The plasticity of WDR5 peptide-binding cleft enables the binding of the SET1 family of histone methyltransferases

In mammals, the SET1 family of lysine methyltransferases (KMTs), which includes MLL1-5, SET1A and SET1B, catalyzes the methylation of lysine-4 (Lys-4) on histone H3. Recent reports have demonstrated that a three-subunit complex composed of WD-repeat protein-5 (WDR5), retinoblastoma-binding protein-5 (RbBP5) and absent, small, homeotic disks-2-like (ASH2L) stimulates the methyltransferase activity of MLL1. On the basis of studies showing that this stimulation is in part controlled by an interaction between WDR5 and a small region located in close proximity of the MLL1 catalytic domain [referred to as the WDR5-interacting motif (Win)], it has been suggested that WDR5 might play an analogous role in scaffolding the other SET1 complexes. We herein provide biochemical and structural evidence showing that WDR5 binds the Win motifs of MLL2-4, SET1A and SET1B. Comparative analysis of WDR5-Win complexes reveals that binding of the Win motifs is achieved by the plasticity of WDR5 peptidyl-arginine-binding cleft allowing the C-terminal ends of the Win motifs to be maintained in structurally divergent conformations. Consistently, enzymatic assays reveal that WDR5 plays an important role in the optimal stimulation of MLL2-4, SET1A and SET1B methyltransferase activity by the RbBP5-ASH2L heterodimer. Overall, our findings illustrate the function of WDR5 in scaffolding the SET1 family of KMTs and further emphasize on the important role of WDR5 in regulating global histone H3 Lys-4 methylation

The Regulation of Satellite Cell Function and Myogenesis by Isoforms of C/EBPβ

Adult skeletal muscles have remarkable regenerative capacity. Muscle regeneration occurs when muscle tissue experiences injury, causing a population of normally quiescent muscle-resident stem cells, called satellite cells, to become activated. The CCAAT/enhancer binding proteins known as C/EBPs are transcription factors belonging to the bZIP family. Previous work from our lab has identified C/EBPβ as an important negative regulator of myogenesis. C/EBPβ expression is localized to muscle satellite cells and is downregulated upon induction to differentiate, mirroring the loss of Pax7 expression in early myogenesis. C/EBPβ expression also negatively regulates MyoD protein expression. Leaky ribosomal scanning of the Cebpb mRNA produces three C/EBPβ isoforms: LAP*, LAP and LIP, though the individual role of each of these isoforms has not been investigated in myoblasts. This thesis focuses on determining the role of each of the C/EBPβ isoforms during skeletal muscle differentiation. Forced expression of the C/EBPβ-LIP isoform in myoblasts led to a decrease in Myf5, MyoD, and myogenin expression under differentiation conditions when compared to empty vector controls. Further, the fusion of cells was greatly reduced following differentiation. C/EBPβ-LIP expressing cells also demonstrated a growth defect, with pronounced G1 arrest and features of senescence. In contrast, myoblasts expressing the C/EBPβ-LAP isoform has impaired differentiation, though this was not as pronounced as in C/EBPβ-LIP expressing cells and proliferated normally. While LIP is not normally expressed in primary myoblasts from healthy muscle, the ratio of LIP:LAP was increased in primary myoblasts isolated from mdx mice, an animal model for Duchenne muscular dystrophy. These findings suggest that the regulation of C/EBPβ isoform expression could regulate stem cell stamina and may contribute to defects in muscle regeneration in disease

Effects of Container Design on the Temperature and Moisture Content Distribution in Pork Patties during Microwave Heating: Experiment and Numerical Simulation

Effects of the container design on the heat transfer rate and food quality during microwave heating were explored and validated with numerical simulations and experiments. The uniformity of moisture content and temperature was investigated, and to describe microwave heating patterns, a simulation model was created. Pork patties with different moisture and salt contents were heated in three different containers (center and edge-perforated lid as well as without lid) to achieve 80 °C using a domestic microwave oven. Compared to the center or mid-way positions, the temperatures at the edge of the patties rose quickly. By containing the evaporated vapor from the heated pork patties inside the container, the container with a center-perforated lid decreased the heating rate and non-uniformity in temperature and moisture content. A simplified numerical model for the electromagnetics, heat, and momentum transfer coupling simulation was developed to understand the moisture and temperature distribution of the pork patties after microwave heating. Heating uniformity and the final quality of the pork patties could be improved by a container with a center-perforated lid. The proposed model was able to describe the microwave warming process for ready-to-eat products; thus, it is a useful tool for designing microwavable ready meals

Using Numerical Analysis to Develop a Retort Process to Enhance Antioxidant Activity and Physicochemical Properties of White Radish (Raphanus sativus L.) in Different-Sized Packages

Thermal processing of white radish using retort sterilization at different temperatures was investigated according to the dimension of the package. Four different samples with the same weight and volume were placed in packages with different dimensions. The degree of sterilization (i.e., F0-value) at the cold point targeted at 6 min was determined based on experimental data and heat transfer simulation. The sterilization time was considerably increased with a decrease in surface area to unit volume ratio (φ) at each temperature. The sterilization time for the sample with the highest φ (155.56) was approximately five times faster than the sample with the lowest φ (72.22) at all heating temperatures. Numerical simulation conducted with a proper heat transfer coefficient (h) showed mostly good agreement with the experimental data (RMSE < 2 °C). Changes in color and total phenolic content were higher for samples heated at higher temperatures. Hardness values of white radish samples measured for center and edge parts separately were more uniform for samples with a high φ. Results in this study suggest that optimizing heating conditions of root vegetables must consider their package dimensions to satisfy quality attributes after sterilization. Numerical simulation can be utilized as a useful tool to design the sterilization process

Effect of Pouch Size on Sterilization of Ready-to-Eat (RTE) Bracken Ferns: Numerical Simulation and Texture Evaluation

Bracken fern (Pteridium aquilium, BF) is a widely consumed vegetable. It has the potential to be manufactured as a ready-to-eat (RTE) product as a cooking ingredient and a side dish. The aim of the current study was to develop sterilized BF RTE products and to investigate textural qualities depending on the size of the pouches. The F0-value at the cold point according to pouch size (100, 150, and 200 g) targeted at 15 min was determined through heat transfer simulation using the calibrated heat transfer coefficient. The location of the cold points in the stand-up pouches was moved upward from the bottom of the pouch by increasing the pouch size. The sterilization time for 100, 150, and 200 g was evaluated as 35.0, 41.5, and 47.5 min, respectively. The textural properties measured using the cutting test showed significant differences according to the location in the pouch. The textural degradation of BF in the top part of the pouch was more extensive than that at the bottom due to the smaller dimensions. In addition, the percentage of textural degradation in the top part increased with increasing pouch sizes. The methods introduced in this study can be applied to validate the degree of sterilization and the texture of various stalk vegetables used for ready-to-eat products packed in stand-up pouches

Effect of Moisture Content on the Grinding Process and Powder Properties in Food: A Review

Grinding is a staple size-reduction process to produce food powders in which the powdered form is chemically and microbiologically stable and convenient to use as end products or intermediate products. The moisture content of food materials before grinding is a particularly important factor, since it determines the materials’ physical properties and the powder properties, such as flowability after grinding. Generally, the moisture content of food materials is closely related to its energy requirement for grinding, because the energy expenditure required to create new surfaces varies. Grinding models used to analyze and predict the grinding characteristics, including energy, have been developed in many studies. The moisture content also influences powder flow properties. The inter-particle liquid bridges among the particles are due to the moisture in powders; therefore, the flowability of powders is interrupted because of the increase of the cohesiveness of the powder. Understanding the grinding characteristics related to various moisture contents is, theoretically and experimentally, an important cornerstone in optimizing the grinding processes used in food industries. In this review, comprehensive research of the effect of moisture content on the grinding process and powder properties is presented

Visualization Technology and Deep-Learning for Multilingual Spam Message Detection

Spam detection is an essential and unavoidable problem in today’s society. Most of the existing studies have used string-based detection methods with models and have been conducted on a single language, especially with English datasets. However, in the current global society, research on languages other than English is needed. String-based spam detection methods perform different preprocessing steps depending on language type due to differences in grammatical characteristics. Therefore, our study proposes a text-processing method and a string-imaging method. The CNN 2D visualization technology used in this paper can be applied to datasets of various languages by processing the data as images, so they can be equally applied to languages other than English. In this study, English and Korean spam data were used. As a result of this study, the string-based detection models of RNN, LSTM, and CNN 1D showed average accuracies of 0.9871, 0.9906, and 0.9912, respectively. On the other hand, the CNN 2D image-based detection model was confirmed to have an average accuracy of 0.9957. Through this study, we present a solution that shows that image-based processing is more effective than string-based processing for string data and that multilingual processing is possible based on the CNN 2D model