From centralized to decentralized approach for optimal Controller of Discrete Manufacturing Systems

International audienceThis paper deals with a comparison of centralized and decentralized approaches to obtain an optimal controller for discrete manufacturing systems. It is based on a modular modeling of the plant to avoid combinatory explosion found in centralized structure and a synthesis algorithm. From the local Plant Elements, local constraints are defined to build local supervisors. Local constraints restrict the system behavior within a desired specification. Global constraints are added to establish high level supervisors. The resulting automata are translated in a normalized language for implementation in a Programmable Logic Controller

Two Cases of Study for Control Reconfiguration of Discrete Event Systems (DES)

International audienceIn this paper, we propose two cases of study for control reconfiguration of Discrete Event Systems. The main contributions are based on a safe centralized and distributed control synthesis founded on timed properties. In fact, if a sensor fault is detected, the controller of the normal behavior is reconfigured to a timed controller where the timed information replaces the information lost on the faulty sensor. Finally, we apply our contribution to a manufacturing system to illustrate our results and compare between the two frameworks

Checking diagnosability on centralized model of the system

International audienceIn this work, the problem of checking diagnosability on Discrete Event System (DES) is considered especially in centralized architecture. Many approaches in literature deals with diagnosability using one or more intermediate models. In this paper, we present a new model based diagnosability algorithms in the framework of set theory for deciding diagnosability, without any intermediate constructions or models and considering several faults at the same time

Near-equivalence of the role of structural unpinning number, basicity and reciprocal average electronegativity in determining the conductivity of glasses

The chemical approach made to investigate the origin of fast ion conduction in Agl-based fast ion conducting (FIC) glasses has been extended to various ionically conducting systems containing Na+ ion. An index known as structural unpinning number (SUN), S, has been defined for this purpose based on the unscreened nuclear charge on the cation and the average electronegativity of all the anions. Variation of the log(conductivity), at a given temperature, as a function of structural unpinning number, optical basicity, λ, and the reciprocal average electronegativity of all the anions, l/χa, has been examined for a number of Na+-ion conducting glasses and a nearly identical variation has been noticed in all the cases. The equivalence of these chemical parameters as determinants of the conductivity behavior of glasses has thus been established and the origin of this equivalence has been discussed

Avaliação de animais silvestres como portadores de patotipos de Escherichia coli patogênicas aos seres humanos

Escherichia coli fazem parte da microbiota entérica de humanos e animais saudáveis, porém algumas cepas são responsáveis por infecções intestinais. Os patotipos E. coli enteropatogênica (EPEC), E. coli shigatoxigênica (STEC) e E. coli enterohemorrágica (EHEC) são importantes agentes zoonóticos, causando infecções assintomáticas, diarreia aguda e até morte em humanos. Bovinos são considerados o principal reservatório destes patógenos, porém já foram identificados em uma variedade de animais domésticos e silvestres. Entretanto, a atuação destes últimos como disseminadores ambientais de E. coli zoonóticas ainda não foi estabelecida na literatura. Com o intuito de identificar animais silvestres como portadores destes patotipos e apontar quais foram mais frequentemente encontrados, foi realizada coleta de suabe retal ou cloacal de 110 animais silvestres, sendo 71 aves, 29 mamíferos e 10 répteis. O material foi cultivado em Ágar MacConkey Sorbitol, e os isolados de interesse foram submetidos à extração de DNA total. Os isolados foram avaliados quanto a presença de quatro genes de virulência de interesse (tir EPEC, stx1, stx2 e tir EHEC) através de PCR convencional para identificação de patotipos. Dos 110 animais coletados, 71 apresentaram crescimento de enterobactérias no cultivo em Ágar MacConkey Sorbitol e a análise de 63 animais foi concluída, configurando o grupo de estudo do presente trabalho. Dos 63 animais analisados, foi detectado pelo menos um dos genes testados em 28. A maior identificação dos genes ocorreu no grupo das aves, sendo identificados em 40,5% dos animais, o gene de virulência mais frequentemente identificado nos animais silvestres foi stx2 estando presente em 19 amostras. O patotipo STEC foi identificado em 23 amostras (36,5%), o patotipo EPEC foi identificado em oito amostras e o patotipo EHEC foi identificado apenas em duas amostras, de Corujinha-do-mato (Megascops choliba) e Graxaim-do-mato (Cerdocyon thous). Em conclusão, a identificação dos patotipos de interesse em animais silvestres foi alta, e novas pesquisas são necessárias para esclarecer o papel destes animais enquanto disseminadores ambientais e possível risco desta disseminação para a saúde humana.Escherichia coli are part of the gut microbiota of humans and animals, but some strains are responsible for intestinal infections. The enteropathogenic E. coli (EPEC), shigatoxigenic E. coli (STEC) and enterohemorrhagic E. coli (EHEC) pathotypes are important zoonotic agents, causing asymptomatic infections, acute diarrhea and even death in humans. Cattle are considered the main reservoir of these pathogens, which have already been identified in a variety of domestic and wild animals, but the role of wild animals as environmental disseminators has not yet been established. In order to identify wild animals as carriers of these pathotypes and point out which are the most frequently found, rectal or cloacal swabs were collected from 110 wild animals(71 birds, 29 mammals, and 10 reptiles) and cultured on MacConkey Sorbitol Agar. Isolates were then submitted to DNA isolation and PCR analyses for the detection of four virulence genes (tir EPEC, stx1, stx2, and tir EHEC) for pathotypic identification. Of the 110 animals collected, 71 showed growth of enterobacteria in MacConkey Sorbitol Agar culture and the analysis of 63 animals was completed, configuring the study group of the present work. Of the 63 analyzed animals, at least one of the tested genes was detected in 28. Most of the target genes were identified in bird samples, being detected in 40.5% (15/37) of the analyzed birds. Stx2 gene was the most frequently identified, being detected in 19/63 samples. The STEC pathotype was identified in 23 samples (36.5%), the EPEC pathotype was identified in eight samples and the EHEC pathotype was identified only in samples of Tropical Screech-Owl (Megascops choliba) and Crab-eating fox (Cerdocyon thous). In conclusion, the identification of pathotypes of interest in wild animals was high, and further research is needed to clarify the role of these animals as environmental disseminators and possible risk of this dissemination to human health

Mannheimia varigena como agente etiológico de claudicação e lesão na banda coronária em bovinos

Mannheimia varigena was identified as the etiologic agent of lameness and coronary band lesion in 30% of cattle in a farm located in Rio Grande do Sul, Brazil. Swab samples from the lesions were cultured in McConkey Agar and Blood Agar for microbiological identification. Culture growth was submitted to Gram staining and Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) identification. Antimicrobial susceptibility test based on disc diffusion was performed for three antibiotics: ceftiofur, gentamicin and florfenicol. Furthermore, molecular characterization of 16S rDNA gene sequencing was performed and the data was used in a phylogenetic analysis. For that purpose, total DNA was extracted by thermo extraction directly from the bacterial colonies and the polymerase chain reaction (PCR) was performed. Gram-negative Mannheimia varigena strain LBV010/22 was identified as the causative of the lesions. The strain was susceptible to all antibiotics tested. The phylogenetic analysis demonstrated that the analyzed strain is closely related to M. varigena strains from pyelonephritis and respiratory tract. Overall, this is the first report of M. varigena as the causative agent of coronary band injury in bovine. Therefore, our findings show the importance of an accurate microbiological identification of infectious agent in lameness cases in order to prevent the occurrence and perform an appropriate treatment in the future.Mannheimia varigena foi identificada como agente etiológico de claudicação e lesão de banda coronária em 30% dos bovinos de uma fazenda localizada no Rio Grande do Sul, Brasil. Amostras de swab das lesões foram cultivadas em Ágar McConkey e Ágar Sangue para identificação microbiológica. O crescimento da cultura foi submetido à coloração de Gram e identificação por Espectrometria de Massa de Ionização por Dessorção a Laser Assistida por Matriz (MALDI-TOF MS). O teste de suscetibilidade antimicrobiana baseado na difusão em disco foi realizado para três antibióticos: ceftiofur, gentamicina e florfenicol. Além disso, foi realizada a caracterização molecular do sequenciamento do gene 16S rDNA e o resultado utilizado para análise filogenética. Para tanto, o DNA total foi extraído por termoextração diretamente das colônias bacterianas e uma reação em cadeia da polimerase (PCR) foi realizada. Foi identificada como causadora das lesões a cepa gram-negativa de Mannheimia varigena_LBV010/22. Ela foi suscetível a todos os antibióticos testados. A análise filogenética demonstrou que a cepa analisada está intimamente relacionada às M. varigena presentes em pielonefrite e no trato respiratório. No geral, este é o primeiro relato de M. varigena como agente causador de lesão de banda coronária em bovinos. Portanto, nossos achados mostram a importância de uma identificação microbiológica precisa do agente infeccioso nos casos de claudicação, a fim de prevenir a ocorrência e realizar um tratamento adequado no futuro

Streptococcus spp. in Equines - Infection and Antimicrobial Susceptibility Profiles

Background: Empirical antimicrobial prescribing is commonly used in equine veterinary. Therefore, professionals can obtain information about antimicrobial susceptibility profile of the bacterial strains based on veterinary literature. Considering equine infections, Streptococcus spp. are important pathogens that can cause serious damage in horses. Therefore, the aim of this study was to describe the antimicrobial susceptibility testing (AST) and infection profiles of Streptococcus spp. strains isolated from equines with infectious diseases subjected to microbiological analysis.   Materials, Methods & Results: Veterinarians sent 13 samples and culture in Blood and MacConkey Agar were performed. After the incubation period, suspected colonies, which showed significative growth, were analyzed by Gram-staining, biochemical tests, and subjected to confirmatory identification in Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry. In vitro AST analysis were performed by disc diffusion method, in accordance with the veterinarians' request. The antimicrobials tested in this study were: ceftiofur, gentamicin, ampicillin, enrofloxacin, amikacin, penicillin, trimethoprim-sulfamethoxazole, ciprofloxacin, doxycycline, vancomycin and metronidazole. The samples included uterine exudate, hock fistula, osteosynthesis exudate, exudate from the guttural pouch, and were originated from animals located in different and distant geographical regions in the cities of Porto Alegre, Pelotas, and Bagé, Rio Grande do Sul, Brazil. Streptococcus dysgalactiae, Streptococcus equi and Streptococcus thoraltensis were the Streptococcus species identified in the samples. S. dysgalactiae was the mainly species found in the uterus samples, while S. thoraltensis, an unusual Streptococcus species, was identified as etiological agent of endometritis in 2 of the analyzed animals. On the other hand, S. equi was found in both the guttural pouch, representing the etiological agent of the strangle case, and in the osteosynthesis exudate, as infectious agent of post-osteosynthesis surgery. The majority of streptococci strains were susceptible to ceftiofur drug. Amikacin and ciprofloxacin, however, were the drugs for which the strains were mainly resistant according to the results. Discussion: The present study provided the AST and infection profile of Streptococcus species related to equine infectious diseases. S. dysgalactiae is considered an unusual bacterium isolated from horses that can be related to endometritis, S. equi is the causative agent of strangles, and S. thoraltensis is unusual in equines. Generally, the observed susceptibility to ceftiofur of the strains analyzed was in agreement with previous results reported in the literature. However, ceftiofur is a third-generation cephalosporin and is considered a critically important antibiotic for human health and its use in veterinary medicine should be cautious. Considering the resistance profile found, Streptococcus spp. can be intrinsically resistant to low drug concentrations of aminoglycosides. Moreover, the emergence and spread of fluoroquinolones resistance may also be due to the acquisition of resistance via horizontal gene transfer. Therefore, the present study described both infection and antimicrobial susceptibility patterns of Streptococcus strains related to equine infectious diseases. Considering the findings, the results found in this study might contribute to the decision-making by veterinarians to further equine treatments. Keywords: antimicrobial susceptibility, pattern, AST, drug, resistant bacteria, horses, veterinarians

Streptococcus spp. in equines : infection and antimicrobial susceptibility profiles

Background: Empirical antimicrobial prescribing is commonly used in equine veterinary. Therefore, professionals can obtain information about antimicrobial susceptibility profile of the bacterial strains based on veterinary literature. Considering equine infections, Streptococcus spp. are important pathogens that can cause serious damage in horses. Therefore, the aim of this study was to describe the antimicrobial susceptibility testing (AST) and infection profiles of Streptococcus spp. strains isolated from equines with infectious diseases subjected to microbiological analysis. Materials, Methods & Results: Veterinarians sent 13 samples and culture in Blood and MacConkey Agar were performed. After the incubation period, suspected colonies, which showed significative growth, were analyzed by Gram-staining, biochemical tests, and subjected to confirmatory identification in Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry. In vitro AST analysis were performed by disc diffusion method, in accordance with the veterinarians’ request. The antimicrobials tested in this study were: ceftiofur, gentamicin, ampicillin, enrofloxacin, amikacin, penicillin, trimethoprim-sulfamethoxazole, ciprofloxacin, doxycycline, van¬comycin and metronidazole. The samples included uterine exudate, hock fistula, osteosynthesis exudate, exudate from the guttural pouch, and were originated from animals located in different and distant geographical regions in the cities of Porto Alegre, Pelotas, and Bagé, Rio Grande do Sul, Brazil. Streptococcus dysgalactiae, Streptococ¬cus equi and Streptococcus thoraltensis were the Streptococcus species identified in the samples. S. dysgalactiae was the mainly species found in the uterus samples, while S. thoraltensis, an unusual Streptococcus species, was identified as etiological agent of endometritis in 2 of the analyzed animals. On the other hand, S. equi was found in both the guttural pouch, representing the etiological agent of the strangle case, and in the osteosynthesis exu¬date, as infectious agent of post-osteosynthesis surgery. The majority of streptococci strains were susceptible to ceftiofur drug. Amikacin and ciprofloxacin, however, were the drugs for which the strains were mainly resistant according to the results. Discussion: The present study provided the AST and infection profile of Streptococcus species related to equine infectious diseases. S. dysgalactiae is considered an unusual bacterium isolated from horses that can be related to endometritis, S. equi is the causative agent of strangles, and S. thoraltensis is unusual in equines. Generally, the observed susceptibility to ceftiofur of the strains analyzed was in agreement with previous results reported in the literature. However, ceftiofur is a third-generation cephalosporin and is considered a critically important antibiotic for human health and its use in veterinary medicine should be cautious. Considering the resistance profile found, Streptococcus spp. can be intrinsically resistant to low drug concentrations of aminoglycosides. Moreover, the emergence and spread of fluoroquinolones resistance may also be due to the acquisition of resistance via horizontal gene transfer. Therefore, the present study described both infection and antimicrobial susceptibility patterns of Streptococcus strains related to equine infectious diseases. Considering the findings, the results found in this study might contribute to the decision-making by veterinarians to further equine treatments