HairStep: Transfer Synthetic to Real Using Strand and Depth Maps for Single-View 3D Hair Modeling

In this work, we tackle the challenging problem of learning-based single-view 3D hair modeling. Due to the great difficulty of collecting paired real image and 3D hair data, using synthetic data to provide prior knowledge for real domain becomes a leading solution. This unfortunately introduces the challenge of domain gap. Due to the inherent difficulty of realistic hair rendering, existing methods typically use orientation maps instead of hair images as input to bridge the gap. We firmly think an intermediate representation is essential, but we argue that orientation map using the dominant filtering-based methods is sensitive to uncertain noise and far from a competent representation. Thus, we first raise this issue up and propose a novel intermediate representation, termed as HairStep, which consists of a strand map and a depth map. It is found that HairStep not only provides sufficient information for accurate 3D hair modeling, but also is feasible to be inferred from real images. Specifically, we collect a dataset of 1,250 portrait images with two types of annotations. A learning framework is further designed to transfer real images to the strand map and depth map. It is noted that, an extra bonus of our new dataset is the first quantitative metric for 3D hair modeling. Our experiments show that HairStep narrows the domain gap between synthetic and real and achieves state-of-the-art performance on single-view 3D hair reconstruction.Comment: CVPR 2023 Highlight, project page: https://paulyzheng.github.io/research/hairstep

Virus-induced gene complementation reveals a transcription factor network in modulation of tomato fruit ripening

Plant virus technology, in particular virus-induced gene silencing, is a widely used reverse- and forward-genetics tool in plant functional genomics. However the potential of virus technology to express genes to induce phenotypes or to complement mutants in order to understand the function of plant genes is not well documented. Here we exploit Potato virus X as a tool for virus-induced gene complementation (VIGC). Using VIGC in tomato, we demonstrated that ectopic viral expression of LeMADS-RIN, which encodes a MADS-box transcription factor (TF), resulted in functional complementation of the non-ripening rin mutant phenotype and caused fruits to ripen. Comparative gene expression analysis indicated that LeMADS-RIN up-regulated expression of the SBP-box (SQUAMOSA promoter binding protein-like) gene LeSPL-CNR, but down-regulated the expression of LeHB-1, an HD-Zip homeobox TF gene. Our data support the hypothesis that a transcriptional network may exist among key TFs in the modulation of fruit ripening in tomato

Associations of HLA-DP Variants with Hepatitis B Virus Infection in Southern and Northern Han Chinese Populations: A Multicenter Case-Control Study

) locus has been reported to be associated with hepatitis B virus (HBV) infection in populations of Japan and Thailand. We aimed to examine whether the association can be replicated in Han Chinese populations. = 0.097∼0.697 and 0.198∼0.615 in northern Chinese population, respectively). loci were strongly associated with HBV infection in southern and northern Han Chinese populations, but not with HBV progression

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Ultrasonic‐Enabled Nondestructive and Substrate‐Independent Liquid Metal Ink Sintering

Abstract Printing or patterning particle‐based liquid metal (LM) ink is a good strategy to overcome poor wettability of LM for its circuits’ preparation in flexible and printed electronics. Subsequently, a crucial step is to recover conductivity of LM circuits consisting of insulating LM micro/nano‐particles. However, most widely used mechanical sintering methods based on hard contact such as pressing, may not be able to contact the LM patterns' whole surface conformally, leading to insufficient sintering in some areas. Hard contact may also break delicate shapes of the printed patterns. Hereby, an ultrasonic‐assisted sintering strategy that can not only preserve original morphology of the LM circuits but also sinter circuits on various substrates of complex surface topography is proposed. The influencing factors of the ultrasonic sintering are investigated empirically and interpreted with theoretical understanding by simulation. LM circuits encapsulated inside soft elastomer are successfully sintered, proving feasibility in constructing stretchable or flexible electronics. By using water as energy transmission medium, remote sintering without any direct contact with substrate is achieved, which greatly protect LM circuits from mechanical damage. In virtue of such remote and non‐contact manipulation manner, the ultrasonic sintering strategy would greatly advance the fabrication and application scenarios of LM electronics

A comprehensive proton exchange membrane fuel cell system model integrating various auxiliary subsystems

© 2019 Elsevier Ltd A comprehensive proton exchange membrane fuel cell (PEMFC) system model is developed, including a pseudo two-dimensional transient multiphase stack model, a one-dimensional transient multiphase membrane humidifier model, a one-dimensional electrochemical hydrogen pump model, an air compressor model with proportion-integral-derivative control and a ribbon-tubular fin radiator model. All sub-models have been rigorously validated against experimental data to guarantee the system model accuracy. The effects of stack operating temperature, gas flow pattern and humidifier structural design are investigated to cast insights into the interaction among stack and auxiliary subsystems. The results indicate that the stack is successfully maintained at required operating temperatures (60 °C, 70 °C, 80 °C) with help of the radiator when the whole system starts from ambient temperature (25 °C). However, the stack is likely to suffer from membrane dehydration when operated at 70 °C, and the problem becomes more severe at 80 °C, causing significant performance deterioration. The water and temperature distribution inside the system are further demonstrated. The co-current flow pattern contributes to better water utilization of the whole system which may lead to higher output performances. But the counter-current flow pattern has positive effects on parameter distribution uniformity inside fuel cell, which is beneficial for the stack durability. As regards the membrane dehydration, it is found that optimizing membrane humidifier area does not fundamentally solve the problem. Increasing humidifier area contributes to higher water vapor transfer rate, however, it results in much slower humidification responses