Where Fail-Safe Default Logics Fail

Reiter's original definition of default logic allows for the application of a default that contradicts a previously applied one. We call failure this condition. The possibility of generating failures has been in the past considered as a semantical problem, and variants have been proposed to solve it. We show that it is instead a computational feature that is needed to encode some domains into default logic

Algebraic entropy for algebraic maps

We propose an extension of the concept of algebraic entropy, as introduced by Bellon and Viallet for rational maps, to algebraic maps (or correspondences) of a certain kind. The corresponding entropy is an index of the complexity of the map. The definition inherits the basic properties from the definition of entropy for rational maps. We give an example with positive entropy, as well as two examples taken from the theory of Backlund transformations

Conjugating Biotin to Ruthenium(II) Arene Units via Phosphine Ligand Functionalization

Two-step functionalization of 4-diphenylphosphino benzoic acid with biotin afforded 2-(biotinyloxy)ethyl 4-(diphenylphosphanyl)benzoate (LP), that was subsequently used to synthesize the Ru(II) arene complexes [RuCl2(η6-p-cymene)(LP)] (1), [Ru(C2O4)(η6-p-cymene)(LP)] (2) and [Ru(curc)(η6-p-cymene)(LP)]NO3 ([3]NO3), the latter incorporating curcumin (curcH) as an additional bioactive fragment. [Ru(curc)(η6-p-cymene)(PPh3)]NO3 ([4]NO3) was also prepared as a reference compound. Compounds 2 and [3]NO3 exhibited excellent stability in water/DMSO solution while being slowly activated in the cell culture medium over 72 hours. Together with LP, they were therefore assessed for their antiproliferative activity towards a panel of cancer cell lines, with different levels of biotin transporter expression. The apparent affinity of the compounds towards avidin varies, and their antiproliferative activity does not correlate with biotin transporter expression, although it is systematically enhanced when biotin-free cell culture medium is used

Rare events, escape rates and quasistationarity: some exact formulae

We present a common framework to study decay and exchanges rates in a wide class of dynamical systems. Several applications, ranging form the metric theory of continuons fractions and the Shannon capacity of contrained systems to the decay rate of metastable states, are given

6 Wyniki leczenia u chorych na chłoniaki nieziarnicze o pośrednim i wysokim stopniu złośliwości po chemioterapii MACOP-B lub VACOP-B i radioterapii. Analiza czynników prognostycznych i próba oceny roli radioterapii

W okresie od 1986 do 1995 w Centrum Onkologii – Oddział w Krakowie u 120 chorych (36 kobiet, 84 mężczyzn) na chłoniaka nieziarniczego o pośrednim (76 chorych) lub wysokim (44 chorych) stopniu złośliwości zastosowano chemioterapię MACOP-B (24 chorych) lub VACOP-B (96 chorych). Stopień zaawansowania klinicznego przedstawiał się następująco: I-7 chorych (5,8%), II-18 chorych (15%), III-41 chorych (34,2%), IV-54 chorych (45%). Objawy ogólne (B) stwierdzono u 38 chorych (31,7%). U 103 chorych (85,8%) określono Międzynarodowy Wskaźnik Rokowniczy: 8 chorych (7,8%) znalazło się w grupie niskiego ryzyka, 34 chorych (33%) – w grupie średniego/niskiego, 32 chorych (31,1%) – w grupie średniego/wysokiego, a 29 chorych (28,2% w grupie wysokiego ryzyka. U 37 chorych (30,8%) chemioterapia skojarzona była z radioterapią. Stosowana dawka wahała się od 10 do 50 Gy (mediana 36 Gy). Po przeprowadzonym leczeniu u 84 chorych (70%) uzyskano całkowitą, a u 25 chorych (20,8%) częściową regresję choroby.W analizowanej grupie 120 chorych uzyskano następujące odsetki 5 letnich przeżyć: całkowitego u 45,7% chorych i bez nawrotu chłoniaka u 38,4% chorych. W trakcie obserwacji u 65 chorych (54,2%) stwierdzono rozwój niepowodzenia, które miało charakter wznowy, progresji klinicznej lub histopatologicznej. U 3 chorych stwierdzono rozwój drugiego nowotworu: raka żołądka, raka odbytnicy, ziarnicę złośliwą.Przeprowadzona analiza wpływu czynników prognostycznych na wyniki leczenia wykazała, że niezależnymi istotnymi statystycznie czynnikami prognostycznymi wykazującymi negatywny wpływ na wyniki leczenia w grupie chorych, u których zastosowano leczenie skojarzone są: lokalizacja pozawęzłowa, podanie niepełnego leczenia chemicznego, obniżona wartość hematokrytu, podwyższony odsetek limfocytów oraz podanie niższej dawki. Natomiast w grupie chorych, którzy otrzymali wyłącznie chemioterapię takimi czynnikami są: podwyższone stężenie dehydrogenazy mleczanowej, lokalizacja pozawęzłowa, niepełne leczenie chemiczne.U chorych, u których zastosowano radioterapię uzyskano wyższy odsetek przeżyć bez nawrotu chłoniaka w porównaniu z grupą leczoną wyłącznie chemioterapią. Szczególnie dotyczy to chorych w wyższym stopniu zaawansowania (III-IV) oraz z obecnością dużej masy nowotworu (bulky disease)

Metal-Dependent Cytotoxic and Kinesin Spindle Protein Inhibitory Activity of Ru, Os, Rh, and Ir Half-Sandwich Complexes of Ispinesib-Derived Ligands

Ispinesib is a potent inhibitor of kinesin spindle protein (KSP), which has been identified as a promising target for antimitotic anticancer drugs. Herein, we report the synthesis of half-sandwich complexes of Ru, Os, Rh, and Ir bearing the ispinesib-derived N,N-bidentate ligands (R)- and (S)-2-(1-amino-2-methylpropyl)-3-benzyl-7-chloroquinazolin-4(3H)-one and studies on their chemical and biological properties. Using the enantiomerically pure (R)- and (S)-forms of the ligand, depending on the organometallic moiety, either the SM,R or RM,S diastereomers, respectively, were observed in the molecular structures of the Ru- and Os(cym) (cym = η6-p-cymene) compounds, whereas the RM,R or SM,S diastereomers were found for the Rh- and Ir(Cp*) (Cp* = η5-pentamethylcyclopentadienyl) derivatives. However, density functional theory (DFT) calculations suggest that the energy difference between the diastereomers is very small, and therefore a mixture of both will be present in solution. The organometallics exhibited varying antiproliferative activity in a series of human cancer cell lines, with the complexes featuring the (R)-enantiomer of the ligand being more potent than the (S)-configured counterparts. Notably, the Rh and Ir complexes demonstrated high KSP inhibitory activity, even at 1 nM concentration, which was independent of the chirality of the ligand, whereas the Ru and especially the Os derivatives were much less active

The compound Poisson limit ruling periodic extreme behaviour of non-uniformly hyperbolic dynamics

We prove that the distributional limit of the normalised number of returns to small neighbourhoods of periodic points of non-uniformly hyperbolic dynamical systems is compound Poisson. The returns to small balls around a fixed point in the phase space correspond to the occurrence of rare events, or exceedances of high thresholds, so that there is a connection between the laws of Return Times Statistics and Extreme Value Laws. The fact that the fixed point in the phase space is a repelling periodic point implies that there is a tendency for the exceedances to appear in clusters whose average sizes is given by the Extremal Index, which depends on the expansion of the system at the periodic point. We recall that for generic points, the exceedances, in the limit, are singular and occur at Poisson times. However, around periodic points, the picture is different: the respective point processes of exceedances converge to a compound Poisson process, so instead of single exceedances, we have entire clusters of exceedances occurring at Poisson times with a geometric distribution ruling its multiplicity. The systems to which our results apply include: general piecewise expanding maps of the interval (Rychlik maps), maps with indifferent fixed points (Manneville-Pomeau maps) and Benedicks-Carleson quadratic maps.Comment: To appear in Communications in Mathematical Physic

A nonlinear dynamic model of DNA with a sequence-dependent stacking term

No simple model exists that accurately describes the melting behavior and breathing dynamics of double-stranded DNA as a function of nucleotide sequence. This is especially true for homogenous and periodic DNA sequences, which exhibit large deviations in melting temperature from predictions made by additive thermodynamic contributions. Currently, no method exists for analysis of the DNA breathing dynamics of repeats and of highly G/C- or A/T-rich regions, even though such sequences are widespread in vertebrate genomes. Here, we extend the nonlinear Peyrard–Bishop–Dauxois (PBD) model of DNA to include a sequence-dependent stacking term, resulting in a model that can accurately describe the melting behavior of homogenous and periodic sequences. We collect melting data for several DNA oligos, and apply Monte Carlo simulations to establish force constants for the 10 dinucleotide steps (CG, CA, GC, AT, AG, AA, AC, TA, GG, TC). The experiments and numerical simulations confirm that the GG/CC dinucleotide stacking is remarkably unstable, compared with the stacking in GC/CG and CG/GC dinucleotide steps. The extended PBD model will facilitate thermodynamic and dynamic simulations of important genomic regions such as CpG islands and disease-related repeats

Large deviations for non-uniformly expanding maps

We obtain large deviation results for non-uniformly expanding maps with non-flat singularities or criticalities and for partially hyperbolic non-uniformly expanding attracting sets. That is, given a continuous function we consider its space average with respect to a physical measure and compare this with the time averages along orbits of the map, showing that the Lebesgue measure of the set of points whose time averages stay away from the space average decays to zero exponentially fast with the number of iterates involved. As easy by-products we deduce escape rates from subsets of the basins of physical measures for these types of maps. The rates of decay are naturally related to the metric entropy and pressure function of the system with respect to a family of equilibrium states. The corrections added to the published version of this text appear in bold; see last section for a list of changesComment: 36 pages, 1 figure. After many PhD students and colleagues having pointed several errors in the statements and proofs, this is a correction to published article answering those comments. List of main changes in a new last sectio