1,793 research outputs found

    Hierarchic Superposition Revisited

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    Many applications of automated deduction require reasoning in first-order logic modulo background theories, in particular some form of integer arithmetic. A major unsolved research challenge is to design theorem provers that are "reasonably complete" even in the presence of free function symbols ranging into a background theory sort. The hierarchic superposition calculus of Bachmair, Ganzinger, and Waldmann already supports such symbols, but, as we demonstrate, not optimally. This paper aims to rectify the situation by introducing a novel form of clause abstraction, a core component in the hierarchic superposition calculus for transforming clauses into a form needed for internal operation. We argue for the benefits of the resulting calculus and provide two new completeness results: one for the fragment where all background-sorted terms are ground and another one for a special case of linear (integer or rational) arithmetic as a background theory

    Scales for co-compact embeddings of virtually free groups

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    Let Γ\Gamma be a group which is virtually free of rank at least 2 and let Ftd(Γ)\mathcal{F}_{td}(\Gamma) be the family of totally disconnected, locally compact groups containing Γ\Gamma as a co-compact lattice. We prove that the values of the scale function with respect to groups in Ftd(Γ)\mathcal{F}_{td}(\Gamma) evaluated on the subset Γ\Gamma have only finitely many prime divisors. This can be thought of as a uniform property of the family Ftd(Γ)\mathcal{F}_{td}(\Gamma).Comment: 12 pages; key words: uniform lattice, virtually free group, totally disconnected group, scale function (Error in references corrected in version 2

    Umweltwirkung von Bio-Betrieben: Ursachen und Optimierungsmöglichkeiten

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    Agriculture has manifold impacts on the environment and plays an important role in the environmental impacts of food chains. Previous studies have shown that organic farming can reduce these environmental impacts. But also within organic farms there is a high variability in their impacts on the environment. In our case study with five organic dairy farms, the farm with the highest energy demand used over 2.5 times more energy than the farm with the lowest energy demand. This indicates that further optimisations are possible. Therefore, the farmer is an important factor. The efficient use of his own resources together with an adept combination of different branches can contribute to the ecological optimisation of his farm. But for every farm and every environmental impact, different means of productions play a crucial role. For a longterm reduction of the environmental impacts of a farm a holistic, individual and detailed analysis considering all impacts of the life cycle is essential

    Queries on medication use during pregnancy: characterisation of the Swiss Teratogen Information Service database.

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    Limited information on medication safety may result in concerns on how to treat pregnant and breast-feeding patients. The Swiss Teratogen Information Service (STIS) provides information to healthcare professionals about medications during pregnancy and breast feeding. Our objective was to describe the queries addressed to the STIS over the past two decades. The STIS maintains a database of queries on pregnancy outcomes after exposure to various substances, which may be a valuable source of information. We initially analysed the general characteristics of all queries. Thereafter, we focused on exposure to medications during singleton pregnancies and associated health-related aspects. From 2000 to 2019, 7148 queries were entered into the database. An increasing number of queries was recorded over the study period, with an average of 357 queries entered into the database per year. Most of the enquirers were physicians; more specifically, gynaecologists/obstetricians (2389/7148; 33.4%) and psychiatrists (1007/7148; 14.1%). Two thirds (4747/7148; 66.4%) of the queries addressed medication intake during pregnancy; the next most frequent queries concerned planned medication in the context of pregnancy (928/7148; 13.0%) or medication use during breast-feeding (873/7148; 12.2%). In more than 50% (3611/7148) of cases, women were treated with more than one drug; altogether, 15193 medications (taken alone or in combination) were identified. The most frequent queries concerned medicines for the nervous system (ATC group N, n = 7042), with selective serotonin reuptake inhibitors (n = 1271) in the leading position, followed by benzodiazepine derivatives (n = 1102) and other antidepressants (n = 780). The next most frequently mentioned drug classes were anti-infectives for systemic use (J, n = 1586) and drugs for the alimentary tract and metabolism (A, n = 1205). Analysis of follow-up information on cases of medication exposure during singleton pregnancies (n = 2672) revealed an offspring malformation rate of 4.2%. The organ system most often affected was the musculoskeletal system, followed by the circulatory system; congenital malformations of the nervous system and chromosomal abnormalities were also seen. The three most frequently documented congenital diagnoses were malformations of cardiac septa, the brain and major arteries. Healthcare professionals often have concerns regarding the treatment of pregnant women with medication, and require professional counselling in this area. A variety of drugs are mentioned in queries addressed to the STIS, of which psycholeptics and psychoanaleptics are the most frequent. Proper guidelines on their use during pregnancy appear particularly urgent

    In search of virus carriers of the 1988 and 2002 phocine distemper virus outbreaks in European harbour seals

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    European harbour seal (Phoca vitulina) populations decreased substantially during the phocine distemper virus (PDV) outbreaks of 1988 and 2002. Different hypotheses have stated that various seals and terrestrial carnivore species might be the source of infection. To further analyse these hypotheses, grey (Halichoerus grypus) and ringed (Phoca hispida) seals, polar bears (Ursus maritimus) and minks (Mustela lutreola) were sampled from the North Sea and East Greenland coasts between 1988 and 2004 and investigated by RT-PCR using a panmorbillivirus primer pair. However, all samples were negative for morbillivirus nucleic acid

    Neural correlates of ‘pessimistic' attitude in depression

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    Background Preparing for potentially threatening events in the future is essential for survival. Anticipating the future to be unpleasant is also a cognitive key feature of depression. We hypothesized that ‘pessimism'-related emotion processing would characterize brain activity in major depression. Method During functional magnetic resonance imaging, depressed patients and a healthy control group were cued to expect and then perceive pictures of known emotional valences - pleasant, unpleasant and neutral - and stimuli of unknown valence that could have been either pleasant or unpleasant. Brain activation associated with the ‘unknown' expectation was compared with the ‘known' expectation conditions. Results While anticipating pictures of unknown valence, activation patterns in depressed patients within the medial and dorsolateral prefrontal areas, inferior frontal gyrus, insula and medial thalamus were similar to activations associated with expecting unpleasant pictures, but not with expecting positive pictures. The activity within a majority of these areas correlated with the depression scores. Differences between healthy and depressed persons were found particularly for medial and dorsolateral prefrontal and insular activations. Conclusions Brain activation in depression during expecting events of unknown emotional valence was comparable with activation while expecting certainly negative, but not positive events. This neurobiological finding is consistent with cognitive models supposing that depressed patients develop a ‘pessimistic' attitude towards events with an unknown emotional meaning. Thereby, particularly the role of brain areas associated with the processing of cognitive and executive control and of the internal state is emphasized in contributing to major depressio

    Graded supplementation of chestnut tannins to dairy cows fed protein-rich spring pasture: effects on indicators of protein utilization

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    An on-farm experiment was conducted in order to evaluate effects of graded supplementation with chestnut tannin extract to cows in situations of excessive dietary protein supply on a low-input organic dairy farm. Respectively 10 Swiss Fleckvieh cows received twice per day 1 kg of experimental pellets containing either 0, 50 or 100 g/kg of chestnut extract (targeted at approximately 0, 5 and 10 g extract/kg of total dietary dry matter). Experimental feeding lasted for 21 days. Measurements and collection of milk, faeces and urine spot samples were performed in weeks 0 (baseline), 1 and 3. All cows were kept in one herd on pasture; fresh grass and grass hay were provided in the barn during night. Milk yield was recorded and cows wore sensor halters for recording chewing activity. In urine, total nitrogen and purine derivatives were measured; faeces were analyzed for protein, fibre and particle fractions; in milk, solid concentrations were determined. The data was analyzed with a general linear model. Cows did not show differences in general eating and rumination behaviour, but needed time to accept the tannin-containing pellets. Milk yield and composition were not affected by treatment, except for lactose content. No relevant differences between treatments were found for urinary and faecal parameters. In conclusion, although technically easy to supplement, pellets containing chestnut tannin extract were not readily accepted by the cows and effects on protein digestion and metabolism were not found. Successful on-farm application of chestnut extract in order to improve nitrogen efficiency therefore seems questionable

    Hair cortisol concentrations in bovine neonates born to healthy and ill cows

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    The goal of this study was to investigate the hair cortisol concentration (HCC) in healthy and ill cows and their newborn calves. A total of 40 cows and their 42 newborn calves were divided into two groups: group 1 consisted of 19 clinically healthy cows and their 20 newborn calves, and group 2 comprised 21 cows that had had a chronic illness in the third trimester of gestation and their 22 newborn calves. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) system was used to measure the HCC in hair samples that were collected from the cows and calves on the day the calves were born. In both groups, the mean HCCs of the calves was significantly higher than that of the cows (group 1, 31,0 vs. 0,6 pg/mg; group 2, 19,4 vs. 0,8 pg/mg; P

    Urinary pyridinoline cross-links as biomarkers of osteogenesis imperfecta.

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    Osteogenesis imperfecta (OI) is a group of genetic heterogeneous connective tissue disorders characterized by increased bone fragility and susceptibility to fractures. Laboratory diagnosis relies on time-consuming and cost-intensive biochemical and molecular genetics analyses. Therefore, it is desirable to identify and establish new diagnostic markers for OI that are reliable, cost-effective and easily accessible. In our study we have identified the ratio of the urinary pyridinoline cross-links lysyl-pyridinoline and hydroxylysyl-pyridinoline as a promising, time- and cost-effective biomarker for osteogenesis imperfecta, that could be used furthermore to investigate cases of suspected non-accidental injury in infants
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