Avian articular cartilage: effects of age, genotype and disease

The degradation of articular cartilage, causing degenerative joint disease (DJD), is a documented cause of lameness in broiler strain fowl, which is a major welfare problem. Broiler strain fowl are both heavier and more susceptible to DJD than laying strain fowl. In this thesis the biochemical and morphological basis for this susceptibility has been investigated, particular attention has been paid to the effects of body weight and genotype on avian articular cartilageArticular cartilage from three distinct sites was analysed. Samples from mature broiler strain females, susceptible to DJD, had higher hydration and uronic acid content than age matched, non -susceptible, laying strain fowl. In addition to these biochemical features (also seen in mammalian DJD), broiler strain fowl exhibited DJD histopathology including cartilage thinning and chondrocyte cluster formation. In general, both strains at one day old showed no significant biochemical differences between the articular cartilage sites sampled. However the cartilage from the broiler strain distal tibiotarsus (DTT) at one day old appeared to be biochemically and morphologically distinct from the cartilage of the layer strain DTT and from the other broiler strain joint surface of the same age.Production of an infectious arthritis by inoculation of mycoplasma into the tibiotarsal joint of broiler strain fowl resulted in variable biochemistry of articular cartilage form this joint. However in the non -injected, contralateral joint, sampled from the DTT, there was an increase in hydration and uronic acid content which is dependent upon the degree of lameness. This indicates the importance of in vivo loading in the biochemical composition of avian articular cartilage.Broiler strain birds fed ad libitum, feed restricted and J -line (wild type) were surveyed over the course of one year. Only the ad libitum fed birds developed overt DJD, which suggests that the mass of the bird, and not an overriding genetic element, is the major cause of the susceptibility of broiler strain fowl to DJD. The joint surface which presented the first and most severe signs indicative of early cartilage degeneration was the DTT. The biochemical results obtained from articular cartilage samples of the three groups include hydration, uronic acid, DNA and hydroxyproline content. Histology of the samples was assessed using haematoxylin and eosin stained sections. Proteoglycan content was investigated further by using selected samples for sulphated glycosaminoglycan assays and staining selected sections with Toludine blue and Safranin O. Samples from diseased and non -diseased groups were assayed for pyridinium in order to investigate the role of mature collagen crosslinking in DJD.The exact role of load and the metabolic consequences of body weight in the development of DJD is controversial. A method for artificially loading non -obese birds has been developed. Loading feed restricted broiler strain fowl with an additional 10% of their body weight over a three week period initiated a response including significant biochemical changes in the cartilage of the DTT. These results again emphasise the importance of load on the articular cartilage and the susceptibility of the DTT to DJD

The role of the A C395 IFNGR1 mutation in determining susceptibility to intracellular infection in Malta

Background: The first human mycobacterial susceptibility gene was identified amongst four children on the island of Malta in 1995. All affected children were homozygous for a nonsense mutation at position 395 of the interferon gamma receptor 1 (IFNGR1) gene, and all but one died of overwhelming mycobacterial infection. The population of Malta has high rates of infection with intracellular pathogens; leishmania, brucellosis and tuberculosis are all endemic, while leprosy, which was previously endemic, has only recently been eradicated. We hypothesised that heterozygous carriers of the IFNGR1 gene mutation, while resistant to infection with poorly pathogenic organisms, may have increased susceptibility to infection with more virulent pathogens. Methodology and Result: Screening patients with a past history of intracellular infection and healthy newborns for the presence of the IFNGR1 A->C395 mutation, using sequence specific primer PCR, did not identify any carriers of the mutation. Conclusion: These results suggest that the IFNGR1 mutation is unlikely to be of public health significance on Malta.peer-reviewe

Higher Degree by Research

This open access book provides insights from Indigenous higher degree research (HDR) students on supervision practices in an Australian context. It examines findings from qualitative studies conducted with Indigenous HDR students from different academic disciplines, enrolled higher education institutions across Australia, and supervisors of Indigenous HDR students. Six types of data and their thematic analyses are presented, to understand the needs and experiences of both Indigenous HDR students and supervisors of Indigenous HDR students. This book also unpacks assumptions and commonly held beliefs about Indigenous HDR students, and shares what Indigenous HDRs report they need to experience success in higher education. It reports the experiences of supervisors of Indigenous HDR students, and explore further opportunities which enhance the higher education experiences of Indigenous HDR students. This book also suggests how successful relationships between Indigenous HDR students, and their supervisors may be fostered, and aims to be a useful resource for Indigenous peoples wishing to pursue higher education, and HDR supervisors in countries with Indigenous populations

The importance of active-learning, student support, and peer teaching networks: A case study from the world’s longest COVID-19 lockdown in Melbourne, Australia

In the Australian state of Victoria, the city of Melbourne endured the world’s longest number of lockdown days, with severe government health orders and travel restrictions in place for extended periods of 2020 and 2021. In common with others, we found the provision of field teaching in introductory geology, structural geology, and volcanology, and the online replacement of practical instruction in petrology and petrography to be the greatest pedagogical challenges. We developed and used a range of different virtual field excursions that, given time and travel constraints imposed on us, were necessarily “low-tech” and non-immersive. Despite this, our students largely engaged enthusiastically with the virtual excursions, met many preexisting learning goals, and gained additional skills, particularly in regional-scale geological synthesis. In teaching petrology and petrography online, curated resources improved student understanding of some fundamental concepts, and it was advantageous that students were all assessed using identical imagery, rather than one sample from a non-identical class-set. On the other hand, we found we were less able to train students in the advanced skills of thin section interpretation. Assessment changes associated with online teaching have resulted in a permanent shift from low-level recall-style assessments to instead emphasizing higher-level synthesis and “geological thinking” skills. Our efforts throughout the pandemic demonstrated the value of instructor-student engagement and yielded teaching resources that have subsequently enhanced our face-to-face teaching and increased flexibility for students. Moreover, the COVID-19 pandemic has highlighted the importance of collaborative teaching practice and we have increasingly seen the benefits of local and national-scale teaching networks for peer support and for resource sharing

Graduate Ethics Education: A Content Analysis of Syllabi

Ethical practice of psychology is emphasized by APA accreditation requirements. The current study is a content analysis of 53 ethics courses syllabi from all APA accredited programs listed in the American Psychologist 2011 annual report. This article is a companion to Domenech Rodríguez et al. (2013) and contributes knowledge on the current state of graduate ethics education. Of the parent project respondents (N = 364), 14% returned syllabi for the present study. General information (e.g., objectives, honor code, academic honesty, common policy, and classroom expectations), assignments, APA format, and teaching sources were coded. Coding of objectives were developed from McKeachie and Svinkicki (2011) definition and de las Fuentes (2005) conceptualization of specific objectives (awareness, skill, and knowledge). A little over half (56.6%) of syllabi stated clear objectives, only 52.8% covered academic honesty, and 16 (30.2%) did not include a section to address accommodations for students with disabilities. Most syllabi used APA format to cite sources, however, most sources used were 5 years or older. Overall, syllabi were quite varied in the information they included. Greater consistency in syllabus content would make future evaluations on the state of graduate ethics education more accurate. Recommendations for observational and self-report alternatives are also presented