Closed Strings with Low Harmonics and Kinks

Low-harmonic formulas for closed relativistic strings are given. General parametrizations are presented for the addition of second- and third-harmonic waves to the fundamental wave. The method of determination of the parametrizations is based upon a product representation found for the finite Fourier series of string motion in which the constraints are automatically satisfied. The construction of strings with kinks is discussed, including examples. A procedure is laid out for the representation of kinks that arise from self-intersection, and subsequent intercommutation, for harmonically parametrized cosmic strings.Comment: 39, CWRUTH-93-

Adsorption of mono- and multivalent cat- and anions on DNA molecules

Adsorption of monovalent and multivalent cat- and anions on a deoxyribose nucleic acid (DNA) molecule from a salt solution is investigated by computer simulation. The ions are modelled as charged hard spheres, the DNA molecule as a point charge pattern following the double-helical phosphate strands. The geometrical shape of the DNA molecules is modelled on different levels ranging from a simple cylindrical shape to structured models which include the major and minor grooves between the phosphate strands. The densities of the ions adsorbed on the phosphate strands, in the major and in the minor grooves are calculated. First, we find that the adsorption pattern on the DNA surface depends strongly on its geometrical shape: counterions adsorb preferentially along the phosphate strands for a cylindrical model shape, but in the minor groove for a geometrically structured model. Second, we find that an addition of monovalent salt ions results in an increase of the charge density in the minor groove while the total charge density of ions adsorbed in the major groove stays unchanged. The adsorbed ion densities are highly structured along the minor groove while they are almost smeared along the major groove. Furthermore, for a fixed amount of added salt, the major groove cationic charge is independent on the counterion valency. For increasing salt concentration the major groove is neutralized while the total charge adsorbed in the minor groove is constant. DNA overcharging is detected for multivalent salt. Simulations for a larger ion radii, which mimic the effect of the ion hydration, indicate an increased adsorbtion of cations in the major groove.Comment: 34 pages with 14 figure

Interaction of inflammatory cytokines and erythropoeitin in iron metabolism and erythropoiesis in anaemia of chronic disease

In chronic inflammatory conditions increased endogenous release of specific cytokines (TNFα, IL-1, IL-6, IFNγ and others) is presumed. It has been shown that those of monocyte lineage play a key role in cytokine expression and synthesis. This may be associated with changes in iron metabolism and impaired erythropoiesis and may lead to development of anaemia in patients with rheumatoid arthritis. Firstly, increased synthesis of acute phase proteins, like ferritin, during chronic inflammation is proposed as the way by which the toxic effect of iron and thereby the synthesis of free oxy-radicals causing the damage on the affected joints, may be reduced. This is associated with a shift of iron towards the mononuclear phagocyte system which may participate in the development of anaemia of chronic disease. Secondly, an inhibitory action of inflammatory cytokines (TNFα, IL-1), on proliferation and differentiation of erythroid progenitors as well as on synthesis of erythropoietin has been shown, thereby also contributing to anaemia. Finally, chronic inflammation causes multiple, complex disturbances in the delicate physiologic equilibrium of interaction between cytokines and cells (erythroid progenitors, cells of mononuclear phagocyte system and erythropoietin producing cells) leading to development of anaemia of chronic disease (Fig. 1)

Non-crossing dependencies: Least effort, not grammar

The use of null hypotheses (in a statistical sense) is common in hard sciences but not in theoretical linguistics. Here the null hypothesis that the low frequency of syntactic dependency crossings is expected by an arbitrary ordering of words is rejected. It is shown that this would require star dependency structures, which are both unrealistic and too restrictive. The hypothesis of the limited resources of the human brain is revisited. Stronger null hypotheses taking into account actual dependency lengths for the likelihood of crossings are presented. Those hypotheses suggests that crossings are likely to reduce when dependencies are shortened. A hypothesis based on pressure to reduce dependency lengths is more parsimonious than a principle of minimization of crossings or a grammatical ban that is totally dissociated from the general and non-linguistic principle of economy.Postprint (author's final draft

Comparison of lumiracoxib with naproxen and ibuprofen in the Therapeutic Arthritis Research and Gastrointestinal Event Trial (TARGET), cardiovascular outcomes: randomised controlled trial.

Contains fulltext : 57937.pdf (publisher's version ) (Closed access)BACKGROUND: The potential for cyclo-oxygenase 2 (COX2)-selective inhibitors to increase the risk for myocardial infarction is controversial. The Therapeutic Arthritis Research and Gastrointestinal Event Trial (TARGET) aimed to assess gastrointestinal and cardiovascular safety of the COX2 inhibitor lumiracoxib compared with two non-steroidal anti-inflammatory drugs, naproxen and ibuprofen. METHODS: 18325 patients age 50 years or older with osteoarthritis were randomised to lumiracoxib 400 mg once daily (n=9156), naproxen 500 mg twice daily (4754), or ibuprofen 800 mg three times daily (4415) in two substudies of identical design. Randomisation was stratified for low-dose aspirin use and age. The primary cardiovascular endpoint was the Antiplatelet Trialists' Collaboration endpoint of non-fatal and silent myocardial infarction, stroke, or cardiovascular death. Analysis was by intention to treat. FINDINGS: 81 (0.44%) patients did not start treatment and 7120 (39%) did not complete the study. At 1-year follow-up, incidence of the primary endpoint was low, both with lumiracoxib (59 events [0.65%]) and the non-steroidal anti-inflammatory drugs (50 events [0.55%]; hazard ratio 1.14 [95% CI 0.78-1.66], p=0.5074). Incidence of myocardial infarction (clinical and silent) in the overall population in the individual substudies was 0.38% with lumiracoxib (18 events) versus 0.21% with naproxen (ten) and 0.11% with lumiracoxib (five) versus 0.16% with ibuprofen (seven). In the naproxen substudy, rates of myocardial infarction (clinical and silent) did not differ significantly compared with lumiracoxib in the population not taking low-dose aspirin (hazard ratio 2.37 [95% CI 0.74-7.55], p=0.1454), overall (1.77 [0.82-3.84], p=0.1471), and in patients taking aspirin (1.36 [0.47-3.93], p=0.5658). In the ibuprofen substudy, these rates did not differ between lumiracoxib and ibuprofen in the population not taking low-dose aspirin (0.75 [0.20-2.79], p=0.6669), overall (0.66 [0.21-2.09], p=0.4833), and in patients taking aspirin (0.47 [0.04-5.14], p=0.5328). INTERPRETATION: The primary endpoint, including incidence of myocardial infarction, did not differ between lumiracoxib and either ibuprofen or naproxen, irrespective of aspirin use. This finding suggests that lumiracoxib is an appropriate treatment for patients with osteoarthritis, who are often at high cardiovascular risk and taking low-dose aspirin