We present a prescriptive framework for the event-triggered control of nonlinear systems. Rather than closing the loop periodically, as traditionally done in digital control, in event-triggered implementations the loop is closed according to a state-dependent criterion. Event-triggered control is especially well suited for embedded systems and networked control systems since it reduces the amount of resources needed for control such as communication bandwidth. By modeling the event-triggered implementations as hybrid systems, we provide Lyapunov-based conditions to guarantee the stability of the resulting closed-loop system and explain how they can be utilized to synthesize event-triggering rules. We illustrate the generality of the approach by showing how it encompasses several existing event-triggering policies and by developing new strategies which further reduce the resources needed for control.

Event-triggered and self-triggered control have recently been proposed as implementation strategies that considerably reduce the resources required for control. Although most of the work so far has focused on closing a single control loop, some researchers have started to investigate how these new implementation strategies can be applied when closing multiple-feedback loops in the presence of physically distributed sensors and actuators. In this paper, we consider a scenario where the distributed sensors, actuators, and controllers communicate via a shared wired channel. We use our recent prescriptive framework for the event-triggered control of nonlinear systems to develop novel policies suitable for the considered distributed scenario. Afterwards, we explain how self-triggering rules can be deduced from the developed event-triggered strategies.

The present study investigated the human ability to discriminate the size of 3-D objects by touch. Experiment 1 measured the just noticeable differences (JNDs) for three tasks: (1) discrimination of volume without availability of weight information, (2) discrimination of volume with weight information available, and (3) discrimination of surface area. Stimuli consisted of spheres, cubes, and tetrahedrons. For all shapes, two reference sizes were used (3.5 and 12 cm3). No significant effect of task on the discriminability of objects was found, but the effects of shape and size were significant, as well as the interaction between these two factors. Post hoc analysis revealed that for the small reference, the Weber fractions for the tetrahedron were significantly larger than the fractions for the cube and the sphere. In Experiment 2, the JNDs for haptic perception of weight were measured for the same objects as those used in Experiment 1. The shape of objects had no significant effect on the Weber fractions for weight, but the Weber fractions for the small stimuli were larger than the fractions for the large stimuli. Surprisingly, a comparison between the two experiments showed that the Weber fractions for weight were significantly larger than the fractions for volume with availability of weight information. Taken together, the results reveal that volume and weight information are not effectively combined in discrimination tasks. This study provides detailed insight into the accuracy of the haptic system in discriminating objects’ size. This substantial set of data satisfies the need for more fundamental knowledge on haptic size perception, necessary for a greater understanding of the perception of related properties, as well as of more general perceptual processes.

We describe a new method using flow-injection analysis with spectro-photometric detection, suitable for the determination of N-acetyl-l-cysteine (NAC). The proposed method is appropriate for the determination of NAC in reaction with Pd2+ ions in the concentration range from 1.0 × 10−5 mol L−1 to 6.0 × 10−5 mol L−1. The detection limit NAC was 5.84 × 10−6 mol L−1 and the recorded relative standard deviation of the method is in the range from 1.67 to 4.11%. NAC and Pd2+ form complexes of Pd2+:NAC molar ratios of 1:1 and 1:2, depending on the ratio of their analytical concentrations. The cumulative conditional stability constant for the Pd(NAC)22+ complex is β12’ = 2.69 × 109 L2 mol−2. The proposed method was compared with the classic spectrophotometric determination of NAC, using the same reagent, PdCl2, and had shown certain advantages: a) shorter analysis time; b) the use of smaller volumes of sample and reagents, which make the proposed method cheaper and faster for NAC determination in real samples without sample pretreatment.

AbstractWe investigate global dynamics of the following systems of difference equations xn+1=α1+β1xnA1+ynyn+1=γ2ynA2+B2xn+yn,n=0,1,2,… where the parameters α1, β1, A1, γ2, A2, B2 are positive numbers, and the initial conditions x0 and y0 are arbitrary nonnegative numbers. We show that this system has rich dynamics which depends on the region of parametric space. We show that the basins of attractions of different locally asymptotically stable equilibrium points or non-hyperbolic equilibrium points are separated by the global stable manifolds of either saddle points or non-hyperbolic equilibrium points. We give examples of a globally attractive non-hyperbolic equilibrium point and a semi-stable non-hyperbolic equilibrium point. We also give an example of two local attractors with precisely determined basins of attraction. Finally, in some regions of parameters, we give an explicit formula for the global stable manifold. Mathematics Subject Classification (2000) Primary: 39A10, 39A11 Secondary: 37E99, 37D10

Endothelial dysfunction is associated with diabetic micro- and macroangiopathy as well as with the decline in creatinine clearance. It has been suggested that endothelial dysfunction presents in patients (pts) on continuous ambulatory peritoneal dialysis (CAPD). The objective of this study was to examine the plasma biomarkers of endothelial dysfunction and their association with IMT of carotid arteries in diabetic and non-diabetic patients on CAPD. This study included 37 CAPD pts (25 with type II diabetes and 12 non-diabetic pts) mean age 59.2 years ± 2.48. Plasma von Willebrand factor (vWF) activity, serum albumin, glucose, total cholesterol, triglycerides and lipoprotein (a) levels, as well as serum level of homocysteine, parathyroid hormone (PTH) in plasma and microalbuminuria was determined. Ultrasound examination of carotid arteries was performed in all patients by measured bilateral intima-media thickness of carotid artery (CIMT). Mean IMT value was significantly higher in type 2 DM patients (0.86 ± 0.04 mm) compared to non-diabetic patients (0.52 ± 0.06 mm) on peritoneal dialysis (p<0.0001). There was also a significant difference in lipids /triglycerides and Lp (a)/, procoagulation (fibrinogen, von Wilebrand factor, factor VIII) and inflammatory markers (CRP) level between type 2 DM and non-diabetic CAPD patients. A stepwise multiple regression analysis revealed that log triglycerides and factor VIII were independent factors for the IMT. The results of this research impose that diabetic type 2 CAPD patients have developed systemic alteration of endothelial function and higher risk of cardiovascular complications compared to non-diabetic CAPD patients.

Complexity of multifactorial diseases as Parkinson's disease (PD) often complicate identifying causal genetic factors by traditional approaches such as positional cloning and candidate gene analyses. PD is etiologically and genetically complex disease and second most common neurodegenerative disorder after Alzheimer's disease. The most cases of PD are idiopathic and small growing subset of individuals have single gene defect as the cause. The main goal of this research was to identify the potential candidate genes for idiopathic PD by using biomedical discovery support system (BITOLA). For detecting the potential candidate genes for PD was used opened system of bioinformatics tool BITOLA. Data of chromosome location, tissue specific expression of potential candidate genes and their potential association with PD were obtained from Medline, Locus Link, Gene Cards and OMIM. By using BITOLA system is identified 17 genes as potential candidate genes for PD. The role of three genes (MAPT, PARK2, UCHL1) in PD were confirmed earlier. Discovering the novel candidate genes for multifactiorial diseases by using specially mentioned bioinformatics tool BITOLA could offer the new opportunity for researching genetics base of PD without using tissue samples of patients.

Malignant tumors of the thyroid gland account for about 1% of thenewly diagnosed malignant tumors each year, and their incidence inwomen is twice the incidence in men. According to the WHO classification (2004) thyroid tumors are divided into: carcinoma of the thyroid,adenoma and similar tumors, and other thyroid tumors whichinclude: teratomas, angiosarcomas, paragangliomas and others, as wellas primary lymphomas and plasmacytomas. Primary thyroid lymphomasare defi ned as lymphomas which originate in the thyroid gland.Th is study presents the case of a 68-year-old patient with a thyroidlymphoma, which caused compression of the airways. In the patientpresented there was reduced activity of the thyroid gland. Th e dominantsymptoms were: breathing diffi culties, hoarse voice and the enlargementof the thyroid. An ultrasound examination was performedbefore surgery on the neck, which showed a multinodular thyroid,with compromised and compressed trachea to the right and rear. Anemergency surgical procedure was performed to reduce the tumor.Pathohistological diagnosis confi rmed diff use large B cell lymphoma.Th e aim of the study was to present a patient with a thyroid lymphoma,who had previously not had any immunological changes to the gland,that is, she had not had any chronic lymphocyte thyroiditis, but due tothe compressive syndrome it was necessary to perform an emergencysurgical procedure to reduce the tumor.