Irrational Rotation Algebra as a Crossed Product

In this paper we will consider the crossed product C(T) ×α Z, where T is the unit circle, α(n) = αn is a rotation through the angle −2πnθ for n ∈ Z, and θ is a fixed irrational number. We will apply some results about patial actions to represent this crossed product as a C ∗ -subalgebra of B(L 2 (T)). Also, by a different method form the proof of Davidson, we show that this crossed product is isomorphic to the irrational rotation algebra

Pathological, bacteriological, and molecular characteristics of natural outbreaks of Johne's disease in goats of Fars Province, Iran

Objective/Background: Johne's disease, also called paratuberculosis, is a very important chronic infectious disease of ruminants worldwide. The causative agent is an acid-fast bacterium, Mycobacterium avium paratuberculosis (MAP). Finding a precise method for detecting MAP is essential for the control and eradication of this disease in small ruminant herds. Methods: In this study, appropriate samples were obtained from the ileum, cecum, colon, and mesenteric lymph nodes of 10 suspected naturally infected goats. Each sample was divided to two parts: the first part was stored at −20°C for bacteriologic culture and the second part was placed in 10% neutral formalin for molecular and histopathologic examination. To isolate MAP, the double incubation method was used for decontaminating the tissues and Middlebrook 7H9 broth-based culture associated with OADC (oleic acid, albumin, dextrose, and catalase) supplement with/without mycobactin J were used. Polymerase chain reaction (PCR; IS 900) was performed for media with positive acid-fast staining. Results: Acid-fast staining was positive in 40% of ileum samples, 50% of cecum samples, 40% of colon samples, and 50% of lymph node samples with mycobactin J and in 60% of ileum samples, 60% of cecum samples, 40% of colon samples, and 40% of lymph node samples without mycobactin J. All samples were confirmed by IS 900 PCR assay. Diffuse granulomatous enteritis with multibacillary lesions and paucibacillary multifocal lymphadenitis associated with calcification were diagnosed histopathologically. Conclusion: MAP detection in intestinal content and in tissues is quite necessary for the diagnosis, control, and eradication of this disease in small ruminant herds

Identification of N-acyl homoserine lactone-degrading bacteria isolated from rainbow trout (Oncorhynchus mykiss)

Aims: A variety of pathogens use quorum sensing (QS) to control the expression of their virulence factors. QS interference has hence been proposed as a promising antivirulence strategy. The specific aim of this study was to isolate bacteria from trout tissue able to degrade N-acyl homoserine lactones (AHL), a QS molecule family. Methods and Results: In total 132 isolates were screened for AHL degradation using Chromobacterium violaceum CV026 as a biosensor. Twenty-four quorum-quenching (QQ) isolates were identified biochemically and characterized using 16S rDNA sequencing. They belong to Bacillus, Enterobacter, Citrobacter, Acinetobacter, Agrobacterium, Pseudomonas and Stentrophomonas genera. Four Bacillus spp. showed the highest and fastest QQ activity. AHL degradation proved to be enzymatic in most isolates (except for Stentrophomonas spp. and Pseudomonas sp.) as QQ activity could be destroyed by heat and/or proteinase K treatments. All QQ activity proved to be cell-bound except for Pseudomonas sp., where it could be detected in the supernatant. The results of aiiA gene homology analysis revealed the presence of aiiA gene encoding AHL lactonase in all examined isolates except Pseudomonas syringae and Enterobacter cloacae. The HXHXDH motif conserved in all AHL lactonases and considered to be essential for AHL degradation was detected in all AiiAs after sequence alignment. Conclusions: Some known and novel QQ bacteria were isolated from trouts and characterized in terms of enzymatic or nonenzymatic AHL degradation activity and their extracellular or intracellular location. In addition, an aiiA gene and its HXHXDH motif were detected in most isolates. Significance and Impact of the Study: We could isolate and identify some novel QQ bacteria including Enterobacter hormaechei, Acinetobacter radioresistens and Citrobacter gillenii. The aiiA gene was detected for the first time in these strains as well as in Stenotrophomonas maltophilia. Our QQ isolates could be used for biocontrol of bacterial infections in aquaculture

Application of Bayesian modeling for diagnostic assays of Mycobacterium avium subsp. paratuberculosis in sheep and goats flocks

Background: This study aimed to screen the sera of goats and sheep from flocks suspected of Mycobacterium avium subsp. paratuberculosis (MAP) infection by a newly standardized Mce-truncated ELISA (Mt-ELISA) kit for the detection of antibodies against MAP. Four diagnostic applied tests were evaluated including Indigenous plate-ELISA (IP-ELISA), Mt-ELISA, fecal Polymerase Chain Reaction (f-PCR) and fecal culture (FC). Materials and methods: Assuming the absence of a gold standard, latent-class models in a Bayesian framework were used to estimate the diagnostic accuracy of the four tests for MAP. Results: Mt-ELISA had higher Sensitivity (Se) in sheep (posterior median: 0.68 (95% Probability Interval (PI): 0.43–0.95), while IP-ELISA recorded the highest Se in goats as 0.83 (95% PI, 0.61–0.97). The f-PCR Se estimate slightly differed between species [sheep 0.36 (0.19–0.58), goats 0.19 (0.08–0.35)], while the Se of FC was similar between species [sheep 0.29 (0.15–0.51), goats 0.27 (0.13–0.45)]. The specificity estimates for all tests were high, close to unity, and similar between species. Conclusion: Overall, the results showed that the Mt-ELISA method can be used for MAP detection in small ruminants’ flocks. © 2022, The Author(s)