Reliability - Based Designof Precast Buildings

We present a numerical analysis of a precast structure regarding random properties of the material characteristics of joints, as well as the random character of loading, especially due to temperature impact. Using FEM we compare some of our results with a deterministic nonlinear solution

Colouring (Pr + Ps)-Free Graphs

The k-Colouring problem is to decide if the vertices of a graph can be coloured with at most k colours for a fixed integer k such that no two adjacent vertices are coloured alike. If each vertex u must be assigned a colour from a prescribed list L(u)⊆{1,…,k}, then we obtain the List k-Colouring problem. A graph G is H-free if G does not contain H as an induced subgraph. We continue an extensive study into the complexity of these two problems for H-free graphs. The graph Pr+Ps is the disjoint union of the r-vertex path Pr and the s-vertex path Ps. We prove that List 3-Colouring is polynomial-time solvable for (P2+P5)-free graphs and for (P3+P4)-free graphs. Combining our results with known results yields complete complexity classifications of 3-Colouring and List 3-Colouring on H-free graphs for all graphs H up to seven vertices

Spatial and temporal characteristics of gait as outcome measures in multiple sclerosis (EDSS 0 to 6.5)

Background: Gait impairment represents one of the most common and disabling symptom of multiple sclerosis. Quantification of the gait is an important aspect of clinical trials. In order to identify which temporal or spatial parameters of gait could be used as outcome measures in interventional studies of patients with different levels of disability, we evaluated characteristics of these parameters in MS patients across the whole spectrum of mobility from EDSS 0 to 6.5. Methods: This is a cross-sectional study of spatial and temporal parameters of gait at self selected speed and at fast speed of walking in 284 patients with multiple sclerosis (108 men, mean age 38 years ± SD 10.8 years, range 18–64) divided into seven levels of disability (EDSS 0 to 1.5, EDSS 2.0 to 2.5, EDSS 3.0 to 3.5, EDSS 4.0 to 4.5, EDSS 5.0 to 5.5, EDSS 6.0, EDSS 6.5). Results: The velocity of gait decreases with increasing EDSS levels. Hovewer, the spatio-temporal parameters of gait that are involved in this process differ across the EDSS levels. The step length is decreased at higher EDSS levels up to the EDSS 6.0, but was not different between EDSS 6.0 and 6.5. The step time is significantly longer at EDSS 6.0 and 6.5, while the step length remains the same at those levels. The increase in percentage of double support time becomes statistically significant at EDSS 3.0-3.5 and continues to increase until EDSS 6.5. Variability of step time, step length or step width did not show significant difference between studied EDSS levels. Conclusions: There is no single spatio-temporal parameter of gait (other than velocity of gait) that would show significant differences among all levels of EDSS. The step length reflects shortening of steps at lower EDSS levels (2.0 to 6.0), and percentage of double support time better reflects changes at higher EDSS levels 3.0 – 6.5. Gait variability is not associated with disability in MS and therefore would not be a suitable outcome measure. T

Increased incidence of traffic accidents in Toxoplasma-infected military drivers and protective effect RhD molecule revealed by a large-scale prospective cohort study

<p>Abstract</p> <p>Background</p> <p>Latent toxoplasmosis, protozoan parasitosis with prevalence rates from 20 to 60% in most populations, is known to impair reaction times in infected subjects, which results, for example, in a higher risk of traffic accidents in subjects with this life-long infection. Two recent studies have reported that RhD-positive subjects, especially RhD heterozygotes, are protected against latent toxoplasmosis-induced impairment of reaction times. In the present study we searched for increased incidence of traffic accidents and for protective effect of RhD positivity in 3890 military drivers.</p> <p>Methods</p> <p>Male draftees who attended the Central Military Hospital in Prague for regular entrance psychological examinations between 2000 and 2003 were tested for <it>Toxoplasma </it>infection and RhD phenotype at the beginning of their 1 to1.5-year compulsory military service. Subsequently, the data on <it>Toxoplasma </it>infection and RhD phenotype were matched with those on traffic accidents from military police records and the effects of RhD phenotype and <it>Toxoplasma </it>infection on probability of traffic accident was estimated with logistic regression.</p> <p>Results</p> <p>We confirmed, using for the first time a prospective cohort study design, increased risk of traffic accidents in <it>Toxoplasma</it>-infected subjects and demonstrated a strong protective effect of RhD positivity against the risk of traffic accidents posed by latent toxoplasmosis. Our results show that RhD-negative subjects with high titers of anti-<it>Toxoplasma </it>antibodies had a probability of a traffic accident of about 16.7%, i.e. a more than six times higher rate than <it>Toxoplasma</it>-free or RhD-positive subjects.</p> <p>Conclusion</p> <p>Our results showed that a common infection by <it>Toxoplasma gondii </it>could have strong impact on the probability of traffic accident in RhD negative subjects. The observed effects could provide not only a clue to the long-standing evolutionary enigma of the origin of RhD polymorphism in humans (the effect of balancing selection), but might also be the missing piece in the puzzle of the physiological function of the RhD molecule.</p

Universal mechanism of discontinuity of commensurate-incommensurate transitions in three-dimensional solids: Strain dependence of soliton self-energy

We show that there exists a universal mechanism of long-range soliton attraction in three-dimensional solids and, therefore, of discontinuity of any commensurate-incommensurate (C-IC) phase transition. This mechanism is due to the strain dependence of the soliton self-energy and specific features of the solid-state elasticity. The role of this mechanism is studied in detail for a class of C-IC transitions where the IC modulation is one-dimensional, the anisotropy in the order parameter space is small, and the symmetry of the systems allows the existence of the Lifshitz invariant. Two other mechanisms of soliton attraction are operative here but the universal mechanism considered in this paper is found to be the most important one in some cases. Comparison with the most extensively studied C-IC transition in $\rm K_2SeO_4$ shows that the experimentally observed thermal anomalies can be understood as a result of the smearing of the theoretically predicted discontinuous transition.Comment: 8 pages (extended version, title changed

Colouring (Pr+Ps)-free graphs.

The k-Colouring problem is to decide if the vertices of a graph can be coloured with at most k colours for a fixed integer k such that no two adjacent vertices are coloured alike. If each vertex u must be assigned a colour from a prescribed list L(u) subseteq {1,...,k}, then we obtain the List k-Colouring problem. A graph G is H-free if G does not contain H as an induced subgraph. We continue an extensive study into the complexity of these two problems for H-free graphs. We prove that List 3-Colouring is polynomial-time solvable for (P_2+P_5)-free graphs and for (P_3+P_4)-free graphs. Combining our results with known results yields complete complexity classifications of 3-Colouring and List 3-Colouring on H-free graphs for all graphs H up to seven vertices. We also prove that 5-Colouring is NP-complete for (P_3+P_5)-free graphs

Changes of Vital Parameters after Administration of Butorphanol during Tiletamine-Zolazepam-Ketamine-Xylazine Anaesthesia for Joint Surgery in Miniature Pigs

The study compares the effects of butorphanol in pigs undergoing joint surgery in tiletamine-zolazepam-ketamine-xylazine (TKX) anaesthesia. A total of 12 pigs were divided into 2 groups by 6 animals - BUT (anaesthetized with TKX combination and butorphanol) and CON (control group - anaesthetized with TKX combination only). All pigs were sedated with a mix of tiletamin-zolazepam-ketamin-xylazin, put into total anaesthesia using propofol, and connected to an anaesthesiology unit (O2-Air). For 40 min we logged the heart rate (HR), respiratory rate (RR), mean arterial pressure (MAP), haemoglobin saturation by oxygen (SpO2) and end-tidal CO2 concentration (ETCO2) values. Ten minutes after connecting to the devices, the pigs in the BUT group were intravenously administered butorphanol (0.2 mg/kg) in the total volume of 2 ml, or physiological saline in the same volume. The pigs in the BUT group had a lower (p th, 10th and 25th min, and a lower RR in the 10th, 15th and 20th min. MAP, ETCO2 and SpO2 values did not differ substantially. Butorphanol can thus be identified as a suitable analgesic TKX supplement to anaesthesia of miniature pigs with minimum effect on vital functions