Non-approximability of weighted multiple sequence alignment for arbitrary metrics

We prove that the multiple sequence alignment problem with weighted sum-of-pairs score is APX-hard for arbitrary metric scoring functions over the binary alphabet. This holds even when the weights are restricted to zero and one.     

Exercise-induced overexpression of key regulatory proteins involved in glucose uptake and metabolism in tetraplegic persons: molecular mechanism for improved glucose homeostasis

Complete spinal cord lesion leads to profound metabolic abnormalities and striking changes in muscle morphology. Here we assess the effects of electrically stimulated leg cycling (ESLC) on whole body insulin sensitivity, skeletal muscle glucose metabolism, and muscle fiber morphology in five tetraplegic subjects with complete C5-C7 lesions. Physical training (seven ESLC sessions/wk for 8 wk) increased whole body insulin-stimulated glucose uptake by 33+/-13%, concomitant with a 2.1-fold increase in insulin-stimulated (100 microU/ml) 3-O-methylglucose transport in isolated vastus lateralis muscle. Physical training led to a marked increase in protein expression of GLUT4 (378+/-85%), glycogen synthase (526+/-146%), and hexokinase II (204+/-47%) in vastus lateralis muscle, whereas phosphofructokinase expression (282+/-97%) was not significantly changed. Hexokinase II activity was significantly increased, whereas activity of phosphofructokinase, glycogen synthase, and citrate synthase was not changed after training. Muscle fiber type distribution and fiber area were markedly altered compared to able-bodied subjects before ESLC training, with no change noted in either parameter after ECSL training. In conclusion, muscle contraction improves insulin action on whole body and cellular glucose uptake in cervical cord-injured persons through a major increase in protein expression of key genes involved in the regulation of glucose metabolism. Furthermore, improvements in insulin action on glucose metabolism are independent of changes in muscle fiber type distribution.     

Smoothed analysis of binary search trees

Binary search trees are one of the most fundamental data structures. While the height of such a tree may be linear in the worst case, the average height with respect to the uniform distribution is only logarithmic. The exact value is one of the best studied problems in average-case complexity.     

Characterization of recombinant type II collagen: arthritogenicity and tolerogenicity in DBA/1 mice

Using new nonisotopic and isotopic methods, we showed previously that fatty acid synthesis was markedly stimulated in weight-stable normal volunteers by a very-low-fat formula diet with 10% of energy as fat and 75% as short glucose polymers. In this study, we determined whether fatty acid synthesis was equally stimulated by a very-low-fat solid diet made with foods consumed typically. Four normal volunteers consumed the same very-low-fat formula diet for 25 d and then an isoenergetic solid food diet with 10% of energy as fat and 75% as starch, simple sugars, and fiber for 25 d. To measure fatty acid synthesis, the fatty acid compositions of the diets were matched to the composition of each subject's adipose tissue and compared with the composition of VLDL-triacylglycerol. In all subjects, the large increases in newly formed palmitate and decreases in linoleate in VLDL-triacylglycerol were quickly reversed by the solid food diet, and the fraction of de novo synthesized fatty acids in fasting VLDL-triacylglycerol decreased from 30-54% to 0-1%. In a second group of subjects, the stimulation of fatty acid synthesis by the formula diet with 75% glucose polymers was similarly reduced by a formula diet with amounts of fat, starch, and sugar chosen to mimic those of the solid food diet, but persisted after the addition of fiber or a diet with 75% sugar. In conclusion, an increase in fatty acid synthesis and palmitaterich, linoleate-poor VLDL-triacylglycerol induced by very-low-fat, high-sugar diets may be reduced by the substitution of dietary starch for sugar with potentially beneficial effects on cardiovascular health.     

Insulin-stimulated Akt kinase activity is reduced in skeletal muscle from NIDDM subjects

The serum lipoprotein(a) [Lp(a)] level is a known risk factor for arteriosclerotic coronary artery disease. However, its association with restenosis after percutaneous transluminal coronary angioplasty (PTCA) is controversial. We hypothesized that the Lp(a) level is a significant risk factor for restenosis after angioplasty through a pathophysiological mechanism leading to excess thrombin generation or inhibition of fibrinolysis. We designed a prospective study of the relation of Lp(a) to outcome after PTCA, in which we measured selected laboratory variables at entry and collected clinical, procedural, lesion-related, and outcome data pertaining to restenosis. Restenosis was defined as >50% stenosis of the target lesion by angiography or as ischemia in the target vessel distribution by radionuclide-perfusion scan. Before the patients underwent PTCA, blood was obtained by venipuncture for measurement of Lp(a), total cholesterol, thrombin-antithrombin (TAT) complex, alpha2-antiplasmin-plasmin (APP) complex, and plasminogen activator inhibitor-1 (PAI-1). Evaluable outcome data were obtained on 162 subjects, who form the basis of this report. Restenosis occurred in 61 subjects (38%). The Lp(a) level was not correlated significantly with TAT, APP, PAI-1, or the TAT-APP ratio. Levels of TAT, APP, and PAI-1 were not statistically different in the patients with versus those without restenosis. The median ratio of TAT to APP was 2-fold higher in the restenosis group, and this difference approached statistical significance (P=0.07). Univariate analysis was performed for the association of clinical, lesion-related, and procedural risk factors with restenosis. Lp(a) levels did not differ significantly in the restenosis versus no-restenosis group, whether assessed categorically (>25 mg/dL versus <25 mg/dL) or as a continuous variable by Mann-Whitney U test. The number of lesions dilated and the lack of family history of premature heart disease were significantly associated with restenosis (P=0.002 and P=0.008, respectively). A history of diabetes mellitus was of borderline significance (P=0.055). By multiple logistic regression analysis, the number of lesions dilated was the only variable significantly associated with restenosis (P=0.03). We conclude that the number of lesions dilated during PTCA is a significant risk factor for restenosis, whereas the serum Lp(a) level was not a significant risk factor for restenosis in our patient population. The TAT to APP ratio merits further study as a possible risk factor for restenosis.     

HiL simulation for testing joint stability after total knee arthroplasty

Instability of total knee replacements (TKRs) remains one of the most prevalent complications after total knee arthroplasty. Especially the actual event of instability involving complex interactions between implant components and soft tissue structures is not well understood. Therefore, the purpose of this work is to introduce a novel approach for testing TKRs with respect to stability of the artificial knee joint based on a mechatronic hardware-in-the-loop (HiL) test system. The mechanical test setup is composed of an industrial robot with a compliant support for the endoprosthesis to be tested. It interacts with a biomechanical multibody model consisting of all relevant body parts of the lower extremity incorporating ligament structures of the knee joint. According to the movement angles and reaction forces/torque provided by the multibody model, the robot rotates and loads the femoral component with respect to the tibial component. The resulting position and loading of the femoral component are measured and fed back into the model, thus closing the control loop for HiL simulations. The functional principle of the HiL simulation is proven by simulating a passive flexion movement of a bicondylar, posterior cruciate ligament retaining TKR using the described biomechanical multibody model.     

Experimental identification of modal parameters of an industrial 2‐MW wind turbine

This contribution presents modal testing of a 2‐MW wind turbine on a 100‐m tubular tower with a 93‐m rotor developed by W2E Wind to Energy GmbH. This research is part of the DYNAWIND project of the University of Rostock and W2E. Beside classical modal analysis schemes, this contribution mainly focusses on the application of operational modal analysis techniques to a wind turbine. Specific problems are addressed, and hints for modal testing on wind turbines are given. Furthermore, an effective measurement setup is proposed for identification of the modal parameters of a wind turbine. The measurement campaign is divided in two parts. First, a measurement campaign using 8 sensor positions on a rotor blade was done while the rotor is lying on ground. Second, a detailed measurement campaign was done on the entire wind turbine with the rotor locked in Y position using 61 sensor positions on the tower, the mainframe, the gearbox, the generator, and the low‐voltage unit. While the rotor blade was tested by classical and operational modal analysis techniques, the entire wind turbine was tested by operational modal analysis techniques only. The mode shapes and eigenfrequencies of the wind turbine identified within the measurement campaigns are within the expected range of the design values of the wind turbine. But in contrast, the damping ratios differ strongly from those given in guidelines and literature. Furthermore, a strong influence of aerodynamic damping compared to structural damping is observed for the first tower mode even for a parked wind turbine.     

Effects of interleukins on Crouzon fibroblast phenotype in vitro. Release of cytokines and IL-6 mRNA expression

In Crouzon's syndrome, the cranial morphogenic processes are altered due to the early fusion of the facial and basal cranial bones. Evidence that Crouzon fibroblasts have an altered phenotype which is modulated by interleukin 1 (IL-1) and interleukin 6 (IL-6) is provided. [3H]Thymidine incorporation and cell count studies showed that Crouzon fibroblasts have an accelerated proliferation rate. [3H]Glucosamine incorporation studies, followed by chromatography analysis of culture medium samples, revealed that the various classes of glycosaminoglycans (GAG) secreted into the medium were differently distributed in Crouzon and normal fibroblasts. Crouzon fibroblasts secreted less total GAG, particularly hyaluronic acid (HA) and heparan sulfate (HS), but a relatively greater quantity of chondroitin sulfate. Type I and III collagen were raised in Crouzon fibroblast medium whereas the concentration of fibronectin was lower than in normal cells. Interleukin treatment induced changes in cell growth and neosynthesis of extracellular matrix macromolecules. Both IL-1 and IL-6 stimulated proliferation of Crouzon fibroblasts, whereas only IL-6 increased [3H]thymidine incorporation in normal cells. IL-1 provided a drop in HA and a rise in GAG sulfates in normal fibroblasts, but caused an opposite effect in Crouzon fibroblasts. Type I collagen and fibronectin secretions are differently modulated by the cytokines in the two populations. Moreover, level of IL-1 able to stimulate [3H] thymidine incorporation into mouse thymocytes, and level of IL-1 receptor antagonist (IL-1ra), as determined by ELISA, were higher in pathological than in normal fibroblasts. Also evidence that levels of IL-1 alpha and IL-6 proteins measured by ELISA and also IL-6 mRNA expression are enhanced in Crouzon fibroblasts is provided. These novel data suggested that, in Crouzon's syndrome, the modifications in the relative concentrations of the extracellular matrix (ECM) components associated with the abnormal cytokine networks may alter the balance of the microenvironment where the morphogenic events take place.     

Fujaba-Based Tool Development for eHome Systems

One of the main reasons preventing a wide application of eHome systems in practice is the effort needed to combine all appliances, necessary controller and infrastructure components to benefit from derived value-added services. The properties, dependencies, locations, and installation conditions have to be properly specified for this composition and its deployment. Due to the great variance in services and eHome configurations there is a need for tool support for eHome systems. In this paper we address the software development issues of such tools. In our approach we base the software development on graph rewriting language techniques. Based on our experience, we consider this approach as a possibility to improve the productivity of the eHome system tool development. With the aid of Fujaba, we created a model capable of specifying functions, devices, environments, and value-added services. Furthermore, we used Fujaba to create the activities as graph rewriting rules for model modifications. To apply the model and to carry out the actual specification for a particular eHome and particular appliances we generated the eHomeSpecificator tool from the model and its activities. This tool can serve as a base for a wider range of tools supporting eHome systems.