Integrating optical imaging techniques for a novel approach to evaluate Siberian wild rye seed maturity

Advances in optical imaging technology using rapid and non-destructive methods have led to improvements in the efficiency of seed quality detection. Accurately timing the harvest is crucial for maximizing the yield of higher-quality Siberian wild rye seeds by minimizing excessive shattering during harvesting. This research applied integrated optical imaging techniques and machine learning algorithms to develop different models for classifying Siberian wild rye seeds based on different maturity stages and grain positions. The multi-source fusion of morphological, multispectral, and autofluorescence data provided more comprehensive information but also increases the performance requirements of the equipment. Therefore, we employed three filtering algorithms, namely minimal joint mutual information maximization (JMIM), information gain, and Gini impurity, and set up two control methods (feature union and no-filtering) to assess the impact of retaining only 20% of the features on the model performance. Both JMIM and information gain revealed autofluorescence and morphological features (CIELab A, CIELab B, hue and saturation), with these two filtering algorithms showing shorter run times. Furthermore, a strong correlation was observed between shoot length and morphological and autofluorescence spectral features. Machine learning models based on linear discriminant analysis (LDA), random forests (RF) and support vector machines (SVM) showed high performance (>0.78 accuracies) in classifying seeds at different maturity stages. Furthermore, it was found that there was considerable variation in the different grain positions at the maturity stage, and the K-means approach was used to improve the model performance by 5.8%-9.24%. In conclusion, our study demonstrated that feature filtering algorithms combined with machine learning algorithms offer high performance and low cost in identifying seed maturity stages and that the application of k-means techniques for inconsistent maturity improves classification accuracy. Therefore, this technique could be employed classification of seed maturity and superior physiological quality for Siberian wild rye seeds

The association between serum phosphorus and common carotid artery intima–media thickness in ischemic stroke patients

PurposeAn elevated concentration of phosphorus is associated with an increased risk of atherosclerosis and cardiovascular diseases. Common carotid artery intima–media thickness (cIMT) is an imaging marker of atherosclerosis. However, data on the relationship between phosphorus and cIMT in ischemic stroke are scarce. We aimed to evaluate the association between serum phosphorus levels and cIMT in patients who had experienced ischemic stroke.Patients and methodsA total of 1,450 ischemic stroke patients were enrolled. Participants were divided into four groups (quartiles) according to baseline serum phosphorus level. Carotid atherosclerosis was identified by measurement of cIMT; abnormal cIMT was defined as a maximum cIMT or mean cIMT ≥ 1 mm. Multivariable logistic regression models were used to assess the association between serum phosphorus level and the presence of abnormal cIMT.ResultsIn the multivariable adjusted analysis, falling into the highest quartile for serum phosphorus (Q4) was associated with a 2.00-fold increased risk of having abnormal maximum cIMT [adjusted odds ratio (OR) 2.00; 95% confidence interval (CI) 1.44–2.79] and a 1.76-fold increased risk of having abnormal mean cIMT (adjusted OR 1.76; 95% CI 1.22–2.53) in comparison to Q1. Furthermore, the association between serum phosphorus and abnormal cIMT was confirmed in analyses treating serum phosphorus as a continuous variable and in subgroup analyses.ConclusionIn acute ischemic stroke patients, baseline elevated serum phosphorus level was found to be independently associated with carotid atherosclerosis, as measured by cIMT

Brain Imaging Signs and Health-Related Quality of Life after Acute Ischemic Stroke: Analysis of ENCHANTED Alteplase Dose Arm.

The influence of specific brain lesions on health-related quality of life (HRQoL) after acute ischemic stroke (AIS) is uncertain. We aimed to identify imaging predictors of poor HRQoL in alteplase-treated participants of the alteplase dose arm of the Enhanced Control of Hypertension and Thrombolysis Stroke Study (ENCHANTED). ENCHANTED was an international trial of low- versus standard-dose intravenous alteplase in AIS patients, with functional outcome (modified Rankin scale [mRS]) and HRQoL on the 5-dimension European Quality of Life Scale (EQ-5D) assessed at 90 days post-randomization. Brain images were analyzed centrally by trained assessors. Multivariable logistic regression was undertaken in the study population randomly divided (2:1) into training (development) and validation (performance) groups, with age (per 10-year increase), ethnicity, baseline National Institutes of Health Stroke Scale (NIHSS) score, diabetes mellitus, premorbid function (mRS score 0 or 1), and proxy respondent, forced into all models. Data are presented with odds ratios (ORs) and 95% confidence intervals (CIs). Eight prediction models were developed and validated in 2,526 AIS patients (median age 67.5 years; 38.4% female; 61.7% Asian) with complete brain imaging and 90-day EQ-5D utility score data. The best performance model included acute ischemic changes in the right (OR 1.69, 95% CI: 1.24-2.29) and deep (OR 1.50, 95% CI: 1.03-2.19) middle cerebral artery (MCA) regions. Several background features of brain frailty - atrophy, white matter change, and old infarcts - were significantly associated with adverse physical but not emotional HRQoL domains. In thrombolysed AIS patients, right-sided and deep ischemia within the MCA territory predict poor overall HRQoL, whilst features of old cerebral ischemia are associated with reduced physical HRQoL. [Abstract copyright: © 2020 S. Karger AG, Basel.

Microstructural Evolution and Refinement Mechanism of a Beta–Gamma TiAl-Based Alloy during Multidirectional Isothermal Forging

Multidirectional isothermal forging (MDIF) was used on a Ti-44Al-4Nb-1.5Cr-0.5Mo-0.2B (at. %) alloy to obtain a crack-free pancake. The microstructural evolution, such as dynamic recovery and recrystallization behavior, were investigated using electron backscattered diffraction and transmission electron microscopy methods. The MDIF broke down the initial near-lamellar microstructure and produced a refined and homogeneous duplex microstructure. γ grains were effectively refined from 3.6 μm to 1.6 μm after the second step of isothermal forging. The ultimate tensile strength at ambient temperature and the elongation at 800 °C increased significantly after isothermal forging. β/B2→α2 transition occurred during intermediate annealing, and α2 + γ→β/B2 transition occurred during the second step of isothermal forging. The refinement mechanism of the first-step isothermal forging process involved the conversion of the lamellar structure and discontinuous dynamic recrystallization (DDRX) of γ grains in the original mixture-phase region. The lamellar conversion included continuous dynamic recrystallization and DDRX of the γ laths and bugling of the γ phase. DDRX behavior of γ grains dominated the refinement mechanism of the second step of isothermal forging

Evolution of the Microstructure and Lamellar Orientation of a β-Solidifying γ-TiAl-Based Alloy during Hot Compression

A type of advanced γ-TiAl-based alloy called β-solidifying γ-TiAl has elicited remarkable research interest in the last few decadesbecause of its excellent workability and homogeneous microstructures. Thermomechanical treatments are widely applied to this alloy to obtain fine duplex microstructures. To investigate the deformation behavior and microstructure evolution of Ti-44Al-4Nb-1.5Cr-0.5Mo-0.2B alloy, we conducted a series of hot compression tests at a temperature of 1473 K and a strain rate of 0.01 s−1. Scanning electron microscopy, electron backscattered diffraction, and transmission electron microscopy were performed to analyze the crystal orientation and microstructures of the alloy. During compression at 1473 K, β/B2→γ transition and α2/γ lamellae→γ+β/B2 transition occurred simultaneously, which increased the content of the γ phase and decreased the content of the α2 phase. The lamellar colonies exhibited distinct anisotropy, which could affect their hot deformation behavior. The colonies that remained after compression had strong texture components

Responses of Seed Yield Components to the Field Practices for Regulating Seed Yield of Smooth Bromegrass (Bromus inermis Leyss.)

Agronomic practices improve seed yield by regulating seed yield components, and the relationship between seed yield and seed yield components is still unclear in smooth bromegrass (Bromus inermis). To optimize seed production and yield in smooth bromegrass, a five-year field trial was designed with split-split-plot to study the combined effects of row spacing (30, 45, 60, and 75 cm), phosphorus (0, 60, 90, and 120 kg P ha(-1)) and nitrogen (0 and 100 kg N ha(-1)) on seed yield and seed yield components including fertile tillers m(-2) (FTs), spikelets per fertile tiller (SFT), florets per spikelet (FS), and seeds per spikelet (SS). The results showed that FTs as a key factor had a positive effect to seed yield with the biggest pathway coefficient, while SS had a negative effect. Meanwhile, an interaction effect between FTs and SS was observed. FS and SS were increased with phosphorus application under the condition of sufficient nitrogen. In addition, sufficient precipitation at the non-growing season resulted in more FTs in the next year in rain-fed regions. Therefore, the optimum seed yield of smooth bromegrass can be obtained with row spacing (45 cm), nitrogen (100 kg N ha(-1)), and phosphorus application (60 kg P ha(-1))

Genomic Identification and Expression Profiling of Lesion Simulating Disease Genes in Alfalfa (<i>Medicago sativa</i>) Elucidate Their Responsiveness to Seed Vigor

Seed aging, a common physiological phenomenon during forage seed storage, is a crucial factor contributing to a loss of vigor, resulting in delayed seed germination and seedling growth, as well as limiting the production of hay. Extensive bodies of research are dedicated to the study of seed aging, with a particular focus on the role of the production and accumulation of reactive oxygen species (ROS) and the ensuing oxidative damage during storage as a primary cause of decreases in seed vigor. To preserve optimal seed vigor, ROS levels must be regulated. The excessive accumulation of ROS can trigger programmed cell death (PCD), which causes the seed to lose vigor permanently. LESION SIMULATING DISEASE (LSD) is one of the proteins that regulate PCD, encodes a small C2C2 zinc finger protein, and plays a molecular function as a transcriptional regulator and scaffold protein. However, genome-wide analysis of LSD genes has not been performed for alfalfa (Medicago sativa), as one of the most important crop species, and, presently, the molecular regulation mechanism of seed aging is not clear enough. Numerous studies have also been unable to explain the essence of seed aging for LSD gene regulating PCD and affecting seed vigor. In this study, we obtained six MsLSD genes in total from the alfalfa (cultivar Zhongmu No. 1) genome. Phylogenetic analysis demonstrated that the MsLSD genes could be classified into three subgroups. In addition, six MsLSD genes were unevenly mapped on three chromosomes in alfalfa. Gene duplication analysis demonstrated that segmental duplication was the key driving force for the expansion of this gene family during evolution. Expression analysis of six MsLSD genes in various tissues and germinating seeds presented their different expressions. RT-qPCR analysis revealed that the expression of three MsLSD genes, including MsLSD2, MsLSD5, and MsLSD6, was significantly induced by seed aging treatment, suggesting that they might play an important role in maintaining seed vigor. Although this finding will provide valuable insights into unveiling the molecular mechanism involved in losing vigor and new strategies to improve alfalfa seed germinability, additional research must comprehensively elucidate the precise pathways through which the MsLSD genes regulate seed vigor

Single Seed Identification in Three Medicago Species via Multispectral Imaging Combined with Stacking Ensemble Learning

Multispectral imaging (MSI) has become a new fast and non-destructive detection method in seed identification. Previous research has usually focused on single models in MSI data analysis, which always employed all features and increased the risk to efficiency and that of system cost. In this study, we developed a stacking ensemble learning (SEL) model for successfully identifying a single seed of sickle alfalfa (Medicago falcata), hybrid alfalfa (M. varia), and alfalfa (M. sativa). SEL adopted a three-layer structure, i.e., level 0 with principal component analysis (PCA), linear discriminant analysis (LDA), and quadratic discriminant analysis (QDA) as models of dimensionality reduction and feature extraction (DRFE); level 1 with support vector machine (SVM), multiple logistic regression (MLR), generalized linear models with elastic net regularization (GLMNET), and eXtreme Gradient Boosting (XGBoost) as basic learners; and level 3 with XGBoost as meta-learner. We confirmed that the values of overall accuracy, kappa, precision, sensitivity, specificity, and sensitivity in the SEL model were all significantly higher than those in basic models alone, based on both spectral features and a combination of morphological and spectral features. Furthermore, we also developed a feature filtering process and successfully selected 5 optimal features out of 33 ones, which corresponded to the contents of chlorophyll, anthocyanin, fat, and moisture in seeds. Our SEL model in MSI data analysis provided a new way for seed identification, and the feature filter process potentially could be used widely for development of a low-cost and narrow-channel sensor

Genome-Wide Analysis and Expression Profiling of Glutathione Reductase Gene Family in Oat (Avena sativa) Indicate Their Responses to Abiotic Stress during Seed Imbibition

Abiotic stress disturbs plant cellular redox homeostasis, inhibiting seed germination and plant growth. This is a crucial limitation to crop yield. Glutathione reductase (GR) is an important component of the ascorbate-glutathione (AsA-GSH) cycle which is involved in multiple plant metabolic processes. In the present study, GRs in A. sativa (AsGRs) were selected to explore their molecular characterization, phylogenetic relationship, and RNA expression changes during seed imbibition under abiotic stress. Seven AsGR genes were identified and mapped on six chromosomes of A, C, and D subgenomes. Phylogenetic analysis and subcellular localization of AsGR proteins divided them into two sub-families, AsGR1 and AsGR2, which were predicted to be mainly located in cytoplasm, mitochondrion, and chloroplast. Cis-elements relevant to stress and hormone responses are distributed in promoter regions of AsGRs. Tissue-specific expression profiling showed that AsGR1 genes were highly expressed in roots, leaves, and seeds, while AsGR2 genes were highly expressed in leaves and seeds. Both AsGR1 and AsGR2 genes showed a decreasing-increasing expression trend during seed germination under non-stress conditions. In addition, their responses to drought, salt, cold, copper, H2O2, and ageing treatments were quite different during seed imbibition. Among the seven AsGR genes, AsGR1-A, AsGR1-C, AsGR2-A, and AsGR2-D responded more significantly, especially under drought, ageing, and H2O2 stress. This study has laid the ground for the functional characterization of GR and the improvement of oat stress tolerance and seed vigor

Dynamic Responses of Antioxidant and Glyoxalase Systems to Seed Aging Based on Full-Length Transcriptome in Oat (Avena sativa L.)

Seed aging is a major challenge for food security, agronomic production, and germplasm conservation, and reactive oxygen species (ROS) and methylglyoxal (MG) are highly involved in the aging process. However, the regulatory mechanisms controlling the abundance of ROS and MG are not well characterized. To characterize dynamic response of antioxidant and glyoxalase systems during seed aging, oat (Avena sativa L.) aged seeds with a range of germination percentages were used to explore physiological parameters, biochemical parameters and relevant gene expression. A reference transcriptome based on PacBio sequencing generated 67,184 non-redundant full-length transcripts, with 59,050 annotated. Subsequently, eleven seed samples were used to investigate the dynamic response of respiration, ROS and MG accumulation, antioxidant enzymes and glyoxalase activity, and associated genes expression. The 48 indicators with high correlation coefficients were divided into six major response patterns, and were used for placing eleven seed samples into four groups, i.e., non-aged (Group N), higher vigor (Group H), medium vigor (Group M), and lower vigor (Group L). Finally, we proposed a putative model for aging response and self-detoxification mechanisms based on the four groups representing different aging levels. In addition, the outcomes of the study suggested the dysfunction of antioxidant and glyoxalase system, and the accumulation of ROS and MG definitely contribute to oat seed aging