Robust controller design and performance for polytopic models

Polytopic models cover a large class of nonlinear dynamic systems. An algorithm is proposed that partitions the state-space into a number of disjoint clusters on which a gain-scheduling controller is defined. Then, an iterative synthesis algorithm based on LMIs is developed that guarantees globally robust stability of the closed loop system. Finally, an analysis method is presented that makes it possible to associate with certain regions of the state-space (a measure of) performance.</p

Bevorderen van natuurlijke vijanden in de boomkwekerij : demonstratie van natuurlijk en biologische bestrijding op kwekerijen, 2006 t/m 2008

Met het project ‘Bevorderen van natuurlijke vijanden in de boomkwekerij 2003-2005’ was een begin gemaakt om natuurlijke vijanden te bevorderen met als doel plagen te onderdrukken. Dat project heeft informatie opgeleverd over de natuurlijke vijanden die spontaan optreden en de mogelijkheid om roofmijten tegen mijten in te zetten

Ontogeny of milky spots in the human greater omentum: an immunochemical study

BACKGROUND: The adrenal gland is a key organ for hibernation (a condition characterized by striking reduction of body functions). Very limited information is available on the fine structure of the gland during hibernation and on the periodical arousal from hibernation. METHODS: Dormice (Muscardinus avellanarius) were maintained in an external animal house and allowed to hibernate spontaneously (November). Arousal was induced in March by exposure to daylight. Euthermic, active dormice were captured in June. The adrenals were taken from four hibernating, three arousing, and four euthermic dormice and processed for resin embedding. The ultrastructure of the adrenal cortex was investigated by transmission electron microscopy. RESULTS: In the zona glomerulosa of hibernating and arousing dormice, the smooth endoplasmic reticulum was prominent in comparison with euthermic animals, and mitochondria showed abundant vesicular cristae. The zona fasciculata and zona reticularis did not show consistent differences, apart from a lower cell lipid content in the outer portion of zona fasciculata of arousing dormice. CONCLUSIONS: The zona glomerulosa showed signs of increased activity during hibernation. This finding is supported by previous biochemical data demonstrating increased production of renin and aldosterone during such extreme physiological conditions. Activation of the zona glomerulosa in hibernation is probably adaptive to a condition of drastically reduced salt intake

Neutrophil Adhesion to Fibrinogen and Fibrin Under Flow Conditions Is Diminished by Activation and L-Selectin Shedding

The adhesion of neutrophils (polymorphonuclear leukocytes [PMNs]) to immobilized fibrinogen/fibrin is mediated by b2-integrins. However, the influence of physiologic flow con- ditions on neutrophil adhesion to these surfaces is poorly defined. In this report, the effect of flow and neutrophil acti- vation on adhesion to immobilized fibrinogen and fibrin was examined. For the evaluation of (the distribution of) neutro- phil adhesion, real-time video-assisted microscopy and custom- made software were used. Under flow conditions, ad- herent neutrophils appeared to support the subsequent margination of other neutrophils, thereby enhancing the ad- herence of these cells to fibrin. Consequently, neutrophils adhered in clusters, especially at higher shear stresses (eg, cluster index 1.4 at shear 80 mPa). Preactivation of PMNs with fMLP (10Ï7 mol/L) or 4b-phorbol, 12-myristate, 13-ace- tate (PMA; 100 ng/mL) resulted in approximately 50% inhibi- tion of adhesion to fibrin and a more random distribution (cluster index Ú0.5). L-selectin antibodies or neuraminidase treatment of PMNs also inhibited adhesion and clustering, indicating a role for L-selectin. Under static conditions, no clustering appeared and PMN activation with fMLP or PMA caused threefold and sevenfold increased adhesion, respec- tively. Under these conditions, anti-L-selectin antibodies or neuraminidase did not affect adhesion. These results indi- cate that, under flow conditions, adherent neutrophils support adhesion of flowing neutrophils by L-selectin-mediated cell-cell interactions. Preactivated neutrophils, with lowered L-selectin expression, are less susceptible for this interac- tion. By this mechanism, adhered leukocytes can modulate the recruitment of leukocytes to the vessel wall at sites of inflammation

Short- and long-term functional effects of percutaneous transluminal angioplasty in hemodialysis vascular access

The efficacy of percutaneous transluminal angioplasty (PTA) is usually expressed as the angiographic result. Access flow (Qa) measurements offer a means to quantify the functional effects. This study was performed to evaluate the short-term functional and angiographic effects of PTA and to determine the longevity of the functional effects during the follow-up period. Patients with an arteriovenous graft (AVG) or an arteriovenous fistula (AVF) who were eligible for PTA (Qa values of <600 ml/min) were included. Ultrasound-dilution Qa measurements were obtained shortly before PTA and periodically after PTA, beginning 1 wk after the procedure. The short-term effects were expressed as the increase in Qa and the reduction of stenosis. The long-term effects were expressed as patency and the decrease in Qa after PTA. Ninety-eight PTA procedures for 60 patients (65 AVG and 33 AVF) were analyzed. Qa improved from 371 +/- 17 to 674 +/- 30 ml/min for AVG and from 304 +/- 24 to 638 +/- 51 ml/min for AVF (both P < 0.0001). In 66% (AVG) and 50% (AVF) of cases, Qa increased to levels of >600 ml/min. The degree of stenosis decreased from 65 +/- 3 to 17 +/- 2% for AVG and from 72 +/- 5 to 23 +/- 7% for AVF (both P < 0.005). The reduction of stenosis was not correlated with DeltaQa (r(2) = 0.066). Six-month unassisted patency rates after PTA were 25% for AVG and 50% for AVF. The decreases in Qa were 3.7 +/- 0.8 ml/min per d for AVG and 1.8 +/- 0.9 ml/min per d for AVF. Qa values before PTA and DeltaQa were correlated with the subsequent decrease in Qa (P < 0.005). In conclusion, Qa increases after PTA but, in a substantial percentage of cases, not to levels of >600 ml/min. Qa values before PTA and the increase in Qa were correlated with long-term outcomes, whereas angiographic results were not. These data, combined with literature data, suggest that there is optimal timing for PTA

Design and performance of a programmable-temperature scanning tunneling microscope

Quantum Matter and Optic

Bulk-sensitive photoemission spectroscopy of A_2FeMoO_6 double perovskites (A=Sr, Ba)

Electronic structures of Sr_2FeMoO_6 (SFMO) and Ba_2FeMoO_6 (BFMO) double perovskites have been investigated using the Fe 2p->3d resonant photoemission spectroscopy (PES) and the Cooper minimum in the Mo 4d photoionization cross section. The states close to the Fermi level are found to have strongly mixed Mo-Fe t_{2g} character, suggesting that the Fe valence is far from pure 3+. The Fe 2p_{3/2} XAS spectra indicate the mixed-valent Fe^{3+}-Fe^{2+} configurations, and the larger Fe^{2+} component for BFMO than for SFMO, suggesting a kind of double exchange interaction. The valence-band PES spectra reveal good agreement with the LSDA+U calculation.Comment: 4 pages, 3 figure

Towards optimal use of antithrombotic therapy of people with cancer at the end of life: a research protocol for the development and implementation of the SERENITY shared decision support tool Thrombosis Research

Background: Even though antithrombotic therapy has probably little or even negative effects on the well-being of people with cancer during their last year of life, deprescribing antithrombotic therapy at the end of life is rare in practice. It is often continued until death, possibly resulting in excess bleeding, an increased disease burden and higher healthcare costs. Methods: The SERENITY consortium comprises researchers and clinicians from eight European countries with specialties in different clinical fields, epidemiology and psychology. SERENITY will use a comprehensive approach combining a realist review, flash mob research, epidemiological studies, and qualitative interviews. The results of these studies will be used in a Delphi process to reach a consensus on the optimal design of the shared decision support tool. Next, the shared decision support tool will be tested in a randomised controlled trial. A targeted implementation and dissemination plan will be developed to enable the use of the SERENITY tool across Europe, as well as its incorporation in clinical guidelines and policies. The entire project is funded by Horizon Europe.Results: SERENITY will develop an information-driven shared decision support tool that will facilitate treatment decisions regarding the appropriate use of antithrombotic therapy in people with cancer at the end of life. Conclusions: We aim to develop an intervention that guides the appropriate use of antithrombotic therapy, prevents bleeding complications, and saves healthcare costs. Hopefully, usage of the tool leads to enhanced empowerment and improved quality of life and treatment satisfaction of people with advanced cancer and their care givers