Lesion detection and Grading of Diabetic Retinopathy via Two-stages Deep Convolutional Neural Networks

We propose an automatic diabetic retinopathy (DR) analysis algorithm based on two-stages deep convolutional neural networks (DCNN). Compared to existing DCNN-based DR detection methods, the proposed algorithm have the following advantages: (1) Our method can point out the location and type of lesions in the fundus images, as well as giving the severity grades of DR. Moreover, since retina lesions and DR severity appear with different scales in fundus images, the integration of both local and global networks learn more complete and specific features for DR analysis. (2) By introducing imbalanced weighting map, more attentions will be given to lesion patches for DR grading, which significantly improve the performance of the proposed algorithm. In this study, we label 12,206 lesion patches and re-annotate the DR grades of 23,595 fundus images from Kaggle competition dataset. Under the guidance of clinical ophthalmologists, the experimental results show that our local lesion detection net achieve comparable performance with trained human observers, and the proposed imbalanced weighted scheme also be proved to significantly improve the capability of our DCNN-based DR grading algorithm

Is there a common water-activity limit for the three domains of life?

Archaea and Bacteria constitute a majority of life systems on Earth but have long been considered inferior to Eukarya in terms of solute tolerance. Whereas the most halophilic prokaryotes are known for an ability to multiply at saturated NaCl (water activity (a w) 0.755) some xerophilic fungi can germinate, usually at high-sugar concentrations, at values as low as 0.650-0.605 a w. Here, we present evidence that halophilic prokayotes can grow down to water activities of <0.755 for Halanaerobium lacusrosei (0.748), Halobacterium strain 004.1 (0.728), Halobacterium sp. NRC-1 and Halococcus morrhuae (0.717), Haloquadratum walsbyi (0.709), Halococcus salifodinae (0.693), Halobacterium noricense (0.687), Natrinema pallidum (0.681) and haloarchaeal strains GN-2 and GN-5 (0.635 a w). Furthermore, extrapolation of growth curves (prone to giving conservative estimates) indicated theoretical minima down to 0.611 a w for extreme, obligately halophilic Archaea and Bacteria. These were compared with minima for the most solute-tolerant Bacteria in high-sugar (or other non-saline) media (Mycobacterium spp., Tetragenococcus halophilus, Saccharibacter floricola, Staphylococcus aureus and so on) and eukaryotic microbes in saline (Wallemia spp., Basipetospora halophila, Dunaliella spp. and so on) and high-sugar substrates (for example, Xeromyces bisporus, Zygosaccharomyces rouxii, Aspergillus and Eurotium spp.). We also manipulated the balance of chaotropic and kosmotropic stressors for the extreme, xerophilic fungi Aspergillus penicilloides and X. bisporus and, via this approach, their established water-activity limits for mycelial growth (∼0.65) were reduced to 0.640. Furthermore, extrapolations indicated theoretical limits of 0.632 and 0.636 a w for A. penicilloides and X. bisporus, respectively. Collectively, these findings suggest that there is a common water-activity limit that is determined by physicochemical constraints for the three domains of life

Nanoscale zerovalent iron (NZVI) for environmental decontamination:A brief history of 20 years of research and field-scale application

Environmental contamination continues to pose a serious threat to human health and the ecosystem. Over the next several decades, remediation research and business will be actively restoring both legacy and newly spilled sites in many countries worldwide. This chapter critically reviews the 20-year progress (1997–2017) in nanoscale zerovalent iron (NZVI) research and development from laboratory testing to pilot- and field-scale demonstrations. Several major areas of NZVI research, including (1) NZVI synthesis and reactivity, (2) aggregation, (3) transport in porous media, (4) polymer modification including carboxymethyl cellulose (CMC), (5) toxicity, (6) sulfidation, and (7) use of electromagnetic fields to enhance remediation, are discussed. Additionally, we summarize important aspects of pilot- and field-scale NZVI applications from 27 peer-reviewed articles and credible reports including the types of contaminants and NZVI used; delivery techniques; injection concentration, rates, and durations; hydrogeological conditions of the sites; pre-operations (before NZVI application); unexpected phenomena (such as clogging) during or after NZVI application; and performance monitoring including the radius of influence, treatment efficiency, and rebound. Finally, this chapter links the past, present, and future of NZVI research and application to the remaining 15 chapters of this book

Electrokinetics and zero valent iron nanoparticles: Experimental and modeling of the transport in different porous media

info:eu-repo/semantics/publishedVersio