Output stabilization and maneuver regulation: A geometric approach

This paper investigates maneuver regulation for single-input control-affine systems from a geometric perspective. The maneuver regulation problem is converted to output stabilization and necessary and sufficient conditions are provided to solve the latter problem by feedback linearizing the dynamics transverse to a suitable embedded submanifold of the state space. When specialized to the linear time invariant setting, this work recovers well-known results on output stabilization.     

On the Expressive Power of Temporal Concurrent Constraint Programming Languages: (invited talk)

The tcc paradigm is a formalism for timed concurrent constraint programming. Several tcc languages differing in their way of expressing infinite behavior have been proposed in the literature. In this work we study the expressive power of some of these languages. In particular, we show that: (1) recursive procedures with parameters can be encoded into parameterless recursive procedures with dynamic scoping, and viceversa. (2) replication can be encoded into parameterless recursive procedures with static scoping, and viceversa. (3) the languages from (1) are strictly more expressive than the languages from (2). Furthermore, we show that behavioral equivalence is undecidable for the languages from (1), but decidable for the languages from (2). The undecidability result holds even if the process variables take values from a fixed finite domain.(Joint work with Mogens Nielsen and Frank D. Valencia)     

Myocardial rupture during exercise ECG

We report a case of heart rupture in connection with a stress test performed nine days after an otherwise uncomplicated myocardial infarction. The Danish Association of Cardiologists recommend stress testing 5-20 days after myocardial infarction. We question whether this timing is appropriate considering the vulnerability of the myocardium at that time.     

Unclear about prophylaxis against Rh-immunization. Much is missing from the guidelines of the National Board of Health and Welfare

A 39-year-old female visited our hospital because of morning stiffness, arthralgia, skin rash of the extremities and general fatigue. On examination, she also had a malar rash and an oral ulcer. Laboratory findings revealed that antinuclear antibodies were positive and complement component levels (C3, C4, CH50) were all low. Serology for human parvovirus B19 (HPV-B19) was positive for both immunoglobulin (Ig)M and IgG. Gradually, her symptoms improved and laboratory data returned to normal range without medications. This case suggests that HPV-B19 infection may be attributed to the pathogenesis of systemic lupus erythematosus.     

Alkyl side-chain derivatives of sordaricin as potent antifungal agents against yeast

Sordarin (1) was converted to 5 and 6, which showed potent antifungal activity against yeast. A series of C1-C9 alkyl side-chain derivatives was prepared, from which it was found that the optimal activity occurred with C5. A comparison of side chains with different unsaturation showed that the cis-alkene was the most active. This result suggested that the folding of the side chains might be crucial for the optimal activity.     

Pain after groin hernia repair

Depression is one of the most common psychiatric illnesses. Its influence on brain perfusion has been demonstrated, but conflicting data exist on follow-up after drug treatment. The aim of our study was to evaluate the effects of antidepressant drugs on regional cerebral blood flow (rCBF) in patients with depression after 3 weeks and 6 months of drug therapy. Clinical criteria for depression without psychosis were met according to psychiatric evaluation. Severity of depression was evaluated with the Hamilton Depression Rating Scale (HAMD) before every scintigraphic study. rCBF was assessed using technetium-99m bicisate (Neurolite) brain single-photon emission tomography in nine patients with severe depression before the beginning of antidepressant drug therapy and 3 weeks and six months after initiation of therapy. Only patients with no change in antidepressant medication during the study were included. No antipsychotic drugs were used. Cerebellum was used as the reference region. rCBF was evaluated for eight regions in each study in three consecutive transversal slices. Follow-up studies were compared with the baseline study. The mean HAMD score was 25.5 points initially, 16 at the second examination and 8.8 after 6 months. Global CBF was decreased compared with the reference region in drug-free patients. Perfusion of left frontal and temporal regions was significantly lower (P < 0.005) in comparison with the contralateral side. After therapy, a moderate decrease in perfusion was seen in the right frontal region (P < 0.05). Perfusion decreased further after 6 months in the right frontal (P < 0.005) and temporal regions (P < 0.01). The highly significant asymmetry in perfusion between the left and right frontal and temporal lobes almost disappeared during treatment. Our findings implicate dysfunction of the frontal and temporal cortex in clinically depressed patients before specific drug treatment. Clinical improvement and decreases in HAMD score after 3 weeks and after 6 months reflect the treatment effect on mood-related rCBF changes.     

A formula for thermal stability (Tm) prediction of PNA/DNA duplexes

An empirical formula for thermal stability (T m) prediction of PNA/DNA duplexes has been derived. The model is based on the T m as calculated for the corresponding DNA/DNA duplex employing a nearest neighbour approach, by including terms for the pyrimidine content and length of the PNA to take into account the increased thermostability of PNA/DNA hybrids and the asymmetry of the PNA-DNA heteroduplex. The predictive power of the T m prediction formula was challenged with an independent data set not used for model building. The T m of >90% of the sequences was predicted within 5 K; 98% of the predicted T ms differ by not more than 10 K from the experimentally determined T m.     

Expression of E-selectin, sialyl Lewis X, and macrophage inflammatory protein-1alpha by colonic epithelial cells in ulcerative colitis

The pathogenic significance of cell adhesion molecules (CAMs) in ulcerative colitis (UC) is largely unknown. Colonic expression of E-selectin, sialyl Lewis X (sLe(x)), and macrophage inflammatory protein-1x (MIP-1alpha) as well as serum concentrations of E-selectin and MIP-1alpha in UC were studied. Thirty patients with UC, 10 patients with irritable bowel syndrome, and 10 healthy subjects were included. Colonic biopsies were stained immunohistochemically, and blood concentrations were measured with an ELISA technique. Soluble E-selectin did not correlate with diagnosis or disease activity. MIP-1alpha was below the detection limit. Epithelial cells expressed all three molecules, both on surface membranes and intracellularly. sLe(x) staining was weaker (P = 0.0002) and MIP-1alpha staining stronger (P = 0.014) in UC patients than in controls. Leukocyte MIP-alpha staining correlated with diagnosis (P = 0.021), sLe(x) staining (P = 0.023), and colonoscopy (P = 0.018). It is shown that E-selectin, sLe(x), and MIP-1alpha are synthesized and expressed by epithelial cells, indicating that CAMs are not only involved in leukocyte extravasation and migration, but also in the interaction between leukocytes and colonic epithelium. This knowledge might contribute to the development of improved treatments in UC.     

Eosinophil markers in seasonal allergic rhinitis. Intranasal fluticasone propionate inhibits local and systemic increases during the pollen season

BACKGROUND: The purpose was to study activation markers of the eosinophil granulocytes in seasonal allergic rhinitis, and the impact of topical steroid therapy thereupon. METHODS: Sixty-three rhinitis patients with monoallergy to grass were examined before and at peak pollen season. Blood eosinophil count, eosinophil cationic protein (ECP), and eosinophil peroxidase (EPO) in serum and nasal lavage fluid were measured. During the season, patients were randomized to treatment with intranasal fluticasone propionate 0.1 mg o.d. (n=26), 0.2 mg o.d. (n=25), or placebo (n=12). Six healthy persons served as controls. RESULTS: During the season, all parameters, except nasal lavage ECP, increased in the placebo group (P<0.001-P<0.05). Significant differences were seen between the steroid groups and the placebo group for all parameters (P<0.001-P<0.05). Higher eosinophil count (P<0.05), serum EPO (P<0.02), and nasal lavage EPO (P<0.05) were found in patients before season than in controls. The following winter, 44 patients returned for repeated measurement. Lower levels of nasal lavage EPO were observed for patients than levels at the beginning of the season (P<0.0001). CONCLUSIONS: Intranasal fluticasone propionate reduced inflammation of the nasal mucosa, demonstrated locally by nasal lavage ECP and EPO, and systemically by blood eosinophils, serum ECP, and serum EPO. EPO seemed more sensitive than ECP as indicator of allergic inflammation. EPO demonstrated some perennial eosinophil activity in hay fever patients, increasing locally during spring.