LZgrep: a Boyer–Moore string matching tool for Ziv–Lempel compressed text

We present a Boyer–Moore (BM) approach to string matching over LZ78 and LZW compressed text. The idea is to search the text directly in compressed form instead of decompressing and then searching it. We modify the BM approach so as to skip text using the characters explicitly represented in the LZ78/LZW formats, modifying the basic technique where the algorithm can choose which characters to inspect. We present and compare several solutions for single and multipattern searches. We show that our algorithms obtain speedups of up to 50% compared to the simple decompress‐then‐search approach. Finally, we present a public tool, LZgrep, which uses our algorithms to offer grep‐like capabilities directly searching files compressed using Unix's Compress, a LZW compressor. LZgrep can also search files compressed with Unix gzip, using new decompress‐then‐search techniques we develop, which are faster than the current tools. This way, users can always keep their files in compressed form and still search them, uncompressing only when they want to see them. Copyright © 2005 John Wiley & Sons, Ltd.     

Influence of sulfur and Mn/S ratio on the hot ductility of steels during continuous casting

The influence of S and (Mn/S) on the crack susceptibility of continuous casting steels was studied. It is theoretically demonstrated that there is a critical value of the (Mn/S) ratio, (Mn/S)_c, under which a high susceptibility to cracking, during casting or deformation of as-cast material, is expected. The value of (Mn/S)_c increases as the S content of the steel decreases. Based on literature data and results from rolling continuous casting billets the following experimental equation has been found: (Mn/S)_c = 1.345 · S^?0.7934. A high similarity between this experimental equation and the theoretical one is achieved. A comparison between the equation found and previous expressions from literature was carried out. The MSC index as the ratio between the (Mn/S) ratio of a steel and the corresponding critical one was defined. The MSC index is a useful tool for the analysis of experimental results from literature.     

Specific heat and quadrupole interactions in uniaxial ferroelectrics

The inclusion of quadrupolar and higher order terms into the effective field in second order transition in uniaxial ferroelectrics is shown to describe well the jump in specific heat at T⋍T_c for crystals of the TGS family. It is shown that the numerical values for the coefficient g≡(γ/β)(Nμ)², corresponding to the quadrupolar interaction term, obtained (a) from specific heat data and (b) from spontaneous polarization data (both at T⋍T_c are in good agreement with each other for crystals of the TGS family.     

RELATIVE POWER OF t TYPE TESTS FOR STATIONARY AND UNIT ROOT PROCESSES

Abstract. This paper shows numerically that the lack of power and size distortions of the Dickey-Fuller type tests for unit roots (very well documented in the unit root literature) are similar to and in many situations even smaller than the lack of power and size distortions of the standard Student t tests for stationary roots of an autoregressive model.     

Prevalence of Blastocystis hominis infection in schoolchildren from Bolivar City, Venezuela

Blastocystis hominis is found in about 25% of feces in normal asymptomatic people. Its pathogenic role is still discussed. A prospective study was performed to determine the prevalence of B. hominis infection in schoolchildren from Bolivar City. We evaluated 446 children, between five and fourteen years old, both sexes, using direct examination of feces and Willis Method. They were also evaluated clinically. Results showed that B. hominis had a prevalence of 16.8%. We did not find a statistically significant association between sex (P > 0.05) or age and infection with B. hominis (x2 = 1.94 g.l = 4). In 39 schoolchildren (52.0%) we identified other parasites along with B. hominis, the most frequent was Trichuris trichiura as helminth and Giardia lamblia as protozoan. We observed B. hominis alone in 36 cases (48.0%). There was a spectrum of clinical symptoms in 41 (54.7%) of all children evaluated. Diarrhea was the most frequently clinical manifestation observed. Other studies are necessary to determine clinical relevance of B. hominis in school population in Bolivar City.     

Liquid chromatographic determination of free and total sulphites in fresh sausages

The present work describes a method for the determination of free and total sulphite in fresh sausages and its implementation on 48 samples. The method includes the extraction of sulphite, both free and total, by dissolution of the sample in a suitable solvent and determination by high performance liquid chromatography with electrochemical detection. The method is that previously reported by Kim and Kim (J Food Sci 51 1986 1360–1361) improved by certain modifications the principal of which consists of working atpH 10 for the extraction of total sulphite. Use of this pH permits reversible dissociation of the combined sulphite. In reproducibility assays carried out on sausages, variation coefficients of 3.3 and 5% were obtained for free and total sulphite, respectively. To evaluate recovery, sulphite was added to the samples as hydroxymethylsulphonate. Mean recovery was 86.4% with a variation coefficient of 3.8%. In 62% of the sausages analysed, amounts of total sulphites higher than 450 μ SO₂ g^?1 were found. Among the samples, considerable variation was observed in the distribution of sulphite between the free and combined forms.     

Generalizacion de un S-Juego estrategias finitamente aditivas

Sumario En la primera parte de este trabajo, se estudia la existencia de estrategias óptimas, en el modelo teórico (P_a F, ρ (P_a,f)) (ref. 3), generalización de un S-juego, dondeP _a es un conjunto de probabilidades finitamente aditivas, yF un subconjunto convexo de funciones reales acotadas. A continuación se analizan las clases de estrategias y se obtiene una clase de estrategiasp _a-Bayes, más amplia que la de Bayes β, y Bayes extendida β_o, que tiene la propiedad de contener siempre a la clase de estrategias admisibles. Se demuestra su completitud con hipótesis adicionales, y se obtienen resultados relativos a estrategias σ-aditivas, como casos particulares. Trabajo realizado con la beca March de Matemáticas, convocatoria 1973–74.     

Association of complementary fragments and the elucidation of protein folding pathways

Natural or engineered sites for chemical cleavage can be usedto generate complementary fragments of well characterized proteins.The peptide fragments represent a unique tool for studying earlyevents in protein folding, since these are usually the mostinaccessible to the experimentalist. Analysis of the isolatedfragments in nondenaturing conditions together with the determinationof the structure of the folded non-covalent complexes and, mostimportantly, the kinetic analysis of the resulting second-orderassociation/folding reaction can give a more complete pictureof a folding pathway. The contribution of fragments to the understandingof some well characterized protein folding pathways is discussed.     

Ferroelectric behavior of TAAP single crystal near Tc

Dielectric and hysteresis loop measurements in good quality telluric acid ammonium phosphate from 20 to 50°C with special attention to the behavior in the vicinity of T_c ≈44.80 °C were performed. The effective field higher order parameters characterizing the temperature dependence of the spontaneous polarization were obtained. The main features of the ferroelectric transition in this “hard” ferroelectric have been compared with those of other well known ferroelectric crystals.