The tonsillar carriage of Yersinia species by pigs: a thesis presented in partial fulfilment of the requirements for the degree of Master of Philosophy in Veterinary Science at Massey University

The impetus for this study arose due to the increasing isolation of species of Yersinia from people, with pigs being suspected as major reservoirs of human pathogenic strains of the organism in New Zealand. The general aims of the study, conducted in two phases, among pigs from several herds sent for slaughter at an abattoir in Palmerston North were: (i) to determine the presence of human pathogenic strains of Yersinia in the tonsils of slaughtered pigs and their distribution among selected herds. (ii) to determine the seasonal effect on prevalence of isolation and type of organism isolated, and (iii) to determine the in vitro virulence characteristics of strains of the organism isolated from the tonsils of slaughter pigs, and their potential public health implications. The first phase involved a cross-sectional study, conducted between August and September, 1993. Tonsils were collected from 124 pigs from eight farms and were examined for the presence of species of Yersinia. A total of 77 (62.1%) strains of Yersinia were isolated, this consisted of 42 (33.9%), 27 (21.8%), 7 (5.6%) and 1 (0.8%) strains of Y. enterocolitica. Y. pseudotuberculosis, Y. frederiksenii and Y. kristensenii respectively. Yersinia enterocolitica serotypes 0:3, 0:5, 27 and Y. pseudotuberculosis comprised 26 (33.8%), 12(15.6%) and 27 (35.1%) of the total number of isolates respectively. Yersiniae were isolated from all eight farms with individual farm prevalences ranging from 20% to 100%, while the number of species per farm ranged from 1 to 3. The pyrazinamidase activity test correctly identified 48 of the isolates as pathogenic or non-pathogenic yersiniae, (a specificity of 96%). The second phase, a longitudinal study, was conducted over a period of twelve months (February 1993 – January 1994), among pigs from four farms, selected according to the particular strain of Yersinia prevailing in the herd. A total of 705 pigs were examined for the carriage of species of Yersinia in their tonsils. A total of 264 isolates were obtained, consisting of 198 (75%), 55 (20.8%), 5 (1.9%), and 1 (0.4%) strains of Y. enterocolitica, Y. pseudotuberculosis, Y. intermedia, Y. frederiksenii and Y. kristensenii respectively. Yersinia enterocolitica serotypes 0:5,27 and 0:3 comprised 105 (39.8%) and 78 (29.5%) of the total number of isolates respectively. Yersinia pseudotuberculosis comprised 55 (20.9%) with serotype III, 39 (14.8%) the most consistently isolated serotype. Yersiniae were isolated throughout the year particularly in the colder months. Yersinia enterocolitica serotypes 0:3 and 0:5,27 were found throughout the year with the lowest prevalence in the warmer months. However, a seasonal variation existed among serotypes of Y. pseudotuberculosis, with serotypes I and II found only in the winter and spring. Serotype III was found throughout the year, except for February. During phase two of the study, 150 isolates of Yersinia were tested for in vitro virulence-associated characteristics. The autoagglutination test. CR-MOX agar, and the pyrazinamidase assay, coupled with salicin and aesculin tests, were highly successful in separating pathogenic from non-pathogenic strains of Y. enterocolitica. Likewise, the three assays successfully identified virulence activity in the majority of strains of Y. pseudotuberculosis with specificity among the three assays ranging between 90-100% for both Y. pseudotuberculosis and Y. enterocolitica. The study also revealed marked variation in prevalence and type of Yersinia species isolated from pigs from different farms. The fact that particular serotypes predominate and persist on specific farms strongly suggest that there are factors such as source of pigs, management practices or contact with other animals which determine their status. Identification of these determinates could lead to control or eradication of important yersiniae from pig farms. The overall prevalence of 41.1% ranks New Zealand among countries with reported high isolation rates of the organism and further emphasises the fact that pigs constitute major reservoirs for human pathogenic strains of Yersinia worldwide. The infection among slaughter pigs in New Zealand may be of human health concern and thus warrants further investigation particularly to determine whether the strains isolated from pigs are identical to those involved in human disease

Transcriptional Regulation of Arabidopsis Polycomb Repressive Complex 2 Coordinates Cell Type Proliferation and Differentiation

Spatiotemporal regulation of transcription is fine-tuned at multiple levels, including chromatin compaction. Polycomb Repressive Complex 2 (PRC2) catalyzes the trimethylation of Histone 3 at lysine 27 (H3K27me3), which is the hallmark of a repressive chromatin state. Multiple PRC2 complexes have been reported in Arabidopsis thaliana to control the expression of genes involved in developmental transitions and maintenance of organ identity. Here, we show that PRC2 member genes display complex spatiotemporal gene expression patterns and function in root meristem and vascular cell proliferation and specification. Furthermore, PRC2 gene expression patterns correspond with vascular and non-vascular tissue-specific H3K27me3-marked genes. This tissue-specific repression via H3K27me3 regulates the balance between cell proliferation and differentiation. Using enhanced yeast-one-hybrid analysis, upstream regulators of the PRC2 member genes are identified, and genetic analysis demonstrates that transcriptional regulation of some PRC2 genes plays an important role in determining PRC2 spatiotemporal activity within a developing organ

ChatGPT and Bard Responses to Polarizing Questions

Recent developments in natural language processing have demonstrated the potential of large language models (LLMs) to improve a range of educational and learning outcomes. Of recent chatbots based on LLMs, ChatGPT and Bard have made it clear that artificial intelligence (AI) technology will have significant implications on the way we obtain and search for information. However, these tools sometimes produce text that is convincing, but often incorrect, known as hallucinations. As such, their use can distort scientific facts and spread misinformation. To counter polarizing responses on these tools, it is critical to provide an overview of such responses so stakeholders can determine which topics tend to produce more contentious responses -- key to developing targeted regulatory policy and interventions. In addition, there currently exists no annotated dataset of ChatGPT and Bard responses around possibly polarizing topics, central to the above aims. We address the indicated issues through the following contribution: Focusing on highly polarizing topics in the US, we created and described a dataset of ChatGPT and Bard responses. Broadly, our results indicated a left-leaning bias for both ChatGPT and Bard, with Bard more likely to provide responses around polarizing topics. Bard seemed to have fewer guardrails around controversial topics, and appeared more willing to provide comprehensive, and somewhat human-like responses. Bard may thus be more likely abused by malicious actors. Stakeholders may utilize our findings to mitigate misinformative and/or polarizing responses from LLM

Facilitators and barriers for clinical implementation of a 30-minute point-of-care test for Neisseria gonorrhoeae and Chlamydia trachomatis into clinical care: A qualitative study within sexual health services in England.

Point-of-care tests (POCTs) to diagnose sexually transmitted infections (STIs) have potential to positively impact patient management and patient perceptions of clinical services. Yet there remains a disconnect between development of new technologies and their implementation into clinical care. With the advent of new STI POCTs arriving to the global market, guidance for their successful adoption and implementation into clinical services is urgently needed. We conducted qualitative in-depth interviews with professionals prior to and post-implementation of a Chlamydia trachomatis/Neisseria gonorrhoeae POCT into clinical services in England to define key stakeholder roles and explore the process of POCT integration. Participants self-identified themselves as key stakeholders in the STI POCT adoption and/or implementation processes. Data consisted of interview transcripts, which were analysed thematically using NVIVO 11. Six sexual health services were included in the study; three of which have implemented POCTs. We conducted 40 total interviews: 31 prior to POCT implementation and 9 follow-up post-implementation. Post-implementation data showed that implementation plans required little or no change during service evaluation. Lead clinicians and managers self-identified as key stakeholders for the decision to purchase, while nurses self-identified as "change champions" for implementation. Many identified senior clinical staff as those most likely to introduce and drive change. However, participants stressed the importance of engaging all clinical staff in implementation. While the accuracy of the POCT, its positive impact on patient management and the ease of its integration within existing pathways were considered essential, costs of purchasing and utilising the technology were identified as central to the decision to purchase. Our study shows that key decision-makers for adoption and implementation require STI POCTs to have laboratory-comparable accuracy and be affordable for purchase and ongoing use. Further, successful integration of POCTs into sexual health services relies on supportive interpersonal relationships between all levels of staff

The Evolution of Primate Short-Term Memory.

Short-term memory is implicated in a range of cognitive abilities and is critical for understanding primate cognitive evolution. To investigate the effects of phylogeny, ecology and sociality on short-term memory, we tested the largest and most diverse primate sample to date (421 non-human primates across 41 species) in an experimental delayed-response task. Our results confirm previous findings that longer delays decrease memory performance across species and taxa. Our analyses demonstrate a considerable contribution of phylogeny over ecological and social factors on the distribution of short-term memory performance in primates; closely related species had more similar short-term memory abilities. Overall, individuals in the branch of Hominoidea performed better compared to Cercopithecoidea, who in turn performed above Platyrrhini and Strepsirrhini. Interdependencies between phylogeny and socioecology of a given species presented an obstacle to disentangling the effects of each of these factors on the evolution of short-term memory capacity. However, this study offers an important step forward in understanding the interspecies and individual variation in short-term memory ability by providing the first phylogenetic reconstruction of this trait’s evolutionary history. The dataset constitutes a unique resource for studying the evolution of primate cognition and the role of short-term memory in other cognitive abilities.info:eu-repo/semantics/publishedVersio