CO2 concentrating mechanism and signal transduction pathway associated with limiting CO2 acclimation in Chlamydomonas reinhardtii

Many aquatic photosynthetic organisms exhibit a variety of acclimation responses to limiting CO2 availability, including induction of CO2 concentrating mechanisms (CCMs), which represent adaptations to environments with changing and, at times, limiting CO2 availability. Although the characteristics and regulation of limiting CO2 acclimation, including the CCM, in the green alga Chlamydomonas reinhardtii have been well demonstrated by physiological and biochemical studies, much less information is available at the molecular level with regard to the components involved in the CCM and other parts of the limiting CO2 acclimation response. We have applied insertional mutagenesis and genetic approaches in an effort to identify the components of the CCM, other pathways essential to limiting CO2 acclimation and of the regulatory pathways controlling limiting CO2 acclimation responses. Many mutants defective in acclimation to limiting CO2 environments were generated by gene tagging, and, although all the identified mutants are phenotypically high-CO2-requiring, they can be distinguished by differences in their ability to survive under various levels of CO2, by differences in heterotrophic growth, and by differences in the gene expression patterns of CO2 responsive genes. Using the insertional tags, several mutant genes have been identified or confirmed, including the transcription factor Cia5, 2-oxoglutarate dehydrogenase (Ogd2), heat shock proteins and LciB , which encodes an unknown protein apparently involved in inorganic carbon transport. The identity of defective genes in the mutants suggests that they are located in various metabolic or regulatory pathways, including the CCM, mitochondrial respiration, chloroplast photoprotection and some not yet identified regulatory pathways. In addition, it has become evident that analysis of insertional mutants in C. reinhardtii is rarely straightforward, even when there is a single insert that co-segregates with the mutant phenotype. We hope that this endeavor will continue to provide information useful in elucidating the networks associated with the limiting CO2 acclimation response and its regulation

Modeling and Experimental Verification of an Electromagnetic and Piezoelectric Hybrid Energy Harvester

This paper describes mathematical models of an electromagnetic and piezoelectric hybrid energy harvesting system and provides an analysis of the relationship between the resonance frequency and the configuration parameters of the system. An electromagnetic and piezoelectric energy harvesting device was designed and the experimental results showed good agreement with the analytical results. The maximum load power of the hybrid energy harvesting system achieved 4.25 mW at a resonant frequency of 18 Hz when the acceleration was 0.7 g, which is an increase of 15% compared with the 3.62 mW achieved by a single electromagnetic technique

Genipin-cross-linked collagen/chitosan biomimetic scaffolds for articular cartilage tissue engineering applications

This was the first study to use genipin to cross-link collagen and chitosan.In this study, genipin-cross-linked collagen/chitosan biodegradable porous scaffolds were prepared for articular cartilage regeneration. The influence of chitosan amount and genipin concentration on the scaffolds physicochemical properties was evaluated. The morphologies of the scaffolds were characterized by scanning electron microscope (SEM) and cross-linking degree was investigated by ninhydrin assay. Additionally, the mechanical properties of the scaffolds were assessed under dynamic compression. To study the swelling ratio and the biostability of the collagen/chitosan scaffold, in vitro tests were also carried out by immersion of the scaffolds in PBS solution or digestion in collagenase, respectively. The results showed that the morphologies of the scaffolds underwent a fiber-like to a sheet-like structural transition by increasing chitosan amount. Genipin cross-linking remarkably changed the morphologies and pore sizes of the scaffolds when chitosan amount was less than 25%. Either by increasing the chitosan ratio or performing cross-linking treatment, the swelling ratio of the scaffolds can be tailored. The ninhydrin assay demonstrated that the addition of chitosan could obviously increase the cross-linking efficiency. The degradation studies indicated that genipin cross-linking can effectively enhance the biostability of the scaffolds. The biocompatibility of the scaffolds was evaluated by culturing rabbit chondrocytes in vitro. This study demonstrated that a good viability of the chondrocytes seeded on the scaffold was achieved. The SEM analysis has revealed that the chondrocytes adhered well to the surface of the scaffolds and contacted each other. These results suggest that the genipin-cross-linked collagen/chitosan matrix may be a promising formulation for articular cartilage scaffolding.Key Projects in the National Science and Technology Pillar Program in the Eleventh Five-year Plan Period. Grant Number: 2006BA116B04Guangdong Natural Science Foundation. Grant Number: 07300602Natural Science Foundation Team Project of Guangdong. Grant Number: 4205786State Key Program of National Natural Science of China. Grant Number: 50732003National Basic Research Program of China. Grant Number: 2005CB62390

The value of Apolipoprotein B/Apolipoprotein A1 ratio for metabolic syndrome diagnosis in a Chinese population: a cross-sectional study

BACKGROUND: The apoB/apoA1 ratio has been reported to be associated with the metabolic syndrome (MetS), and it may be a more convenient biomarker in MetS predicting. However, whether apoB/apoA1 ratio is a better indicator of metabolic syndrome than other biomarkers and what is the optimal cut-off value of apoB/apoA1 ratio as an indicator of metabolic syndrome in Chinese population remain unknown. Thus, we carried out the current study to assess the predictive value of apoB/apoA1 ratio and determine the optimal cut-off value of apoB/apoA1 ratio for diagnosing MetS in a Chinese population. METHOD: We selected 1,855 subjects with MetS and 6,265 individuals without MetS based on the inclusion and exclusion criteria from the China Health Nutrition Survey (CHNS) in 2009. MetS was identified based on the diagnostic criteria of International Diabetes Federation (2005). Logistic regression was used to estimate the association between the apoB/apoA1 ratio and risk of MetS, and receiver operating characteristics (ROC) curve analysis was performed to test the predictive value of apoB/apoA1 ratio and calculate the appropriate cut-off value. RESULTS: Compared with the lowest quartile of apoB/apoA1 ratio, subjects in the fourth quartile had a higher risk of MetS in both men [odds ratio (OR) = 2.64, 95% confidence interval (CI) =1.82-3.83] and women (OR = 5.18, 95% CI = 3.87-6.92) after adjustment for potential confounders. The optimal cut-off value of apoB/apoA1 ratio for MetS detection was 0.85 in men and 0.80 in women. Comparisons of ROC curves indicated that apoB/apoA1 ratio was better than traditional biomarkers in predicting MetS. CONCLUSION: Our results suggest that, apoB/apoA1 ratio has a promising predictive effectiveness in detection of MetS. An apoB/apoA1 ratio higher than 0.85 in men and 0.80 in women may be a promising and convenient marker of MetS

A New Systemic Safety Detecting Software

Because it is hard to find and to clear cockhorse and virus developed by root kit technology, antivirus soft at present is hard to clear virus in the system, which make the system in dangers status of hazard. So, designing a speedy clear Trojan and virus makes by root kit is very important. The article.is based on SDK, adopting the technology.of kernel to design the Clairvoyant systemic safety detecting software. It major function is monitors.the service of the system and the operation. Monitor the register changer. Search the file, process, system module hided by the virus. It can also end protected processes and delete protected files forcibly. Through the port.mapping of processes, it can find.port messages opened.by system, processes opening ports and.cockhorse effectively. http://dx.doi.org/10.11591/telkomnika.v12i10.5345

Multiple-relaxation-time lattice Boltzmann model for compressible fluids

We present an energy-conserving multiple-relaxation-time finite difference lattice Boltzmann model for compressible flows. This model is based on a 16-discrete-velocity model. The collision step is first calculated in the moment space and then mapped back to the velocity space. The moment space and corresponding transformation matrix are constructed according to the group representation theory. Equilibria of the nonconserved moments are chosen according to the need of recovering compressible Navier-Stokes equations through the Chapman-Enskog expansion. Numerical experiments showed that compressible flows with strong shocks can be well simulated by the present model. The used benchmark tests include (i) shock tubes, such as the Sod, Lax, Sjogreen, Colella explosion wave and collision of two strong shocks, (ii) regular and Mach shock reflections, and (iii) shock wave reaction on cylindrical bubble problems. The new model works for both low and high speeds compressible flows. It contains more physical information and has better numerical stability and accuracy than its single-relaxation-time version.Comment: 11 figures, Revte

Research on measuring method of large-caliber gun muzzle vibration

In this paper, a measuring system based on binocular vision is developed for the research on large-caliber gun muzzle vibration. The system is consisted of two high-speed cameras and other equipment. The two-step calibration method based on radial constraint is adopted in order to complete the calibration, the inter-frame differential multiplication method is used to detect the centroid of moving target accurately, the improved Kalman filter tracking algorithm is used to obtain the motion trajectory of the muzzle identification point. The system is applied to practice for a type of muzzle vibration measurement and meaningful original data is acquired