138 research outputs found
Lineage tracing of skeletal progenitor cells during postnatal bone formation
INTRODUCTION: Fractures represent a common orthopaedic injury and create a large financial burden for the health care system. Non-union fractures often require surgery to assist the healing process. Understanding the origin of the postnatal skeletal stem cells will allow for locally delivered therapeutic treatments to be more exactly spatially targeted for fracture healing. Two forms of post-natal bone formation were studied, callus formation after fracture and ectopic bone growth. Both forms of bone formation closely follow the mechanisms of endochondral ossification. The Prx1 gene that is known to be expressed by skeletal stem/progenitor cells within the periosteal tissues was used to spatially follow this cell population during ectopic and fracture induced bone formation.
OBJECTIVES: The purpose of this study was to define the cell lineages that arise from Prx1 expressing cells in fracture and ectopic bone models.
METHODS: Prx1 expressing cells were tracked using Prx1CreER-GFP x RosaAi14 (dTomato indicator) and Prx1CreER-GFP x Ai14i (dTomato indicator) in the Rag1tm strain of transgenic mice. These mice strains respectively received a closed stabilized fracture or human demineralized bone matrix (DBM) that was surgically implanted onto the periosteal surface of the femur to initiate the development of ectopic bone. Tissue was collected at either day 10 or 14 post-fracture surgery or day 8 post-DBM implantation. Prx1CreER-GFP expression was induced by tamoxifen or control animals received no injection or corn oil. Three different tamoxifen induction protocols (30 days prior to surgery to allow for washout, three days prior to, or continuously after either fracture or ectopic bone induction were used. Fluorescent microscopy of the histological images were performed to assess the cell populations that expressed Prx1 and cell counting was used to quantify the percentages of Prx1 positive cells in specific regions of interest. qRT-PCR of Prx-1 mRNA expression was used to provide the relative gene expression of Prx1 in a variety of different tissues.
RESULTS: Control animals that received corn oil or no Tamoxifen showed low levels (~5-15%) labeled cells, however there was a ~2 fold increase in labeling with Tamoxifen washout. Labeled cells were present within calvaria, femur, tibia, and forelimb bones, while very low amounts were located at the sternum rib junction but were absent in the vertebra. Up to 55-65% of the cells within fracture callus and ectopic bone models showed Prx1 labeled in both cartilage and bone cells. Most interestingly however was the increased presence of Prx1 positive cells throughout the skeletal muscle, growth plate, medial layers of blood vessels, and adipose tissue of appendiculum. Labeling was not in muscles of the chest and back. Upon investigation of several different organs very low levels of Prx1 positive cells in the kidney, aorta and brain.. However, no Prx1 cells were located in the heart, spleen or liver tissues.
CONCLUSIONS: While a population of Prx1 cells was shown previously to be localized to the periosteum and contribute to fracture repair this study showed these cells in multiple tissue types throughout the appendiculum. Our results are the first in vivo demonstration to suggest that there is a multi-potential post natal mesenchymal stem population. This Prx1 positive cell population was not seen in ectopic bone that was induced outside the appendiculum indicating that these cells retained their original embryonic specification into the adult animal
Effective Coaching in Cricket, Rugby League and Rugby Union: A Qualitative Investigation Involving Professional Coaches and Players from Australia
This study examines professional Australian coach and athlete perceptions of effective coaching. Rather than assess the ability or effectiveness of the coaches and teams involved, the purpose was to gather perceptions of what professional coaches and players believe it takes to be an effective coach. Given the broad range of tasks that fit under the auspice of coaching, an important question to address was āwhatā a coach does in order to be considered effective. In addition, an understanding of āwhyā and āhowā these factors are effective was also essential. These questions formed a starting point in order to find out what professional coaches do (including how they behave), and why players and coaches perceive certain coaching strategies to be effective. This study employed a qualitative research design to identify perceptions about, and strategies of, effective coaching within the professional sport context. Interviews enabled participants to discuss their interpretations of the world in which they live, from their own point of view ā a key feature of the present research. Observational data allowed me to view coaching behaviours and interactions with players in training and competition contexts. Using professional Australian coaches and players from cricket, rugby union and rugby league, 6 coaches and 25 players were interviewed while up to 16 coaches and 80 players were observed during 41 observation sessions at training and competition venues. The constant comparative method (CĆ“tĆ©, Salmela, Baria, & Russell, 1993; CĆ“tĆ©, Salmela, & Russell, 1995b; Glaser & Strauss, 1967) was used to analyse the observation and interview accounts. This enabled rich descriptions of what effective coaches do as well as providing information regarding how and why they carry out certain actions. Findings from the current research indicated that an effective coach possesses specific personal characteristics, qualities and skills as well as a general philosophy or direction for the team. The effective coach uses their own unique leadership, player management, communication and planning skills to create and maintain the team environment to ensure that everyone involved with the team āworks off the same pageā. The interaction of all these features leads to the primary goal of player development, improvement in player performance and winning matches. This thesis identified key perceptions and applications of effective coaching based on Australian professional coach and player experiences
The relation between environmental protection and 'development' : a case study of the social dynamics iinvolved in the proposed mining at Xolobeni, Wild Coast.
This research report analyses the social dynamics involved in a proposed project to mine the sand dunes along a 22km stretch of the Wild Coast for titanium products, named the Xolobeni Heavy Minerals Sands Project. The proposal has been presented by a small Australian mining company, Mineral Commodities (MRC), and its local subsidiary, Transworld Energy and Minerals Resources (TEM), and would directly impact an area of the Wild Coast known as Mgungundlovu, situated in the Amadiba Tribal Administrative Area. It has become a highly contested process, with the affected communities ultimately rejecting the proposal.
The report aims to analyse these social dynamics through the frame of ādevelopmentā and its relation to environmental protection. It argues that participation is central in ādevelopmentā and that in this case study, such participation is crucial in highlighting the centrality of subsistence livelihoods, based on local natural resources, to the people of Mgungundlovu. That is, ādevelopmentā options should be based on the recognition of the importance of local livelihoods in this instance, and not on their destruction for ādevelopmentā to occur.
The report begins with a discussion of the notion of ādevelopmentā and adopts a critical view of it that acknowledges its socially, historically, and discursively constructed nature. It also adopts a skeptical view of āsustainable developmentā, which largely fails to analyse power relations and social inequality. It therefore proposes the discourse of environmental justice as a more suitable alternative to analysing the relationship between power, participation and ādevelopmentā. The report presents two case studies in order to provide a comparison with the case of Xolobeni, and it then describes the local social context. Given this context, it then moves on to analyse the extent to which the environmental management regime in South Africa allowed for participation by the affected communities. Following this, it analyses the roles played by the various social actors in terms of participation, power, environment and ādevelopmentā.
The research finds that participation in ādevelopmentā by the affected communities was minimal, and that the process was instead driven by particular interests and
broader discourses of the relation between environmental protection and ādevelopmentā that position the environment in opposition to ādevelopmentā and prioritise economic growth over the local social, cultural and environmental context. The degree of control exercised by the affected residents over the dynamics surrounding the proposed mining have therefore been minimal, and have instead been driven by institutions of the market and state, disconnected from local needs. This in turn highlights the role of power in ādevelopmentā
Seeing the woods for the trees - when is microclimate important in species distribution models?
Coaching Unlimited: Empowering Generations of Aboriginal and Torres Strait Islander Leaders: A Research Report Commissioned by Netball Australia and Netball New South Wales
Background: The Coaching Unlimited program aspires to empower coaches with tangible coaching, employment, and health promotion skills to build individual and community capacity. This report discusses the delivery and evaluation of an Aboriginal and Torres Strait Islander Peoplesā netball coaching workshop delivered on August 6, 2017 at Genea Netball Centre, Sydney Olympic Park.
Methods: To ensure the success of the first Coaching Unlimited, we conducted a mixed method study to evaluate the netball-coaching workshop.
Key Results: Based on the survey and interview results, the workshop was enjoyable and well delivered; included useful information, skills, and resources; and provided coaches with practical ideas for future coaching and leadership roles within their communities. In sum, all coaches either agreed or strongly agreed that the Coaching Unlimited workshop:
ā¢ Included useful resources
ā¢ Increased their interest in, and understanding of, the workshop topics
ā¢ Enhanced their ability to implement strategies relating to the workshop Recommendations
ā¢ This model of delivering health promotion education alongside coaching accreditation was perceived as highly useful and enjoyable
ā¢ Penrith, Mt Druitt, and Blacktown have been suggested as potential areas for future workshops, as has Bathurst and Orange as ideal regional locations.
ā¢ Holding workshops earlier in the netball season were recommended so that coaches could implement their new knowledge immediately.
ā¢ Moving forward, Coaching Unlimited will conduct a series of similar workshops across different sports in order to continue to provide Aboriginal and Torres Strait Islander peoples with opportunities to both gain coaching accreditation, and become leaders and mentors within their community
Fine-scale climate change: modelling spatial variation in biologically meaningful rates of warming
The existence of fineāgrain climate heterogeneity has prompted suggestions that species may be able to survive future climate change in pockets of suitable microclimate, termed āmicrorefugiaā. However, evidence for microrefugia is hindered by lack of understanding of how rates of warming vary across a landscape. Here, we present a model that is applied to provide fineāgrained, multidecadal estimates of temperature change based on the underlying physical processes that influence microclimate. Weather station and remotely derived environmental data were used to construct physical variables that capture the effects of terrain, sea surface temperatures, altitude and surface albedo on local temperatures, which were then calibrated statistically to derive gridded estimates of temperature. We apply the model to the Lizard Peninsula, United Kingdom, to provide accurate (mean error = 1.21 Ā°C; RMS error = 1.63 Ā°C) hourly estimates of temperature at a resolution of 100 m for the period 1977ā2014. We show that rates of warming vary across a landscape primarily due to longāterm trends in weather conditions. Total warming varied from 0.87 to 1.16 Ā°C, with the slowest rates of warming evident on northāeastāfacing slopes. This variation contributed to substantial spatial heterogeneity in trends in bioclimatic variables: for example, the change in the length of the frostāfree season varied from +11 to ā54 days and the increase in annual growing degreeādays from 51 to 267 Ā°C days. Spatial variation in warming was caused primarily by a decrease in daytime cloud cover with a resulting increase in received solar radiation, and secondarily by a decrease in the strength of westerly winds, which has amplified the effects on temperature of solar radiation on westāfacing slopes. We emphasize the importance of multidecadal trends in weather conditions in determining spatial variation in rates of warming, suggesting that locations experiencing least warming may not remain consistent under future climate change
Funding and service organization to achieve universal health coverage for medicines : an economic evaluation of the best investment and services organization for the Brazilian scenario
Background: There are many health benefits since 31 years after the foundation of the National Health Service (NHS) in Brazil, especially the increase in life expectancy. However, family-income inequalities, insufficient funding, and suboptimal private sectorāpublic sector collaboration are still areas for improvement. The efforts of Brazil to achieve universal health coverage (UHC) for medicines have resulted in increased public financing of medicines and their availability, reducing avoidable hospitalization and mortality. However, lack of access to medicines still remains. Due to historical reasons, pharmaceutical service organization in developing countries may have important differences from high-income countries. In some cases, developing countries finance and promote medicine access by using the public infrastructure of health care/medical units as dispensing sites and cover all costs of medicines dispensed. In contrast, many high-income countries use private community pharmacies and cover the costs of medicines dispensed plus a fee, which includes all logistic costs. In this study, we will undertake an economic evaluation to understand the funding needs of the Brazilian NHS to reduce inequalities in access to medicines through adopting a pharmaceutical service organization similar to that seen in many high-income countries with hiring/accrediting private pharmacies. Methods: We performed an economic evaluation of a model to provide access to medicines within public funds based on a decision tree model with two alternative scenarios public pharmacies (NHS, state-owned facilities) versus private pharmacies (NHS, agreements). The analysis assumed the perspective of the NHS. We identified the types of resources consumed, the amount, and costs in both scenarios. We also performed a budget impact forecast to estimate the incremental funding required to reduce inequalities in access to essential medicines in Brazil. Findings: The model without rebates for medicines estimated an incremental cost of US1.3 billion per year (30%). The impact of incremental funding is related to medicine access improvement of 25% in the second year when paying by dispensing fee. The estimate of the incremental budget in five years would be US9 billion and US$1.4 billion PPP respectively in 2017. Interpretation: The results of the economic evaluation demonstrate potential savings for the NHS and society. Achieving UHC for medicines reduces household expenses with health costs, health litigation, outpatient care, hospitalization, and mortality. An optimal private sectorāpublic sector collaboration model with private community pharmacy accreditation is economically dominant with a feasible medicine price negotiation. The results show the potential to improve access to medicines by 25% for all income classes. This is most beneficial to the poorest families, whose medicines account for 76% of their total health expenses, with potential savings of lives and public resources
School physical activity intervention effect on adolescents' performance in mathematics
Purpose: The primary aim of this study was to test the effect of a school-based physical activity intervention on adolescentsā performance in mathematics. A secondary aim was to explore potential mechanisms that might explain the intervention effect.
Methods: The Activity and Motivation in Physical EDucation intervention was evaluated using a two-arm cluster randomized controlled trial in 14 secondary schools located in low socioeconomic areas of Western Sydney, Australia. Study participants (n = 1173) were grade 8 students (mean age = 12.94 yr, SD = 0.54). The multicomponent intervention was designed to help teachers maximize studentsā opportunities for moderate-to-vigorous physical activity (MVPA) during physical education (PE) and enhance studentsā motivation toward PE. Mathematics performance was assessed as part of national testing in grade 7, which was the year before the trial began and then again in grade 9. Potential mediators were: (i) proportion of PE lesson time that students spent in MVPA and leisure time MVPA (%), measured using Actigraph GT3X+ accelerometers, and (ii) studentsā self-reported engagement (behavioral, emotional, and cognitive) during mathematics lessons. Mediators were assessed at baseline (grade 8) and follow-up (grade 9, 14ā15 months after baseline).
Results: The effect of the intervention on mathematics performance was small-to-medium (Ī² = 0.16, P < 0.001). An intervention effect was observed for MVPA% in PE (Ī² = 0.59, P < 0.001), but not for leisure time MVPA or any of the engagement mediators. There were no significant associations between changes in potential mediators and mathematics performance.
Conclusions: The Activity and Motivation in Physical EDucation intervention had a significant positive effect on mathematics performance in adolescents. However, findings should be interpreted with caution as the effect was small and not associated with changes in hypothesized mediators
Popular interest in vertebrates does not reflect extinction risk and is associated with bias in conservation investment
<div><p>The interrelationship between public interest in endangered species and the attention they receive from the conservation community is the āflywheelā driving much effort to abate global extinction rates. Yet big international conservation non-governmental organisations have typically focused on the plight of a handful of appealing endangered species, while the public remains largely unaware of the majority. We quantified the existence of bias in popular interest towards species, by analysing global internet search interest in 36,873 vertebrate taxa. Web search interest was higher for mammals and birds at greater risk of extinction, but this was not so for fish, reptiles and amphibians. Our analysis reveals a global bias in popular interest towards vertebrates that is undermining incentives to invest financial capital in thousands of species threatened with extinction. Raising the popular profile of these lesser known endangered and critically endangered species will generate clearer political and financial incentives for their protection.</p></div
- ā¦