Recursive linearization of multibody dynamics equations of motion

The equations of motion of a multibody system are nonlinear in nature, and thus pose a difficult problem in linear control design. One approach is to have a first-order approximation through the numerical perturbations at a given configuration, and to design a control law based on the linearized model. Here, a linearized model is generated analytically by following the footsteps of the recursive derivation of the equations of motion. The equations of motion are first written in a Newton-Euler form, which is systematic and easy to construct; then, they are transformed into a relative coordinate representation, which is more efficient in computation. A new computational method for linearization is obtained by applying a series of first-order analytical approximations to the recursive kinematic relationships. The method has proved to be computationally more efficient because of its recursive nature. It has also turned out to be more accurate because of the fact that analytical perturbation circumvents numerical differentiation and other associated numerical operations that may accumulate computational error, thus requiring only analytical operations of matrices and vectors. The power of the proposed linearization algorithm is demonstrated, in comparison to a numerical perturbation method, with a two-link manipulator and a seven degrees of freedom robotic manipulator. Its application to control design is also demonstrated

Man-in-the-control-loop simulation of manipulators

A method to achieve man-in-the-control-loop simulation is presented. Emerging real-time dynamics simulation suggests a potential for creating an interactive design workstation with a human operator in the control loop. The recursive formulation for multibody dynamics simulation is studied to determine requirements for man-in-the-control-loop simulation. High speed computer graphics techniques provides realistic visual cues for the simulator. Backhoe and robot arm simulations are implemented to demonstrate the capability of man-in-the-control-loop simulation

Complete genomic sequence of the temperate bacteriophage ΦAT3 isolated from Lactobacillus casei ATCC 393

AbstractThe complete genomic sequence of a temperate bacteriophage ΦAT3 isolated from Lactobacillus (Lb.) casei ATCC 393 is reported. The phage consists of a linear DNA genome of 39,166 bp, an isometric head of 53 nm in diameter, and a flexible, noncontractile tail of approximately 200 nm in length. The number of potential open reading frames on the phage genome is 53. There are 15 unpaired nucleotides at both 5′ ends of the ΦAT3 genome, indicating that the phage uses a cos-site for DNA packaging. The ΦAT3 genome was grouped into five distinct functional clusters: DNA packaging, morphogenesis, lysis, lysogenic/lytic switch, and replication. The amino acid sequences at the NH2-termini of some major proteins were determined. An in vivo integration assay for the ΦAT3 integrase (Int) protein in several lactobacilli was conducted by constructing an integration vector including ΦAT3 int and the attP (int-attP) region. It was found that ΦAT3 integrated at the tRNAArg gene locus of Lactobacillus rhamnosus HN 001, similar to that observed in its native host, Lb. casei ATCC 393

Analysis of Agreement on Traditional Chinese Medical Diagnostics for Many Practitioners

In Traditional Chinese Medicine (TCM) diagnostics, it is an important issue to study the degree of agreement among several distinct practitioners. In order to study the reliability of TCM diagnostics, we have to design an experiment to simultaneously deal with both of the cases when the data is ordinal and when there are many TCM practitioners. In this study, we consider a reliability measure called “Krippendorff's alpha” to investigate the agreement of tongue diagnostics in TCM. Besides, since it is not easy to obtain a large data set with patients rated simultaneously by many TCM practitioners, we use the renowned “bootstrapping” to obtain a 95% confidence interval for the Krippendorff's alpha. The estimated Krippendorff's alpha for the agreement among ten physicians that discerned fifteen randomly chosen patients is 0.7343, and the 95% bootstrapping confidence interval for the true alpha coefficient is [0.6570, 0.7349]. The data was collected and analyzed at the Department of Traditional Chinese Medicine, Changhua Christian Hospital (CCH) in Taiwan

LrrA, a novel leucine-rich repeat protein involved in cytoskeleton remodeling, is required for multicellular morphogenesis in Dictyostelium discoideum

AbstractCell sorting by differential cell adhesion and movement is a fundamental process in multicellular morphogenesis. We have identified a Dictyostelium discoideum gene encoding a novel protein, LrrA, which composes almost entirely leucine-rich repeats (LRRs) including a putative leucine zipper motif. Transcription of lrrA appeared to be developmentally regulated with robust expression during vegetative growth and early development. lrrA null cells generated by homologous recombination aggregated to form loose mounds, but subsequent morphogenesis was blocked without formation of the apical tip. The cells adhered poorly to a substratum and did not form tight cell–cell agglomerates in suspension; in addition, they were unable to polarize and exhibit chemotactic movement in the submerged aggregation and Dunn chamber chemotaxis assays. Fluorescence-conjugated phalloidin staining revealed that both vegetative and aggregation competent lrrA− cells contained numerous F-actin-enriched microspikes around the periphery of cells. Quantitative analysis of the fluorescence-stained F-actin showed that lrrA− cells exhibited a dramatically increase in F-actin as compared to the wild-type cells. When developed together with wild-type cells, lrrA− cells were unable to move to the apical tip and sorted preferentially to the rear and lower cup regions. These results indicate that LrrA involves in cytoskeleton remodeling, which is needed for normal chemotactic aggregation and efficient cell sorting during multicellular morphogenesis, particularly in the formation of apical tip

Bronchiolitis Obliterans Organizing Pneumonia in Swine Associated with Porcine Circovirus Type 2 Infection

Bronchiolitis obliterans organizing pneumonia (BOOP) is a chronic respiratory disease. Although the pathogenesis of BOOP is still incompletely understood, BOOP is responsive to steroids and has a good prognosis. In our five pigs with chronic postweaning multisystemic wasting syndrome (PMWS), typical BOOP lesions were revealed. All five porcine lungs showed typical intraluminal plugs, and porcine circovirus type 2 (PCV2) was identified. They also exhibited similar pathologic findings such as proliferation of type II pneumocytes and myofibroblasts (MFBs), extracellular collagen matrix (ECM) deposition, and fragmentation of elastic fibers. MFBs migration correlative molecules, for instance, gelatinase A, B and osteopontin, appeared strongly in the progressing marginal area of polypoid intraluminal plugs of fibrotic lesion. These molecules colocalized with the active MFBs. Both gelatinase activity and intercellular level of active MFBs were significantly increased (P < .05). Porcine chronic bronchopneumonia leads to BOOP and it is associated with PCV2 persistent infection. Swine BOOP demonstrates similar cellular constituents with human BOOP. Perhaps their molecular mechanisms of pathogenesis operate in a similar way. Thus we infer that the swine BOOP can be considered as a potential animal model for human BOOP associated with natural viral infection. Moreover, it is more convenient to obtain samples

TREATING PEDIATRIC ASTHMA WITH HOLISTIC APPROACHES OF TRADITIONAL CHINESE MEDICINE: A RETROSPECTIVE STUDY

Background: Asthma is a chronic disease increasingly found in children. To find more economical and efficient alternatives to treat pediatric asthma, the Bureau of National Health Insurance of Taiwan launched the Traditional Chinese Medicine Holistic Treatment Program (TCMHTP). The effect of traditional Chinese medicine (TCM) holistic treatments on pediatric asthma was evaluated based on data collected from the program. Materials and Methods: A retrospective study was performed by analyzing a dataset from Changhua Christian Hospital, Taiwan, between January 1st, 2006 and December 31st, 2010. Patients aged between 2 and 15 years, who had been diagnosed with asthma, and had participated in the TCMHTP were recruited, whereas those with other severe diseases were excluded. We analyzed the frequency of emergency department visits (EDV), inpatient admission rate (IAR), and length of hospitalization (LH) of the patients, before and after TCM treatments. Spectral analysis of heart rate variability (HRV) was also conducted. Results: Fifty-eight patients were recruited. The average age of the patients receiving TCM treatments was 5.67±3.03 years. The frequency of EDV decreased from 0.94±0.85 to 0.67±1.19 times annually (p=0.095), the annual IAR decreased from 0.62±0.78 to 0.26±0.67 (p=0.002) and the average LH decreased from 3.32±4.25 to 0.80±1.64 (p=0.000) days per year. Parasympathetically mediated HRV decreased significantly from 60.42±15.33 to 54.89±16.45 nu (p=0.016). Conclusion: The present study revealed that an appropriate period of TCM holistic treatment intervention can not only significantly lower exacerbations and hospitalization frequency but also reduce vagal tone in asthmatic children

The nucleolar protein NIFK promotes cancer progression via CK1α/β-catenin in metastasis and Ki-67-dependent cell proliferation.

Nucleolar protein interacting with the FHA domain of pKi-67 (NIFK) is a Ki-67-interacting protein. However, its precise function in cancer remains largely uninvestigated. Here we show the clinical significance and metastatic mechanism of NIFK in lung cancer. NIFK expression is clinically associated with poor prognosis and metastasis. Furthermore, NIFK enhances Ki-67-dependent proliferation, and promotes migration, invasion in vitro and metastasis in vivo via downregulation of casein kinase 1α (CK1α), a suppressor of pro-metastatic TCF4/β-catenin signaling. Inversely, CK1α is upregulated upon NIFK knockdown. The silencing of CK1α expression in NIFK-silenced cells restores TCF4/β-catenin transcriptional activity, cell migration, and metastasis. Furthermore, RUNX1 is identified as a transcription factor of CSNK1A1 (CK1α) that is negatively regulated by NIFK. Our results demonstrate the prognostic value of NIFK, and suggest that NIFK is required for lung cancer progression via the RUNX1-dependent CK1α repression, which activates TCF4/β-catenin signaling in metastasis and the Ki-67-dependent regulation in cell proliferation

Protective effects of Scoparia dulcis L. extract on high glucose-induced injury in human retinal pigment epithelial cells

Diabetic retinopathy (DR) is a major cause of vision loss in diabetic patients. Hyperglycemia-induced oxidative stress and the accumulation of inflammatory factors result in blood-retinal barrier dysfunction and the pathogenesis of DR. Scoparia dulcis L. extract (SDE), a traditional Chinese medicine, has been recently recognized for its various pharmacological effects, including anti-diabetic, anti-hyperlipidemia, anti-inflammatory, and anti-oxidative activities. However, there is no relevant research on the protective effect of SDE in DR. In this study, we treated high glucose (50 mM) in human retinal epithelial cells (ARPE-19) with different concentrations of SDE and analyzed cell viability, apoptosis, and ROS production. Moreover, we analyzed the expression of Akt, Nrf2, catalase, and HO-1, which showed that SDE dose-dependently reduced ROS production and attenuated ARPE-19 cell apoptosis in a high-glucose environment. Briefly, we demonstrated that SDE exhibited an anti-oxidative and anti-inflammatory ability in protecting retinal cells from high-glucose (HG) treatment. Moreover, we also investigated the involvement of the Akt/Nrf2/HO-1 pathway in SDE-mediated protective effects. The results suggest SDE as a nutritional supplement that could benefit patients with DR