Mechanical Behavior of Articular Cartilage After Osteochondral Autograft Transfer in an Ovine Model

BACKGROUND: Grafting of autologous hyaline cartilage and bone for articular cartilage repair is a well-accepted technique. Although encouraging midterm clinical results have been reported, no information on the mechanical competence of the transplanted joint surface is available. HYPOTHESIS: The mechanical competence of osteochondral autografts is maintained after transplantation. STUDY DESIGN: Controlled laboratory study. METHODS: Osteochondral defects were filled with autografts (7.45 mm in diameter) in one femoral condyle in 12 mature sheep. The ipsilateral femoral condyle served as the donor site, and the resulting defect (8.3 mm in diameter) was left empty. The repair response was examined after 3 and 6 months with mechanical and histologic assessment and histomorphometric techniques. RESULTS: Good surface congruity and plug placement was achieved. The Young modulus of the grafted cartilage significantly dropped to 57.5% of healthy tissue after 3 months (P < .05) but then recovered to 82.2% after 6 months. The aggregate and dynamic moduli behaved similarly. The graft edges showed fibrillation and, in some cases (4 of 6), hypercellularity and chondrocyte clustering. Subchondral bone sclerosis was observed in 8 of 12 cases, and the amount of mineralized bone in the graft area increased from 40% to 61%. CONCLUSIONS: The mechanical quality of transplanted cartilage varies considerably over a short period of time, potentially reflecting both degenerative and regenerative processes, while histologically signs of both cartilage and bone degeneration occur. CLINICAL RELEVANCE: Both the mechanically degenerative and restorative processes illustrate the complex progression of regeneration after osteochondral transplantation. The histologic evidence raises doubts as to the long-term durability of the osteochondral repair.

Long-term effects of hydrogel properties on human chondrocyte behavior

Hydrogels provide a 3-dimensional network for embedded cells and offer promise for cartilage tissue engineering applications. Nature-derived hydrogels, including alginate, have been shown to enhance the chondrocyte phenotype but are variable and not entirely controllable. Synthetic hydrogels, including polyethylene glycol (PEG)-based matrices, have the advantage of repeatability and modularity; mechanical stiffness, cell adhesion, and degradability can be altered independently. In this study, we compared the long-term in vitro effects of different hydrogels (alginate and Factor XIIIa-cross-linked MMP-sensitive PEG at two stiffness levels) on the behavior of expanded human chondrocytes and the development of construct properties. Monolayer-expanded human chondrocytes remained viable throughout culture, but morphology varied greatly in different hydrogels. Chondrocytes were characteristically round in alginate but mostly spread in PEG gels at both concentrations. Chondrogenic gene (COL2A1, aggrecan) expression increased in all hydrogels, but alginate constructs had much higher expression levels of these genes (up to 90-fold for COL2A1), as well as proteoglycan 4, a functional marker of the superficial zone. Also, chondrocytes expressed COL1A1 and COL10A1, indicative of de-differentiation and hypertrophy. After 12 weeks, constructs with lower polymer content were stiffer than similar constructs with higher polymer content, with the highest compressive modulus measured in 2.5% PEG gels. Different materials and polymer concentrations have markedly different potency to affect chondrocyte behavior. While synthetic hydrogels offer many advantages over natural materials such as alginate, they must be further optimized to elicit desired chondrocyte responses for use as cartilage models and for development of functional tissue-engineered articular cartilage.

Employers and child workers : an institutional approach

This article explores employers' perspectives on the introduction of child employment legislation in Australia through the lens of the three pillars—regulative, normative and cultural-cognitive—of institutional theory. The study extends the traditional industrial relations (IR) focus on regulation to examine how human resource (HR) practices around child employment become legitimised, normalised and socially supported.

Who wants to work in childcare? Pre-service early childhood teachers' consideration of work in the child care sector

Australia is currently witnessing considerable change in conceptualisation of the role of child care. This is a response to the strong evidence from developmental science that demonstrates the lifelong impact of early experiences. The recent commitment made by the Council of Australian Governments (COAG) (Communiqué, December 2009a) to improved qualifications and quality of those working in child care is a manifestation of this shift and highlights the importance of the childcare workforce. This study focused on the considerations of a third year cohort of B.Ed (EC) pre-service teachers (n = 55), about entering the childcare workforce. It examines their willingness to work in child care and identifies barriers and incentives for so doing. Our results indicate that, although attitudes to maternal work and child care were largely positive, few would prefer to work in child care under the current conditions. Key barriers were the pay and work conditions, particularly as they compare to other forms of potential employment. Incentives were the opportunity for leadership, creativity and a commitment to advocate for the rights of children. Those more willing to consider work in child care were distinguished from those less willing by altruism—foregoing personal gain to advocate for improved quality as a child’s right.

The impact of school connectedness on violent behavior, transport risk taking behavior and associated injuries in adolescence

Adolescents engage in many risk-taking behaviors that have the potential to lead to injury. The school environment has a significant role in shaping adolescent behavior, and this study aimed to provide additional information about the benefits associated with connectedness to school. Early adolescents aged 13 to 15 years (N = 509, 49% boys) were surveyed about school connectedness, engagement in transport and violence risk-taking, and injury experiences. Significant relations were found between school connectedness and reduced engagement in both transport and violence risk-taking, as well as fewer associated injuries. This study has implications for the area of risk-taking and injury prevention, as it suggests the potential for reducing adolescents' injury through school based interventions targeting school connectedness.

Everything is child abuse

In 2008, the Australian federal Senate held an Inquiry into the Sexualisation of Children in the Contemporary Media Environment. I made a submission to this Inquiry, noting that in public debate about this topic a number of quite distinct issues, with distinct aetiologies, were collapsed together. These included: child pornography; children being targeted by any form of marketing; young people becoming sexually active; sexual abuse of children; raunch culture; protecting children from any sexualised material in the media; and body image disorders. I suggested that commentators had collapsed these issues together because the image of the helpless child is a powerful one for critics to challenge undesirable aspects of contemporary culture. The result of many different ideological viewpoints all using the same argument - that the forms of culture they didn't like were damaging children - gives the impression that there is no element of culture today that isn't (somebody claims) causing harm to children: everything is child abuse. The danger of such discourses is that they draw attention away from the real harm that is being caused to children by sexual and other forms of maltreatment - which overwhelmingly occur within families, and for reasons ignored in these debates.

Children’s food and activity patterns following a six-month child weight management program

Objective To describe the impact of a parent-led, family focused child weight management program on the food intake and activity patterns of pre-pubertal children. Methods n assessor-blinded, randomized controlled trial involving 111 (64% female) overweight, pre-pubertal children 6 to 9 years of age randomly assigned to parenting-skills training plus intensive lifestyle education, parenting-skills training alone, or a 12-month wait-listed control. Study outcomes were assessed at baseline, 6 months, and 12 months. This paper presents data on food intake assessed via a validated 54-item parent completed dietary questionnaire and activity behaviours assessed via a parent-report 20-item activity questionnaire. Results Intake of energy-dense nutrient poor foods was lower in both intervention groups at 6 months (mean difference, P+DA -1.5 serves [CI -2.0;-1.0]; P -1.0 serves [-2.0;-0.5]) and 12 months (mean difference P+DA -1.0 serves [CI -2.0;-0.5]; P -1.0 serves [-1.5; 0.0]) compared to baseline. Intake of vegetables, fruit, breads and cereals, meat and alternatives and dairy foods remained unchanged. Regardless of study group there were significant reductions over time in the reported time spent engaged in small screen activities and an increase in the time reported spent in active play. Conclusion Child weight management intervention that promotes food intake in line with national dietary guidelines achieves a reduction in children’s intake of energy dense, nutrient poor foods. This was achieved without compromising intake of nutrient-rich food and changes in were maintained even once the intervention ceased.

Thermal behavior and decomposition of kaolinite-potassium acetate intercalation composite

A series of kaolinite-potassium acetate intercalation composite was prepared. The thermal behavior and decomposition of these composites were investigated by simultaneous differential scanning calorimetry-thermogravimetric analysis (DSC-TGA), X-ray diffraction (XRD) and Fourier-transformation infrared (FT-IR). The XRD pattern at room temperature indicated that intercalation of potassium acetate into kaolinite causes an increase of the basal spacing from 0.718 to 1.428nm. The peak intensity of the expanded phase of the composite decreased with heating above 300°C, and the basal spacing reduced to 1.19nm at 350°C and 0.718nm at 400°C. These were supported by DSC-TGA and FT-IR measurements, where the endothermic reactions are observed between 300 and 600°C. These reactions can be divided into two stages: 1) Removal of the intercalated molecules between 300-400°C. 2) Dehydroxylation of kaolinite between 400-600°C. Significant changes were observed in the infrared bands assigned to outer surface hydroxyl, inner surface hydroxyl, inner hydroxyl and hydrogen bands.

Why a child needs a critical eye, and why the art classroom is central in developing it

It is a common acceptance that contemporary schoolchildren live in a world that is intensely visual and commercially motivated, where what is imagined and what is experienced intermingle. Because of this, contemporary education should encourage a child to make reference to, and connection with their ‘out-of-school’ life. The core critical underpinnings of curriculum based arts appreciation and theory hinge on educators and students taking a historical look at the ways artists have engaged with, and made comment upon, their contemporary societies. My article uses this premise to argue for the need to persist with pushing for critique of/through the visual, that it be delivered as an active process via the arts classroom rather than as visual literacy, here regarded as a more passive process for interpreting and understanding visual material. The article asserts that visual arts lessons are best placed to provide fully students with such critique because they help students to develop a ’critical eye’, an interpretive lens often used by artists to view, analyse and independently navigate and respond to contemporary society.

Mother and child sharing through drawing: Intergenerational collaborative processes for making artworks

This paper presents a preliminary study into collaborated processes for art-making, undertaken by a young child and an adult. The study explores collaborative drawing in the context of sociocultural research into early childhood education. The study particularly examines whether childhood techniques for making marks, creative processing and art-making could be ‘re-learned’ by the adult, while new opportunities for expanding on extant repertoire could be available to the child. In this context the child teaches and learns from the adult, and the adult teaches and learns from the child. The study utilised video-data-recording to facilitate microanalysis of the researchers in action, enabling the adult researcher to present a discourse into the dynamics of how the visual, mark-making repertoires of an adult and child can be co-developed. Preliminary findings help contribute to the various discourses available into sociocultural research that supports processes for exploring and making art, and which allows a challenge to the role of the adult educator as a provider or director of what is learned.

Parents’ views about child sexual abuse prevention education : a systematic review

This paper presents the results of a systematic review of literature on the topic of parents’ views about child sexual abuse prevention education. It describes: i) what parents know about child sexual abuse prevention education; ii) what child sexual abuse prevention messages parents provide to their children and what topics they discuss; iii) what parents’ attitudes are towards child sexual abuse prevention education in schools; and iv) their preferences for content. Electronic database searches were conducted to identify relevant literature published in English relating to child sexual abuse prevention programs and parent’s views. A total of 429 papers were evaluated with 13 studies identified as meeting the study’s inclusion criteria. Worldwide, empirical research on parents’ views about child sexual abuse prevention programs is limited and more research is needed in Australia. Implications for future research and practice are outlined.

Locating child protection in preservice teacher education

A recent report delivered by the Australian Centre for Child Protection has highlighted the need for empirical evidence of effective pedagogies for supporting teaching and learning of child protection content in Australian teacher education programs (Arnold & Maio-Taddeo, 2007). This paper advances this call by presenting case study accounts of different approaches to teaching child protection content in University-based teacher education programs across three Australian States. These different cases provide a basis for understanding existing strategies as an important precursor to improving practice. Although preschool, primary and secondary schools have been involved in efforts to protect children from abuse and neglect since the 1970s, teacher education programs, including preservice and inservice programs, have been slow to align their work with child protection agendas. This paper opens a long-overdue discussion about the extent and nature of child protection content in teacher education and proposes strategies for translating research into practice.

Queensland College of Teachers annual lecture 2010 : child protection

Teachers have a crucial role as “sentinels” for children who have been abused or neglected. This professional development session will provide a framework for understanding the types, incidence and causes of child abuse and neglect, and teachers’ role in reporting suspected cases. The session will provide participants with knowledge and skills to enable them to identify warning signs and indicators of child abuse and neglect, know the basis of their duties to report suspected cases of abuse and neglect, and respond to the needs of abused and neglected children at school. The presentation will focus on: • the reasons why child abuse and neglect can occur; • the different types of child abuse and neglect and their effects on children; • the warning signs and indicators of physical abuse, emotional abuse, sexual abuse and neglect; • applying knowledge of indicators to make judgements about risk of harm; • responding to indications of risk of harm, including complying with legislative and policy-based duties to report suspected child abuse and neglect.

Preferences of first-time expectant mothers for care of their child : 'I wouldn't leave them somewhere that made me feel insecure'

Australia has witnessed a continual increase in maternal employment over the past two decades, which places focus on both supply of childcare and a demand for high quality care. This study examined childcare preferences regarding the return to paid work of 124 Australian women who were expecting their first child. In contrast with most studies that have retrospective designs, the design of this study presents the perspectives of women prior to the birth of their first child-that is, before they have made a final decision about child care. This study found that the majority (78 per cent) of the women intended to re-commence work within the 12 months after the birth of their child. There were two factors that were the most salient features in their decision making-the quality of care and the personal satisfaction of engaging in paid work. The findings suggest that family friendly employment practices and access to secure, high-quality child care are key to women's secure participation in the paid workforce.