribute to adverse post-MI LV remodeling, making inflammation an important therapeutic target for improving outcomes following AMI. In this article, we provide an overview of the multiple players (and their dynamic roles) involved in the complex inflammatory response to AMI and subsequent LV remodeling, and highlight future opportunities for targeting inflammation as a therapeutic strategy for limiting MI size, preventing adverse LV remodeling, and reducing heart failure in AMI patients

Rural livelihood diversification in the South Central Coast of Vietnam

Agriculture is still a key livelihood earning for most rural households and working for wages does not seem to dramatically increase household income. Moreover, diversification of income sources is found to be influenced by these variables: age of household head, female head, ethnicity of household head, number of dependents, household labor, and community infrastructure. In addition, household labors, and average years of education have positive and statistically significant effects on household income. Households need to be acquainted with educational and training programs. These factors should be considered in policy decisions towards enhancing household income in the region

Use of Valacyclovir for the treatment of cytomegalovirus antigenemia after hematopoietic stem cell transplantation

10.1186/s12878-015-0028-2BMC Hematology151

Institutional leadership—the historical case study of a religious organisation

In this chapter, I discuss institutional leadership vis-à-vis the value of poverty. To do so, I analyse how poverty has been conceptualised within a Catholic religious organisation, the Jesuits. The chapter shows that, in the Jesuit case, poverty is not strictly defined. Instead, poverty results from the constant dialogue between the individual Jesuit and their leader. This means that the understanding of what constitutes poverty is neither explicit nor implicit. The chapter contributes to our understanding of institutional leadership as the promotion and protection of values, as per Selznick’s classical definition. However, we discuss a less known part of Selznick’s work in which the ambiguous character of values is highlighted. In this sense, and after the Jesuit case, we advance the possibility that the promotion and protection of institutional values by institutional leaders does not necessarily imply the definition of what a value is. As values are not defined beforehand but the result of a constant dialogue between the leader and their followers, institutional leadership can be revisited and freed from the heroic view that has long characterised it

Pulmonary Deposition of Radionucleotide-Labeled Palivizumab: Proof-of-Concept Study

Objective: Current prevention and/or treatment options for respiratory syncytial virus (RSV) infections are limited as no vaccine is available. Prophylaxis with palivizumab is very expensive and requires multiple intramuscular injections over the RSV season. Here we present proof-of-concept data using nebulized palivizumab delivery as a promising new approach for the prevention or treatment of severe RSV infections, documenting both aerosol characteristics and pulmonary deposition patterns in the lungs of lambs. Design: Prospective animal study. Setting: Biosecurity Control Level 2-designated large animal research facility at the Murdoch Children’s Research Institute, Melbourne, Australia. Subjects: Four weaned Border-Leicester/Suffolk lambs at 5 months of age. Interventions: Four lambs were administered aerosolized palivizumab conjugated to Tc-99m, under gaseous anesthesia, using either the commercially available AeroNeb Go® or the investigational HYDRA device, placed in-line with the inspiratory limb of a breathing circuit. Lambs were scanned in a single-photon emission computed tomography (SPECT/CT) scanner in the supine position during the administration procedure. Measurements and Main Results: Both the HYDRA and AeroNeb Go® produced palivizumab aerosols in the 1–5 µm range with similar median (geometric standard deviation and range) aerosol droplet diameters for the HYDRA device (1.84 ± 1.40 μm, range = 0.54–5.41μm) and the AeroNeb Go® (3.07 ± 1.56 μm, range = 0.86–10 μm). Aerosolized palivizumab was delivered to the lungs at 88.79–94.13% of the total aerosolized amount for all lambs, with a small proportion localized to either the trachea or stomach. No difference between devices were found. Pulmonary deposition ranged from 6.57 to 9.25% of the total dose of palivizumab loaded in the devices, mostly in the central right lung. Conclusions: Aerosolized palivizumab deposition patterns were similar in all lambs, suggesting a promising approach in the control of severe RSV lung infections