Modeling surface color discrimination under different lighting environments using image chromatic statistics and convolutional neural networks

We modeled discrimination thresholds for object colors under different lighting environments [J. Opt. Soc. Am. 35, B244 (2018)]. First, we built models based on chromatic statistics, testing 60 models in total. Second, we trained convolutional neural networks (CNNs), using 160,280 images labeled by either the ground-truth or human responses. No single chromatic statistics model was sufficient to describe human discrimination thresholds across conditions, while human-response-trained CNNs nearly perfectly predicted human thresholds. Guided by region-of-interest analysis of the network, we modified the chromatic statistics models to use only the lower regions of the objects, which substantially improved performance

Less-invasive Treatment for Group A Streptococcal Fasciitis with Rapid Antigen Detection Test and Collagen/Gelatin Sponge

Patients with severe group A Streptococcus (GAS) induced necrotizing soft tissue infection sometimes develop Streptococcal toxic shock syndrome, which is a life-threatening condition with an extremely high fatality rate. Obtaining survival is the most important goal; however, an early diagnosis for debridement surgery and quick granulation formation for skin grafting surgery can better preserve the extremity functions. The patient was a 47-year-old man with a history of atopic dermatitis who presented with GAS-induced necrotizing soft tissue infection in his left lower extremity. His vital signs indicated shock, and he was diagnosed with streptococcal toxic shock syndrome. Emergency surgery was performed with his body pressure maintained with noradrenaline. Intraoperatively, rapid antigen detection tests (RADTs) were negative in the medial thigh and positive in the lower leg, which helped in decision-making regarding the area of aggressive debridement surgery. The wound culture results matched the intraoperative rapid antigen detection test results. A collagen/gelatin sponge with the sustained release of basic fibroblast growth factor was used as an artificial dermis before skin grafting. Excellent granulation was obtained, and skin grafting surgery was performed on the 11th day after collagen/gelatin sponge placement. He was discharged home on the 42nd day with normal lower extremity functions. First, an intraoperative diagnosis using GAS-rapid antigen detection tests with an appropriate sampling method from small incisions avoided excessive surgical debridement. Second, collagen/gelatin sponge with the sustained release of basic fibroblast growth factor promoted quick granulation tissue formation for wound bed preparation. These efforts resulted in the successful less-invasive treatment of a patient with streptococcal toxic shock syndrome caused by GAS-induced necrotizing soft tissue infection

Empirical Calculation Method of Bypass Leakage in Scroll Compressors

This study presents an empirical method to calculate the bypass leakage mass flow rate along the tip seal in a scroll compressor. The leakage flows through small axial and radial clearances between the orbiting and fixed scrolls of scroll compressor were previously studied by Ishii et al. In these earlier studies, the pressure decay in the pressurized vessel due to leakage through the axial and radial clearances was measured using a maximum pressure of 3 MPa for CO2 and 0.6 MPa for R22. The Darcy-Weisbach equation for incompressible, viscous fluid flow through the thin rectangular cross-section was applied to calculate the leakage mass flow rate that matched the pressure decay characteristics. The empirical friction factors were determined and plotted on a Moody diagram. As a result, the empirical friction factors for both axial and radial clearance leakage flows have been determined and shown to take on essentially the same value for both CO2 and R22, despite the significantly different working pressures. In contrast, the flow patterns in bypass leakage along the tip seal are so complicated that not even the leakage characteristics are known definitively. No method exists for calculating the bypass leakage mass flow rate. In the present study, a bypass leakage model was constructed, compatible with a production-type scroll compressor with a large cooling capacity. A similar test of the pressure decay in the pressurized vessel due to bypass leakages were conducted with the refrigerant gas R410A. The measured pressure decay characteristics were then simulated by the Darcy-Weisbach equation with the empirical friction factors from our previous study for the leakage flow through the axial clearance. In the present simulations of the measured pressure decay, the complicated flow patterns through bypass clearances were classified into two representative rectangular thin cross-section leakage passes, one with an equivalent width and the other with an equivalent length. Empirical friction factor values for the equivalent pass width and length were determined to match the measured pressure decays. As a result, the calculation of the bypass leakage flow rate along the tip seal in scroll compressors can be accomplished using a simple scheme in terms of the equivalent pass width and equivalent pass length for two representative leakage passes forming a thin rectangular cross-section and applying empirically determined friction factors,

Randomized controlled trial of daily teriparatide, weekly high-dose teriparatide, or bisphosphonate in patients with postmenopausal osteoporosis: The TERABIT study

Purpose: The effects of daily teriparatide (20 μg) (D-PTH), weekly high-dose teriparatide (56.5 μg) (W-PTH), or bisphosphonates (BPs) on areal bone mineral density (aBMD), bone turnover markers (BTMs), volumetric BMD (vBMD), microarchitecture, and estimated strength were investigated in postmenopausal osteoporosis patients.Methods: The study participants were 131 women with a history of fragility fractures. They were randomized to receive D-PTH, W-PTH, or BPs (alendronate or risedronate) for 18 months. Dual-energy X-ray absorptiometry (DXA), BTMs, and high-resolution peripheral quantitative CT (HR-pQCT) parameters were evaluated at baseline and after 6 and 18 months of treatment. The primary endpoint was the change (%) in cortical thickness (Ct.Th) after 18 months\u27 treatment compared with baseline.Results: DXA showed that D-PTH, W-PTH, and BPs increased lumbar spine aBMD (+12.0%, +8.5%, and +6.8%) and total hip aBMD (+3.0%, +2.1%, and +3.0%), but D-PTH and W-PTH decreased 1/3 radius aBMD (− 4.1%, − 3.0%, − 1.4%) after 18 months. On HR-pQCT, D-PTH increased trabecular vBMD (Tb.vBMD) at the distal radius and tibia after 18 months (+6.4%, +3.7%) compared with the BPs group, decreased cortical volumetric tissue mineral density (Ct.vTMD) (− 1.8%, − 0.9%) compared with the other groups, increased Ct.Th (+1.3%, +3.9%), and increased failure load (FL) (+4.7%, +4.4%). W-PTH increased Tb.vBMD (+5.3%, +1.9%), maintained Ct.vTMD (− 0.7%, +0.2%) compared with D-PTH, increased Ct.Th (+0.6%, +3.6%), and increased FL (+4.9%, +4.5%). The BPs increased Tb.vBMD only in the radius (+2.0%, +0.2%), maintained Ct.vTMD (− 0.6%, +0.3%), increased Ct.Th (+0.5%, +3.4%), and increased FL (+3.9%, +2.8%).Conclusions: D-PTH and W-PTH comparably increased Ct.Th, the primary endpoint. D-PTH had a strong effect on trabecular bone. Although D-PTH decreased Ct.vTMD, it increased Ct.Th and total bone strength. W-PTH had a moderate effect on trabecular bone, maintained Ct.vTMD, and increased Ct.Th and total bone strength to the same extent as D-PTH

Crystal structures of Lymnaea stagnalis AChBP in complex with neonicotinoid insecticides imidacloprid and clothianidin

Neonicotinoid insecticides, which act on nicotinic acetylcholine receptors (nAChRs) in a variety of ways, have extremely low mammalian toxicity, yet the molecular basis of such actions is poorly understood. To elucidate the molecular basis for nAChR–neonicotinoid interactions, a surrogate protein, acetylcholine binding protein from Lymnaea stagnalis (Ls-AChBP) was crystallized in complex with neonicotinoid insecticides imidacloprid (IMI) or clothianidin (CTD). The crystal structures suggested that the guanidine moiety of IMI and CTD stacks with Tyr185, while the nitro group of IMI but not of CTD makes a hydrogen bond with Gln55. IMI showed higher binding affinity for Ls-AChBP than that of CTD, consistent with weaker CH–π interactions in the Ls-AChBP–CTD complex than in the Ls-AChBP–IMI complex and the lack of the nitro group-Gln55 hydrogen bond in CTD. Yet, the NH at position 1 of CTD makes a hydrogen bond with the backbone carbonyl of Trp143, offering an explanation for the diverse actions of neonicotinoids on nAChRs

Elasto-Hydrodynamic Lubrication Effect in Thrust-Slide Bearings of Scroll Compressors

This paper presents the concept of the Elasto-Hydrodynamic Lubrication (EHL) effect for the thrust slide-bearings in scroll compressors, which accounts for the superior lubrication characteristics of these bearings. The thrust plate undergoes elastic deformation due to axial loading, resulting in the formation of a fluid wedge between the orbiting and fixed thrust plates, a region with very high induced oil film pressure which, in turn, accounts for the remarkably good lubrication characteristics of the thrust slide-bearing. Furthermore, the high oil film pressure induces further elastic deformation of the thrust plate, which forms a lubrication pocket with the thrust plate, more effectively increasing the oil film pressure between the sliding surfaces. The formation of the lubrication pocket was confirmed using FEM analysis and lubrication tests on the elastic deformation of the thrust plate. Subsequently a computer simulation flow chart to analyze the elasto-hydrodynamic lubrication of thrust slide-bearing is presented

Modelling surface color discrimination under different lighting environments using image chromatic statistics and convolutional neural networks

We modeled discrimination thresholds for object colors under different lighting environments [1]. Firstly we built models based on chromatic statistics, testing 60 models in total. Secondly we trained convolutional neural networks (CNNs), using 160,280 images labeled either by the ground-truth or by human responses. No single chromatic statistics model was sufficient to describe human discrimination thresholds across conditions, while human-response-trained CNNs nearly perfectly predicted human thresholds. Guided by region-of- interest analysis of the network, we modified the chromatic statistics models to use only the lower regions of the objects, which substantially improved performance

Invariant categorical color regions across illuminant change coincide with focal colors

Are there regions in a color space where color categories are invariant across illuminant changes? If so, what characteristics make them more stable than other regions? To address these questions, we asked observers to give a color name to 424 colored surfaces, presented one at a time, under various chromatic illuminants. Results showed a high degree of categorical color constancy, especially under illuminants that occur in the natural environment. It was also shown that surfaces selected as a focal color (the best example of a color category) are more resistant to illuminant change than nonfocal color samples. We additionally ran an asymmetric color matching experiment to quantify the shift of color appearance induced by illuminant changes using surfaces that were all named gray, thereby disentangling the appearance-based color constancy from the categorical color constancy (which are often confounded). Results suggested that the appearance of color samples largely shifted owing to illuminant changes, even though all samples were named gray; showing that the constancy of a color category is substantially more robust than the constancy of color appearance