Pluripotency, differentiation, and reprogramming: A gene expression dynamics model with epigenetic feedback regulation

Characterization of pluripotent states, in which cells can both self-renew and differentiate, and the irreversible loss of pluripotency are important research areas in developmental biology. In particular, an understanding of these processes is essential to the reprogramming of cells for biomedical applications, i.e., the experimental recovery of pluripotency in differentiated cells. Based on recent advances in dynamical-systems theory for gene expression, we propose a gene-regulatory-network model consisting of several pluripotent and differentiation genes. Our results show that cellular-state transition to differentiated cell types occurs as the number of cells increases, beginning with the pluripotent state and oscillatory expression of pluripotent genes. Cell-cell signaling mediates the differentiation process with robustness to noise, while epigenetic modifications affecting gene expression dynamics fix the cellular state. These modifications ensure the cellular state to be protected against external perturbation, but they also work as an epigenetic barrier to recovery of pluripotency. We show that overexpression of several genes leads to the reprogramming of cells, consistent with the methods for establishing induced pluripotent stem cells. Our model, which involves the inter-relationship between gene expression dynamics and epigenetic modifications, improves our basic understanding of cell differentiation and reprogramming

Application of poly CDME (PCDME) gel to the palatal plate

In some patients with cleft lip and palate, the palatal cleft is wide and three-dimensionally deformed at birth. This can result in difficulty in sucking, which subsequently causes poor weight and development. The resin-based palatal plate for patients is maintained in position with retentive components such as a ball clasp and Adams clasp. In this study, we report on our experience conducting research and developing a palatal plate that consists of PCDME [Poly-N-(carboxymethyl)-N,N-dimethyl-2-(methacryloyloxy) ethanaminium] gel adhered to a polycarbonate frame. The gel is viscous and adheres to the mucosa, thereby maintaining the plate. Moreover, there are no retentive components, such as clasps for attachment and detachment ; therefore, it can been worn with a comfortable fitting, i.e ., tight and with sufficient pressure. If this device is put to practical use, the burden on patients with cleft palate could be reduced considerably

INFLUENCE OF THE BALL SPEED ON THE DISPLACEMENT OF THE CENTER OF GRAVITY DURING BASEBALL BATTING MOTION

The purpose of this study was to investigate the modification in batting motion with different pitching speeds focusing on differences in batting technical level. The subjects were 10 experienced university baseball player. The subjects batted toward the center field, both fastballs and slowballs, aimed near the center of the strike zone from a pitching machine. Data were collected using a three dimensional automatic motion analysis system (Vicon MX). The displacement of the center of gravity(CG) were computed. Significant differences were seen due to difference in pitching speed in unskilled player. Conversely, in skilled player, no significant difference was found in the movement of CG due to the difference in pitching speed. It was revealed that it was not preferable for movement of the CG to fluctuate by difference in pitching speeds

KINEMATIC ANALYSIS OF BASEBALL BATTING MOTION WHEN BATTING PITCHES WITH VARYING VELOCITIES

The purpose of this study was to identify effect of moving the center of gravity of the body and rotating the torso when batting pitches with varying velocity. The subjects were 10 experienced university baseball player. The subjects batted toward the center field, both fastballs and slowballs, aimed near the center of the strike zone from a pitching machine. Data were collected using a three dimensional automatic motion analysis system (Vicon MX). The rotation angle of the torso and displacement of the center of gravity were computed. Due to differences in the shoulder rotation from the latter half of stepping leg touchdown through impact, we believe that the motion is adapted to pitch differences starting from the latter half of stepping leg touchdown. Comparing the shift in the center of gravity of the body during fastballs and slowballs, the forward motion and downward sinking of the center of gravity were significantly larger for slowballs

Coevolutionary GA with schema extraction by machine learning techniques and its application to knapsack problems

The authors introduce a novel coevolutionary genetic algorithm with schema extraction by machine learning techniques. Our CGA consists of two GA populations: the first GA (H-GA) searches for the solutions in the given problems and the second GA (P-GA) searches for effective schemata of the H-GA. We aim to improve the search ability of our CGA by extracting more efficiently useful schemata from the H-GA population, and then incorporating those extracted schemata in a natural manner into the P-GA. Several computational simulations on multidimensional knapsack problems confirm the effectiveness of the proposed method</p

Kinematic analysis of punt kick in football goalkeepers based on the level of kick effort

In the present study, we aimed to investigate the differences in punt kicks by football goalkeepers based on the level of effort required. Twelve experienced goalkeepers participated in the study. The participants were instructed to kick the ball as far as possible in the maximum distance trial (100% trial) and to have a more controlled approach for the 80% and 60% trials. Each punt kick was divided into three events: release of the ball from the left hand (BR), pivot foot ground-contact (LFC), and ball impact (IMP). Right lower limb joint velocity, right hip and knee joint angles, flight distance, ball velocity, and kick angle were calculated. The 80% and 100% trials yielded almost the same velocity for each part of the right leg; however, in the 60% trial, the level of kicking effort was managed by adjusting the velocity of the right ankle joint, starting from BR, in addition to adjustment of the velocity of the right knee joint at LFC. Compared to punt kicks with a lower level of effort, the punt kicks with a higher level of effort involved an increase in the hip joint extension angle for the right leg during the backswing and the lowering of the knee joint angle of the right leg at the start of the forward swing, thus producing forward swing velocity for the right foot