1,412 research outputs found

    Quantum advantage by relational queries about physically realizable equivalence classes

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    Relational quantum queries are sometimes capable to effectively decide between collections of mutually exclusive elementary cases without completely resolving and determining those individual instances. Thereby the set of mutually exclusive elementary cases is effectively partitioned into equivalence classes pertinent to the respective query. In the second part of the paper, we review recent progress in theoretical certifications (relative to the assumptions made) of quantum value indeterminacy as a means to build quantum oracles for randomness.Comment: 8 Pages, one figure, invited contribution to TopHPC2019, Tehran, Iran, April 22-25, 201

    Generating natural language specifications from UML class diagrams

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    Early phases of software development are known to be problematic, difficult to manage and errors occurring during these phases are expensive to correct. Many systems have been developed to aid the transition from informal Natural Language requirements to semistructured or formal specifications. Furthermore, consistency checking is seen by many software engineers as the solution to reduce the number of errors occurring during the software development life cycle and allow early verification and validation of software systems. However, this is confined to the models developed during analysis and design and fails to include the early Natural Language requirements. This excludes proper user involvement and creates a gap between the original requirements and the updated and modified models and implementations of the system. To improve this process, we propose a system that generates Natural Language specifications from UML class diagrams. We first investigate the variation of the input language used in naming the components of a class diagram based on the study of a large number of examples from the literature and then develop rules for removing ambiguities in the subset of Natural Language used within UML. We use WordNet,a linguistic ontology, to disambiguate the lexical structures of the UML string names and generate semantically sound sentences. Our system is developed in Java and is tested on an independent though academic case study

    Matrix metalloproteinase-9 activity and a downregulated Hedgehog pathway impair blood-brain barrier function in an <i>in vitro</i> model of CNS tuberculosis

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    Central nervous system tuberculosis (CNS TB) has a high mortality and morbidity associated with severe inflammation. The blood-brain barrier (BBB) protects the brain from inflammation but the mechanisms causing BBB damage in CNS TB are uncharacterized. We demonstrate that Mycobacterium tuberculosis (Mtb) causes breakdown of type IV collagen and decreases tight junction protein (TJP) expression in a co-culture model of the BBB. This increases permeability, surface expression of endothelial adhesion molecules and leukocyte transmigration. TJP breakdown was driven by Mtb-dependent secretion of matrix metalloproteinase (MMP)-9. TJP expression is regulated by Sonic hedgehog (Shh) through transcription factor Gli-1. In our model, the hedgehog pathway was downregulated by Mtb-stimulation, but Shh levels in astrocytes were unchanged. However, Scube2, a glycoprotein regulating astrocyte Shh release was decreased, inhibiting Shh delivery to brain endothelial cells. Activation of the hedgehog pathway by addition of a Smoothened agonist or by addition of exogenous Shh, or neutralizing MMP-9 activity, decreased permeability and increased TJP expression in the Mtb-stimulated BBB co-cultures. In summary, the BBB is disrupted by downregulation of the Shh pathway and breakdown of TJPs, secondary to increased MMP-9 activity which suggests that these pathways are potential novel targets for host directed therapy in CNS TB

    Dacron® vs. PTFE as bypass materials in peripheral vascular surgery – systematic review and meta-analysis

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    Roll S, Müller-Nordhorn J, Keil T, et al. Dacron® vs. PTFE as bypass materials in peripheral vascular surgery – systematic review and meta-analysis. BMC Surgery. 2008;8(1): 22.Background: In peripheral vascular bypass surgery different synthetic materials are available for bypass grafting. It is unclear which of the two commonly used materials, polytetrafluoroethylene (PTFE) or polyester (Dacron®) grafts, is to be preferred. Thus, the aim of this meta-analysis and systematic review was to compare the effectiveness of these two prosthetic bypass materials (Dacron® and PTFE). Methods: We performed a systematic literature search in MEDLINE, Cochrane-Library – CENTRAL, EMBASE and other databases for relevant publications in English and German published between 1999 and 2008. Only randomized controlled trials were considered for inclusion. We assessed the methodological quality by means of standardized checklists. Primary patency was used as the main endpoint. Random-effect meta-analysis as well as pooling data in life table format was performed to combine study results. Results: Nine randomized controlled trials (RCT) were included. Two trials showed statistically significant differences in primary patency, one favouring Dacron® and one favouring PTFE grafts, while 7 trials did not show statistically significant differences between the two materials. Meta-analysis on the comparison of PTFE vs. Dacron® grafts yielded no differences with regard to primary patency rates (hazard ratio 1.04 (95% confidence interval [0.85;1.28]), no significant heterogeneity (p = 0.32, I2 = 14%)). Similarly, there were no significant differences with regard to secondary patency rates. Conclusion: Systematic evaluation and meta-analysis of randomized controlled trials comparing Dacron® and PTFE as bypass materials for peripheral vascular surgery showed no evidence of an advantage of one synthetic material over the other

    External decontamination of wild leeches with hypochloric acid

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    BACKGROUND: Medicinal leech, Hirudo medicinalis, has been used in plastic and reconstructive surgery, to relieve venous congestion and to improve the microrevascularization of flaps. In many countries, wild leeches are still provided from local markets and utilised with antibiotic prophylaxies. In this research, results of identification of bacteria in the transport fluid is reported, oral and intestinal floras and the antibiograms of the identified microorganisms are investigated. Also, to avoid possible infections, the ability of hypochloric acid, a disinfectant, to suppress the relevant microorganisms without changing the life style and behavior of leeches in terms of sucking function, is investigated. METHODS: Bacterial identifications and antibiograms of oral and intestinal flora and transport medium were performed for 10 leeches. The optimum concentration of hypochloric acid which eliminated microorganisms without affecting the viability and sucking function of the leeches were determined by dilution of hypochloric acid to 100, 50, 25, 12.5, 6.25 ppm concentrations in different groups of 25 leeches. Finally, 20 leeches were applied atraumatically to the bleeding areas of rats, the duration of suction was determined and compared statistically between the leeches treated and not treated with hypochloric acid solution. RESULTS: Aeromonas hydrophilia was the most commonly identified microorganism and found to be resistant to first generation cephalosporins, frequently used in prophylaxis at surgical wards. In the next stages of the study, the leeches were subjected to a series of diluted hypochloric acid solutions. Although disinfection of the transport material and suppression of the oral flora of hirudo medicinalis were successful in 100, 50, 25, 12.5, 6.25 ppm concentrations; 12.5 ppm solution was the greatest concentration in which hirudo medicinalis could survive and sucking function was not affected significantly. CONCLUSIONS: External decontamination of wild leeches with 12.5 ppm hypochloric acid enables bacterial suppression without causing negative effects on leech sucking function and life

    Analysis of Dentists’ Participation in Continuing Professional Development Courses from 2001-2006

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    Currently in Western Australia (WA) there is no requirement for dentists to participate in continuing professional development (CPD). The aim of this study was to determine the participation pattern of dentists in WA in CPD activities. Data was collated regarding registrants for courses conducted by the University Continuing Dental Education Committee. Information concerned number of courses attended by each dentist, location of work and year of graduation from university. Details of subject, length and type of courses conducted were also gathered. Most courses were half to one day in duration with many subjects covered. Between 10.1-24.4% of dentists registered in WA attended at least one course each year. Low numbers of recently graduated and older dentists attended courses. Similar percentages of metropolitan and rural dentists attended courses. Participation in CPD activities of dentists in WA was low. Half day or evening courses appear to be favoured by dentists

    Heterosynaptic plasticity in the neocortex

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    Ongoing learning continuously shapes the distribution of neurons’ synaptic weights in a system with plastic synapses. Plasticity may change the weights of synapses that were active during the induction—homosynaptic changes, but also may change synapses not active during the induction—heterosynaptic changes. Here we will argue, that heterosynaptic and homosynaptic plasticity are complementary processes, and that heterosynaptic plasticity might accompany homosynaptic plasticity induced by typical pairing protocols. Synapses are not uniform in their susceptibility for plastic changes, but have predispositions to undergo potentiation or depression, or not to change. Predisposition is one of the factors determining the direction and magnitude of homo- and heterosynaptic changes. Heterosynaptic changes which take place according to predispositions for plasticity may provide a useful mechanism(s) for homeostasis of neurons’ synaptic weights and extending the lifetime of memory traces during ongoing learning in neuronal networks

    Coincident Activity of Converging Pathways Enables Simultaneous Long-Term Potentiation and Long-Term Depression in Hippocampal CA1 Network In Vivo

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    Memory is believed to depend on activity-dependent changes in the strength of synapses, e.g. long-term potentiation (LTP) and long-term depression (LTD), which can be determined by the sequence of coincident pre- and postsynaptic activity, respectively. It remains unclear, however, whether and how coincident activity of converging efferent pathways can enable LTP and LTD in the pathways simultaneously. Here, we report that, in pentobarbital-anesthetized rats, stimulation (600 pulses, 5 Hz) to Schaffer preceding to commissural pathway within a 40-ms timing window induced similar magnitudes of LTP in both pathways onto synapses of CA1 neurons, with varied LTP magnitudes after reversal of the stimulation sequence. In contrast, in urethane-anesthetized or freely-moving rats, the stimulation to Schaffer preceding to commissural pathway induced Schaffer LTP and commissural LTD simultaneously within a 40-ms timing window, without affecting synaptic efficacy in the reversed stimulation sequence. Coincident activity of Schaffer pathways confirmed the above findings under pentobarbital and urethane anesthesia. Thus, coincident activity of converging afferent pathways tends to switch the pathways to be LTP only or LTP/LTD depending on the activity states of the hippocampus. This network rule strengthens the view that activity-dependent synaptic plasticity may well contribute to memory process of the hippocampal network with flexibility or stability from one state to another
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