Control of locomotion systems and dynamics in relative periodic orbits

The connection between the dynamics in relative periodic orbits of vector fields with noncompact symmetry groups and periodic control for the class of control systems on Lie groups known as `(robotic) locomotion systems' is well known, and has led to the identification of (geometric) phases. We take an approach which is complementary to the existing ones, advocating the relevance|for trajectory generation in these control systems|of the quali-tative properties of the dynamics in relative periodic orbits. There are two particularly important features. One is that motions in relative periodic orbits of noncompact groups can only be of two types: Either they are quasi-periodic, or they leave any compact set as t →±∞ (`drifting motions'). Moreover, in a given group, one of the two behaviours may be predominant. The second is that motions in a relative periodic orbit exhibit `spiralling', `meandering' behaviours, which are routinely detected in numerical integrations. Since a quantitative description of meandering behaviours for drifting motions appears to be missing, we provide it here for a class of Lie groups that includes those of interest in locomotion (semidirect products of a compact group and a normal vector space). We illustrate these ideas on some examples (a kinematic car robot, a planar swimmer)

The role of metal ions in the uptake of aspartate aminotransferase and malate dehydrogenase into isolated rat liver mitochondria in vitro

AbstractTo gain further insight into the mitochondrial receptor area which allows selective uptake of both purified aspartate aminotransferase and malate dehydrogenase into mitochondria, the inhibition of metal complexing agents such as bathophenanthroline and tiron on the uptake of both enzymes has been investigated. In view of the nature of the inhibition found, we propose the existence of metal ion(s) at or near the aspartate aminotransferase, but far from the malate dehydrogenase binding site

Segmentasi Citra Digital Menggunakan Thresholding Otsu untuk Analisa Perbandingan Deteksi Tepi

Pendeteksian tepi menjadi salah satu tahapan penting pengolahan citra dalam proses segmentasi karena dapat mempertegas batas-batas antara objek dan latar belakang. Banyaknya metode deteksi tepi saat ini menimbulkan keraguan dalam memilih metode deteksi tepi yang tepat dan sesuai dengan kondisi citra. Berdasarkan masalah tersebut dilakukan penelitian untuk menganalisis kinerja metode deteksi tepi Sobel, Prewitt, Roberts dan Canny menggunakan thresholding Otsu berdasarkan nilai threshold, waktu proses dan pengamatan visual. Program dibuat menggunakan perangkat lunak Microsoft Visual C# 2010 Express. Hasil penelitian terhadap tiga citra uji bahwa metode Canny menghasilkan tepian yang tipis dan halus serta tidak menghilangkan informasi penting pada gambar meskipun membutuhkan waktu komputasi yang tidak sedikit. Nilai threshold yang diperoleh dari Otsu merupakan nilai ambang terbaik dan optimal untuk setiap metod

Hand Gesture Recognition as Password to Open the Door with Camera and Convexity Defect Method

Computer Vision is one of reasearch that gets a lot of attention with many applications. One of the application is the hand gesture recognition system. By using EmguCV, will be obtained camera images from webcam camera. The Pictures will be disegmented by using skin detection method for decrease noises in order to obtain the information needed. The final project of this system is to implement the convexity defect method for extracting images and recognize patterns of hand gesture that represent the characters A, B, C, D, and E. The parameters used in pattern recognition of hand gesture is the number and length of the line connecting the hull and defects derived from the pattern of hand gesture

Reactive oxygen species inhibit the succinate oxidation-supported generation of membrane potential in wheat mitochondria

In order to gain a first insight into the effects of reactive oxygen species (ROS) on plant mitochondria, we studied the effect of the ROS producing system consisting of xanthine plus xanthine oxidase on the rate of membrane potential (ΔΨ) generation due to either succinate or NADH addition to durum wheat mitochondria as monitored by safranin fluorescence. We show that the early ROS production inhibits the succinate-dependent, but not the NADH-dependent, ΔΨ generation and oxygen uptake. This inhibition appears to depend on the impairment of mitochondrial permeability to succinate. It does not involve mitochondrial thiol groups sensitive to either mersalyl or N-ethylmaleimide and might involve both protein residues and/or membrane lipids, as suggested by the mixed nature. We propose that, during oxidative stress, early generation of ROS can affect plant mitochondria by impairing metabolite transport, thus preventing further substrate oxidation, ΔΨ generation and consequent large-scale ROS production. © 2002 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved

Design and Synthesis of Hsp90 Inhibitors with B-Raf and PDHK1 Multi-Target Activity

5noopenThe design of multi-target ligands has become an innovative approach for the identification of effective therapeutic treatments against complex diseases, such as cancer. Recent studies have demonstrated that the combined inhibition of Hsp90 and B-Raf provides synergistic effects against several types of cancers. Moreover, it has been reported that PDHK1, which presents an ATP-binding pocket similar to that of Hsp90, plays an important role in tumor initiation, maintenance and progression, participating also to the senescence process induced by B-Raf oncogenic proteins. Based on these premises, the simultaneous inhibition of these targets may provide several benefits for the treatment of cancer. In this work, we set up a design strategy including the assembly and integration of molecular fragments known to be important for binding to the Hsp90, PDHK1 and B-Raf targets, aided by molecular docking for the selection of a set of compounds potentially able to exert Hsp90-B-Raf-PDHK1 multi-target activities. The designed compounds were synthesized and experimentally validated in vitro. According to the in vitro assays, compounds 4 a, 4 d and 4 e potently inhibited Hsp90 and moderately inhibited the PDHK1 kinase. Finally, molecular dynamics simulations were performed to provide further insights into the structural basis of their multi-target activity.openPinzi L.; Foschi F.; Christodoulou M.S.; Passarella D.; Rastelli G.Pinzi, L.; Foschi, F.; Christodoulou, M. S.; Passarella, D.; Rastelli, G

Increase of proton electrochemical potential and ATP synthesis in rat liver mitochondria irradiated in vitro by helium-neon laser

Mitochondria Laser Transmembrane proton gradient Membrane potential ATP synthesis Oxygen uptake. © 1984

Survival and Functional Outcomes After Hip Fracture Among Nursing Home Residents

Importance Little is known regarding outcomes after hip fracture among long-term nursing home residents. Objective To describe patterns and predictors of mortality and functional decline in activities of daily living (ADLs) among nursing home residents after hip fracture. Design, Setting, and Participants Retrospective cohort study of 60 111 Medicare beneficiaries residing in nursing homes who were hospitalized with hip fractures between July 1, 2005, and June 30, 2009. Main Outcomes and Measures Data sources included Medicare claims and the Nursing Home Minimum Data Set. Main outcomes included death from any cause at 180 days after fracture and a composite outcome of death or new total dependence in locomotion at the latest available assessment within 180 days. Additional analyses described within-residents changes in function in 7 ADLs before and after fracture. Results Of 60 111 patients, 21 766 (36.2%) died by 180 days after fracture; among patients not totally dependent in locomotion at baseline, 53.5% died or developed new total dependence within 180 days. Within individual patients, function declined substantially after fracture across all ADL domains assessed. In adjusted analyses, the greatest decreases in survival after fracture occurred with age older than 90 years (vs ≤75 years: hazard ratio [HR], 2.17; 95% CI, 2.09-2.26 [P \u3c .001]), nonoperative fracture management (vs internal fixation: HR for death, 2.08; 95% CI, 2.01-2.15 [P \u3c .001]), and advanced comorbidity (Charlson score of ≥5 vs 0: HR, 1.66; 95% CI, 1.58-1.73 [P \u3c .001]). The combined risk of death or new total dependence in locomotion within 180 days was greatest among patients with very severe cognitive impairment (vs intact cognition: relative risk [RR], 1.66; 95% CI, 1.56-1.77 [P \u3c .001]), patients receiving nonoperative management (vs internal fixation: RR, 1.48; 95% CI, 1.45-1.51 [P \u3c .001]), and patients older than 90 years (vs ≤75 years: RR, 1.42; 95% CI, 1.37-1.46 [P \u3c .001]). Conclusions and Relevance Survival and functional outcomes are poor after hip fracture among nursing home residents, particularly for patients receiving nonoperative management, the oldest old, and patients with multiple comorbidities and advanced cognitive impairment. Care planning should incorporate appropriate prognostic information related to outcomes in this population