Improving Prolog Programs: Refactoring for Prolog

Refactoring is an established technique from the OO-community to restructure code: it aims at improving software readability, maintainability and extensibility. Although refactoring is not tied to the OO-paradigm in particular, its ideas have not been applied to Logic Programming until now. This paper applies the ideas of refactoring to Prolog programs. A catalogue is presented listing refactorings classified according to scope. Some of the refactorings have been adapted from the OO-paradigm, while others have been specifically designed for Prolog. Also the discrepancy between intended and operational semantics in Prolog is addressed by some of the refactorings. In addition, ViPReSS, a semi-automatic refactoring browser, is discussed and the experience with applying \vipress to a large Prolog legacy system is reported. Our main conclusion is that refactoring is not only a viable technique in Prolog but also a rather desirable one.Comment: To appear in ICLP 200

Dynamical model of sequential spatial memory: winnerless competition of patterns

We introduce a new biologically-motivated model of sequential spatial memory which is based on the principle of winnerless competition (WLC). We implement this mechanism in a two-layer neural network structure and present the learning dynamics which leads to the formation of a WLC network. After learning, the system is capable of associative retrieval of pre-recorded sequences of spatial patterns.Comment: 4 pages, submitted to PR

The quality of political information

The article conceptualizes the quality of political information and shows how the concept can be used for empirical research. I distinguish three aspects of quality (intelligibility, relevance, validity) and use them to judge the constituent foundations of political information, that is component claims (statements of alleged facts) and connection claims (argumentative statements created by causally linking two component claims). The resulting conceptual map thus entails six manifestations of information quality (component claimintelligibility, connection claim intelligibility, component claimrelevance, connection claim relevance, component claim validity, and connection claim validity). I explain how the conceptual map can be used to make sense of the eclectic variety of existing research, and how it can advance new empirical research, as a guide for determining variation in information quality, as a conceptual template for the analysis of different types of political messages and their common quality deficiencies, and as a generator of new research questions and theoretical expectations

Predictive validity of the UK clinical aptitude test in the final years of medical school:a prospective cohort study

Peer reviewedPublisher PD

A new skeleton of the cryptoclidid plesiosaur Tatenectes laramiensis reveals a novel body shape among plesiosaurs

Current knowledge of plesiosaurs of clade Cryptoclidia is constrained by a lack of fossils from outside the Oxford Clay deposits of England. Recent fieldwork in the Sundance Formation of the Bighorn Basin, Wyoming, has resulted in the recovery of significant new fossils of cryptoclidid plesiosaurs, including the small-bodied form Tatenectes laramiensis. A new partial skeleton of this taxon is reported here; it is the most complete and best-preserved example of the taxon found to date, comprising a complete dorsal vertebral series, many ribs and gastralia, and a complete pelvic girdle. This skeleton illuminates several unique features of the taxon, including a novel pattern of midline pachyostosis in the gastralia. In addition, a range of both axial and appendicular morphological features reveals that Tatenectes had a body shape unique among known plesiosaurs, characterized by extreme dorsoventral compression, and modest anteroposterior reduction. The combination of the new skeleton with information from previous finds allows the first reconstruction of the taxon. Tatenectes had a dorsoventrally compressed, oblate spheroid body shape, with a high skeletal mass concentration in the ventral elements. We hypothesize that these features were adaptations for increased near-surface stability, perhaps allowing access to above normal wave base, inshore environments in the shallow Sundance Seaway

The Co-occurrence of child and intimate partner maltreatment in the family: characteristics of the violent perpetrators

This study considers the characteristics associated with mothers and fathers who maltreat their child and each other in comparison to parents who only maltreat their child. One hundred and sixty-two parents who had allegations of child maltreatment made against them were considered. The sample consisted of 43 fathers (Paternal Family—PF) and 23 mothers (Maternal Family—MF) who perpetrated both partner and child maltreatment, together with 23 fathers (Paternal Child—PC) and 26 mothers (Maternal Child—MC) who perpetrated child maltreatment only. In addition, 2 fathers (Paternal Victim—PV) and 23 mothers (Maternal Victim—MV) were victims of intimate partner maltreatment and perpetrators of child maltreatment and 7 fathers (Paternal Non-abusive Carer—PNC) and 15 mothers (Maternal Non-abusive Carer—MNC) did not maltreat the child but lived with an individual who did. Within their family unit, 40.7% of parents perpetrated both intimate partner and child maltreatment. However, fathers were significantly more likely to maltreat both their partner and child than mothers and mothers were significantly more likely to be victims of intimate partner violence than fathers. PF fathers conducted the highest amount of physical and/or sexual child maltreatment while MC and MV mothers perpetrated the highest amount of child neglect. Few significant differences between mothers were found. PF fathers had significantly more factors associated with development of a criminogenic lifestyle than PC fathers. Marked sex differences were demonstrated with PF fathers demonstrating significantly more antisocial characteristics, less mental health problems and fewer feelings of isolation than MF mothers. MC mothers had significantly more childhood abuse, mental health problems, parenting risk factors and were significantly more likely to be biologically related to the child than PC fathers. This study suggests that violent families should be assessed and treated in a holistic manner, considering the effects of partner violence upon all family members, rather than exclusively intervening with the violent man

Multicolour interphase cytogenetics: 24 chromosome probes, 6 colours, 4 layers

From the late 1980s onwards, the use of DNA probes to visualise sequences on individual chromosomes (fluorescent in-situ hybridisation - FISH) revolutionised the study of cytogenetics. Following single colour experiments, more fluorochromes were added, culminating in a 24 colour assay that could distinguish all human chromosomes. Interphase cytogenetics (the detection of chromosome copy number in interphase nuclei) soon followed, however 24 colour experiments are hampered for this application as mixing fluorochromes to produce secondary colours produces images that are not easily distinguishable from overlapping signals. This study reports the development and use of a novel protocol, new fast hybridising FISH probes, and a bespoke image capture system for the assessment of chromosome copy number in interphase nuclei. The multicolour probe sets can be used individually or in sequential hybridisation layers to assess ploidy of all 24 human chromosomes in the same nucleus. Applications of this technique are in the investigation of chromosome copy number and the assessment of nuclear organisation for a range of different cell types including human sperm, cancer cells and preimplantation embryos

Doing what others do: norms, science, and collective action on global warming

Does rhetoric highlighting social norms or mentioning science in a communication affect individuals’ beliefs about global warming and/or willingness to take action? We draw from framing theory and collective-interest models of action to motivate hypotheses that are tested in two large web-based survey-experiments using convenience samples. Our results show that attitudes about global warming, support for policies that would reduce carbon emissions, and behavioral intentions to take voluntary action are strongly affected by norm- and science-based interventions. This has implications for information campaigns targeting voluntary efforts to promote lifestyle changes that would reduce greenhouse gas emissions

Active versus passive acquisition of spatial knowledge while controlling a vehicle in a virtual urban space in drivers and non-drivers

Historically real world studies have indicated a spatial learning advantage for active explorers of environments over those whose experience is more passive; a common contrast is made between car drivers and passengers. An experiment was conducted to explore the dual hypotheses that active explorers learn more about the layout of a virtual environment than passive observers and that real world car drivers will learn more regardless of their experimental Active/Passive status. Consistent with earlier studies in VEs, there was no benefit from activity (controlling exploration/movement), arguably because input control competes with spatial information acquisition. However, the results showed that Drivers were more accurate than Non-Drivers at indicating the positions of target locations on a map, in both active and passive conditions and had better route scores than Non-Drivers in the passive condition. It is argued that driving experience may convey a spatial learning advantage over and above activity per se

High-resolution spectroscopy of the R Coronae Borealis and Other Hydrogen Deficient Stars

High-resolution spectroscopy is a very important tool for studying stellar physics, perhaps, particularly so for such enigmatic objects like the R Coronae Borealis and related Hydrogen deficient stars that produce carbon dust in addition to their peculiar abundances. Examples of how high-resolution spectroscopy is used in the study of these stars to address the two major puzzles are presented: (i) How are such rare H-deficient stars created? and (ii) How and where are the obscuring soot clouds produced around the R Coronae Borealis stars?Comment: 16 pages, 9 figures, Astrophysics and Space Science Proceedings, Springer-Verlag, Berlin, 201