583 research outputs found

    The complexity of linear-time temporal logic over the class of ordinals

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    We consider the temporal logic with since and until modalities. This temporal logic is expressively equivalent over the class of ordinals to first-order logic by Kamp's theorem. We show that it has a PSPACE-complete satisfiability problem over the class of ordinals. Among the consequences of our proof, we show that given the code of some countable ordinal alpha and a formula, we can decide in PSPACE whether the formula has a model over alpha. In order to show these results, we introduce a class of simple ordinal automata, as expressive as B\"uchi ordinal automata. The PSPACE upper bound for the satisfiability problem of the temporal logic is obtained through a reduction to the nonemptiness problem for the simple ordinal automata.Comment: Accepted for publication in LMC

    Diversity of Listeria monocytogenes strains of clinical and food chain origins in Belgium between 1985 and 2014

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    Listeriosis is a rare but severe disease, mainly caused by Listeria monocytogenes. This study shows the results of the laboratory-based surveillance of Listeriosis in Belgium over the period 1985-2014. Besides the incidence and some demographic data we present also more detailed microbiological and molecular characteristics of human strains isolated since 2000. The strains from the latter period were compared to food and animal strains from the same period. Our study shows that different food matrices were commonly contaminated with L. monocytogenes presenting the same PFGE profile as in patient's isolates. Since 1985, we observed a significant decrease in incidence of the Materno-Neonatal cases (from 0.15 to 0.04 cases /100,000 inhabitants-year), which is probably to be attributed to active prevention campaigns targeting pregnant women. Despite the strengthening of different control measures by the food industry, the incidence of non-Materno-Neonatal listeriosis increased in Belgium (from 0.3 to 0.7 cases /100,000 inhabitants-year), probably due to the rise of highly susceptible patients in an aging population. This significant increase found in non-Materno-Neonatal cases (slope coefficient 7.42%/year, P< 0.0001) can be attributed to significant increase in incidence of isolates belonging to serovars 1/2a (n = 393, slope coefficient 6.62%/year, P< 0.0001). Although resistance to antimicrobials is rare among L. monocytogenes isolates, a trend to increasing MIC values is evident with chloramphenicol, amoxicillin, tetracycline and ciprofloxacin. We show that fluoroquinolone resistance is not linked to chromosomal mutations, but caused by a variety of efflux pumps. Our study also shows that huge majority of known underlying pathologies (426 out of 785 cases) were cancers (185/426, 43.1%) and haematological malignancies (75/185, 40.5%). Moreover the risk population is susceptible to low levels of contamination in food stressing the need of prevention campaigns specifically targeting these persons

    A Survey of Languages for Specifying Dynamics: A Knowledge Engineering Perspective

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    A number of formal specification languages for knowledge-based systems has been developed. Characteristics for knowledge-based systems are a complex knowledge base and an inference engine which uses this knowledge to solve a given problem. Specification languages for knowledge-based systems have to cover both aspects. They have to provide the means to specify a complex and large amount of knowledge and they have to provide the means to specify the dynamic reasoning behavior of a knowledge-based system. We focus on the second aspect. For this purpose, we survey existing approaches for specifying dynamic behavior in related areas of research. In fact, we have taken approaches for the specification of information systems (Language for Conceptual Modeling and TROLL), approaches for the specification of database updates and logic programming (Transaction Logic and Dynamic Database Logic) and the generic specification framework of abstract state machine

    The Nordic Maintenance Care Program – An interview study on the use of maintenance care in a selected group of Danish chiropractors

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    <p>Abstract</p> <p>Background</p> <p>Although maintenance care appears to be relatively commonly used among chiropractors, the indications for its use are incompletely understood. A questionnaire survey was recently carried out among Swedish chiropractors in order to identify their choice of various management strategies, including maintenance care. That study revealed a common pattern of choice of strategies. However, it would be necessary to verify these findings in another study population and to obtain some additional information best collected through an interview.</p> <p>Objectives</p> <p>The main aim of the present study was to attempt to reproduce the findings in the Swedish study and to obtain more information on the use of maintenance care.</p> <p>Method</p> <p>A group of 11 chiropractors were selected because they used maintenance care. They were interviewed using the questionnaire from the previous Swedish survey. The questionnaire consisted of a simple description of a hypothetical patient with low back pain and nine possible ways in which the case could develop ("scenarios"). They could choose between six different management strategies for each scenario. In addition, the chiropractors were encouraged to provide their own definition of maintenance care in an open-ended question. Interviews were taped, transcribed and analyzed. For the open-ended question, statements were identified relating to six pre hoc defined topics on the inclusion criteria/rationale for maintenance care, the frequency of treatments, and the duration of the maintenance care program.</p> <p>Results</p> <p>The open-ended question revealed that in patients with low back pain, maintenance care appears to be offered to prevent new events. The rationale was to obtain optimal spinal function. There appears to be no common convention on the frequency of treatments and duration of the treatment program was not mentioned by any of the interviewees.</p> <p>Conclusion</p> <p>The results from the questionnaire in the Danish survey showed that the response pattern for the nine scenarios was similar to that obtained in the Swedish survey. There seems to be relative agreement between chiropractors working in different countries and sampled through different methods in relation to their choice of management strategies in patients with low back pain. However, more precise information is needed on the indications for maintenance care and its treatment program, before proceeding to studying its clinical validity.</p

    The Nordic back pain subpopulation program: predicting outcome among chiropractic patients in Finland

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    <p>Abstract</p> <p>Background</p> <p>In a previous Swedish study it was shown that it is possible to predict which chiropractic patients with persistent LBP will not report definite improvement early in the course of treatment, namely those with LBP for altogether at least 30 days in the past year, who had leg pain, and who did not report definite general improvement by the second treatment. The objectives of this study were to investigate if the predictive value of this set of variables could be reproduced among chiropractic patients in Finland, and if the model could be improved by adding some new potential predictor variables.</p> <p>Methods</p> <p>The study was a multi-centre prospective outcome study with internal control groups, carried out in private chiropractic practices in Finland. Chiropractors collected data at the 1st, 2<sup>nd </sup>and 4<sup>th </sup>visits using standardized questionnaires on new patients with LBP and/or radiating leg pain. Status at base-line was identified in relation to pain and disability, at the 2<sup>nd </sup>visit in relation to disability, and "definitely better" at the 4<sup>th </sup>visit in relation to a global assessment. The Swedish questionnaire was used including three new questions on general health, pain in other parts of the spine, and body mass index.</p> <p>Results</p> <p>The Swedish model was reproduced in this study sample. An alternative model including leg pain (yes/no), improvement at 2<sup>nd </sup>visit (yes/no) and BMI (underweight/normal/overweight or obese) was also identified with similar predictive values. Common throughout the testing of various models was that improvement at the 2<sup>nd </sup>visit had an odds ratio of approximately 5. Additional analyses revealed a dose-response in that 84% of those patients who fulfilled none of these (bad) criteria were classified as "definitely better" at the 4<sup>th </sup>visit, vs. 75%, 60% and 34% of those who fulfilled 1, 2 or all 3 of the criteria, respectively.</p> <p>Conclusion</p> <p>When treating patients with LBP, at the first visits, the treatment strategy should be different for overweight/obese patients with leg pain as it should be for all patients who fail to improve by the 2<sup>nd </sup>visit. The number of predictors is also important.</p

    Prevalence and tracking of back pain from childhood to adolescence

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    <p>Abstract</p> <p>Background</p> <p>It is generally acknowledged that back pain (BP) is a common condition already in childhood. However, the development until early adulthood is not well understood and, in particular, not the individual tracking pattern. The objectives of this paper are to show the prevalence estimates of BP, low back pain (LBP), mid back pain (MBP), neck pain (NP), and care-seeking because of BP at three different ages (9, 13 and15 years) and how the BP reporting tracks over these age groups over three consecutive surveys.</p> <p>Methods</p> <p>A longitudinal cohort study was carried out from the years of 1997 till 2005, collecting interview data from children who were sampled to be representative of Danish schoolchildren. BP was defined overall and specifically in the three spinal regions as having reported pain within the past month. The prevalence estimates and the various patterns of BP reporting over time are presented as percentages.</p> <p>Results</p> <p>Of the 771 children sampled, 62%, 57%, and 58% participated in the three back surveys and 34% participated in all three. The prevalence estimates for children at the ages of 9, 13, and 15, respectively, were for BP 33%, 28%, and 48%; for LBP 4%, 22%, and 36%; for MBP 20%, 13%, and 35%; and for NP 10%, 7%, and 15%. Seeking care for BP increased from 6% and 8% at the two youngest ages to 34% at the oldest. Only 7% of the children who participated in all three surveys reported BP each time and 30% of these always reported no pain. The patterns of development differed for the three spinal regions and between genders. Status at the previous survey predicted status at the next survey, so that those who had pain before were more likely to report pain again and vice versa. This was most pronounced for care-seeking.</p> <p>Conclusion</p> <p>It was confirmed that BP starts early in life, but the patterns of onset and development over time vary for different parts of the spine and between genders. Because of these differences, it is recommended to report on BP in youngsters separately for the three spinal regions, and to differentiate in the analyses between the genders and age groups. Although only a small minority reported BP at two or all three surveys, tracking of BP (particularly NP) and care seeking was noted from one survey to the other. On the positive side, individuals without BP at a previous survey were likely to remain pain free at the subsequent survey.</p

    The Nordic Subpopulation Research Programme: prediction of treatment outcome in patients with low back pain treated by chiropractors - does the psychological profile matter?

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    <p>Abstract</p> <p>Background</p> <p>It is clinically important to be able to select patients suitable for treatment and to be able to predict with some certainty the outcome for patients treated for low back pain (LBP). It is not known to what degree outcome among chiropractic patients is affected by psychological factors.</p> <p>Objectives</p> <p>To investigate if some demographic, psychological, and clinical variables can predict outcome with chiropractic care in patients with LBP.</p> <p>Methods</p> <p>A prospective multi-center practice-based study was carried out, in which demographic, clinical and psychological information was collected at base-line. Outcome was established at the 4<sup>th </sup>visit and after three months. The predictive value was studied for all base-line variables, individually and in a multivariable analysis.</p> <p>Results</p> <p>In all, 55 of 99 invited chiropractors collected information on 731 patients. At the 4<sup>th </sup>visit data were available on 626 patients and on 464 patients after 3 months. Fee subsidization (OR 3.2; 95% CI 1.9-5.5), total duration of pain in the past year (OR 1.5; 95% CI 1.0-2.2), and general health (OR 1.2; 95% CI 1.1-1.4) remained in the final model as predictors of treatment outcome at the 4<sup>th </sup>visit. The sensitivity was low (12%), whereas the specificity was high (97%). At the three months follow-up, duration of pain in the past year (OR 2.1; 95% CI 1.4-3.1), and pain in other parts of the spine in the past year (OR1.6; 1.1-2.5) were independently associated with outcome. However, both the sensitivity and specificity were relatively low (60% and 50%). The addition of the psychological variables did not improve the models and none of the psychological variables remained significant in the final analyses. There was a positive gradient in relation to the number of positive predictor variables and outcome, both at the 4<sup>th </sup>visit and after 3 months.</p> <p>Conclusion</p> <p>Psychological factors were not found to be relevant in the prediction of treatment outcome in Swedish chiropractic patients with LBP.</p

    The journal 'chiropractic & osteopathy' changes its title to 'chiropractic & manual therapies'. a new name, a new era

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    Chiropractic & Osteopathy changes its title to Chiropractic & Manual Therapies in January 2011. This change reflects the expanding base of submissions from clinical scientists interested in the discipline of manual therapy. It is also in accord with the findings of a review of the journal content and a joint venture between the original parent organisation the Chiropractic and Osteopathic College of Australasia and a new partner the European Academy of Chiropractic, which is a subsidiary body of the European Chiropractors' Union. The title change should encourage submissions from all professionals interested in manual therapy including chiropractors, osteopaths, physiotherapists, medical doctors and scientists interested in this field
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