37 research outputs found
DESCN: Deep Entire Space Cross Networks for Individual Treatment Effect Estimation
Causal Inference has wide applications in various areas such as E-commerce
and precision medicine, and its performance heavily relies on the accurate
estimation of the Individual Treatment Effect (ITE). Conventionally, ITE is
predicted by modeling the treated and control response functions separately in
their individual sample spaces. However, such an approach usually encounters
two issues in practice, i.e. divergent distribution between treated and control
groups due to treatment bias, and significant sample imbalance of their
population sizes. This paper proposes Deep Entire Space Cross Networks (DESCN)
to model treatment effects from an end-to-end perspective. DESCN captures the
integrated information of the treatment propensity, the response, and the
hidden treatment effect through a cross network in a multi-task learning
manner. Our method jointly learns the treatment and response functions in the
entire sample space to avoid treatment bias and employs an intermediate pseudo
treatment effect prediction network to relieve sample imbalance. Extensive
experiments are conducted on a synthetic dataset and a large-scaled production
dataset from the E-commerce voucher distribution business. The results indicate
that DESCN can successfully enhance the accuracy of ITE estimation and improve
the uplift ranking performance. A sample of the production dataset and the
source code are released to facilitate future research in the community, which
is, to the best of our knowledge, the first large-scale public biased treatment
dataset for causal inference.Comment: Accepted by SIGKDD 2022 Applied Data Science Trac
Piezoelectric Properties of Electrospun Polymer Nanofibers and Related Energy Harvesting Applications
Abstract Electrospinning (ES) methods that can produce piezoelectricity in polymer nanofibers have attracted tremendous research attention. These electrospun polymer nanofibers can be employed for sensors, energy harvesting, tissue engineering, and filtration applications. This paper reviews the performance of a variety of electrospun piezoelectric polymer nanofibers produced by different ES methods, including nearâfield electrospinning and conventional farâfield electrospinning methods. Herein, it is described how the ES method can affect the piezoelectric properties of various polymer nanofibers, including poly(vinylidene difluorine), poly(vinylidene fluorideâtrifluoroethylene), nylon 11, poly(lâlactic acid), and poly(αâbenzylâlâglutamate). Due to the varied matrix structures of piezoelectric polymer nanofibers, the ES method may conduct variable effects on the piezoelectric properties of polymer nanofibers. After characterizations by Xâray diffraction, Fourier transform infrared spectrum, dielectric spectra, and piezoelectric coefficient measurements, it is found that the piezoelectric properties of the polymer nanofibers can be significantly affected by the ES parameters. Most of previous review articles focus on the output performance of electrospun polymer nanofibers. A detailed description of how different ES methods affect the piezoelectricity of polymer nanofibers is still lacking. In this review paper, the basic principle behind ES methods and the way in which different ES methods affect the properties of polymer nanofibers are examined
Isolation and Characterization of Three Chalcone Synthase Genes in Pecan (Carya illinoinensis)
Phenolics are a group of important plant secondary metabolites that have been proven to possess remarkable antioxidant activity and to be beneficial for human health. Pecan nuts are an excellent source of dietary phenolics. In recent years, many studies have focused on the separation and biochemical analysis of pecan phenolics, but the molecular mechanisms of phenolic metabolism in pecans have not been fully elucidated, which significantly hinders quality breeding research for this plant. Chalcone synthase (CHS) plays crucial roles in phenolic biosynthesis. In this study, three Carya illinoinensis CHSs (CiCHS1, CiCHS2, and CiCHS3), were isolated and analyzed. CiCHS2 and CiCHS3 present high expression levels in different tissues, and they are also highly expressed at the initial developmental stages of kernels in three pecan genotypes. A correlation analysis was performed between the phenolic content and CHSs expression values during kernel development. The results indicated that the expression variations of CiCHS2 and CiCHS3 are significantly related to changes in total phenolic content. Therefore, CiCHSs play crucial roles in phenolic components synthesis in pecan. We believe that the isolation of CiCHSs is helpful for understanding phenolic metabolism in C. illinoinensis, which will improve quality breeding and resistance breeding studies in this plant
Efficient Micro/Nanoparticle Concentration using Direct Current-Induced Thermal Buoyancy Convection for Multiple Liquid Media
Thermal-based microparticle focusing has recently received increasing attention due to its noninvasive nature and simple manipulation mechanism. However, its further application is limited by current complicated fluid heating systems and low particle focusing velocity. Using simple indium tin oxide-made microheaters, herein we propose a flexible and novel approach for efficient particle focusing based on direct current-induced thermal buoyancy convection. Importantly, for avoiding possible electrochemical reactions on the electrode, the microheaters are isolated from the granular fluids of interest by a thin glass slide. The concentration performance of the designed chip was first demonstrated by statically focusing 4-mu m silica particles, yeast cells, silica particles in insulating buffer, and 100-nm copper microspheres. Also the trapping of a mixture of 5-mu m and 2-mu m polystyrene microbeads indicated that the chip can either simultaneously concentrate two kinds of particles or selectively focus the heavier ones by adjusting the voltages. Then the different concentration patterns of microbeads exhibited that the microspheres can be flexibly manipulated by changing the configurations of microheaters. Furthermore, for the first time, we achieved thermal-based continuous particle focusing in both conducting and insulating solutions using buoyancy convection, demonstrating that this method can be utilized to achieve both static and continuous particle manipulations in multiple liquid media. Finally, the feasibility of this device in effective wear measurement of machines was demonstrated by conducting systematic experiments of focusing nanocopper particles in the hydraulic oil. Therefore, this presented approach would be promising for a broad range of on-chip applications
An efficient micromixer actuated by induced-charge electroosmosis using asymmetrical floating electrodes
Efficient microfluid mixing is an important process for various microfluidic-based biological and chemical reactions. Herein we propose an efficient micromixer actuated by induced-charge electroosmosis (ICEO). The microchannel of this device is easy to fabricate for its simple straight channel structure. Importantly, unlike previous design featuring complicated three-dimensional conducting posts, we utilize the simpler asymmetrical planar floating-electrodes to induce asymmetrical microvortices. For evaluating the mixing performance of this micromixer, we conducted a series of simulations and experiments. The mixing performance was quantified using the mixing index, specifically, the mixing efficiency can reach 94.7% at a flow rate of 1500 mu m/s under a sinusoidal wave with a peak voltage of 14 V and a frequency of 400 Hz. Finally, we compared this micromixer with different micromixing devices using a comparative mixing index, demonstrating that this micromixer remains competitive among these existing designs. Therefore, the method proposed herein can offer a simple solution for efficient fluids mixing in microfluidic systems
MagneticâForceâInducedâLuminescent Effect in Flexible ZnS:Cu/PDMS/NdFeB Composite
Abstract The forceâinduced lightâemitting phenomenon in polymer composites plays an important role in the soft electronic field due to its display function. Here, a magneticâforceâinducedâluminescence (MFIL) effect is reported in ZnS:Cu particleâdoped polydimethylsiloxane incorporated with a NdFeB magnetic tip mass for realâtime incident magnetic field strength lightâemitting display. Investigations show that the luminescence intensity increases nearly linear in response to the applied AC magnetic field, HAC; meanwhile, the minimum HAC for inducing MFIL is as low as 0.1 mT (1Â Oe) at the resonance. The MFIL effect is 1000 times better and more energyâefficient than the best result published previously. The findings, thus, indicate that the MFIL effect could serve as an effective method for lightâemitting display triggered by HAC; MFIL essentially originates from the donorâacceptor recombination between shallow donor level and the t2 level of Cu2 in ZnS:Cu semiconductor particles. The present results could, thus, provide a viable pathway toward multifunctional flexible electronic designs and applications, especially toward those for the realâtime visualization of remote magnetic field sensing
Quality Analysis and Comprehensive Evaluation of Fruits from Different Cultivars of Pecan (Carya illinoinensis (Wangenheim) K. Koch)
A comprehensive method for evaluating kernel quality was established by estimating in detail the kernel quality of 27 pecan cultivars introduced into China and by exploring the major trait differences among the different cultivars of pecan. The contents of crude fat, crude protein, soluble sugar, and tannin; the fatty acid composition; the amino acid composition; and the mineral element composition of 27 pecan cultivars were analyzed and tested using the national standards for principal component analysis (PCA), and orthogonal partial least-squares discriminant analysis (OPLS-DA) was used to comprehensively evaluate the 34 characteristic indicators. The fatty acids in the kernel were dominated by unsaturated fats, with oleic acid having the highest content relative to linoleic acid; the amino acid composition was dominated by medicinal amino acids; and potassium, magnesium, and calcium were the predominant mineral elements. Systematic cluster analysis revealed that the 27 pecan cultivars could be classified into three categories (relatively optimal, general, and poorest kernel quality) and 21 indexes, including oleic, linoleic, linolenic, crude fat, soluble sugars, aspartic acid, and threonine, served as indexes of the differences among the 27 tested cultivars. Combined with principal component analysis and stepwise regression analysis, a kernel quality evaluation model was established and verified, and reliable evaluation results were obtained. In addition, Nos. 9, 65, 66, 72, 8, and 21, which had the best quality, were further ranked using the probability ranking method within the third category of optimal quality cultivars. There were obvious differences in kernel characteristics among the different cultivars of pecan. Six cultivars with potential to be developed into excellent cultivars were preliminarily screened out. It was found that the organic combination of cluster analysis, principal component analysis, and orthogonal partial least-squares discriminant analysis can provide a reliable method for the quality evaluation of pecans
Oxidation stability of seed oils from four woody oil plant species
ABSTRACTThe oil content, fatty acid, oil quality and oxidation stability of seeds of four woody oil plants (pecan, Camellia oleifera, Torreya grandis and walnut) were analyzed. The results showed that pecan oil had the strongest antioxidant activity, the variation range of FFA, peroxide value(PV), UV absorption, carbonyl value(CV) and OSI were the lowest; C. oleifera oil and T. grandis oil were the next, and walnut oil had the greatest variation range; besides, pecan oil contained higher tocopherol and total phenol(TP) content. Correlation analysis showed that, OSI was significantly positively correlated with OA, tocopherol and TP, and significantly negatively correlated with PA, LA, LOA and PV. The oxidation stability from superior to inferior is pecan oil, C. oleifera oil, T. grandis oil and walnut oil. Meanwhile, the oil content of pecan kernel was the highest, the fatty acid composition of pecan oil fulfills human dietary needs, itâs an high-quality edible oil.Abbreviations: PA: palmitic acid; POA: palmitoleic acid; SA: stearic acid; OA: oleic acid; LA: linoleic acid; LOA: linolenic acid; AA: arachidic acid; EA: cis-11-eicosenoic acid; UFA: unsaturated fatty acid;SFA: saturated fatty acid; FFA: free fatty acid; PV: peroxide value; CV: carbonyl value; TP: total phenols; OSI: oil stability index; UV: ultraviolet
Metabolomics and Transcriptomics Analyses Reveal Regulatory Networks Associated with Fatty Acid Accumulation in Pecan Kernels
Pecans are a globally important tree nut crop. Pecan
nuts are rich
in fatty acids (FAs), proteins, and flavonoids in addition to thiamine
and numerous micronutrients. Although several of these nutriments
have been studied in this plant, the comprehensive metabolite variations
and molecular mechanisms associated with them have not been fully
elucidated. In this study, untargeted metabolomics and transcriptomics
were integrated to reveal the metabolite accumulation patterns and
their associated molecular mechanisms during pecan kernel development.
In total, 4260 (under positive mode) and 2726 (under negative mode)
high quality features were retained. Overall, 163 differentially accumulated
metabolites were identified. Most components were classified into
the categories âorganic acids and derivativesâ and âlipids
and lipid-like molecules.â The accumulation patterns of amino
acids, FAs, carbohydrates, organic acids, vitamins, flavonoids, and
phenylpropanoids alongside embryo development were determined. Furthermore,
transcriptomes from four pecan kernel developmental stages were used
to assess transcript expression levels. Coexpression analyses were
performed between FAs and their related genes. This study provides
a comprehensive overview of the metabolic changes and regulations
during pecan kernel development. We believe that the identification
of nutriment accumulation trends and hub genes associated with the
biosynthesis of the components will be valuable for genetically improving
this plant
Metabolomics and Transcriptomics Analyses Reveal Regulatory Networks Associated with Fatty Acid Accumulation in Pecan Kernels
Pecans are a globally important tree nut crop. Pecan
nuts are rich
in fatty acids (FAs), proteins, and flavonoids in addition to thiamine
and numerous micronutrients. Although several of these nutriments
have been studied in this plant, the comprehensive metabolite variations
and molecular mechanisms associated with them have not been fully
elucidated. In this study, untargeted metabolomics and transcriptomics
were integrated to reveal the metabolite accumulation patterns and
their associated molecular mechanisms during pecan kernel development.
In total, 4260 (under positive mode) and 2726 (under negative mode)
high quality features were retained. Overall, 163 differentially accumulated
metabolites were identified. Most components were classified into
the categories âorganic acids and derivativesâ and âlipids
and lipid-like molecules.â The accumulation patterns of amino
acids, FAs, carbohydrates, organic acids, vitamins, flavonoids, and
phenylpropanoids alongside embryo development were determined. Furthermore,
transcriptomes from four pecan kernel developmental stages were used
to assess transcript expression levels. Coexpression analyses were
performed between FAs and their related genes. This study provides
a comprehensive overview of the metabolic changes and regulations
during pecan kernel development. We believe that the identification
of nutriment accumulation trends and hub genes associated with the
biosynthesis of the components will be valuable for genetically improving
this plant