659 research outputs found
Polyteam Semantics
Team semantics is the mathematical framework of modern logics of dependence and independence in which formulae are interpreted by sets of assignments (teams) instead of single assignments as in first-order logic. In order to deepen the fruitful interplay between team semantics and database dependency theory, we define "Polyteam Semantics" in which formulae are evaluated over a family of teams. We begin by defining a novel polyteam variant of dependence atoms and give a finite axiomatisation for the associated implication problem. We also characterise the expressive power of poly-dependence logic by properties of polyteams that are downward closed and definable in existential second-order logic (ESO). The analogous result is shown to hold for poly-independence logic and all ESO-definable properties.Peer reviewe
Parametrised Complexity of Model Checking and Satisfiability in Propositional Dependence Logic
In this paper, we initiate a systematic study of the parametrised complexity
in the field of Dependence Logics which finds its origin in the Dependence
Logic of V\"a\"an\"anen from 2007. We study a propositional variant of this
logic (PDL) and investigate a variety of parametrisations with respect to the
central decision problems. The model checking problem (MC) of PDL is
NP-complete. The subject of this research is to identify a list of
parametrisations (formula-size, treewidth, treedepth, team-size, number of
variables) under which MC becomes fixed-parameter tractable. Furthermore, we
show that the number of disjunctions or the arity of dependence atoms
(dep-arity) as a parameter both yield a paraNP-completeness result. Then, we
consider the satisfiability problem (SAT) showing a different picture: under
team-size, or dep-arity SAT is paraNP-complete whereas under all other
mentioned parameters the problem is in FPT. Finally, we introduce a variant of
the satisfiability problem, asking for teams of a given size, and show for this
problem an almost complete picture.Comment: Update includes refined result
Baltic Ecological Recycling Agriculture and Society (BERAS project) - a case of Juva milk system
The aim of the study was to determine the potential, impact and prerequisites of localization and enhanced recycling in a rural food system, illustrated by the case of Juva milk. An interdisciplinary scenario based on the increase of local, organic milk to 50 % of milk comsumption was created and the sustainability was compared, on the basis of the statistics and data collected from the actors, with the present milk system
Facets of Distribution Identities in Probabilistic Team Semantics
We study probabilistic team semantics which is a semantical framework allowing the study of logical and probabilistic dependencies simultaneously. We examine and classify the expressive power of logical formalisms arising by different probabilistic atoms such as conditional independence and different variants of marginal distribution equivalences. We also relate the framework to the first-order theory of the reals and apply our methods to the open question on the complexity of the implication problem of conditional independence.Peer reviewe
Affect in mathematics education
There are two different uses for the word “affect” in behavioral sciences. Often it is used as an overarching umbrella concept that covers attitudes, beliefs, motivation, emotions, and all other noncognitive aspects of human mind. In this article, however, the word affect is used in a more narrow sense, referring to emotional states and traits. A more technical definition of emotions, states, and traits will follow later.Peer reviewe
The Temporal Relationship between Stress and Spasticity, a Comparison between Subjects with and without Intact Thyroid Function
Purpose/Hypothesis: Stress has been studied as a credible trigger of spasticity, but evidence is limited concerning temporal relationships. Case studies of complex regional pain syndrome (CRPS) and fibromyalgia (FM) have established a ten-day delay between psychogenic stress and episodic pain flares. This is explained by a stress induced release of thyroxine (T4) from the thyroid gland via the hypothalamus-pituitary-thyroid (HPT) axis, which reaches its peak effect by day 10. Models suggest that T4 may increase peripheral nerve excitability, which could increase sensitivity in 1A fibers from muscle spindles, leading to hyper-excitability in motor neuron pools. The purpose of our study is to explore the temporal relationship between stress & spasticity, to see if subjects experience latent increases in spasticity due to stress.
Subjects: Subjects ranged from 48-84 years old, including one male with CVA history & one female with CVA history s/p thyroidectomy.
Materials/Methods: Every day for 12 weeks, participants completed stress and spasticity inventories. Stress was measured with a visual analog stress scale (VASS) and spasticity with a visual analog functional scale (VAFS) assessing the degree of difficulty to execute a standard daily task due to spasticity severity. Quantitative criteria were established defining days of peak stress and days of peak spasticity. Final temporal relationship results between stress and spasticity were analyzed with serial lag correlations for 0-12 day lags.
Results: After 12 weeks of data collection, the male manifested a significant correlation to spasticity related function ten days after criterion peak stress days. Serial lag analysis on peak stress days for this person revealed a 70% correlation supporting a 10-day impact on peak spasticity. The female subject revealed one event in spasticity-related function 10 days after peak stress event, which yields an insignificant 10-day lag correlation of 9.1%. This subject, with history of thyroidectomy, reports taking daily administration of levothyroxine. Consequently, her results are not surprising, since her HTP pathway cannot be influenced by stress.
Conclusions: Based on results, evidence supports an increase in CVA-related spasticity ten days after high stress episodes. This relationship was not observed in our female subject s/p thyroidectomy, lending inverse support to the hypothesis that latent ten-day effects may be due to the HPT axis.
Clinical Relevance: Patients and therapists frequently are at a loss to explain episodic elevations in spasticity severity. If a consistent temporal relationship between stress and spasticity is confirmed, it would give caregivers, patients, and therapists insight into understanding and predicting episodes of decreased function following high stress days
Development of EMFI-sensor based pressure sensitive insole for gait analysis
Abstract- The pressure distribution of the sole includes important information of gait during walking or running. For example, by monitoring the details ofpressure distributions in the sole in normal walking many malpositions of the foot can be easily detected. In this study a simple and versatile EMFI sensor based real-time pressure mapping system was developed for gait analysis purposes. The system consists ofa thin andflexible insole, including 16 tiny EMFI sensor elements, connected via a customized analog amplifier and digital data acquisition card to a PC computer. The PC-software of the measurement system shows the pressure in each small sensor element of the sole in real time, and records the data to a file. The accuracy and reliability of the system was preliminarily evaluated by experimental measurements. The results showed out that the system has capability to measure the pressure distributions of the foot sole reliably. The correlation coefficient between the applied pressure and the sensor output was 0,99. The next phase of the research project is to evaluate applicability of the system for evaluation ofgait with large number oftest subjects
Nanosilver-Silica Composite : Prolonged Antibacterial Effects and Bacterial Interaction Mechanisms for Wound Dressings
Infected superficial wounds were traditionally controlled by topical antibiotics until the emergence of antibiotic-resistant bacteria. Silver (Ag) is a kernel for alternative antibacterial agents to fight this resistance quandary. The present study demonstrates a method for immobilizing small-sized (similar to 5 nm) silver nanoparticles on silica matrix to form a nanosilver-silica (Ag-SiO2) composite and shows the prolonged antibacterial effects of the composite in vitro. The composite exhibited a rapid initial Ag release after 24 h and a slower leaching after 48 and 72 h and was effective against both methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli). Ultraviolet (UV)-irradiation was superior to filter-sterilization in retaining the antibacterial effects of the composite, through the higher remaining Ag concentration. A gauze, impregnated with the Ag-SiO2 composite, showed higher antibacterial effects against MRSA and E. coli than a commercial Ag-containing dressing, indicating a potential for the management and infection control of superficial wounds. Transmission and scanning transmission electron microscope analyses of the composite-treated MRSA revealed an interaction of the released silver ions with the bacterial cytoplasmic constituents, causing ultimately the loss of bacterial membranes. The present results indicate that the Ag-SiO2 composite, with prolonged antibacterial effects, is a promising candidate for wound dressing applications.Peer reviewe
Effects of tomato inoculation with the entomopathogenic fungus Metarhizium brunneum on spider mite resistance and the rhizosphere microbial community
Environmental Biolog
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