885 research outputs found
Zipf law in the popularity distribution of chess openings
We perform a quantitative analysis of extensive chess databases and show that
the frequencies of opening moves are distributed according to a power-law with
an exponent that increases linearly with the game depth, whereas the pooled
distribution of all opening weights follows Zipf's law with universal exponent.
We propose a simple stochastic process that is able to capture the observed
playing statistics and show that the Zipf law arises from the self-similar
nature of the game tree of chess. Thus, in the case of hierarchical
fragmentation the scaling is truly universal and independent of a particular
generating mechanism. Our findings are of relevance in general processes with
composite decisions.Comment: 5 pages, 4 figure
Section 6.1 The finds: The pottery
The site of Warren Field in Scotland revealed two unusual and enigmatic features; an alignment of pits and a large, rectangular feature interpreted as a timber building. Excavations confirmed that the timber structure was an early Neolithic building and that the pits had been in use from the Mesolithic. This report details the excavations and reveals that the hall was associated with the storage and or consumption of cereals, including bread wheat, and pollen evidence suggests that the hall may have been part of a larger area of activity involving cereal cultivation and processing. The pits are fully documented and environmental evidence sheds light on the surrounding landscape
Bioclipse: an open source workbench for chemo- and bioinformatics
BACKGROUND: There is a need for software applications that provide users with a complete and extensible toolkit for chemo- and bioinformatics accessible from a single workbench. Commercial packages are expensive and closed source, hence they do not allow end users to modify algorithms and add custom functionality. Existing open source projects are more focused on providing a framework for integrating existing, separately installed bioinformatics packages, rather than providing user-friendly interfaces. No open source chemoinformatics workbench has previously been published, and no sucessful attempts have been made to integrate chemo- and bioinformatics into a single framework. RESULTS: Bioclipse is an advanced workbench for resources in chemo- and bioinformatics, such as molecules, proteins, sequences, spectra, and scripts. It provides 2D-editing, 3D-visualization, file format conversion, calculation of chemical properties, and much more; all fully integrated into a user-friendly desktop application. Editing supports standard functions such as cut and paste, drag and drop, and undo/redo. Bioclipse is written in Java and based on the Eclipse Rich Client Platform with a state-of-the-art plugin architecture. This gives Bioclipse an advantage over other systems as it can easily be extended with functionality in any desired direction. CONCLUSION: Bioclipse is a powerful workbench for bio- and chemoinformatics as well as an advanced integration platform. The rich functionality, intuitive user interface, and powerful plugin architecture make Bioclipse the most advanced and user-friendly open source workbench for chemo- and bioinformatics. Bioclipse is released under Eclipse Public License (EPL), an open source license which sets no constraints on external plugin licensing; it is totally open for both open source plugins as well as commercial ones. Bioclipse is freely available at
Parenting interventions for male young offenders: a review of the evidence on what works
Approximately one in four incarcerated male young offenders in the UK is an actual or expectant father. This paper reviews evidence on the effectiveness of parenting interventions for male young offenders. We conducted systematic searches across 20 databases and consulted experts. Twelve relevant evaluations were identified: 10 from the UK, of programmes for incarcerated young offenders, and two from the US, of programmes for young parolees. None used experimental methods or included a comparison group. They suggest that participants like the courses, find them useful, and the interventions may improve knowledge about, and attitudes to, parenting. Future interventions should incorporate elements of promising parenting interventions with young fathers in the community, for example, and/or with older incarcerated parents. Young offender fathers have specific developmental, rehabilitative, and contextual needs. Future evaluations should collect longer-term behavioural parent and child outcome data and should use comparison groups and, ideally, randomization
The Personality and Cognitive Traits Associated with Adolescentsâ Sensitivity to Social Norms
Little is known about the personality and cognitive traits that shape adolescentsâ sensitivity to social norms. Further, few studies have harnessed novel empirical tools to elicit sensitivity to social norms among adolescent populations. This paper examines the association between sensitivity to norms and various personality and cognitive traits using an incentivised rule-following task grounded in Game Theory. Cross-sectional data were obtained from 1274 adolescents. Self-administered questionnaires were used to measure personality traits as well as other psychosocial characteristics. Incentivised rule-following experiments gauged sensitivity to social norms. A series of multilevel mixed effects ordered logistic regression models were employed to assess the association between sensitivity to norms and the personality and cognitive traits. The results highlighted statistically significant univariate associations between the personality and cognitive traits and sensitivity to norms. However, in the multivariate adjusted model, the only factor associated with sensitivity to norms was gender. The gender-stratified analyses revealed differences in the personality and cognitive traits associated with sensitivity to norms across genders. For males need to belong was significantly negatively associated with sensitivity to norms in the multivariate model. By comparison, emotional stability was negatively associated with sensitivity to norms for females. This study reinforced the findings from an earlier study and suggested female adolescents had higher levels of sensitivity to norms. The results indicated no consistent pattern between sensitivity to norms and the personality and cognitive traits. Our findings provide a basis for further empirical research on a relatively nascent construct, and bring a fresh perspective to the question of norm-following preferences among this age group
A new mathematical model for environmental monitoring and assessment
VersĂŁo dos Autores para este artigo.In this paper we are concerned with a quantitative method of Landscape Ecology. More in details we consider an environmental system distributed in landscape units (ecological sectors) and we propose a new mathematical model in order to implement a method for the evaluation of the ecological state of the system under investigation. After having performed a stability analysis of the model, we apply the proposed procedure first by considering separately each landscape unit and then extending our investigation to the system as a whole, by taking into account the connections between all the landscape units themselves. Our investigation includes some numerical computations that were performed for a Northern district of the Turin Province, using an approximation procedure that should avoid stiffness problems.National Group GNFM of INdAM, Italyinfo:eu-repo/semantics/publishedVersio
Dependence of a planet's chaotic zone on particle eccentricity: the shape of debris disc inner edges
The orbit of a planet is surrounded by a chaotic zone wherein nearby
particles' orbits are chaotic and unstable. Wisdom (1980) showed that the chaos
is driven by the overlap of mean motion resonances which occurs within a
distance (da/a)_chaos = 1.3 mu^2/7 of the planet's orbit. However, the width of
mean motion resonances grows with the particles' eccentricity, which will
increase the width of the chaotic zone at higher eccentricities. Here we
investigate the width of the chaotic zone using the iterated encounter map and
N-body integrations. We find that the classical prescription works well for
particles on low-eccentricity orbits. However, above a critical eccentricity,
dependent upon the mass of the planet, the width of the chaotic zone increases
with eccentricity. An extension of Wisdom's analytical arguments then shows
that, above the critical eccentricity, the chaotic zone width is given by
(da/a)_chaos = 1.8 e^1/5 mu^1/5, which agrees well with the encounter map
results. The critical eccentricity is given by e_cr = 0.21 mu^3/7. This
extended chaotic zone results in a larger cleared region when a planet sculpts
the inner edge of a debris disc comprised of eccentric planetesimals. Hence,
the planet mass estimated from the classical chaotic zone may be erroneous. We
apply this result to the HR8799 system, showing that the masses of HR8799b
inferred from the truncation of the disc may vary by up to 50% depending on the
disc particles' eccentricities. With a disc edge at 90AU, the necessary mass of
planet b to cause the truncation would be 8-10 Jovian masses if the disc
particles have low eccentricities (<0.02), but only 4-8 Jovian masses if the
disc particles have higher eccentricities. Our result also has implications for
the ability of a planet to feed material into an inner system, a process which
may explain metal pollution in White Dwarf atmospheres.Comment: 7 pages, 5 figures. Accepted to MNRA
Association between circulating levels of sex steroid hormones and esophageal adenocarcinoma in the FINBAR Study
Funding: The study was supported by NIH Intramural Research Program, National Cancer Institute; Cancer Focus Northern Ireland (formerly the Ulster Cancer Foundation); the Northern Ireland R&D office; and the Health Research Board, Ireland. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD
Comparative Network Analysis of Preterm vs. Full-Term Infant-Mother Interactions
Several studies have reported that interactions of mothers with preterm infants show differential characteristics compared to that of mothers with full-term infants. Interaction of preterm dyads is often reported as less harmonious. However, observations and explanations concerning the underlying mechanisms are inconsistent. In this work 30 preterm and 42 full-term mother-infant dyads were observed at one year of age. Free play interactions were videotaped and coded using a micro-analytic coding system. The video records were coded at one second resolution and studied by a novel approach using network analysis tools. The advantage of our approach is that it reveals the patterns of behavioral transitions in the interactions. We found that the most frequent behavioral transitions are the same in the two groups. However, we have identified several high and lower frequency transitions which occur significantly more often in the preterm or full-term group. Our analysis also suggests that the variability of behavioral transitions is significantly higher in the preterm group. This higher variability is mostly resulted from the diversity of transitions involving non-harmonious behaviors. We have identified a maladaptive pattern in the maternal behavior in the preterm group, involving intrusiveness and disengagement. Application of the approach reported in this paper to longitudinal data could elucidate whether these maladaptive maternal behavioral changes place the infant at risk for later emotional, cognitive and behavioral disturbance
Evaluating the discriminatory power of EQ-5D, HUI2 and HUI3 in a US general population survey using Shannonâs indices
OBJECTIVES: To compare quantitatively the discriminatory power of the EQ-5D, HUI2 and HUI3 in terms of absolute and relative informativity, using Shannon's indices. METHODS: EQ-5D and HUI2/3 data completed by a sample of the general adult US population (N = 3,691) were used. Five dimensions allowed head-to-head comparison of informativity: Mobility/Ambulation; Anxiety/Depression/Emotion; Pain/Discomfort (EQ-5D; HUI2; HUI3); Self-Care (EQ-5D; HUI2); and Cognition (HUI2; HUI3). Shannon's index and Shannon's Evenness index were used to assess absolute and relative informativity, both by dimension and by instrument as a whole. RESULTS: Absolute informativity was highest for HUI3, with the largest differences in Pain/Discomfort and Cognition. Relative informativity was highest for EQ-5D, with the largest differences in Mobility/Ambulation and Anxiety/Depression/Emotion. Absolute informativity by instrument was consistently highest for HUI3 and lowest for EQ-5D, and relative informativity was highest for EQ-5D and lowest for HUI3. DISCUSSION: Performance in terms of absolute and relative informativity of the common dimensions of the three instruments varies over dimensions. Several dimensions are suboptimal: Pain/Discomfort (EQ-5D) seems too crude with only 3 levels, and the level descriptions of Ambulation (HUI3) and Self-Care (HUI2) could be improved. In absence of a formal measure, Shannon's indices provide useful measures for assessing discriminatory power of utility instrument
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