1,944 research outputs found
Logic of agreement: Foundations, semantic system and proof theory
AbstractIn this paper a multi-valued propositional logic â logic of agreement â in terms of its model theory and inference system is presented. This formal system is the natural consequence of a new way to approach concepts as commonsense knowledge, uncertainty and approximate reasoning â the point of view of agreement. Particularly, it is discussed a possible extension of the Classical Theory of Sets based on the idea that, instead of trying to conceptualize sets as âfuzzyâ or âvagueâ entities, it is more adequate to define membership as the result of a partial agreement among a group of individual agents. Furthermore, it is shown that the concept of agreement provides a framework for the development of a formal and sound explanation for concepts (e.g. fuzzy sets) which lack formal semantics. According to the definition of agreement, an individual agent agrees or not with the fact that an object possesses a certain property. A clear distinction is then established, between an individual agent â to whom deciding whether an element belongs to a set is just a yes or no matter â and a commonsensical agent â the one who interprets the knowledge shared by a certain group of people. Finally, the logic of agreement is presented and discussed. As it is assumed the existence of several individual agents, the semantic system is based on the perspective that each individual agent defines her/his own conceptualization of reality. So the semantics of the logic of agreement can be seen as being similar to a semantics of possible worlds, one for each individual agent. The proof theory is an extension of a natural deduction system, using supported formulas and incorporating only inference rules. Moreover, the soundness and completeness of the logic of agreement are also presented
A Multiple Criteria Framework to Evaluate Bank Branch Potential Attractiveness
Remarkable progress has occurred over the years in the performance evaluation of bank branches. Even though financial measures are usually considered the most important in assessing branch viability, we posit that insufficient attention has been given to other factors that affect the branchesâ potential profitability and attractiveness. Based on the integrated used of cognitive maps and MCDA techniques, we propose a framework that adds value to the way that potential attractiveness criteria to assess bank branches are selected and to the way that the trade-offs between those criteria are obtained. This framework is the result of a process involving several directors from the five largest banks operating in Portugal, and follows a constructivist approach. Our findings suggest that the use of cognitive maps systematically identifies previously omitted criteria that may assess potential attractiveness. The use of MCDA techniques may clarify and add transparency to the way trade-offs are dealt with. Advantages and disadvantages of the proposed framework are also discussed.
Gas exchange in the salt marsh species Atriplex portulacoides L. and Limoniastrum monopetalum L. in Southern Portugal
Salt marshes are ecosystems subjected to a
variety of environmental stresses like high salinity, water
deficit, intense radiation or high temperatures. Field measurements
were conduced in two halophyte species, Atriplex
portulacoides L. and Limoniastrum monopetalum L., in the
Reserva Natural do Sapal de Castro Marim, to compare their
physiological response, i.e., water potential (w), net photosynthetic
rate (A), stomatal conductance (gs) under natural
conditions. Both species demonstrated marked variations in
w throughout the year, with very low values in the summer,
the period of higher salinity, drought and temperature. Deficit
water potential (Dw = wmidday wpredawn) was lower in
the summer than in other seasons in A. portulacoides but not
in L. monopetalum. The highest values for A and gs in
L. monopetalum were observed in autumn and for A. portulacoides
in winter, presenting both lowest values in spring
and summer. Amax was particularly high for L. monopetalum
than for A. portulacoides in summer and autumn, despite
gsmax was similar in both species. Diurnal pattern ofAand gs
were similar in both species, with higher values in the
morning, decreasing throughout the day
Utilising PRA to develop a postgraduate qualification in visual impairment studies
This article reports on the study that focused on the utilisation of a Participatory Reflection and Action (PRA) methodology in order to develop a postgraduate qualification in visual impairment studies. The broader project aims to create ways in which learners with visual impairment can be included in South African schools. In lieu of this, it has therefore come to our attention that teachers of these learners in full service schools (FSS) and special needs schools may require appropriate education and training so as to effectively work with learners with visual impairment. For our exploration, we followed a case study design and utilised PRA approach as the main data generation source in the five provinces that were involved in the study. The sample involved 255 teachers in full service and special needs schools and 50 expert stakeholders in the field of visual impairment. To most teachers, being involved in PRA-based workshops was somewhat new, thus, our study found that teachers have varying views in terms of them (teachers) being part of PRA-based workshops. Although most of them commend the process of these workshops, others feel that there could be an opportunity for improvement
GuiMarket Specification Using the Unified Modeling Language
AbstractGuiMarket is an e-Marketplace of health care, social care services developed as a pilot project in a Northern Portuguese Municipality, with the main objective of improving the well-being of elderly people and people with special needs staying at home, or their caregivers. This paper makes a brief introduction of this platform, explains its overall implementation and operation using an IDEF0 (Integration DEFinition) diagram, and presents the specification of the main services of the e-Marketplace using UML (Unified Modeling Language)
A Step Forward in Breast Cancer Research: Gold Nanoparticles as Photothermal Therapy Enhancers
Gold nanoparticles (AuNPs) have been widely used and characterized for multiple biomedical applications, including the enhancement of photothermal therapy (PTT). AuNPs present a particular plasmon resonance band and are able to convert the absorbed optical radiation into heat, which validates their use in PTT. Several production methods have already been proposed for the synthesis of AuNPs, allowing to optimize the particles' morphology, size and optical properties. However, the production methods commonly used are frequently associated with the use of toxic reagents such as Cetyltrimethylammonium bromide, which presents some concerns for clinical applications. Herein, it is proposed a novel AuNPs' core synthesis method using tetrachloroauric acid and a mixture of reducing agents, later on coated with a combination of hyaluronic and oleic acids. The coating here represents a potential improvement of AuNPs biocompatibility, biodegradability and lifetime, while simultaneously potentiating the attachment towards specific ligands, such as the CD44 receptor, to develop more localized and highly selective tools. The produced functionalized nanoparticles were characterized by Dynamic Light Scattering, Microscopy Techniques and Spectroscopy, showing diameter sizes under 350 nm, polydispersity index smaller than 0.4 and enhanced absorbance in the Near Infrared (NIR, 650 to 900 nm) range. Moreover, the AuNPs safety and efficacy were preliminarily assessed in vitro using breast cancer cell lines. No toxicity was observed by MTT assay, both in breast cancer cell lines, and red blood cells. The irradiation process was proved to be safe; however, when combined with the AuNPs administration, it resulted in a significant reduction of cell viability for some of the breast cell lines tested. Thus, the results highlight the potential of the proposed system for some type of tumors, even though further tests are required to better understand the mechanisms behind the obtained results
Development of a robust HS-SPME-GC-MS method for the analysis of solid food samples. Analysis of volatile compounds in fresh raw beef of differing lipid oxidation degrees
This work presents a headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) method for the analysis of solid food samples in extended experiments. The final procedure was used to quantify 30 volatile compounds in fresh beef. The strategy adds robustness to the classic SPME methods for solid samples, by including a control solution that solves several challenges. The control solution contained one representative compound for each studied family of beef, and two internal standards. Response factors were calculated for each family, and were subsequently applied to every compound belonging to the same family. This strategy allowed control of the quantification procedure even when the fibre, column or control solution changed. Repeatability and reproducibility had relative standard deviation values below 17%, except for phenylacetaldehyde, (E)-2-nonenal and (E, Z)-2, 4-decadienal. Although the method described here was applied to animal products, it has also been successfully used to distinguish between samples from different lipid oxidation stabilities
Psychometric evaluation of the French version of the questionnaire attitudes towards morphine use; a cross-sectional study in Valais, Switzerland.
BACKGROUND: In Switzerland, nurses are allowed to prescribe and administer morphine in emergency situations without a doctor. Still, nurses and other health professionals are often reluctant to prescribe and administer morphine for pain management in patients. No valid French-speaking instrument is available in Switzerland to assess the attitudes of nurses and other health professionals towards the prescription and administration of morphine. In this study, we evaluated the psychometric properties of the French version of the questionnaire "Attitudes towards morphine use".
METHODS: The instrument was derived from an Italian version. Forward and back translations of the questionnaire were performed. Item analysis and construct validity were assessed between April and December 2010 in a cross sectional study including five Swiss hospitals in a sample of 588 health professionals (533 nurses, mean age 38.3â±â10.2 years). Thirty subjects participated in test-retest reliability.
RESULTS: The time to complete the instrument ranged between 12 and 15 minutes and neither floor nor ceiling effect were found. The initial 24-item instrument showed an intraclass correlation (ICC) of 0.69 (95% CI: 0.64 to 0.73, Pâ<â0.001), and a Cronbach's α of 0.700. Factor analysis led to a six-component solution explaining 52.4% of the total variance. After excluding five items, the shortened version showed an ICC of 0.74 (95% CI, 0.70 to 0.77, Pâ<â0.001) and a Cronbach's α of 0.741. Factor analysis led to a five-component solution explaining 54.3% of the total variance. The five components were named "risk of addiction/dependence"; "operational reasons for not using morphine"; "risk of escalation"; "other (non-dependence) risks" and "external (non-operational) reasons". In test-retest, the shortened instrument showed an ICC of 0.797 (95% CI, 0.630 to 0.911, Pâ<â0.001) and a Cronbach's α of 0.797.
CONCLUSIONS: The 19-item shortened instrument assessing attitudes towards the prescription and administration of morphine showed adequate content and construct validity
Wild mushroom extracts potentiate the action of standard antibiotics against multi-resistant bacteria
The indiscriminate use of antibiotics and chemotherapeutic agents and the genetic ability of bacteria to transmit and acquire resistance resulted in the
development of resistant species. In the last few years, several studies have been conducted in different countries to demonstrate the efficacy of natural products, not
only studying their direct antimicrobial activity but also their capacity as resistance-modifying agents. The main objective of the present work was to evaluate the
capacity of five wild mushroom extracts to potentiate the action of standard antibiotics, through synergisms that allow a decrease in their therapeutic doses and
ultimately contribute to the reduction of resistances.The authors are grateful to Portuguese Foundation for Science and Technology (FCT) and COMPETE/QREN/EU for the financial support
through the research project PTDC/AGR-ALI/110062/2009, and to CHTMAD â Hospital Center of TrĂĄs-os-Montes e Alto Douro and
Siemens for all the supportinfo:eu-repo/semantics/publishedVersio
Some thoughts on neural network modelling of micro-abrasion-corrosion processes
There is increasing interest in the interactions of microabrasion, involving small particles of less than 10 ÎŒm in size, with corrosion. This is because such interactions occur in many environments ranging from the offshore to health care sectors. In particular, micro-abrasion-corrosion can occur in oral processing, where the abrasive components of food interacting with the acidic environment, can lead to degradation of the surface dentine of teeth. Artificial neural networks (ANNs) are computing mechanisms based on the biological brain. They are very effective in various areas such as modelling, classification and pattern recognition. They have been successfully applied in almost all areas of engineering and many practical industrial applications. Hence, in this paper an attempt has been made to model the data obtained in microabrasion-corrosion experiments on polymer/steel couple and a ceramic/lasercarb coating couple using ANN. A multilayer perceptron (MLP) neural network is applied and the results obtained from modelling the tribocorrosion processes will be compared with those obtained from a relatively new class of neural networks namely resource allocation network
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