On extensions of representations for compact Lie groups

Let $H$ be a closed normal subgroup of a compact Lie group $G$ such that $G/H$ is connected. This paper provides a necessary and sufficient condition for every complex representation of $H$ to be extendible to $G$, and also for every complex $G$-vector bundle over the homogeneous space $G/H$ to be trivial. In particular, we show that the condition holds when the fundamental group of $G/H$ is torsion free.Comment: 10 pages, AMS-LaTeX v1.

A Study on Verification of the Dynamic Modeling for a Submerged Body Based on Numerical Simulation

This study proposed a procedure to identify maneuvering coefficients that brought about abnormal motions in the simulation of a submerged body. The first step in responding to abnormal motions was conducting stability analysis to determine whether the submerged body could be simulated. If doing so was feasible, sensitivity analysis was then performed to determine maneuvering coefficients that caused the abnormal motion in the simulation. Finally, we analyzed the order of maneuvering coefficients identified by the sensitivity analysis. We also compared it with empirical formulas and other results obtained from model tests. The dynamics model targeting a high-speed submerged body was indirectly verified by the above procedure. In this study, the effectiveness of the dynamic model was verified, and parameters causing the abnormal motion were identified in accordance with the developed procedure

Technological Progress in Generation of Induced Pluripotent Stem Cells for Clinical Applications

Reprogramming of somatic cells into induced pluripotent stem cells (iPSCs) is achieved by viral-mediated transduction of defined transcription factors. Generation of iPSCs is of great medical interest as they have the potential to be a source of patient-specific cells. For the eventual goal of clinical application, it is necessary to overcome the limitations of low reprogramming efficiency and chromosomal abnormalities due to viral DNA integration. In this paper, we summarize the current state of reprogramming technology for generation of iPSCs and also discuss potential approaches to the development of safe iPSCs for personalized cell-based replacement therapy

Effects of Jae-Seng Acupuncture Treatment on the Improvement of Nasolabial Folds and Eye Wrinkles

The microneedle therapy system (MTS), a mechanical method involving making minute multiple holes in the skin, reportedly improves skin condition, such as by reducing flushing and melanin. A newly attempted bloodletting therapy, Jae-Seng Acupuncture, has several advantages over traditional mechanical punching methods because it allows the practitioner to regulate the depth and direction of needle stimulations and to choose whether to stimulate the muscle layers. This study was conducted to determine the efficacy of Jae-Seng Acupuncture in the treatment of nasolabial folds and eye wrinkles. The nasolabial folds and eye wrinkles of 107 patients ranging in age from their 20s to their 70s were subjected to DermaVision, a digital skin image analyzer, before the treatment and one to six months after treatment. Additionally, stimulation of the meridians, such as Taeyang, Tongjaryo, Chongmyong, Sungup, Sabaek, Yonghyang, Chichang, Taeyong, was performed to improve the function of the stomach, large intestine. Analyses of the images indicate that Jae-Seng Acupuncture improved nasolabial folds and eye wrinkles, suggesting that this technique is a safe and effective method for the improvement of facial skin conditions

Role of Staphylococcal Superantigen in Atopic Dermatitis: Influence on Keratinocytes

Staphylococcus aureus may perform an crucial function in atopic dermatitis (AD), via the secretion of superantigens, including staphylococcal enterotoxins (SE) A or B, and toxic shock syndrome toxin-1 (TSST-1). Dysregulated cytokine production by keratinocytes (KCs) upon exposure to staphylococcal superantigens (SsAgs) may be principally involved in the pathophysiology of AD. We hypothesized that lesional KCs from AD may react differently to SsAgs compared to nonlesional skin or normal skin from nonatopics. We conducted a comparison of HLA-DR or CD1a expression in lesional skin as opposed to that in nonlesional or normal skin by immunohistochemistry (IHC). We also compared, using ELISA, the levels of IL-1α, IL-1β, and TNF-α secreted by cultured KCs from lesional, nonlesional, and normal skin, after the addition of SEA, SEB and TSST-1. IHC revealed that both HLA-DR and CD1a expression increased significantly in the epidermis of lesional skin versus nonlesional or normal skin in quite a similar manner. IL-1α, IL-1β, and TNF-α secretion was also significantly elevated in the cultured KCs from lesional skin after the addition of SsAgs. Our results indicated that KCs from lesional skin appear to react differently to SsAgs and increased proinflammatory cytokine production in response to SsAgs may contribute to the pathogenesis of AD

Reduction of dimensionality of a cellular actuator array for driving a robotic hand

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.Includes bibliographical references (p. 89-93).In an attempt to explore an alternative to today's robot actuators, a new approach to artificial muscle actuator design and control is presented. The objective of this research is to coordinate the multitude of artificial muscle actuator axes for a large DOF (degree of freedom) robotic system based on dimensionality reduction. An array of SMA actuators is segmented into many independently controlled, spatially discrete volumes, each contributing a small displacement to create a large motion. Segmented Binary Control is proposed where each segment is controlled in an on-off manner, creating a stepper-motor like actuator. This overcomes hysteresis and other nonlinearities of the actuator material. The segmented cellular architecture of SMA wires is extended to a multi-axis actuator array by arranging the segments in a two-dimensional array. The multi-axis control is streamlined and coordinated using a grouping of segments called C-segments in order to activate multiple links of a robot mechanism in a coordinated manner. This allows control of large DOF with a small number of controls. The proposed approach is inspired by the segmented architecture of biological muscles and synergies, a strategy of grouping output variables to simplify the control of large number of muscles. Data from various hand postures are collected using data glove and used in creating the C-segment design that is capable of performing the given postures. A lightweight Robotic Hand with 16 DOF is built using shape memory alloy actuators. This hand weighs less than 1kg including 32 SMA actuators and control circuitry. Eight C-segments that are ON-off controlled are used to create sixteen given postures. In the future, this approach can be applied to applications where the control signal is inherently limited due to limited amount of information that can be extracted or transferred to the robot, such as brain machine interface and tele-operation.by Kyu-Jin Cho.Ph.D

Meibomian Epithelioma of the Lower Eyelid in a Thoroughbred Horse

A 9-year old, castrated male, thoroughbred horse presented for a left lower eyelid mass with ocular signs of mucopurulent discharge, conjunctival hyperemia and ocular discomfort. On physical examination, there was no other abnormality. Surgically, the mass arising from the inner surface of left lower eyelid was excised and examined histopathologically. Microscopically, the eyelid mass exhibited neoplastic basaloid cells forming irregular cell masses of variable size separated by thin fibrous tissues. The basaloid cells showed mildly pleomorphic and undifferentiated appearances with prominent oval nuclei and scant cytoplasm. Poorly differentiated meibocytes were observed occasionally in the periphery regions of the cell masses suggesting the mass of lower eyelid originated from meibomian glands. Based on histopathological observation, the present case was diagnosed as an equine meibomian epithelioma in the lower eyelid. To the author’s knowledge, the present case is the first report of equine meibomian epithelioma in veterinary literatures

Multiphysics analysis of heat pipe cooled microreactor core with adjusted heat sink temperature for thermal stress reduction using OpenFOAM coupled with neutronics and heat pipe code

Heat-pipe-cooled microreactors (HPRs) have advantages such as a compact design, easy transportation, and improved system reliability and stability. The core of an HPR consists of fuel rods and heat pipes in a monolith, which is a solid block structure containing many holes for the fuel rods and heat pipes. When designing the core of an HPR, high thermal stress and reactivity feedback owing to thermal expansion are important considerations. Therefore, a high-fidelity multiphysics analysis tool is required for accurately analyzing an HPR core. When performing a multiphysics analysis, it is necessary to couple the heat pipe thermal analysis code, thermal-structural analysis code, and neutronics code. To develop a multiphysics analysis tool, OpenFOAM, an open source Computational Fluid Dynamics (CFD) tool, and ANLHTP, a heat pipe thermal analysis code, were coupled. In this process, the structural analysis solver of OpenFOAM was verified, and its limitations were improved. To confirm the proper working of the code, the mini-core problem was analyzed using the OpenFOAM-ANLHTP coupled code. Next, to consider the reactivity feedback, coupling with PRAGMA, a GPU-based continuous-energy-Monte Carlo neutronics code was performed, and the multiphysics analysis capability of the OpenFOAM-ANLHTP-PRAGMA coupled code was confirmed through an analysis of the MegaPower reactor core. To reduce the temperature distribution within the monolith, the temperature distribution of the heat pipe sink was adjusted, and the reduced thermal stress of an HPR core was observed

Development and assessment of a hand assist device: GRIPIT

Background Although various hand assist devices have been commercialized for people with paralysis, they are somewhat limited in terms of tool fixation and device attachment method. Hand exoskeleton robots allow users to grasp a wider range of tools but are heavy, complicated, and bulky owing to the presence of numerous actuators and controllers. The GRIPIT hand assist device overcomes the limitations of both conventional devices and exoskeleton robots by providing improved tool fixation and device attachment in a lightweight and compact device. GRIPIT has been designed to assist tripod grasp for people with spinal cord injury because this grasp posture is frequently used in school and offices for such activities as writing and grasping small objects. Methods The main development objective of GRIPIT is to assist users to grasp tools with their own hand using a lightweight, compact assistive device that is manually operated via a single wire. GRIPIT consists of only a glove, a wire, and a small structure that maintains tendon tension to permit a stable grasp. The tendon routing points are designed to apply force to the thumb, index finger, and middle finger to form a tripod grasp. A tension-maintenance structure sustains the grasp posture with appropriate tension. Following device development, four people with spinal cord injury were recruited to verify the writing performance of GRIPIT compared to the performance of a conventional penholder and handwriting. Writing was chosen as the assessment task because it requires a tripod grasp, which is one of the main performance objectives of GRIPIT. Results New assessment, which includes six different writing tasks, was devised to measure writing ability from various viewpoints including both qualitative and quantitative methods, while most conventional assessments include only qualitative methods or simple time measuring assessments. Appearance, portability, difficulty of wearing, difficulty of grasping the subject, writing sensation, fatigability, and legibility were measured to assess qualitative performance while writing various words and sentences. Results showed that GRIPIT is relatively complicated to wear and use compared to a conventional assist device but has advantages for writing sensation, fatigability, and legibility because it affords sufficient grasp force during writing. Two quantitative performance factors were assessed, accuracy of writing and solidity of writing. To assess accuracy of writing, we asked subjects to draw various figures under given conditions. To assess solidity of writing, pen tip force and the angle variation of the pen were measured. Quantitative evaluation results showed that GRIPIT helps users to write accurately without pen shakes even high force is applied on the pen. Conclusions Qualitative and quantitative results were better when subjects used GRIPIT than when they used the conventional penholder, mainly because GRIPIT allowed them to exert a higher grasp force. Grasp force is important because disabled people cannot control their fingers and thus need to move their entire arm to write, while non-disabled people only need to move their fingers to write. The tension-maintenance structure developed for GRIPIT provides appropriate grasp force and moment balance on the users hand, but the other writing method only fixes the pen using friction force or requires the users arm to generate a grasp force