Evaluation of Moisture Content Changes in Taiwan Red Cypress During Drying Using Ultrasonic and Tap-Tone Testing

Moisture content affects most of the important properties of wood, therefore it is important to control during drying and in use. The purpose of this study was to investigate moisture content changes in Taiwan red cypress during drying. Two types of nondestructive testing were used, ultrasonic and tap-tone. The results showed that ultrasonic and tap-tone velocities increased with decreasing moisture content with the major effect below the FSP. A second-order regression relationship was found between ultrasonic and tap-tone velocities with moisture content desorption during drying with a coefficient of determination of 0.77 and 0.88, respectively. Moreover, the effects of moisture content desorption on dynamic moduli, calculated from ultrasonic and tap-tone methods, were demonstrated. Finally, a new parameter (Vi/Vx), the ratio of initial velocity (before drying) to the velocity at any moisture content, was effectively applied to evaluate moisture content changes in wood during drying. The tap-tone method was found to be a reliable tool to measure moisture content changes during the drying of wood

A Simple Model for Cavity Enhanced Slow Lights in Vertical Cavity Surface Emission Lasers

We develop a simple model for the slow lights in Vertical Cavity Surface Emission Lasers (VCSELs), with the combination of cavity and population pulsation effects. The dependences of probe signal power, injection bias current and wavelength detuning for the group delays are demonstrated numerically and experimentally. Up to 65 ps group delays and up to 10 GHz modulation frequency can be achieved in the room temperature at the wavelength of 1.3 $\mu$m. The most significant feature of our VCSEL device is that the length of active region is only several $\mu$m long. Based on the experimental parameters of quantum dot VCSEL structures, we show that the resonance effect of laser cavity plays a significant role to enhance the group delays

IDENTIFYING GAIT ASYMMETRY USING DIGITAL SENSORS

The purpose of this study was to determine which phases and kinematics were easier to identify gait asymmetry by using digital sensors. Sixteen participants were recruited in this study. The participants were requested to walk naturally under two conditions (with or without asymmetrical load). Four digital sensor sets were attached on 4 limbs to collect kinematics data. The results showed that only the AS1 of Medial-Later acceleration of upper limb on the stance phase significantly different between unloading and loading conditions; on the lower limb were AS1 of Superior-Inferior acceleration and Flex/Extension angular velocity on the swing phase. The digital sensors that attach on upper and lower limbs both can detect gait asymmetry, but the asymmetrical phase and kinematics are different on upper and lower limbs

Anti-Hyperglycemic Properties of Crude Extract and Triterpenes from Poria cocos

Poria cocos, Bai Fu Ling in Chinese, is used in traditional Chinese medicine to treat diabetes. However, its claimed benefits and mechanism are not fully understood. This study aimed to investigate the effect and action of P. cocos on type 2 diabetes. We first performed phytochemical analysis on the crude extract and factions of P. cocos. P. cocos crude extract at 50 mg/kg body weight or more significantly decreased blood glucose levels in db/db mice. Based on a bioactivity-directed fractionation and isolation (BDFI) strategy, chloroform fraction and subfractions 4 and 6 of the P. cocos crude extract possessed a blood glucose-lowering effect. Dehydrotumulosic acid, dehydrotrametenolic acid, and pachymic acid were identified from the chloroform sub-fractions 4, 3, and 2, respectively. Dehydrotumulosic acid had anti-hyperglycemic effect to a greater extent than dehydrotrametenolic acid and pachymic acid. Mechanistic study on streptozocin- (STZ-) treated mice showed that the crude extract, dehydrotumulosic acid, dehydrotrametenolic acid, and pachymic acid of P. cocos exhibited different levels of insulin sensitizer activity. However, the P. cocos crude extract and triterpenes appeared not to activate PPAR-γ pathway. Overall, the data suggest that the P. cocos extract and its triterpenes reduce postprandial blood glucose levels in db/db mice via enhanced insulin sensitivity irrespective of PPAR-γ

RANKL Deletion in Periodontal Ligament and Bone Lining Cells Blocks Orthodontic Tooth Movement

The bone remodeling process in response to orthodontic forces requires the activity of osteoclasts to allow teeth to move in the direction of the force applied. Receptor activator of nuclear factor-κB ligand (RANKL) is essential for this process although its cellular source in response to orthodontic forces has not been determined. Orthodontic tooth movement is considered to be an aseptic inflammatory process that is stimulated by leukocytes inclduing T and B lymphocytes which are presumed to stimulate bone resorption. We determined whether periodontal ligament and bone lining cells were an essential source of RANKL by tamoxifen induced deletion of RANKL in which Cre recombinase was driven by a 3.2 kb reporter element of the Col1α1 gene in experimental mice (Col1α1.CreERTM+.RANKLf/f) and compared results with littermate controls (Col1α1.CreERTM-.RANKLf/f). By examination of Col1α1.CreERTM+.ROSA26 reporter mice we showed tissue specificity of tamoxifen induced Cre recombinase predominantly in the periodontal ligament and bone lining cells. Surprisingly we found that most of the orthodontic tooth movement and formation of osteoclasts was blocked in the experimental mice, which also had a reduced periodontal ligament space. Thus, we demonstrate for the first time that RANKL produced by periodontal ligament and bone lining cells provide the major driving force for tooth movement and osteoclastogenesis in response to orthodontic forces

Communication-efficient three-party protocols for authentication and key agreement

AbstractEncrypted key exchange (EKE) authentication approaches are very important for secure communicating over public networks. In order to solve the security weaknesses three-party EKE, Yeh et al. [H.T. Yeh, H.M. Sun, T. Hwang, Efficient three-party authentication and key agreement protocols resistant to password guessing attacks, Information Science and Engineering 19 (6) (2003) 1059–1070.] proposed two secure and efficient three-party EKE protocols. Based on the protocol developed by Yeh et al., two improved EKE protocols for authentication and key agreement are proposed in this study. The computational costs of the proposed protocols are the same as those of the protocols of Yeh et al. However, the numbers of messages in the communication are fewer than those of the protocols of Yeh et al. Furthermore, the round efficient versions of our proposed protocols are also described

Lowly Expressed Ribosomal Protein S19 in the Feces of Patients with Colorectal Cancer

Colorectal cancer (CRC) has become one of the most common fatal cancers. CRC tumorigenesis is a complex process involving multiple genetic changes to several sequential mutations or molecular alterations. P53 is one of the most significant genes; its mutations account for more than half of all CRC. Therefore, understanding the cellular genes that are directly or indirectly related to p53 is particularly crucial for investigating CRC tumorigenesis. In this study, a p53-related ribosomal protein, ribosomal protein S19 (RPS19), obtained from the feces of CRC patients is evaluated by using specifically quantitative real-time PCR and knocked down in the colonic cell line by gene silencing. This study found that CRC patients with higher expressions of RPS19 in their feces had a better prognosis and consistent expressions of RPS19 and BAX in their colonic cells. In conclusion, the potential mechanism of RPS19 in CRC possibly involves cellular apoptosis through the BAX/p53 pathway, and the levels of fecal RPS19 may function as a prognostic predictor for CRC patients