Authorship Attribution with Support Vector Machines

In this paper we explore the use of text-mining methods for the identification of the author of a text. We apply the support vector machine (SVM) to this problem, as it is able to cope with half a million of inputs it requires no feature selection and can process the frequency vector of all words of a text. We performed a number of experiments with texts from a German newspaper. With nearly perfect reliability the SVM was able to reject other authors and detected the target author in 60–80% of the cases. In a second experiment, we ignored nouns, verbs and adjectives and replaced them by grammatical tags and bigrams. This resulted in slightly reduced performance. Author detection with SVMs on full word forms was remarkably robust even if the author wrote about different topics.     

Hallin and Mancini Revisited: Four Empirical Types of Western Media Systems

The analysis of media systems has become a cornerstone in the field of comparative communication research. Ten years after its publication, we revisit the landmark study in the field, Hallin and Mancini's “Comparing Media Systems”, and operationalize its framework for standardized measurement. The study at hand is, to the best of our knowledge, the first to comprehensively validate the original dimensions and models using aggregated data from the same sample of Western countries. Three out of four dimensions of media systems show relatively high levels of internal consistency, but “role of the state” should be disaggregated into 3 subdimensions. A cluster analysis reveals 4 empirical types of media systems that differentiate and extend the original typology.     

Synthesis and Stretching of Rolling Circle Amplification Products in a Flow‐Through System

Enzymatic isothermal rolling circle amplification (RCA) produces long concatemeric single‐stranded DNA (ssDNA) molecules if a small circular ssDNA molecule is applied as the template. A method is presented here in which the RCA reaction is carried out in a flow‐through system, starting from isolated surface‐tethered DNA primers. This approach combines gentle fluidic handling of the single‐stranded RCA products, such as staining or stretching via a receding meniscus, with the option of simultaneous (fluorescence) microscopic observation. It is shown that the stretched and surface‐attached RCA products are accessible for hybridization of complementary oligonucleotides, which demonstrates their addressability by complementary base pairing. The long RCA products should be well suited to bridge the gap between biomolecular nanoscale building‐blocks and structures at the micro‐ and macroscale, especially at the single‐molecule level presented here.     

Milk availability modulates weaning in the Norway rat (Rattus norvegicus).

Beginning on Day 14 postnatally, 368 Sprague-Dawley rat pups were exposed to different levels of milk supply by changing litter size of 10 dams from 8 to 4 or 12 (Exp I) or limiting temporally Ss' access to a lactating dam (1 of 36) to 8, 14, or 24 hrs/day (Exp II). Both manipulations accelerated weaning in milk-deprived Ss. By adding solid food and water to their diet, early weaning Ss compensated for the negative energy consequences of milk reduction and achieved premanipulation growth rates. Milk availability thus appears to affect weaning, and it is suggested that the developmental changes in the nutritive energy balance between mother and offspring contribute to the emergence of independent ingestion. (43 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modelling the dynamics of the yeast pheromone pathway

We present a mathematical model of the dynamics of the pheromone pathways in haploid yeast cells of mating type MATa after stimulation with pheromone alpha-factor. The model consists of a set of differential equations and describes the dynamics of signal transduction from the receptor via several steps, including a G protein and a scaffold MAP kinase cascade, up to changes in the gene expression after pheromone stimulation in terms of biochemical changes (complex formations, phosphorylations, etc.). The parameters entering the models have been taken from the literature or adapted to observed time courses or behaviour. Using this model we can follow the time course of the various complex formation processes and of the phosphorylation states of the proteins involved. Furthermore, we can explain the phenotype of more than a dozen well-characterized mutants and also the graded response of yeast cells to varying concentrations of the stimulating pheromone.     

Session effects, comparability, and managed care in the psychotherapies.

Reviews dose–effect relationship studies (e.g., K. I. Howard et al; see record 1986-17818-001) and duration comparability studies (e.g., M. P. Koss and J. N. Butcher, 1986) which provide direction for effective time guidelines for outpatient psychotherapy. The dose–effect research appears to be a useful estimate of duration effectiveness that deserves more attention in designing mental health funding policies. Current managed care approaches appear inappropriate in emphasizing usage rather than effectiveness curves. Guidelines are suggested for basic, intermediate, and extended treatment with different goals, dosages, and managed care policies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Study of Dissolution Behavior of Matrices Tablets Based on Alginate—Gelatin Mixtures as Prolonged Diltiazem Hydrochloride Release Systems

ABSTRACT

The aim of this work was to develop prolonged diltiazem hydrochloride release matrices based on alginate-gelatin mixtures and establish the drug release mechanism. The erosion, swelling, and dissolution behavior of the tablets in different medium were evaluated. The different polyelectrolyte behavior and gel strength between type A Gelatin and type B Gelatin would explain the different swelling, erosion and dissolution behavior in the media with sudden pH change. The similar dissolution behavior in the pH, which simulates the physiological pH through the gastrointestinal tract, should be explained because the same main species for gelatin A and Gelatin B would be present in this media.     

Model for the influence of mass transport on enzymatic hydrolysis of polysaccharides

In this paper enzymatic hydrolysis reactions have been considered as integration-limited reactions analogous to crystal growth. Based on the mathematical formulation of diffusion of polysaccharide substrate molecules to binding sites of the enzyme, integration kinetics were derived and compared to measured data. Significant is the measured and calculated decrease of the ratio of the specific activity and the Michaelis-Menten parameter with increasing molar mass of the enzymes with an exponent more than unity.     

Micropatterned Ceramic Surfaces by Coating with Filled Preceramic Polymers

Surface structures in micrometer scale were prepared on different substrates by a coating process using particle-filled slurries based on a blend of preceramic polymers. Parameters like solvent fraction, substrate material, filler particle size, and layer thickness were varied. Demixing reactions of solvent and polymers led to surface structures with pores of 1–60 μm in diameter. The solubility parameters δ_t of the polysiloxanes used are about 18.7 MPa^1/2 for poly(methyl phenyl vinyl siloxane) and 19.5 MPa^1/2 for poly(methyl siloxane), respectively. By pyrolysis of the green layers, ceramic coatings were obtained by keeping the particular surface structures.