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We give a new proof of the Nirenberg-Treves conjecture: that local solvability of principal type pseudodifferential operators is equivalent to condition (Psi). This condition rules out sign changes from - to + of the imaginary part of the principal symbol along the oriented bicharacteristics of the real part. We obtain local solvability by proving a localizable a priori estimate for the adjoint op

Popular Abstract in Swedish Polyaminer finns i alla levande celler, såväl i bakterier som i växter, djur och människor, och utgör en mycket viktig beståndsdel i dessa. Utan dessa polyaminer kan inte cellerna växa och dela sig. Polyaminerna putrescin, spermidin och spermin bildas i cellen från aminosyran ornitin. Till sin hjälp för denna bildning har cellerna ett enzym vid namn ornitindekarboxylas The polyamines putrescine, spermidine and spermine have been shown to be involved in cell growth and differentiation, and are considered to be crucial components of the living cell. The synthesis of polyamines in the cell is strictly regulated. The first and rate-limiting step in the biosynthesis of polyamines is catalysed by the enzyme ornithine decarboxylase (ODC). Mammalian ODC has a very fast

A methodology for safety verification of nonlinear systems using barrier certificates has been proposed recently. The condition was stated in a sufficiency form: if there exists a barrier certificate, then the system is safe, in the sense that there is no trajectory starting from a given set of initial states that reaches some given unsafe region. Using the concepts of convex duality and density,

We show that certain weak feedback polynomials allow very efficient distinguishing attacks on the selfshrinking generator. This gives a new improved attack if the generator uses a secret feedback polynomial.

There has been little development regarding analysis of polonium (Po) in environmental samples since the 1960ies. This is due to the straightforward spontaneous deposition of this element on silver (Ag), nickel (Ni) or copper (Cu) without any radiochemical separation. For many years, no radiochemical yield determinant was used and it was generally supposed that the yield was 100% after two deposit

Across a range of organisms, related species or even populations of the same species exhibit strikingly different scales and patterns of movement. A significant proportion of the phenotypic variance in migratory traits is genetic, but the genes involved in shaping these phenotypes are still unknown. Although recent achievements in genomics will evolve migratory genetics research from a phenotypic

For and α, we consider sets of numbers x such that for infinitely many n, x is 2−αn -close to some ∑ n i=1 ω i λ i , where ω i ∈{0,1}. These sets are in Falconer’s intersection classes for Hausdorff dimension s for some s such that −(1/α)(log λ /log 2 )≤s≤1/α. We show that for almost all , the upper bound of s is optimal, but for a countable infinity of values of λ the lower bound is the best poss

Abstract in UndeterminedLet us by first-order beliefs mean beliefs about the world, such as the belief that it will rain tomorrow, and by second-order beliefs let us mean beliefs about the reliability of first-order, belief-forming processes. In formal epistemology, coherence has been studied, with much ingenuity and precision, for sets of first-order beliefs. However, to the best of our knowledge

Abstract is not available.

Heating equimolar mixtures of Sb2O3 and V2O5 at 800 degrees C in flowing gas with varying O-2/N-2 ratios produces a continuous nonstoichiometric series of rutile type, i.e., Sb(0.9)V(0.9+x)square(0.2-x)O(4), 0 < x < 0.2, and varying amounts of alpha-Sb2O4. Oxidized Sb(0.9)V(0.9)square(0.2)O(4), a = 4.63, c = 3.03 Angstrom (X ray powder data, XRD), is formed in pure oxygen and exhibits a modulated

We analyze the ripening process where, in a dispersion of vesicles, amphiphile monomers diffuse between vesicles of different sizes, leading to a change in the size distribution. Since, typically, vesicles are not under tension, the driving force for the process comes from the curvature energy. With the conventional expansion of the curvature energy density, g,, to harmonic order we find that the

Milk proteins have a rich diversity of physical chemistry and biodegradable properties which makes them appealing for different food and pharmaceutical applications. Theoretical coarse grained models and numerical simulations were employed here in order to gain novel insight into the understanding of the fundamental mechanisms of the process of milk proteins complexation in a diversity of environm

It is known that the overall charge of a protein can change as the molecule approaches a charged object like another protein or a cell membrane. We have formalized this mechanism using a statistical mechanical framework and show how this rather overlooked interaction increases the attraction between protein molecules. From the theory, we can identify a unique property, the protein charge capacitan

The bit-search generator (BSG) was proposed in 2004 and can be seen as a variant of the shrinking and self-shrinking generators. It has the advantage that it works at rate 1/3 using only one LFSR and some selection logic. We present various attacks on the BSG based on the fact that the output sequence can be uniquely defined by the differential of the input sequence. By knowing only a small part o