bluuebunny/crossref_metadata_2025 huggingface dataset:
Collagen atomic scale molecular disorder in ochronotic cartilage from an alkaptonuria patient, observed by solid state NMR
Authors: Chow Wing Ying , Taylor Adam M. , Reid David G. , Gallagher James A. , Duer Melinda J.
Published: July 2011

In pilot studies of the usefulness of solid state nuclear magnetic resonance spectroscopy in characterizing chemical and molecular structural effects of alkaptonuria on connective tissue, we have obtained 13 C spectra from articular cartilage from an AKU patient. An apparently normal anatomical location yielded a cross polarization magic angle spinning spectrum resembling literature spectra and dominated by collagen and glycosaminoglycan signals. All spectral linewidths from strongly pigmented ochronotic cartilage however were considerably increased relative to the control indicating a marked increase in collagen molecular disorder. This disordering of cartilage structural protein parallels, at the atomic level, the disordering revealed at higher length scales by microscopy. We also demonstrate that the abnormal spectra from ochronotic cartilage fit with the abnormality in the structure of collagen fibres at the ultrastructural level, whereby large ochronotic deposits appear to alter the structure of the collagen fibre by invasion and cross linking. Summary: Increased signal linewidths in solid state NMR spectra of ochronotic articular cartilage from an AKU patient relative to linewidths in normal, control, cartilage reveals a marked decrease in collagen molecular order in the diseased tissue. This atomic level disordering parallels higher length scale disorder revealed by microscopic techniques.
Detecting and cleaning outliers for robust estimation of variogram models in insect count data
Authors: Park Jung‐Joon , Shin Key‐Il , Lee Joon‐Ho , Lee Sung Eun , Lee Woo‐Kyun , Cho Kijong
Published: July 2011

Outlier detection and cleaning procedures were evaluated to estimate mathematical restricted variogram models with discrete insect population count data. Because variogram modeling is significantly affected by outliers, methods to detect and clean outliers from data sets are critical for proper variogram modeling. In this study, we examined spatial data in the form of discrete measurements of insect counts on a rectangular grid. Two well‐known insect pest population data were analyzed; one data set was the western flower thrips,Frankliniella occidentalis(Pergande) on greenhouse cucumbers and the other was the greenhouse whitefly,Trialeurodes vaporariorum(Westwood) on greenhouse cherry tomatoes. A spatial additive outlier model was constructed to detect outliers in both the isolated and patchy spatial distributions of outliers, and the outliers were cleaned with the neighboring median cleaner. To analyze the effect of outliers, we compared the relative nugget effects of data cleaned of outliers and data still containing outliers after transformation. In addition, the correlation coefficients between the actual and predicted values were compared using the leave‐one‐out cross‐validation method with data cleaned of outliers and non‐cleaned data after unbiased back transformation. The outlier detection and cleaning procedure improved geostatistical analysis, particularly by reducing the nugget effect, which greatly impacts the prediction variance of kriging. Consequently, the outlier detection and cleaning procedures used here improved the results of geostatistical analysis with highly skewed and extremely fluctuating data, such as insect counts.
Microfungal diversity associated with Kindbergia oregana in successional forests of British Columbia
Authors: Osono Takashi , Trofymow John A.
Published: July 2011

Species richness and species composition of microfungi associated with Oregon beaked moss (Kindbergia oregana) were studied at two forest chronosequences on southeast Vancouver Island, British Columbia, Canada. The purposes were to investigate the effects of clear‐cutting and the transformation of old‐growth forests into secondary forests on microfungi and the succession of microfungi in relation to long‐term stand development. Green and brown parts of moss were collected from the forest floor of Douglas‐fir (Pseudotsuga menziesii) stands of four age classes: post‐harvest regeneration (13–14 years), immature (50–51 years), and mature (85–101 years) stands, and a control old‐growth (296–324 years) stand, and used for the isolation of microfungi. A total of 49 microfungal species were recorded. Study site, stand age, and moss parts significantly affected the species richness and species composition of microfungi. The species richness of microfungi was significantly greater on brown than on green moss parts and lower in post‐harvest regenerations than in forest stands of the other age classes. The species composition of major microfungal species changed gradually along the seral stages. Possible environmental and biological factors that could account for the succession of microfungi were discussed.
Synthesis and Characterization of Silicone‐Based Surfactants as Anti‐Foaming Agents
Authors: Kekevi Burcu , Berber Hale , Yıldırım Hüseyin
Published: July 2011

Silicone‐based amphiphilic surfactants were synthesized as anti‐foaming agents through a polycondensation reaction between chlorine‐terminated polysiloxane and polyethers. Poly(ethylene glycol) (PEG) and poly(propylene glycol) of different molecular weights were used. The structures of these tri‐block co‐polymers were characterized by FTIR, 1H NMR and ESI–MS analysis. Surface tension, foam height and foam destruction properties of these co‐polymers were determined. Spectroscopic analysis confirmed that bonding of polyether to polysiloxane was successful and two types of different tri‐block co‐polymers were obtained. The anti‐foaming efficiency of these co‐polymers tended to increase with an increase in the hydrophilic character of the co‐polymer chains. The synthesized tri‐block co‐polymers, which can be used as anti‐foaming agents in paper‐coating applications of poly(vinyl acetate‐co‐butyl acrylate) latexes, showed low surface tension values, fast liquid drainage and efficient foam destruction. PEG 200‐b‐PDMS‐b‐PEG 200 was determined to be the most efficient anti‐foaming agent among all co‐polymers synthesized.
Unique patterns of evolutionary conservation of imprinted genes
Authors: Paulsen Martina
Published: July 2011

During mammalian evolution, complex systems of epigenetic gene regulation have been established: Epigenetic mechanisms control tissue-specific gene expression, X chromosome inactivation in females and genomic imprinting. Studying DNA sequence conservation in imprinted genes, it becomes evident that evolution of gene function and evolution of epigenetic gene regulation are tightly connected. Furthermore, comparative studies allow the identification of DNA sequence features that distinguish imprinted genes from biallelically expressed genes. Among these features are CpG islands, tandem repeats and retrotransposed elements that are known to play major roles in epigenetic gene regulation. Currently, more and more genetic and epigenetic data sets become available. In future, such data sets will provide the basis for more complex investigations on epigenetic variation in human populations. Therein, an exciting topic will be the genetic and epigenetic variability of imprinted genes and its input on human disease.
Chronic arsenic exposure and its adverse health effects in Taiwan: A paradigm for management of a global environmental problem
Authors: Lan Cheng‐Che , Yu Hsin‐Su , Ko Ying‐Chin
Published: July 2011

It was estimated that, nearly 100 million people are at risk for drinking arsenic (As)‐contaminated drinking water. Although the WHO guideline recommends that levels of As in drinking water should not exceed 10 μm/L, it was estimated that more than 30 million people drink As‐containing water at levels more than 50 μm/L in Bangladesh and India alone. Therefore, the adverse health effects resulting from chronic As exposure pose a global threat. In Taiwan, studies focusing on the health effects resulting from chronic As exposure through contaminated drinking water have been ongoing for more than 50 years. During the past half century, it was recognized that the impact of high As exposure on human health is much more complicated than originally anticipated. Chronic As exposure resulted in infamous blackfoot disease, which is unique to As endemic areas in Taiwan, and various diseases including cancers and non‐cancers. Although the potential‐biological outcomes have been well‐documented, the pathomechanisms leading from As exposure to occurrence and development of the diseases remain largely unclear. One of the major obstacles that hindered further understanding regarding the adverse health effect resulting from chronic As exposure is documentation of cumulative As exposure from the distant past, which remains difficult as the present technologies mostly document relatively recent As exposure. Furthermore, the susceptibility to As exposure appears to differ between different ethnic groups and individuals and is modified by lifestyle factors including smoking habits and nutrition status. No consensus data has yet been reached even after comparing the study results obtained from different parts of the world focusing on associations between human As toxicity and genetic polymorphisms in terms of cellular detoxification enzymes, tumor suppressor proteins, and DNA repair pathway. With the availability of the new powerful “OMIC” technologies, it may now be possible to gain new path‐breaking insights regarding this important environmental health issue. The lessons learned from the past half‐century placed Taiwan in an experienced position to actively participate in the international collaborative projects using these novel technologies and standardized methods.
Coexisting mechanical hypersensitivity and anxiety in a rat model of spinal cord injury and the effect of pregabalin, morphine, and midazolam treatment
Authors: Baastrup Cathrine , Jensen Troels S. , Finnerup Nanna B.
Published: July 2011

Background and purpose

Spinal cord injury (SCI) has detrimental consequences that include chronic neuropathic pain, which is seen in 40-50% of patients, and symptoms of anxiety and depression, which affect 13-45% of SCI patients. The coexistence of pain, anxiety, and depression is known from other neuropathic pain conditions, but the relationship between these symptoms is not clear and has not been investigated in a preclinical model of SCI so far.

The aim of this study was to investigate anxiety-like behavior and at-level mechanical hypersensitivity following experimental spinal cord contusion (SCC) in female Sprague-Dawley rats, and the effects of analgesic and anxiolytic drugs.

Methods

Mechanical sensitivity and elevated plus maze (EPM) behavior were measured pre- and postinjury in SCC and sham animals. Pregabalin 30 mg/kg, morphine 3 mg/kg, midazolam 0.5 mg/kg, and 0.9% NaCl were evaluated in a randomly allocated, blinded balanced design.

Results

SCC animals developed persistent at-level mechanical hypersensitivity and decreased open arm activity in the EPM, which indicates an anxiety-like state. Pregabalin, a dual-acting analgesic and anxiolytic drug reduced both hypersensitivity and anxiety-like behavior, while the analgesic drug morphine only reduced hypersensitivity. The anxiolytic drug midazolam in the dose used had no effect on either parameter.

Conclusions

SCC animals developed long lasting coexisting at-level mechanical hypersensitivity and anxiety-like behavior, but there was no evidence to support a causal relationship between pain and anxiety following SCI.

Implications

The findings that at-level mechanical hypersensitivity and anxiety-like behavior develops concomitantly in the spinal cord contusion models and that both symptoms is persistent provide basis for further investigation of the mechanisms and connection behind these two clinically relevant symptoms after injury to the central nervous system.
Review of neuroimaging studies related to pain modulation
Authors: Knudsen Lone , Petersen Gitte Laue , Nørskov Kathrine Næsted , Vase Lene , Finnerup Nanna , Jensen Troels Staehelin , Svensson Peter
Published: July 2011

Background and purpose: A noxious stimulus does not necessarily cause pain. Nociceptive signals arising from a noxious stimulus are subject to modulation via endogenous inhibitory and facilitatory mechanisms as they travel from the periphery to the dorsal horn or brainstem and on to higher brain sites. Research on the neural structures underlying endogenous pain modulation has largely been restricted to animal research due to the invasiveness of such studies (e.g., spinal cord transection, brain lesioning, brain site stimulation). Neuroimaging techniques (e.g., magnetoencephalography (MEG), positron emission tomography (PET) and functional magnetic resonance imaging (fMRI)) provide non-invasive means to study neural structures in humans. The aim is to provide a narrative review of neuroimaging studies related to human pain control mechanisms.

Methods: The approach taken is to summarise specific pain modulation mechanisms within the somatosensory (diffuse noxious inhibitory controls, acupuncture, movement), affective (depression, anxiety, catastrophizing, stress) and cognitive (anticipation/placebo, attention/distraction, hypnosis)domains with emphasis on the contribution of neuroimaging studies.

Results and conclusions: Findings from imaging studies are complex reflecting activation or deactivation in numerous brain areas. Despite this, neuroimaging techniques have clarified supraspinal sites involved in a number of pain control mechanisms. The periaqueductal grey (PAG) is one area that has consistently been shown to be activated across the majority of pain mechanisms. Activity in the rostral ventromedial medulla known to relay descending modulation from the PAG, has also been observed both during acupuncture analgesia and anxiety-induced hyperalgesia. Other brain areas that appear to be involved in a number of mechanisms are the anterior cingulate cortex, prefrontal cortex, orbitofrontal cortex and nucleus accumbens, but their exact role is less clear.

Implications: Neuroimaging studies have provided essential information about the pain modulatory pathways under normal conditions, but much is still to be determined. Understanding the mechanisms of pain control is important for understanding the mechanisms that contribute to failed pain control in chronic pain. Applying fMRI outside the brain, such as in the trigeminal nucleus caudalis of the spinotrigeminal pathway and in the dorsal horn of the spinal cord, and coupling brain activity with activity at these sites may help improve our understanding of the function of brain sites and shed light on functional connectivity in the pain pathway.

© 2011 Scandinavian Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.
Fine metabolic regulation in ruminants via nutrient–gene interactions: saturated long-chain fatty acids increase expression of genes involved in lipid metabolism and immune response partly through PPAR-α activation
Authors: Bionaz Massimo , Thering Betsy J. , Loor Juan J.
Published: July 2011

Madin–Darby Bovine Kidney cells cultured with 150 μm of Wy-14 643 (WY, PPARα agonist) or twelve long-chain fatty acids (LCFA; 16 : 0, 18 : 0, cis-9–18 : 1, trans-10–18 : 1, trans-11–18 : 1, 18 : 2n-6, 18 : 3n-3, cis-9, trans-11–18 : 2, trans-10, cis-12–18 : 2, 20 : 0, 20 : 5n-3 and 22 : 6n-3) were used to uncover PPAR-α target genes and determine the effects of LCFA on expression of thirty genes with key functions in lipid metabolism and inflammation. Among fifteen known PPAR-α targets in non-ruminants, ten had greater expression with WY, suggesting that they are bovine PPAR-α targets. The expression of SPP1 and LPIN3 was increased by WY, with no evidence of a similar effect in the published literature, suggesting that both represent bovine-specific PPAR-α targets. We observed the strongest effect on the expression of PPAR-α targets with 16 : 0, 18 : 0 and 20 : 5n-3.When considering the overall effect on expression of the thirty selected genes 20 : 5n-3, 16 : 0 and 18 : 0 had the greatest effect followed by 20 : 0 and c9t11–18 : 2. Gene network analysis indicated an overall increase in lipid metabolism by WY and all LCFA with a central role of PPAR-α but also additional putative transcription factors. A greater increase in the expression of inflammatory genes was observed with 16 : 0 and 18 : 0. Among LCFA, 20 : 5n-3, 16 : 0 and 18 : 0 were the most potent PPAR-α agonists. They also affected the expression of non-PPAR-α targets, eliciting an overall increase in the expression of genes related to lipid metabolism, signalling and inflammatory response. Data appear to highlight a teleological evolutionary adaptation of PPAR in ruminants to cope with the greater availability of saturated rather than unsaturated LCFA.
Factors affecting commercial trawl fleet landings in a multispecies fishery
Authors: Labropoulou M. , Maravelias C.D. , Papaconstantinou C.
Published: July 2011

Retained catches of trawl fleet in Chalkis fishing port-market, Greece, were analysed using generalized linear models (GLMs) in an attempt to identify factors that influence the total landings of the groundfish fisheries. Main effects in the model included a factor for vessel tonnage that determined fishing power, as well as factors for month and fishing area. Covariates examined were all found to have a significant effect on the retained catches, with month and vessel capacity alone explaining 38% and 30% respectively of the total variation of the data. Significant interactions observed indicate that the fluctuations in retained catch differed by fishing area and month as well as by fishing area and vessel category. Within vessel categories, month and fishing area also had significant effects on the retained catches, with fishing area being more important than month for the smallest vessels. Results indicate that the modelling approach of retained catches from trawl fisheries is a promising method for obtaining representative abundance indices.
Reckoning with London: interpreting theBills of Mortalitybefore John Graunt
Authors: Robertson J.C.
Published: July 2011

Early modern Londoners had access to weekly reports on the numbers of deaths. These weekly ‘books of death’ that the Parish Clerks' Company compiled provided the base for a city-wide system whereby the number of deaths in every parish was reported to the Lord Mayor and the monarch. Under James and Charles royal interest led to the extension of the parishes listed in theBills of Mortalityto cover the wider metropolis while readers developed strategies for interpreting these weekly figures. In 1662 statistics derived from the annual summaries of the LondonBillsprovided the base for John Graunt's path-breaking actuarial calculations. However, despite Graunt's demonstration of the importance of supplementary data that theBillshad incorporated, a system geared to report the weekly ebb and flow of epidemics was unable to provide the statistics that statisticians wanted. Rather than blaming theBills, disappointed scholars claimed that the female parish searchers were incompetent.
The Scottish house factoring profession
Authors: Sim Duncan
Published: July 2011

The tenement is the traditional form of urban housing in Scotland and most tenements were built for rent. From the early nineteenth century onwards, private landlords in Scotland employed ‘factors’ to manage the houses on their behalf, responsible for houseletting, rent collection and the organization of repairs and maintenance. This paper examines the nature of the house factoring profession in terms of its organization and uses case studies to illustrate the way individual firms operated. The representation of the profession through factors’ associations is also examined and there is a consideration of the negative image which factors have acquired. The paper explores the changing nature of factoring as tenement flats have been sold off and factors have become agents not for individual landlords but for a multiplicity of owner-occupiers.
Correlations between Psychosocial Factors and Psychological Trauma Symptoms among Rescue Personnel
Authors: Soffer Yechiel , Wolf Jonathan Jacob , Ben-Ezra Menachem
Published: July 2011

During large-scale, sudden-onset disasters, resscue personnel experience severe stress due to the brief window of opportunity for saving lives. Following the earthquake in Haiti, rescue personnel worked in Port-au-Prince under harsh conditions in order to save lives and extricate bodies. Reactions to this disaster among rescue personnel were examined using self-report questionnaires. Correlations between psychosocial factors and psychological trauma (dissociation and post-traumatic stress disorder (PTSD) symptoms) were examined in a sample of 20 rescue personnel who worked in Haiti. The study indicated that negative affect and crisis of meaning were associated with higher levels of dissociative and PTSD symptoms. The results suggest that rescue personnel who are overwhelmed by the destruction and number of bodies being extricated may exhibit negative affect and loss of meaning along with dissociative and PTSD symptoms.
ALPprolog – A new logic programming method for dynamic domains
Authors: DRESCHER CONRAD , THIELSCHER MICHAEL
Published: July 2011

Logic programming is a powerful paradigm for programming autonomous agents in dynamic domains as witnessed by languages such as Golog and Flux. In this work we present ALPprolog, an expressive, yet efficient, logic programming language for the online control of agents that have to reason about incomplete information and sensing actions.
Observational equivalences for linear logic concurrent constraint languages
Authors: HAEMMERLÉ RÉMY
Published: July 2011

Linear logic Concurrent Constraint programming (LCC) is an extension of concurrent constraint programming (CC), where the constraint system is based on Girard's linear logic instead of the classical logic. In this paper, we address the problem of program equivalence for this programming framework. For this purpose, we present a structural operational semantics for LCC based on a label transition system and investigate different notions of observational equivalences inspired by the state of art of process algebras. Then, we demonstrate that the asynchronous π-calculus can be viewed as simple syntactical restrictions of LCC. Finally, we show that LCC observational equivalences can be transposed straightforwardly to classical Concurrent Constraint languages and Constraint Handling Rules, and investigate the resulting equivalences.
Abstract diagnosis for timed concurrent constraint programs
Authors: COMINI MARCO , TITOLO LAURA , VILLANUEVA ALICIA
Published: July 2011

The timed concurrent constraint language (tccp in short) is a concurrent logic language based on the simple but powerful concurrent constraint paradigm of Saraswat. In this paradigm, the notion of store-as-value is replaced by the notion of store-as-constraint, which introduces some differences w.r.t. other approaches to concurrency. In this paper, we provide a general framework for the debugging of tccp programs. To this end, we first present a new compact, bottom-up semantics for the language that is well suited for debugging and verification purposes in the context of reactive systems. We also provide an abstract semantics that allows us to effectively implement debugging algorithms based on abstract interpretation. Given a tccp program and a behavior specification, our debugging approach automatically detects whether the program satisfies the specification. This differs from other semi-automatic approaches to debugging and avoids the need to provide symptoms in advance. We show the efficacy of our approach by introducing two illustrative examples. We choose a specific abstract domain and show how we can detect that a program is erroneous.
Parallel backtracking with answer memoing for independent and-parallelism
Authors: DE GUZMÁN PABLO CHICO , CASAS AMADEO , CARRO MANUEL , HERMENEGILDO MANUEL V.
Published: July 2011

Goal-level Independent and-parallelism (IAP) is exploited by scheduling for simultaneous execution of two or more goals, which will not interfere with each other at run time. This can be done safely even if such goals can produce multiple answers. The most successful IAP implementations to date have used recomputation of answers and sequentially ordered backtracking. While in principle simplifying the implementation, recomputation can be very inefficient if the granularity of the parallel goals is large enough and they produce several answers, while sequentially ordered backtracking limits parallelism. And, despite the expected simplification, the implementation of the classic schemes has proved to involve complex engineering, with the consequent difficulty for system maintenance and extension, while still frequently running into the well-known trapped goal and garbage slot problems. This work presents an alternative parallel backtracking model for IAP and its implementation. The model features parallel out-of-order (i.e., nonchronological) backtracking and relies on answer memoization to reuse and combine answers. We show that this approach can bring significant performance advantages. Also, it can bring some simplification to the important engineering task involved in implementing the backtracking mechanism of previous approaches.
(Co-)Inductive semantics for Constraint Handling Rules
Authors: HAEMMERLÉ RÉMY
Published: July 2011

In this paper, we address the problem of defining a fixpoint semantics for Constraint Handling Rules (CHR) that captures the behavior of both simplification and propagation rules in a sound and complete way with respect to their declarative semantics. Firstly, we show that the logical reading of states with respect to a set of simplification rules can be characterized by a least fixpoint over the transition system generated by the abstract operational semantics of CHR. Similarly, we demonstrate that the logical reading of states with respect to a set of propagation rules can be characterized by the greatest fixpoint. Then, in order to take advantage of both types of rules without losing fixpoint characterization, we present a new operational semantics with persistent constraints.

We finally establish that this semantics can be characterized by two nested fixpoints, and we show that the resulting language is an elegant framework to program using coinductive reasoning.
A structured alternative to Prolog with simple compositional semantics
Authors: PORTO ANTÓNIO
Published: July 2011

Prolog's very useful expressive power is not captured by traditional logic programming semantics, due mainly to the cut and goal and clause order. Several alternative semantics have been put forward, exposing operational details of the computation state. We propose instead to redesign Prolog around structured alternatives to the cut and clauses, keeping the expressive power and computation model but with a compositional denotational semantics over much simpler states—just variable bindings. This considerably eases reasoning about programs, by programmers and tools such as a partial evaluator, with safe unfolding of calls through predicate definitions. Anif-then-elseacross clauses replaces most uses of the cut, but the cut's full power is achieved by anuntilconstruct. Disjunction, conjunction anduntil, along with unification, are the primitive goal types with a compositional semantics yielding sequences of variable-binding solutions. This extends to programs via the usual technique of a least fixpoint construction. A simple interpreter for Prolog in the alternative language, and a definition ofuntilin Prolog, establish the identical expressive power of the two languages. Many useful control constructs are derivable from the primitives, and the semantic framework illuminates the discussion of alternative ones. The formalisation rests on a term language with variable abstraction as in the λ-calculus. A clause is an abstraction on the call arguments, a continuation, and the local variables. It can be inclusive or exclusive, expressing a local case bound to a continuation by either a disjunction or anif-then-else. Clauses are open definitions, composed (and closed) with simple functional application β-reduction). This paves the way for a simple account of flexible module composition mechanisms.Cube, a concrete language with the exposed principles, has been implemented on top of a Prolog engine and successfully used to build large real-world applications.
Transition systems for model generators—A unifying approach
Authors: LIERLER YULIYA , TRUSZCZYNSKI MIROSLAW
Published: July 2011

A fundamental task for propositional logic is to compute models of propositional formulas. Programs developed for this task are called satisfiability solvers. We show that transition systems introduced by Nieuwenhuis, Oliveras, and Tinelli to model and analyze satisfiability solvers can be adapted for solvers developed for two other propositional formalisms: logic programming under the answer-set semantics, and the logic PC(ID). We show that in each case the task of computing models can be seen as “satisfiability modulo answer-set programming,” where the goal is to find a model of a theory that also is an answer set of a certain program. The unifying perspective we develop shows, in particular, that solvers clasp and minisat(id) are closely related despite being developed for different formalisms, one for answer-set programming and the latter for the logic PC(ID).
Actual causation in CP-logic
Authors: VENNEKENS JOOST
Published: July 2011

Given a causal model of some domain and a particular story that has taken place in this domain, the problem of actual causation is deciding which of the possible causes for some effect actually caused it. One of the most influential approaches to this problem has been developed by Halpern and Pearl (Halpern, J. and Pearl, J. 2005. Causes and explanations: A structural-model approach. Part I: Causes.British Journal for the Philosophy of Science56(4), 843–887) in the context of structural models. In this paper, I argue that this is actually not the best setting for studying this problem. As an alternative, I offer the probabilistic logic programming language of CP-logic. Unlike structural models, CP-logic incorporates the deviant/default distinction that is generally considered an important aspect of actual causation, and it has an explicitly dynamic semantics, which helps to formalize the stories that serve as input to an actual causation problem.
The magic of logical inference in probabilistic programming
Authors: GUTMANN BERND , THON INGO , KIMMIG ANGELIKA , BRUYNOOGHE MAURICE , DE RAEDT LUC
Published: July 2011

Today, there exist many different probabilistic programming languages as well as more inference mechanisms for these languages. Still, most logic programming-based languages use backward reasoning based on Selective Linear Definite resolution for inference. While these methods are typically computationally efficient, they often can neither handle infinite and/or continuous distributions nor evidence. To overcome these limitations, we introduce distributional clauses, a variation and extension of Sato's distribution semantics. We also contribute a novel approximate inference method that integrates forward reasoning with importance sampling, a well-known technique for probabilistic inference. In order to achieve efficiency, we integrate two logic programming techniques to direct forward sampling. Magic sets are used to focus on relevant parts of the program, while the integration of backward reasoning allows one to identify and avoid regions of the sample space that are inconsistent with the evidence.
On combining linear-based strategies for tabled evaluation of logic programs
Authors: AREIAS MIGUEL , ROCHA RICARDO
Published: July 2011

Tabled evaluation is a recognized and powerful technique that overcomes some limitations of traditional Prolog systems in dealing with recursion and redundant subcomputations. We can distinguish two main categories of tabling mechanisms: suspension-based tabling and linear tabling. While suspension-based mechanisms are considered to obtain better results in general, they have more memory space requirements and are more complex and harder to implement than linear tabling mechanisms. Arguably, the SLDT and Dynamic Reordering of Alternatives (DRA) strategies are the two most successful extensions to standard linear tabled evaluation. In this work, we propose a new strategy, named dynamic reordering of solutions, and we present a framework, on top of the Yap system, that supports the combination of all these three strategies. Our implementation shares the underlying execution environment and most of the data structures used to implement tabling in Yap. We thus argue that all these common features allows us to make a first and fair comparison between these different linear tabling strategies and, therefore, better understand the advantages and weaknesses of each, when used solely or combined with the others.
Efficient instance retrieval of subgoals for subsumptive tabled evaluation of logic programs
Authors: CRUZ FLÁVIO , ROCHA RICARDO
Published: July 2011

Tabled evaluation is an implementation technique that solves some problems of traditional Prolog systems in dealing with recursion and redundant computations. Most tabling engines determine if a tabled subgoal will produce or consume answers by using variant checks. A more refined method, named call subsumption, considers that a subgoal A will consume from a subgoal B if A is subsumed by (an instance of) B, thus allowing greater answer reuse. We recently developed an extension, called Retroactive Call Subsumption, that improves upon call subsumption by supporting bidirectional sharing of answers between subsumed/subsuming subgoals. In this paper, we present both an algorithm and an extension to the table space data structures to efficiently implement instance retrieval of subgoals for subsumptive tabled evaluation of logic programs. Experiments results using the YapTab tabling system show that our implementation performs quite well on some complex benchmarks and is robust enough to handle a large number of subgoals without performance degradation.
Optimal placement of valves in a water distribution network with CLP(FD)
Authors: CATTAFI MASSIMILIANO , GAVANELLI MARCO , NONATO MADDALENA , ALVISI STEFANO , FRANCHINI MARCO
Published: July 2011

This paper presents a new application of logic programming to a real-life problem in hydraulic engineering. The work is developed as a collaboration of computer scientists and hydraulic engineers, and applies Constraint Logic Programming to solve a hard combinatorial problem. This application deals with one aspect of the design of a water distribution network, i.e., the valve isolation system design. We take the formulation of the problem by Giustolisi and Savić (2008 Optimal design of isolation valve system for water distribution networks. InProceedings of the 10th Annual Water Distribution Systems Analysis Conference WDSA2008, J. Van Zyl, A. Ilemobade, and H. Jacobs, Eds.) and show how, thanks to constraint propagation, we can get better solutions than the best solution known in the literature for the Apulian distribution network. We believe that the area of the so-calledhydroinformaticscan benefit from the techniques developed in Constraint Logic Programming and possibly from other areas of logic programming, such as Answer Set Programming.
Automatic network reconstruction using ASP
Authors: DURZINSKY MARKUS , MARWAN WOLFGANG , OSTROWSKI MAX , SCHAUB TORSTEN , WAGLER ANNEGRET
Published: July 2011

Building biological models by inferring functional dependencies from experimental data is an important issue in Molecular Biology. To relieve the biologist from this traditionally manual process, various approaches have been proposed to increase the degree of automation. However, available approaches often yield a single model only, rely on specific assumptions, and/or use dedicated, heuristic algorithms that are intolerant to changing circumstances or requirements in the view of the rapid progress made in Biotechnology. Our aim is to provide a declarative solution to the problem by appeal to Answer Set Programming (ASP) overcoming these difficulties. We build upon an existing approach to Automatic Network Reconstruction proposed by part of the authors. This approach has firm mathematical foundations and is well suited for ASP due to its combinatorial flavor providing a characterization of all models explaining a set of experiments. The usage of ASP has several benefits over the existing heuristic algorithms. First, it is declarative and thus transparent for biological experts. Second, it is elaboration tolerant and thus allows for an easy exploration and incorporation of biological constraints. Third, it allows for exploring the entire space of possible models. Finally, our approach offers an excellent performance, matching existing, special-purpose systems.
Constraint-based deadlock checking of high-level specifications
Authors: HALLERSTEDE STEFAN , LEUSCHEL MICHAEL
Published: July 2011

Establishing the absence of deadlocks is important in many applications of formal methods. The use of model checking for finding deadlocks in formal models is often limited. In this paper, we propose a constraint-based approach to finding deadlocks employing the ProB constraint solver. We present the general technique, as well as various improvements that had to be performed on ProB's Prolog kernel, such as reification of membership and arithmetic constraints. This work was guided by an industrial case study, where a team from Bosch was modelling a cruise control system. Within this case study, ProB was able to quickly find counterexamples to very large deadlock-freedom constraints. In the paper, we also present other successful applications of this new technique. Experiments using SAT and SMT solvers on these constraints were thus far unsuccessful.
Complex optimization in answer set programming
Authors: GEBSER MARTIN , KAMINSKI ROLAND , SCHAUB TORSTEN
Published: July 2011

Preference handling and optimization are indispensable means for addressing nontrivial applications in Answer Set Programming (ASP). However, their implementation becomes difficult whenever they bring about a significant increase in computational complexity. As a consequence, existing ASP systems do not offer complex optimization capacities, supporting, for instance, inclusion-based minimization or Pareto efficiency. Rather, such complex criteria are typically addressed by resorting to dedicated modeling techniques, likesaturation. Unlike the ease of common ASP modeling, however, these techniques are rather involved and hardly usable by ASP laymen. We address this problem by developing a general implementation technique by means of meta-prpogramming, thus reusing existing ASP systems to capture various forms of qualitative preferences among answer sets. In this way, complex preferences and optimization capacities become readily available for ASP applications.
Introduction to the 27th International Conference on Logic Programming Special Issue
Authors: GALLAGHER JOHN , GELFOND MICHAEL
Published: July 2011

Following the initiative in 2010 taken by the Association for Logic Programming and Cambridge University Press, the full papers accepted for the International Conference on Logic Programming again appear as a special issue of Theory and Practice of Logic Programming (TPLP)—the 27th International Conference on Logic Programming Special Issue. Papers describing original, previously unpublished research and not simultaneously submitted for publication elsewhere were solicited in all areas of logic programming including but not restricted to: Theory: Semantic Foundations, Formalisms, Non- monotonic Reasoning, Knowledge Representation. Implementation: Compilation, Memory Management, Virtual Machines, Parallelism. Environments: Program Analysis, Transformation, Validation, Verification, Debugging, Profiling, Testing. Language Issues: Concurrency, Objects, Coordination, Mobility, Higher Order, Types, Modes, Assertions, Programming Techniques. Related Paradigms: Abductive Logic Programming, Inductive Logic Programming, Constraint Logic Programming, Answer-Set Programming. Applications: Databases, Data Integration and Federation, Software Engineering, Natural Language Processing, Web and Semantic Web, Agents, Artificial Intelligence, Bioinformatics.
Entwicklung und Validierung eines Fragebogens zu räumlichen Strategien
Authors: Münzer Stefan , Hölscher Christoph
Published: July 2011

Zusammenfassung. Selbstauskünfte leisten bedeutsame Beiträge zur Aufklärung interindividueller Unterschiede in der räumlichen Orientierung. Es wird über die Entwicklung und Validierung des deutschen Fragebogens Räumliche Strategien (FRS) berichtet, der Selbstauskünfte zu räumlichen Strategien für die Orientierung in realen Umgebungen erhebt. Die mehrdimensionale Faktorstruktur des Fragebogens reflektiert unterschiedliche räumliche Strategiekomponenten. In der FRS-Skala „Orientierung global/egozentrisch” werden Strategien erfasst, die auf einer egozentrischen räumlichen Perspektive basieren. Diese Strategiekomponenten sind mit einer globalen Einschätzung der eigenen Orientierungsfähigkeit assoziiert. Die FRS-Skala „Überblick” erfasst eine allozentrische Strategie zur Bildung einer mentalen Karte. Die FRS-Skala „Himmelsrichtung” erfasst die Kenntnis der Himmelsrichtungen. Die Skalen prädizieren das räumliche Lernen in einer realen Umgebung und besitzen inkrementelle Validität über relevante kognitive Prädiktoren der visuell-räumlichen Informationsverarbeitung hinaus. Eine konfirmatorische Faktorenanalyse bestätigte die Dimensionalität des Instruments.
Psychometrische Evaluation der deutschen Barratt Impulsiveness Scale – Kurzversion (BIS-15)
Authors: Meule Adrian , Vögele Claus , Kübler Andrea
Published: July 2011

Zusammenfassung. Impulsivität ist ein Persönlichkeitsmerkmal, das mit schnellen, unüberlegten Handlungen ohne Beachtung möglicher negativer Konsequenzen einhergeht. Eines der am weitesten verbreiteten Verfahren zur Erfassung von Impulsivität ist die Barratt Impulsiveness Scale (BIS-11; Patton, Stanford & Barratt, 1995 ). Es wurde gezeigt, dass die drei Faktoren nicht-planende, motorische und aufmerksamkeitsbasierte Impulsivität auch ausreichend gut mit einer verkürzten Form der BIS-11 erfasst werden können (BIS-15; Spinella, 2007 ). Die vorliegende Arbeit stellt diese Kurzversion der BIS-11 in einer deutschen Übersetzung vor. Reliabilität und Faktorstruktur des Fragebogens wurden in einer Stichprobe (N = 752) von überwiegend Studierenden getestet. Die dreifaktorielle Struktur von Spinella (2007) konnte bestätigt werden. Die interne Konsistenz war gut (Cronbachs α = .81). In einer zweiten Studie (N = 51) zeigte sich konvergente Validität durch Zusammenhänge mit einem anderen Impulsivitätsmaß (UPPS). Die BIS-15 empfiehlt sich durch ihre guten psychometrischen Kennwerte und ihre ökonomische Durchführbarkeit für die Erfassung von Impulsivität im deutschen Sprachraum.
BMZI – Berner Motiv- und Zielinventar im Freizeit- und Gesundheitssport
Authors: Lehnert Katrin , Sudeck Gorden , Conzelmann Achim
Published: July 2011

Zusammenfassung. Der Bedarf an einer multidimensionalen Erfassung von Motiven und Zielen im Freizeit- und Gesundheitssport wird von vorliegenden Testinventaren nur unzureichend befriedigt. Das BMZI schließt diese Lücke. Es ist spezifisch für Personen im mittleren und höheren Erwachsenenalter konzipiert und ermöglicht eine Individualdiagnose von Motivprofilen. Das BMZI erfasst mit 24 Items die sieben Dimensionen Kontakt, Wettkampf/Leistung, Ablenkung/Katharsis, Figur/Aussehen, Fitness/Gesundheit, Aktivierung/Freude und Ästhetik. Die psychometrische Qualität des Inventars wurde in mehreren Studien mit 1098 Erwachsenen explorativ analysiert und konfirmatorisch kreuzvalidiert. Hierbei konnte eine gute Modellanpassung festgestellt werden. Die internen Konsistenzen sowie die konvergente und diskriminante Validität können als gut bewertet werden. Die Validierung mit dem Konstrukt Selbstkonkordanz ergab erwartungsgemäße Korrelationen. Mit dem BMZI liegt ein ökonomisches, reliables und valides Instrument vor, welches sich zum Screening von multidimensionalen Motivprofilen und zur Beschreibung von Zielgruppen im Freizeit- und Gesundheitssport eignet.
Revisiting scaling laws in river basins: New considerations across hillslope and fluvial regimes
Authors: Gangodagamage Chandana , Belmont Patrick , Foufoula‐Georgiou Efi
Published: July 2011

Increasing availability of high‐resolution (1 m) topography data and enhanced computational processing power present new opportunities to study landscape organization at a detail not possible before. Here we propose the use of “directed distance from the divide” as the scale parameter (instead of Horton's stream order or upstream contributing area) for performing detailed probabilistic analysis of landscapes over a broad range of scales. This scale parameter offers several advantages for applications in hydrology, geomorphology, and ecology in that it can be directly related to length‐scale dependent processes, it can be applied seamlessly across the hillslope and fluvial regimes, and it is a continuous parameter allowing accurate statistical characterization (higher‐order statistical moments) across scales. Application of this scaling formalism to three basins in California demonstrates the emergence of three distinct geomorphic regimes of divergent, highly convergent, and moderately convergent fluvial pathways, with notable differences in their scaling relationships and in the variability, or spatial heterogeneity, of topographic attributes in each regime. We show that topographic attributes, such as slopes and curvatures, conditional on directed distance from the divide exhibit less variability than those same attributes conditional on upstream contributing area, thus affording a sharper identification of regime transitions and increased accuracy in the scaling analysis.
Deriving meteorological variables from numerical weather prediction model output: A nearest neighbor approach
Authors: Muluye Getnet Y.
Published: July 2011

This paper presents the application of variations in a nearest neighbor resampler approach for generating local‐scale meteorological variables from numerical weather prediction model output. On the basis of measure of closeness and sampling strategy, six nearest neighbor models were designed. The proposed models were applied to downscale station daily precipitation and minimum and maximum temperature fields for the Chute‐du‐Diable meteorological station in northeastern Canada. Suites of deterministic diagnostic measures were employed for evaluating individual models as well as for intercomparison among the downscaling models. On the basis of intercomparison among models a relatively better nearest neighbor resampler was identified and the subsequent model was further investigated with a focus on downscaling daily precipitation. Suites of conventional and distribution‐based diagnostic measures were employed for evaluating the skill of the downscaled precipitation over the raw numerical model output. The comparative results showed that the downscaled precipitation had greater skill values based on different performance measures which include median bias, Brier skill score, ranked probability skill score, discrimination, reliability, and relative operating characteristics.