It is generally difficult to specify the sources of infection by which domestic animals may acquire pathogens. Through 16S rRNA gene amplicon sequencing, we compared the composition of microbiota in the saliva, vaginal mucus, and feces of pigs, and in swabs of feeder troughs and water dispensers collected from pig farms in Vietnam. The composition of the microbiota differed between samples in each sample group. Streptococcus , Actinobacillus , Moraxella , and Rothia were the most abundant genera and significantly discriminative in saliva samples, regardless of the plasticity and changeability of the composition of microbiota in saliva. Moreover, species assignment of the genus Streptococcus revealed that Streptococcus suis was exceptional in the salivary microbiota, due to being most abundant among the streptococcal species and sharing estimated proportions of 5.7%–9.4% of the total bacteria in saliva. Thus, pig oral microbiota showed unique characteristics in which the major species was the pig pathogen. On the other hand, β-diversity analysis showed that the microbiota in saliva was distinct from those in the others. From the above results, pig saliva was shown to be the major natural habitat of S . suis , and is suggested to be the most probable source of S . suis infection.

In this report we present the initial results of the use of different silver nanostructures deposited on silicon for trace detection of paraquat (a commonly used herbicide) using the surfaceenhanced Raman scattering (SERS) effect. More specifically, the SERS-active substrates were fabricated from silver nanoparticles (AgNPs) deposited onto the flat surface of a silicon wafer (AgNPs@Si substrate), as well as on the surface of an obliquely aligned silicon nanowire (SiNW) array (AgNPs@SiNWs substrate), and from silver nanodendrites (AgNDs) deposited onto the flat surface of a silicon wafer (AgNDs@Si substrate). Results showed that with the change of the structure of the SERS-active substrate, higher levels of SERS enhancement have been achieved. Specifically, with the fabricated AgNDs@Si substrate, paraquat concentration as low as 1 ppm can be detected.

This study aims to explore the farmers’ perceptions of foot-and-mouth disease (FMD) vaccination using a reflexive research method called Q methodology. A structured sample was composed of 46 farmers selected according to gender, farming experience, level of education, and production type. Statements relevant to the farmers’ perceptions of and attitudes toward FMD vaccination, related to confidence, logistics, costs, and impacts of vaccination were developed. Results were analyzed by principal component analysis and factor analysis. The influence of demographics and characterized variables on the respondent’s contribution to each factor was also tested. Regarding the different beliefs and behavior toward FMD vaccination, the common perceptions held by Vietnamese cattle and pig farmers were divided into three discourses named Confidence (24 subjects), Belief (12 subjects), and Challenge (6 subjects). The identified discourses represented 57.3% of the variances. Consensus points were found, such as the feeling of being more secure after FMD vaccination campaigns; the fact that farmers take vaccination decisions themselves without being influenced by other stakeholders; the opinion that FMD vaccination is cheaper than the costs of treating a sick animal; and that vaccines provided by governmental authorities are of high quality. Part of the studied population did not consider vaccination to be the first choice strategy in prevention. This raises the question of how to improve the active participation of farmers in the FMD vaccine strategy. Taking into consideration farmers’ perceptions can help to implement feasible vaccination strategies at the local level.

In this report we will present completely new results on the improvement of the graphene quantum dots (GQDs) and nitrogen-doped graphene quantum dots (N-GQD) production method, using the microwave with different power levels and durations, from citric acid and urea. This is a new and unprecedented method of fabrication. The use of microwave has allowed ultra-fast fabrication of GQDs and nitrogen doped GQDs. These GQDs had their characteristics identified by Raman scattering spectra for the characteristic C-C graphene vibration mode (G-peak) and defects of GQDs (D-peak). The absorption spectra of GQDs samples were fabricated under different conditions, with the expectation of different sizes, to be compared and analyzed. These absorption spectra were also compared with those of the N-GQD produced under the same conditions. The absorption mechanism of GQDs and N-GQD will be presented in detail. Measurements of the photoluminescence (PL) spectra in GQDs and N-GQD have also been recorded and analyzed. The fluorescence mechanism will be presented, explained, and compared with other international publications of other authors. Some of the TEM and HR-TEM images of these two samples were also presented to confirm the shape, size and in-plane spacing lattice of the GQD structure.

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