Observability and Synchronization of Neuron Models

Observability is the property that enables to distinguish two different locations in $n$-dimensional state space from a reduced number of measured variables, usually just one. In high-dimensional systems it is therefore important to make sure that the variable recorded to perform the analysis conveys good observability of the system dynamics. In the case of networks composed of neuron models, the observability of the network depends nontrivially on the observability of the node dynamics and on the topology of the network. The aim of this paper is twofold. First, a study of observability is conducted using four well-known neuron models by computing three different observability coefficients. This not only clarifies observability properties of the models but also shows the limitations of applicability of each type of coefficients in the context of such models. Second, a multivariate singular spectrum analysis (M-SSA) is performed to detect phase synchronization in networks composed by neuron models. This tool, to the best of the authors' knowledge has not been used in the context of networks of neuron models. It is shown that it is possible to detect phase synchronization i)~without having to measure all the state variables, but only one from each node, and ii)~without having to estimate the phase

The Universal Cardinal Ordering of Fixed Points

We present the theorem which determines, by a permutation, the cardinal ordering of fixed points for any orbit of a period doubling cascade. The inverse permutation generates the orbit and the symbolic sequence of the orbit is obtained as a corollary. The problem present in the symbolic sequences is solved. There, repeated symbols appear, for example, the R (right), which cannot be distinguished among them as it is not known which R is the rightmost of them all. Therefore, there is a lack of information about the dynamical system. Interestingly enough, it is important to point that this theorem needs no previous information about any other orbit.Comment: 19 pages, 4 figure

A semantic web approach for built heritage representation

In a built heritage process, meant as a structured system of activities aimed at the investigation, preservation, and management of architectural heritage, any task accomplished by the several actors involved in it is deeply influenced by the way the knowledge is represented and shared. In the current heritage practice, knowledge representation and management have shown several limitations due to the difficulty of dealing with large amount of extremely heterogeneous data. On this basis, this research aims at extending semantic web approaches and technologies to architectural heritage knowledge management in order to provide an integrated and multidisciplinary representation of the artifact and of the knowledge necessary to support any decision or any intervention and management activity. To this purpose, an ontology-based system, representing the knowledge related to the artifact and its contexts, has been developed through the formalization of domain-specific entities and relationships between them

Detection of hepatitis e virus (HEV) antibiodies in swine herds in Québec, Canada

Hepatitis E virus (HEV) has a zoonotic potential and pork products have been identified as possible human infection sources. Swine HEV infection in pigs have now been reported in pigs in many countries and generally occurs at about 2-3 months of age. Data from USA indicated that about 80-100% of pigs in commercial farms are infected. The objective of this study was to estimate prevalence of HEV in selected Canadian herds by serology using the PrioCHECK HEV Ab porcine-ELISA kit

Effect of mash feed on swine intestinal microflora and non-specific immune response.

Pelleting of feed was recommended in the past to reduce the risk of introduction of Salmonella in swine herds. However it was shown more recently that consumption of pelleted feed was associated with an increased probability of seropositivity Furthermore, several studies showed that the prevalence of Salmonella is decreased when mash feed is used. The objective of this study was to evaluate the effect of mash feed as a pre-harvest intervention strategy to prevent Salmonella colonization, to mod1fy of intestinal microflora and to stimulate of the immune system in swine

Protection of pigs against experimental Salmonella Typhimurium infection by use of a single dose subunit slow delivery vaccine

Infections caused by septicemic strains of Salmonella are significant animal health as well as food safety concerns for the North American swine industry. Among the various strategies to control these infections at the herd level, development of vaccines are attractive alternatives. In this study, based on previous studies of immune response to various protems following natural and experimental infections of pigs by Salmonella, we designed a subunit slow delivery vaccine and tested it in an experimental model of infection. The selected immunogenic protein was cloned and purified by chromatography. The purified protein was then incorporated m PLGA (a polymer that is slowly degraded within the animal\u27s gastro-intestinal system) microspheres and given orally once to groups of pigs (n=8) while control animals (n=8) received only PBS. Animals were challenged orally 4 weeks after the vaccmation with 108 cells of a virulent strains of Salmonella Typhimurium. Animals were examined twice a day and climcal signs evaluated using a predetermined scoring grid. Pigs were sacrificed 12 days later and bacterial cultures of vanous organs, electron microscopy and evaluation of lgA response by ELISA were performed. No significant difference was found at bacteriology and ELISA but marked differences in clinical signs were observed between vaccinated and non vaccinated animals. None of vaccmated animals showed fever exceeding 40°C while it was observed in 5 out of 8 non vaccinated Only one of vaccmated pigs showed mild diarrhea while severe diarrhea was observed in all control animals different sizes of microspheres were observed in intestinal crypts of vaccinated animals at electron microscopy. We concluded that this vaccine can protect pigs against clinical signs associated with experimental infection by Salmonella Typhimunum

Evolution of Salmonella excretion by sows during gestation in link with the faecal microbiome

Pork meat is estimated to be responsible of 10 to 20% of human salmonellosis cases. Control strategies at the farm could reduce contamination at the slaughterhouse. One of the targeted sector of the production is the maternity, where sows could be Salmonella reservoirs. The aim of this study was to characterize the faecal microbiome of sows excreting or not Salmonella during gestation phases. A total of 76 sows were selected and fecal matters were analysed at the beginning or the end of gestation period. Salmonella detection was conducted using a method including two selective enrichment media (MSRV and TBG). Nine (9) isolates per positive samples were collected. Among the 76 sows tested, 31 were shedding Salmonella. The sows in the first third of their gestation shed significantly more frequently Salmonella (22/29) than those in the last third (9/47) (χ² P \u3c 0.05). The shedding status of 19 of the sows that were previously sampled in the first third of their gestation was followed, this time in the last third, confirming reduction of the shedding. Association between changes in the intestinal microbiome and this evolution of Salmonella shedding will be explored. MiSeq sequencing is currently being conducted on the feces to identify shifts in the composition or diversity in the microbial community that could be associated to these variations. A large number of Salmonella isolates that were collected were genotyped by a high resolution melt (HRM) technique. These results showed the presence of a major HRM profile (136 isolates / 169) and two minor profiles (24 and 9 /169)

Residual contamination detection and serovar distribution of Listeria monocytogenes isolates in pork slaughterhouse and cutting facilities in province of Quebec

L. monocytogenes (L. mono) is recognised as a zoonotic foodborne pathogen. Its control is focused on the “Readyto Eat” food production level. Recently, Health Canada had reinforced its “Policy on L. mono in Ready-to-Eat Foods”, highlighting environmental surveillance and control of meat processing facilities as important risk reduction tools. The industry wants to improve its management of L. mono risk, taking into account previous steps of meat production. Nowadays, few information are available on the presence, distribution and types of strains in the environments concerning this pathogen in pork slaughterhouses and cutting facilities in Canada. Our objective was to detect and described residual L. mono contamination and analyse serovars distribution in different areas in the pork production continuum in and between slaughterhouses and cutting facilities in province of Quebec, during a one year period. Such data are a pre-requisite to achieve the optimization of the management measures by the industrials