1,226 research outputs found

    Variable abstraction and approximations in supervisory control synthesis

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    This paper proposes a method to simplify Extended Finite-state Automata (EFA) in such a way the least restrictive controllable supervisor is preserved. The method is based on variable abstraction, which involves the identification and removal of irrelevant variables from a model. Variable abstraction preserves controllability, and the paper shows how approximations can be used to ascertain least restrictiveness of the synthesis result. The approach has the modelling benefits of Extended Finite-state Automata, leads to optimal control solutions, and reduces the synthesis cost. An example of a manufacturing system illustrates the contributions

    Generalised verification of the observer property in discrete event systems

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    The observer property is an important condition to be satisfied by abstractions of Discrete Event Systems (DES) models. This paper presents a generalised version of a previous algorithm which tests if an abstraction of a DES obtained through natural projection has the observer property. The procedure called OP-verifier II overcomes the limitations of the previously proposed verifier while keeping its computational complexity. Results are illustrated by a case study of a transfer line system

    Generalised verification of the observer property in discrete event systems

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    The observer property is an important condition to be satisfied by abstractions of Discrete Event Systems (DES) models. This paper presents a generalised version of a previous algorithm which tests if an abstraction of a DES obtained through natural projection has the observer property. The procedure called OP-verifier II overcomes the limitations of the previously proposed verifier while keeping its computational complexity. Results are illustrated by a case study of a transfer line system

    Effect of saccharin on antibacterial activity of chlorhexidine gel

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    Although chlorhexidine is the most effective agent against dental plaque it is extremely bitter. To prepare formulations, it is necessary to use flavoring and sweetening, which can inhibit the antibacterial effect of chlorhexidine. Saccharin has been considered a compatible substance to use in chlorhexidine rinse or gel preparations; however, the effect of a range of concentrations has not been studied. To evaluate the effect of different concentrations of saccharin on the antibacterial activity of chlorhexidine gel, hydroxy-ethyl-cellulose gels containing 1.0% chlorhexidine digluconate and 0.0 to 1.0% sodium saccharin were prepared. Activity against Streptococcus mutans was evaluated using the agar diffusion method and determination of MIC values. The inhibitory zones of growth were 7.83 +/- 0.54 mm when no saccharin was added to the chlorhexidine gel and 7.75 +/- 0.50, 7.63 +/- 0.48, 6.21 +/- 0.40, 4.13 +/- 0.38, when the concentrations of saccharin in the gels were 0.02, 0.10, 0.5, and 1.0%, respectively. The range of MIC values was 1-2 micrograms/ml, with saccharin concentrations of 0%, 0.02, and 0.1%. In contrast, the MIC values were 4-8 and 8-16 micrograms/ml with saccharin concentrations of 0.5% and 1.0%, respectively. The paired "t" test showed that 0.5 and 1.0% sodium saccharin inhibit the antibacterial activity of 1% digluconate chlorhexidine gel. These in vitro results suggest that saccharin may inhibit the efficacy of chlorhexidine against mutans streptococci, depending on the concentration.Although chlorhexidine is the most effective agent against dental plaque it is extremely bitter. To prepare formulations, it is necessary to use flavoring and sweetening, which can inhibit the antibacterial effect of chlorhexidine. Saccharin has been considered a compatible substance to use in chlorhexidine rinse or gel preparations; however, the effect of a range of concentrations has not been studied. To evaluate the effect of different concentrations of saccharin on the antibacterial activity of chlorhexidine gel, hydroxy-ethyl-cellulose gels containing 1.0% chlorhexidine digluconate and 0.0 to 1.0% sodium saccharin were prepared. Activity against Streptococcus mutans was evaluated using the agar diffusion method and determination of MIC values. The inhibitory zones of growth were 7.83 +/- 0.54 mm when no saccharin was added to the chlorhexidine gel and 7.75 +/- 0.50, 7.63 +/- 0.48, 6.21 +/- 0.40, 4.13 +/- 0.38, when the concentrations of saccharin in the gels were 0.02, 0.10, 0.5, and 1.0%, respectively. The range of MIC values was 1-2 micrograms/ml, with saccharin concentrations of 0%, 0.02, and 0.1%. In contrast, the MIC values were 4-8 and 8-16 micrograms/ml with saccharin concentrations of 0.5% and 1.0%, respectively. The paired "t" test showed that 0.5 and 1.0% sodium saccharin inhibit the antibacterial activity of 1% digluconate chlorhexidine gel. These in vitro results suggest that saccharin may inhibit the efficacy of chlorhexidine against mutans streptococci, depending on the concentration1112934Embora clorexidina seja reconhecida como o agente antimicrobiano mais eficiente contra placa dental, seu gosto extremamente amargo é uma limitação nos preparos farmacêuticos. Substâncias adoçantes e flavorizantes usadas para preparar formulações podem inibir a atividade antibacteriana da clorexidina. Sacarina tem sido considerada uma substância compatível para ser usada em enxaguatórios bucais ou géis, entretanto o efeito da concentração deste adoçante não tem sido estudado. A atividade antibacteriana de géis de clorexidina a 1%, contendo sacarina de 0,0 a 1,0%, foi avaliada a partir de preparações farmacêuticas formuladas. Atividade contra Streptococcus mutans foi avaliada através da inibição do crescimento em ágar e determinação da concentração inibitória mínima (CIM). Os halos de inibição de crescimento foram de 7,83 ± 0,54 mm, na ausência de sacarina, e de 7,75 ± 0,50, 7,63 ± 0,48, 6,21 ± 0,40 e 4,13 ± 0,38 quando da presença de sacarina a 0,02, 0,10, 0,5 e 1%, respectivamente, nos géis de clorexidina a 1%. A faixa de CIM foi de 1-2 µg/ml quando da presença de 0,0, 0,02 e 0,1% de sacarina nos géis. Quando o gel de clorexidina a 1% continha sacarina a 0,5 e 1% a CIM foi de 4-8 e 8-16 µg/ml, respectivamente. Teste "t" pareado mostrou que sacarina sódica nas concentrações de 0,5 e 1% inibiu a atividade anti mutans de digluconato de clorexidina a 1% em gel. Estes resultados in vitro sugerem que sacarina pode inibir a eficácia de clorexidina contra streptococcus do grupo mutans, dependendo da concentração usad

    Verification of the observer property in discrete event systems

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    The observer property is an important condition to be satisfied by abstractions of Discrete Event System (DES) models. This technical note presents a new algorithm that tests if an abstraction of a DES obtained through natural projection has the observer property. The procedure, called OP-Verifier, can be applied to (potentially nondeterministic) automata, with no restriction on the existence of cycles of 'non-relevant' events. This procedure has quadratic complexity in the number of states. The performance of the algorithm is illustrated by a set of experiments

    Antidepressant-induced hyponatremia

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    The Influence of Human-Milk Substitutes Marketing on Breastfeeding Intention and Practice among Native and Immigrant Brazilians

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    Background: The International Code of Marketing of Breast-Milk Substitutes is a global public health policy aiming to protect breastfeeding from the influence of human-milk substitutes marketing. Brazil is one of the few countries substantially implementing it. Most countries adopted selected provisions, including Portugal. Research Aim: To explore whether Brazilians’ perspectives about breastfeeding intention and practice are influenced by human-milk substitutes marketing upon migration to Portugal. Methods: A qualitative, prospective, cross-sectional survey design was conducted in Brazil and Portugal (2018–2019). Qualitative semi-structured interviews were performed with native (n = 16) and immigrant (n = 15) Brazilians. Women aged 18 or above, mothers of 0–12 month infants, and without contraindications to breastfeed, were eligible for the study. Heterogeneity sampling was employed based on socioeconomic status and infants’ age. Content analysis was conducted using NVivo. Results: Brazilian immigrants were more aware of the potential negative influence of human-milk substitutes marketing than natives. Sociocultural factors contributed to Brazilian immigrants being less permeable to the influence of human-milk substitutes marketing in the host country, where a less protective breastfeeding environment was perceived. Conclusions: Sociocultural factors including breastfeeding promotion strategies and a strong breastfeeding culture in the home country appear to play a protective role on breastfeeding intention and practice among Brazilians migrating to Portugal. © The Author(s) 2022.The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study is funded by FEDER funds through the Operational Programme for Competitiveness and Internationalization, and by national funding through the Foundation for Science and Technology (FCT; Portuguese Ministry of Science, Technology and Higher Education), under the scope of the project ‘‘Perinatal Health in Migrants: Barriers, Incentives and Outcomes’’ (POCI-01-0145-FEDER-016874; PTDC/DTPSAP/6384/2014), the projects UIDB/04750/2020 e LA/P/0064/2020, the PhD grant PD/BD/128082/2016 (C. L.) co-funded by the FCT and Human Potential Operating Program of the European Social Fund (POPH/FSE Program) and the contract DL57/2016/CP1336/CT0001 (C.F.). A. M. has a research scholarship from the Brazilian National Council for Scientific and Technological Development (CNPq)

    The infectivity of SfMNPV on fall armyworm is influenced by the host plant.

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    This work evaluated the infectivity and production of occlusion bodies (OBs) of the SfMNPV-6NR on fall armyworm (FAW), Spodoptera frugiperda, when fed on different host plants. The experiment was performed in laboratory, in a completely randomized design using two concentrations of SfMNPV-6NR (2×106 and 2×107 OBs/mL) and six different host plants (soybean, corn, cotton, bean, sorghum and millet). The larval mortality, larval weight (LW), pupal weight (PW) of S. frugiperda and the production of OBs by virus were evaluated. S. frugiperda larvae were less susceptible to baculovirus when fed on cotton leaves (38 ± 4.17 and 70 ± 6.44% mortality) in the two concentrations tested (2×106 and 2×107 OBs/mL, respectively). The LW was affected by the virus concentration depending on the plant species consumed and the virus concentrations. The PW was affected by the plant species used to feed larvae. There was no effect of the host plant on the OBs virus production. The results demonstrate adverse effects of the host plant on the infectivity of the SfMNPV-6NR in S. frugiperda, especially a deleterious effect of the cotton plant in the virus infection capacity

    O uso da laserterapia em dose específica modula o processo inflamatório pulmonar em um modelo experimental de sepse em ratos

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    This study aimed to determine the effectiveness of LLLT in decreasing the lung inflammatory process in septic rats. A total of 32 male Wistar rats were divided into four groups (n=8): control group (CG), sepsis 24h (S24), sepsis and LLLT with 30 J/cm² (S24L30); sepsis and LLLT with 65 J/cm² (S24L65). The irradiation was performed immediately after surgery in the anterior region of the trachea and ventral regions of the chest, bilaterally, just below the ribs. Histological analysis of lung tissue was performed and the number of inflammatory cells was quantified. The S24 group showed an increase of inflammatory cells compared to the CG (pEl objetivo del estudio es determinar la eficacia de la LLLT en la disminución del proceso inflamatorio pulmonar en ratones sépticos. Se utilizaron 32 ratones machos Wistar divididos en cuatro grupos (n=8): control (CG); sepsis 24h (S24); sepsis y tratamiento con LLLT 30 J/cm2 (S24L30); sepsis y tratamiento con LLLT 65 J/cm2 (S24L65). Se realizó la irradiación inmediatamente después de la cirugía en la región anterior de la tráquea y en las regiones ventrales del tórax, bilateralmente, debajo de las costillas. Se realizó un análisis histológico del tejido pulmonar y se cuantificó el número de células inflamatorias. El grupo S24 presentó un aumento de células inflamatorias en comparación al CG (pO objetivo do estudo foi determinar a eficácia da LLLT na diminuição do processo inflamatório pulmonar em ratos sépticos. Foram utilizados 32 ratos machos Wistar divididos em quatro grupos (n=8): controle (CG); sepse 24h (S24); sepse e tratamento com LLLT 30 J/cm² (S24L30); sepse e tratamento com LLLT 65 J/cm² (S24L65). A irradiação foi realizada imediatamente após a cirurgia na região anterior de traqueia e nas regiões ventrais do tórax, bilateralmente, logo abaixo das costelas. Foi realizada análise histológica do tecido pulmonar e o número de células inflamatórias foi quantificado. O grupo S24 apresentou um aumento de células inflamatórias comparado ao CG (
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