An Evolutionary Reduction Principle for Mutation Rates at Multiple Loci

A model of mutation rate evolution for multiple loci under arbitrary selection is analyzed. Results are obtained using techniques from Karlin (1982) that overcome the weak selection constraints needed for tractability in prior studies of multilocus event models. A multivariate form of the reduction principle is found: reduction results at individual loci combine topologically to produce a surface of mutation rate alterations that are neutral for a new modifier allele. New mutation rates survive if and only if they fall below this surface - a generalization of the hyperplane found by Zhivotovsky et al. (1994) for a multilocus recombination modifier. Increases in mutation rates at some loci may evolve if compensated for by decreases at other loci. The strength of selection on the modifier scales in proportion to the number of germline cell divisions, and increases with the number of loci affected. Loci that do not make a difference to marginal fitnesses at equilibrium are not subject to the reduction principle, and under fine tuning of mutation rates would be expected to have higher mutation rates than loci in mutation-selection balance. Other results include the nonexistence of 'viability analogous, Hardy-Weinberg' modifier polymorphisms under multiplicative mutation, and the sufficiency of average transmission rates to encapsulate the effect of modifier polymorphisms on the transmission of loci under selection. A conjecture is offered regarding situations, like recombination in the presence of mutation, that exhibit departures from the reduction principle. Constraints for tractability are: tight linkage of all loci, initial fixation at the modifier locus, and mutation distributions comprising transition probabilities of reversible Markov chains.Comment: v3: Final corrections. v2: Revised title, reworked and expanded introductory and discussion sections, added corollaries, new results on modifier polymorphisms, minor corrections. 49 pages, 64 reference

Learning Analogies and Semantic Relations

We present an algorithm for learning from unlabeled text, based on the Vector Space Model (VSM) of information retrieval, that can solve verbal analogy questions of the kind found in the Scholastic Aptitude Test (SAT). A verbal analogy has the form A:B::C:D, meaning "A is to B as C is to D"; for example, mason:stone::carpenter:wood. SAT analogy questions provide a word pair, A:B, and the problem is to select the most analogous word pair, C:D, from a set of five choices. The VSM algorithm correctly answers 47% of a collection of 374 college-level analogy questions (random guessing would yield 20% correct). We motivate this research by relating it to work in cognitive science and linguistics, and by applying it to a difficult problem in natural language processing, determining semantic relations in noun-modifier pairs. The problem is to classify a noun-modifier pair, such as "laser printer", according to the semantic relation between the noun (printer) and the modifier (laser). We use a supervised nearest-neighbour algorithm that assigns a class to a given noun-modifier pair by finding the most analogous noun-modifier pair in the training data. With 30 classes of semantic relations, on a collection of 600 labeled noun-modifier pairs, the learning algorithm attains an F value of 26.5% (random guessing: 3.3%). With 5 classes of semantic relations, the F value is 43.2% (random: 20%). The performance is state-of-the-art for these challenging problems

The Predicate Appositive as Object Modifier

故田中茂和教授追悼

STUDI PENINJAUAN PENGGUNAAN PERTAMAX SEBAGAI MODIFIER PADA ASBUTON BERAGREGAT CAMPURAN DINGIN UNTUK PERKERASAN JALAN

The road is a means of land transportation which consists of some materials, such as coarse aggregate, fine aggregate, filler (filler) and bitumen. In the process of maintenance, damage sometimes occur earlier than the service one of which is caused by the use of modifier factors of Cold Mixed Lasbutag in road pavement .. This study aimed to find out is there any influence of modifier on the properties such as Marshall stability, flow on plastic (flow), Results For Marshall (Marshall Quotient), and air cavities. And how many variations of the ideal mixture by using modifier Pertamax Asbuton? By using bitumen oil 2%, 2.2%, 2.4%, 2.6%, 2.8% and 3%,, then made the specimens of 3 x 6 specimens (for statistical test) that shaped cylinder with a heavy volume of 1200 grams. The variation of the total modifier used in this study was 3.75%, 3.85%, 3.95%, 4.05%, 4.15%, and 4.25% and for each - each variation modifier using 3 objects test. Marshall stability shown by the equation: Y = 1048.6 X - 3659. Marshall Stability is estimated to reach under the terms of the use of modifier total 3.83% and will reach maximum requirements on the use of modifier total of 4.68%. Value on plastic flow (Flow), shown by the equation: Y = -3.457 X + 17.156. Score Results For Marshall indicated equation: Y = 520.79 X - 1906. And for the air cavity is indicated by the equation: Y = -0.618 X + 12.879, so the statistical test found no effect with variation of modifier, because it is expected to achieve the mimimum requirements for a total of 17.6% on the modifier and will meet the maximum requirements on the total modifier 14, 37%. According to the equation Eq modifier variation of Cold Mixed Lasbutag obtained all affect the Marshall Stability, Flow and Marshall Quotient, but less influential in the air cavity. Of the 6 variations modifier on Marshall Stability, Flow and Marshall Quotient that in only 5 trials that meet the requirements. So the effect of modifier on the Marshall Stability, Flow and Marshall Quotient ± 83%. While at 0% air voids. And from the variation of modifier that meets the requirements of ISO-06-2489-1991 Lasbutag Cold Mixture for Stability, Flow, Air and Marshall Quotient cavity is known, can be calculated modifier mixture is ideal for Cold Lasbutag ie ± 4.10%

Spectrometric study of condensed phase species of thorium and palladium-based modifiers in a complex matrix for electrothermal atomic absorption spectrometry

The chemical and morphological transformations of condensed phase species of a thorium-based modifier were studied over the temperature range 200–2500 °C, without and with the presence of aluminium and silicon as matrix components, and in some instances, arsenic as an analyte element. A similar study was also conducted with palladium as the modifier, for comparison. Results were derived using scanning electron microscopy (SEM), energy dispersive (ED) X-ray spectrometry, Raman microanalysis and attenuated total reflectance (ATR) Fourier transform-infrared (FT-IR) spectrometry. Comparable results were found using pyrolytic and non-pyrolytic graphite platforms, with processes occurring at slightly higher temperatures on the pyrolytic graphite platform. With thorium as the modifier, metal oxides were the predominant species on the platform surface at relatively low temperatures (<1500 °C), whereas metal phases became prevalent at high temperatures, when thorium and aluminium tended to behave independently from one other. Some spatial variations in the composition of the salt residues on different regions of the platform were observed (from the region closest to the slot in the tube, to the region furthest from the slot). Nonetheless, thorium metal remained on the graphite platform to higher temperatures than did aluminium metal. In the presence of arsenic, the existence of mixtures of thorium and arsenic oxides, just before the appearance temperature of gas phase arsenic atoms, was confirmed by SEM studies, ED X-ray spectra and Raman microanalysis. This suggests that any modifying effect of thorium on arsenic occurs while the modifier is in the oxide phase rather than in the metal phase. The presence of silicon added as silica, did not influence significantly the thermochemical behaviour of mixtures of thorium and aluminium. However, coexistence of silicon and arsenic oxides at the appearance temperature of the atomic absorption signal of arsenic was obtained, confirming that silicon can act as an internal modifier for arsenic. In the presence of palladium, aluminium exhibited greater interaction with the modifier; consequently, aluminium metal was retained on the platform surface to higher temperatures than thorium, which could explain how interference effects of aluminium on e.g. arsenic are avoided or reduced. Similarly, there was evidence for interaction of palladium and arsenic in the reduced state. However, when aluminium and silicon were present, the transformation of the palladium oxide to the metallic state was affected, which could diminish the modifying benefits of palladium for arsenic in the presence of aluminium

Write Free or Die: Vol. 03, No. 02

Writing & Reading, Page 1-2 Upcoming Events, Page 1 Writing Committee Members, Page 2 Dangling Modifier, Page 3-4 Ask Matt, Page 5 Student Profile, Page 6 Grammar Box, Page 7 Past Perfect, Page

Inter-observer agreement of the Coronary Artery Disease Reporting and Data System (CAD-RADS^{TM}) in patients with stable chest pain

Purpose: To assess inter-observer variability of the Coronary Artery Disease - Reporting and Data System (CAD-RADS) for classifying the degree of coronary artery stenosis in patients with stable chest pain. Material and methods: A prospective study was conducted upon 96 patients with coronary artery disease, who underwent coronary computed tomography angiography (CTA). The images were classified using the CAD-RAD system according to the degree of stenosis, the presence of a modifier: graft (G), stent (S), vulnerable plaque (V), or non-diagnostic (n) and the associated coronary anomalies, and non-coronary cardiac and extra-cardiac findings. Image analysis was performed by two reviewers. Inter-observer agreement was assessed. Results: There was excellent inter-observer agreement for CAD-RADS (k = 0.862), at 88.5%. There was excellent agreement for CAD-RADS 0 (k = 1.0), CAD-RADS 1 (k = 0.92), CAD-RADS 3 (k = 0.808), CAD-RADS 4 (k = 0.826), and CAD-RADS 5 (k = 0.833) and good agreement for CAD-RADS 2 (k = 0.76). There was excellent agreement for modifier G (k = 1.0) and modifier S (k = 1.0), good agreement for modifier N (k = 0.79), and moderate agreement for modifier V (k = 0.59). There was excellent agreement for associated coronary artery anomalies (k = 0.845), non-coronary cardiac findings (k = 0.857), and extra-cardiac findings (k = 0.81). Conclusions: There is inter-observer agreement of CAD-RADS in categorising the degree of coronary arteries stenosis, and the modifier of the system and associated cardiac and extra-cardiac findings

Macrostructure and microstructure in narratives of Spanish/English bilingual children with and without language impairment (LI)

There is limited research on character mention and noun phrase elaboration in the narratives of Spanish-English kindergarten and first graders. The current study was designed to determine whether typically developing (TD) Spanish- English bilingual children differed from children with language impairment (LI) in their use of character mentions, noun phrase elaboration, and noun modifier agreement in their English and Spanish narrative productions at kindergarten and first grade. The current study is a longitudinal study including 16 children with LI and 16 TD peers who were matched on age, sex, nonverbal IQ and language exposure. In kindergarten and first grade, the children retold a narrative using a wordless picture book in both Spanish and English. The findings revealed that the ability groups (LI and TD) significantly differed in their use of English character mention, English and Spanish noun phrase elaboration, use of Spanish type of noun phrase elaboration (level I), and noun-modifier agreement in narrative retells. Children in both groups (TD, LI) retold more complex narratives that vii included more characters and noun phrase elaboration at first grade than kindergarten. Despite these significant findings, the two groups did not develop character mention or noun phrase elaboration in their Spanish or English narratives at different rates across the two years. In the children’s Spanish retells, the children with LI committed more noun modifier agreement errors than the TD children; however, the two ability groups (LI, TD) did not develop noun modifier agreement at different rates. Similarity between the TD and the LI groups on character mention and noun phrase elaboration development may be due to the fact that both children were only beginning to incorporate noun phrase elaboration (i.e. adjectives, ENP) in their narrative retells.Communication Sciences and Disorder