Experimental and theoretical studies of sequence effects on the fluctuation and melting of short DNA molecules

Understanding the melting of short DNA sequences probes DNA at the scale of the genetic code and raises questions which are very different from those posed by very long sequences, which have been extensively studied. We investigate this problem by combining experiments and theory. A new experimental method allows us to make a mapping of the opening of the guanines along the sequence as a function of temperature. The results indicate that non-local effects may be important in DNA because an AT-rich region is able to influence the opening of a base pair which is about 10 base pairs away. An earlier mesoscopic model of DNA is modified to correctly describe the time scales associated to the opening of individual base pairs well below melting, and to properly take into account the sequence. Using this model to analyze some characteristic sequences for which detailed experimental data on the melting is available [Montrichok et al. 2003 Europhys. Lett. {\bf 62} 452], we show that we have to introduce non-local effects of AT-rich regions to get acceptable results. This brings a second indication that the influence of these highly fluctuating regions of DNA on their neighborhood can extend to some distance.Comment: To be published in J. Phys. Condensed Matte

USE OF INTENSIVE METHODS FOR TREATMENT OF RENAL DISEASES

No abstrac

Mini Max Wallpaper

Mini Max company formulated a problem for the automatic calculation of the number of wallpaper rolls necessary for decorating a room with wallpaper. The final goal is the development of a web-based calculator open for use to both Mini Max staff and the general public. We propose an approach for reducing the studied problem to the one-dimensional cutting-stock problem. We show this in details for the case of plain wallpapers as well as for the case of patterned wallpapers with straight match. The one-dimensional cutting-stock problem can be formulated as a linear integer programming problem. We develop an approach for calculating the needed number of wallpapers for relatively small problems, create an algorithm in a suitable graphical interface and make different tests. The tests show the efficiency of the proposed approach compared with the existent (available) wallpapers’ calculators

Chemical Composition and Energy Nutritional Value of the Meat of Guinea Fowls (Numidameleagris), Fattened to different Ages

The aim of the study was to investigate the chemical composition and energy content of the meat of young Guinea-fowls, with different duration of the fattening period, raised in a free-range, semi-intensive production system. The authors establish the following data: dry matter content- from 27.08 to 28.82% in breast muscle and from 23.83 to 26.56% in thigh muscle; crude protein in dry matter –from 86.19to 93.54% in breastand from 82.02 to 87.84% in thigh muscle; crude fat in dry matter - from 5.64 to 7.58% in breast and from 9.02 to 11.05% in thigh muscles. The average energy content in 100 g dry matter varies from 23.7 (breast muscle, 16 weeks of age) to 25.07 kJ (thigh muscle, 24 weeks of age)

Učinci UV zračenja visokog intenziteta na izdvojen i s dna interkaliran etidium bromid

High-intensity picosecond laser flash photolysis has been used for investigating ethidium bromide (EtBr). The quantum yield of primary photoproducts as a function of the laser intensity has been obtained. DNA intercalated EtBr and water solutions of EtBr have been investigated. The results have been compared. They show that two-photon processes are predominantly responsible for generation of hydrated electron (eaq-). The primary processes of DNA photosensitization have also been discussed.Istraživali smo etidium bromid (EtBr) pomoću pikosekundne bljeskovne fotolize velikog intenziteta. Određeni su kvantni prinosi fotoprodukata u ovisnosti o intenzitetu laserskog snopa. Istraživao se je EtBr u vodenoj otopini i interkalirani s DNA. Rezultati se uspoređuju i oni pokazuju da pretežno dvofotonski procesi tvore hidrirane elektrone eaq-. Raspravljaju se također primarni procesi fotosenzitiranja DNA

Laserska izravna dvofotonska fotoliza guanina u DNK

Nanosecond laser-induced oxidative lesions at guanines within DNA were investigated using sequencing gel electrophoresis analysis. Strong sequence-specific lesions on guanines were revealed by either Fpg or piperidine treatments and assigned to 8-oxoG and oxazolone, respectively. It was shown that both the biphotonic ionization process and the chemical reactivity of the radical cation (G+) are dependent on the DNA sequence. The former were explained by the occurrence of energy and charge migration phenomena, while the latter in terms of local DNA hydration peculiarities.Istraživali smo lomove DNK izazvane nanosekundnim laserskim impulsima primjenom gel elektroforeze za određivanje nizova. Otkrili smo snažne nizovno specifične lomove kod guanina djelovanjem sa Fpg ili piperidinom i oni se pripisuju 8-oxoG odnosno oxazolonu. Pokazali smo da su i dvofotonski ionizacijski proces i kemijska reaktivnost radikala kationa (G+) nizovno ovisni. Prvi se objašnjava selenjem energije i naboja, a drugi kao posebnosti lokalnog hidriranja DNK

On the muon neutrino mass

During the runs of the PS 179 experiment at LEAR of CERN, we photographed an event of antiproton-Ne absorption, with a complete pi+ -> mu+ ->e+ chain. From the vertex of the reaction a very slow energy pi+ was emitted. The pi+ decays into a mu+ and subsequently the mu+ decays into a positron. At the first decay vertex a muon neutrino was emitted and at the second decay vertex an electron neutrino and a muon antineutrino. Measuring the pion and muon tracks and applying the momentum and energy conservation and using a classical statistical interval estimator, we obtained an experimental upper limit for the muon neutrino mass: m_nu < 2.2 MeV at a 90% confidence level. A statistical analysis has been performed of the factors contributing to the square value of the neutrino mass limit.Comment: 18 pages, 5 eps figure