Embryonic stem cell differentiation and the analysis of mammalian development

© UBC PressMolecular and cellular analysis of early mammalian development is compromised by the experimental inaccessibility of the embryo. Pluripotent embryonic stem (ES) cells are derived from and retain many properties of the pluripotent founder population of the embryo, the inner cell mass. Experimental manipulation of these cells and their environment in vitro provides an opportunity for the development of differentiation systems which can be used for analysis of the molecular and cellular basis of embryogenesis. In this review we discuss strengths and weaknesses of the available ES cell differentiation methodologies and their relationship to events in vivo. Exploitation of these systems is providing novel insight into embryonic processes as diverse as cell lineage establishment, cell progression during differentiation, patterning, morphogenesis and the molecular basis for cell properties in the early mammalian embryo.Stephen J. Rodda, Steven J. Kavanagh, Joy Rathjen and Peter D. Rathje

The whole of university experience: retention, attrition, learning and personal support interventions during undergraduate business studies

The Whole of University Experience (WoUE) project examined factors underpinning attrition in the first, second and third year of a business degree at six Australian universities – Griffith University, Monash University, Murdoch University, University of South Australia, University of Southern Queensland, and University of the Sunshine Coast. A questionnaire completed in 2008, 2009, and 2010 by a total of 7,486 students enabled gathering of data relating to demographics; students’ experience of university; their use and perceptions of the usefulness of student support interventions; open-ended comments about the best and worst aspects of the university experience; and aspects in need of improvement. In each year a small number of students were also interviewed for the purpose of fleshing out the survey data and exploring the interactions between various factors associated with attrition. Overall, the data strongly indicates that factors related to attrition are generally university-specific and reflect both student characteristics and their responses to the specific institutional culture and environment. The only attrition triggers which span most universities and most years of study are ‘lack of a clear reason for being at university’ and ‘the feeling of having insufficient ability to succeed at university’. Correlation analysis relating 70 statements probing students’ experience of university to the strength of their intention to leave before completing a degree revealed notable differentiation in attrition triggers on the basis of year of study. Follow-up analysis in one university indicated further differentiation in the triggers for attrition, semester by semester. It seems that many different factors underpin attrition decisions in any one institution and for any one individual, for whom attrition appears to be the result of the aggregation of diverse factors generally followed by ‘the straw that broke the camel’s back’. When responses are grouped by demographic variables some difference in the factors associated with domestic and international student attrition is apparent, but no difference in the factors associated with their sense of satisfaction or belonging is obvious. In the responses of international and domestic students to issues of teaching quality, differences primarily related to expectations regarding teaching staff approachability, availability and helpfulness. For students enrolled part-time or full-time different factors underpin attrition, and attrition triggers also differ on the basis of time spent on campus and average grades. Preliminary analysis suggests that having to take a loan or engage in full-time work to fund studies is a greater attrition risk factor in most universities than is the receipt of Centrelink benefits (which may be seen as a proxy indicator for low socio-economic status). Analysis of responses to questions about the use and usefulness of student support interventions indicates that, in general, when students use personal support interventions these are mostly seen as very useful. However, data also indicate that many, and often the majority of, students have either not used or are not aware of the support services available. Practically, the project has delivered, and will continue to deliver, significant value to the higher education sector. On the basis of evidence from the project, partner universities have begun addressing high-value student retention issues and it is expected that this evidence will continue to influence institutional decision-making for several years beyond the life of the project. Dissemination activities external to partner universities, including publication of five journal articles and numerous workshops or presentations, have assisted staff in other universities to reflect upon issues critical to student retention in both first year and beyond. Further publication outcomes are expected. Critically, as indicated in the independent project evaluation, “the project has directed much needed attention to factors associated with attrition in later years of the student experience (second and third years) … facilitated discussion around frameworks for evidence-based institutional responses that constitute effective interventions … [and] reinforced the need for institutions to collect their own data on the student experience to inform individual institutional responses and interventions”

Analysis of the effect of Bacillus velezensis culture filtrate on the growth and proteome of Cladobotryum mycophilum

peer-reviewedCladobotryum mycophilum, the causative agent of cobweb disease on Agaricus bisporus results in significant crop losses for mushroom growers worldwide. Cobweb disease is treated through strict hygiene control methods and the application of chemical fungicides but an increase in fungicide resistant Cladobotryum strains has resulted in a need to develop alternative biocontrol treatment methods. The aim of the work presented here was to evaluate the response of C. mycophilum to a Bacillus velezensis isolate to assess its potential as a novel biocontrol agent. Exposure of 48 hr C. mycophilum cultures to 25% v/v 96 hr B. velezensis culture filtrate resulted in a 57% reduction in biomass (P < 0.0002), a disruption in hyphal structure and morphology, and the appearance of aurofusarin, a secondary metabolite which is a known indicator of oxidative stress, in culture medium. Proteomic analysis of B. velezensis culture filtrate revealed the presence of peptidase 8 (subtilisin), peptide deformylase and probable cytosol aminopeptidase which are known to induce catalytic activity. Characterisation of the proteomic response of C. mycophilum following exposure to B. velezensis culture filtrate revealed an increase in the abundance of a variety of proteins associated with stress response (ISWI chromatin-remodelling complex ATPase ISW2 (+24 fold), carboxypeptidase Y precursor (+3 fold) and calmodulin (+2 fold). There was also a decrease in the abundance of proteins associated with transcription (40 S ribosomal protein S30 (−26 fold), 40 S ribosomal protein S21 (−3 fold) and carbohydrate metabolism (l-xylulose reductase (−10 fold). The results presented here indicate that B. velezensis culture filtrate is capable of inhibiting the growth of C. mycophilum and inducing a stress response, thus indicating its potential to control this important pathogen of mushrooms

Analysis of the effect of Bacillus velezensis culture filtrate on the growth and proteome of Cladobotryum mycophilum

Cladobotryum mycophilum, the causative agent of cobweb disease on Agaricus bisporus results in significant crop losses for mushroom growers worldwide. Cobweb disease is treated through strict hygiene control methods and the application of chemical fungicides but an increase in fungicide resistant Cladobotryum strains has resulted in a need to develop alternative biocontrol treatment methods. The aim of the work presented here was to evaluate the response of C. mycophilum to a Bacillus velezensis isolate to assess its potential as a novel biocontrol agent. Exposure of 48 hr C. mycophilum cultures to 25% v/v 96 hr B. velezensis culture filtrate resulted in a 57% reduction in biomass (P < 0.0002), a disruption in hyphal structure and morphology, and the appearance of aurofusarin, a secondary metabolite which is a known indicator of oxidative stress, in culture medium. Proteomic analysis of B. velezensis culture filtrate revealed the presence of peptidase 8 (subtilisin), peptide deformylase and probable cytosol aminopeptidase which are known to induce catalytic activity. Characterisation of the proteomic response of C. mycophilum following exposure to B. velezensis culture filtrate revealed an increase in the abundance of a variety of proteins associated with stress response (ISWI chromatin-remodelling complex ATPase ISW2 (+24 fold), carboxypeptidase Y precursor (+3 fold) and calmodulin (+2 fold). There was also a decrease in the abundance of proteins associated with transcription (40 S ribosomal protein S30 (−26 fold), 40 S ribosomal protein S21 (−3 fold) and carbohydrate metabolism (l-xylulose reductase (−10 fold). The results presented here indicate that B. velezensis culture filtrate is capable of inhibiting the growth of C. mycophilum and inducing a stress response, thus indicating its potential to control this important pathogen of mushrooms

Characterising the proteomic response of mushroom pathogen Lecanicillium fungicola to Bacillus velezensis QST 713 and Kos biocontrol agent

The fungal pathogen Lecanicillium fungicola causes dry bubble disease in Agaricus bisporus cultivation and affected mushrooms significantly reduce the yield and revenue for mushroom growers. Biocontrol agents may represent an alternative and more environmentally friendly treatment option to help control dry bubble on mushroom farms. Serenade ® is a commercially available biocontrol product used for disease treatment in plant crops. In this work, the in vitro response of L. fungicola to the bacterial strain active in Serenade, Bacillus velezensis (QST 713) and a newly isolated B. velezensis strain (Kos) was assessed. B. velezensis (QST713 and Kos) both produced zones of inhibition on plate cultures of L. fungicola, reduced the mycelium growth in liquid cultures and damaged the morphology and structure of L. fungicola hyphae. The proteomic response of the pathogen against these biocontrol strains was also investigated. Proteins involved in growth and translation such as 60S ribosomal protein L21-A (−32- fold) and 40S ribosomal protein S30 (−17-fold) were reduced in abundance in B. velezensis QST 713 treated samples, while proteins involved in a stress response were increased (norsolorinic acid reductase B (47-fold), isocitrate lyase (11-fold) and isovaleryl-CoA dehydrogenase (8-fold). L. fungicola was found to have a similar proteomic response when exposed to B. velezensis (Kos). This work provides information on the response of L. fungicola to B. velezensis (QST 713) and indicates the potential of B. velezensis Kos as a novel biocontrol agent

Determination of a suitable low-dose abdominopelvic CT protocol using model-based iterative reconstruction through cadaveric study.

Introduction: Cadaveric studies provide a means of safely assessing new technologies and optimizing scanning prior to clinical validation. Reducing radiation exposure in a clinical setting can entail incremental dose reductions to avoid missing important clinical findings. The use of cadavers allows assessment of the impact of more substantial dose reductions on image quality. Our aim was to identify a suitable low‐dose abdominopelvic CT protocol for subsequent clinical validation. Methods: Five human cadavers were scanned at one conventional dose and three low‐dose settings. All scans were reconstructed using three different reconstruction algorithms: filtered back projection (FBP), hybrid iterative reconstruction (60% FBP and 40% adaptive statistical iterative reconstruction (ASIR40)), and model‐based iterative reconstruction (MBIR). Two readers rated the image quality both quantitatively and qualitatively. Results: Model‐based iterative reconstruction images had significantly better objective image noise and higher qualitative scores compared with both FBP and ASIR40 images at all dose levels. The greatest absolute noise reduction, between MBIR and FBP, of 34.3 HU (equating to a 68% reduction) was at the lowest dose level. MBIR reduced image noise and improved image quality even in CT images acquired with a mean radiation dose reduction of 62% compared with conventional dose studies reconstructed with ASIR40, with lower levels of objective image noise, superior diagnostic acceptability and contrast resolution, and comparable subjective image noise and streak artefact scores. Conclusion: This cadaveric study demonstrates that MBIR reduces image noise and improves image quality in abdominopelvic CT images acquired with dose reductions of up to 62%

Law, criminalisation and HIV in the world: have countries that criminalise achieved more or less successful pandemic response?

How do choices in criminal law and rights protections affect disease-fighting efforts? This long-standing question facing governments around the world is acute in the context of pandemics like HIV and COVID-19. The Global AIDS Strategy of the last 5 years sought to prevent mortality and HIV transmission in part through ensuring people living with HIV (PLHIV) knew their HIV status and could suppress the HIV virus through antiretroviral treatment. This article presents a cross-national ecological analysis of the relative success of national AIDS responses under this strategy, where laws were characterised by more or less criminalisation and with varying rights protections. In countries where same-sex sexual acts were criminalised, the portion of PLHIV who knew their HIV status was 11% lower and viral suppression levels 8% lower. Sex work criminalisation was associated with 10% lower knowledge of status and 6% lower viral suppression. Drug use criminalisation was associated with 14% lower levels of both. Criminalising all three of these areas was associated with approximately 18%-24% worse outcomes. Meanwhile, national laws on non-discrimination, independent human rights institutions and gender-based violence were associated with significantly higher knowledge of HIV status and higher viral suppression among PLHIV. Since most countries did not achieve 2020 HIV goals, this ecological evidence suggests that law reform may be an important tool in speeding momentum to halt the pandemic

Biological Effects of Antiprotons Are Antiprotons a Candidate for Cancer Therapy?

2009 Status Report of AD-4 Experimen

Fluorescent Risedronate Analogues Reveal Bisphosphonate Uptake by Bone Marrow Monocytes and Localization Around Osteocytes In Vivo

Bisphosphonates are effective antiresorptive agents owing to their bone-targeting property and ability to inhibit osteoclasts. It remains unclear, however, whether any non-osteoclast cells are directly affected by these drugs in vivo. Two fluorescent risedronate analogues, carboxyfluorescein-labeled risedronate (FAM-RIS) and Alexa Fluor 647–labeled risedronate (AF647-RIS), were used to address this question. Twenty-four hours after injection into 3-month-old mice, fluorescent risedronate analogues were bound to bone surfaces. More detailed analysis revealed labeling of vascular channel walls within cortical bone. Furthermore, fluorescent risedronate analogues were present in osteocytic lacunae in close proximity to vascular channels and localized to the lacunae of newly embedded osteocytes close to the bone surface. Following injection into newborn rabbits, intracellular uptake of fluorescently labeled risedronate was detected in osteoclasts, and the active analogue FAM-RIS caused accumulation of unprenylated Rap1A in these cells. In addition, CD14high bone marrow monocytes showed relatively high levels of uptake of fluorescently labeled risedronate, which correlated with selective accumulation of unprenylated Rap1A in CD14+ cells, as well as osteoclasts, following treatment with risedronate in vivo. Similar results were obtained when either rabbit or human bone marrow cells were treated with fluorescent risedronate analogues in vitro. These findings suggest that the capacity of different cell types to endocytose bisphosphonate is a major determinant for the degree of cellular drug uptake in vitro as well as in vivo. In conclusion, this study shows that in addition to bone-resorbing osteoclasts, bisphosphonates may exert direct effects on bone marrow monocytes in vivo. © 2010 American Society for Bone and Mineral Researc

The Science Performance of JWST as Characterized in Commissioning

This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies.Comment: 5th version as accepted to PASP; 31 pages, 18 figures; https://iopscience.iop.org/article/10.1088/1538-3873/acb29